KR102733735B1 - Plasma processing apparatus, monitoring method, and monitoring program - Google Patents

Abstract

(Task) Detecting the occurrence of an abnormality without placing sensors.
(Solution) A plasma processing device has a memory unit, a second acquisition unit, and a monitoring unit. The memory unit stores change information indicating a change in a value related to the temperature of the mounting table when a processing condition for plasma processing for a wafer mounted on the mounting table changes. The second acquisition unit acquires a value related to the temperature of the mounting table in a predetermined cycle. The monitoring unit monitors a change in the processing condition for plasma processing from a change in the value related to the temperature of the mounting table acquired by the second acquisition unit based on the change information.

Description

{PLASMA PROCESSING APPARATUS, MONITORING METHOD, AND MONITORING PROGRAM}

The present disclosure relates to a plasma processing device, a monitoring method, and a monitoring program.

Patent Document 1 proposes a technology for obtaining the difference between the input power value of a matching device and the power setting value of high-frequency power supplied to a processing room from a high-frequency power source through a matching device, and controlling the output power of a high-frequency power source so that the input power value of the matching device becomes the power setting value.

Patent Document 1: Japanese Patent Publication No. 2008-251462

The present disclosure provides a technique capable of detecting the occurrence of an abnormality without deploying a sensor.

A plasma processing device according to one aspect of the present disclosure has a memory unit, an acquisition unit, and a monitoring unit. The memory unit stores change information indicating a change in a temperature value of a mounting platform when a processing condition for plasma processing for a processing target mounted on a mounting platform changes. The acquisition unit acquires a temperature value of the mounting platform in a predetermined cycle. The monitoring unit monitors a change in a processing condition for plasma processing from a change in the temperature value of the mounting platform acquired by the acquisition unit based on the change information.

According to the present disclosure, the occurrence of an abnormality can be detected without placing a sensor.

Figure 1 is a drawing schematically showing a plasma processing device related to an embodiment.
Figure 2 is a plan view showing a mounting platform related to the embodiment.
Figure 3 is a block diagram showing a schematic configuration of a control unit that controls a plasma processing device related to an embodiment.
Figure 4 is a diagram schematically showing the flow of energy that affects the temperature of the wafer.
Figure 5a is a diagram schematically showing the flow of energy in an unignited state.
Figure 5b is a diagram schematically showing the flow of energy in the ignition state.
Figure 6 is a diagram showing an example of changes in the temperature of a wafer and the power supplied to the heater.
Figure 7 is a diagram schematically showing the flow of energy in an ignition state.
Figure 8a is a drawing showing an example of a change in the amount of heat generated from a heater when the temperature of the upper electrode and the sediment shield changes.
Figure 8b is a drawing showing an example of a change in the amount of heat generated from a heater when the first high-frequency power and the second high-frequency power are changed.
Figure 8c is a drawing showing an example of a change in the amount of heat generated from a heater when the pressure inside the processing vessel changes.
Figure 8d is a drawing showing an example of a change in thermal resistance when the pressure of the heating gas and the thickness of the backside film of the wafer W are changed.
Figure 9 is a flowchart showing an example of the flow of generation processing related to the embodiment.
Figure 10 is a flowchart showing an example of the flow of surveillance processing related to the embodiment.
Figure 11a is a plan view showing a mounting platform related to another embodiment.
Figure 11b is a plan view showing a mounting platform related to another embodiment.
Figure 11c is a plan view showing a mounting platform related to another embodiment.

Hereinafter, with reference to the drawings, embodiments of the plasma processing device, the monitoring method, and the monitoring program disclosed in the present invention will be described in detail. In the present disclosure, a specific example of the plasma processing device is a device that performs plasma etching, and this will be described in detail. In addition, the plasma processing device, the monitoring method, and the monitoring program disclosed in the present embodiment are not limited thereto.

However, for example, in plasma processing devices, there are those that place sensors such as various probes or various electrical sensors inside the processing vessel to detect the state of the plasma with the sensors and detect abnormal occurrences from changes in the state of the plasma. However, if a sensor is placed inside the processing vessel, the manufacturing cost of the plasma processing device increases. Furthermore, if a sensor is placed inside the processing vessel, the sensor becomes a singular point, and the uniformity of the plasma processing deteriorates around the singular point. Therefore, in plasma processing devices, it is expected to detect abnormal occurrences without placing a sensor.

[Composition of plasma treatment device]

First, the configuration of the plasma processing device (10) related to the embodiment will be described. Fig. 1 is a drawing schematically showing the plasma processing device related to the embodiment. Fig. 1 schematically shows the structure of the plasma processing device (10) related to the embodiment in a cross-sectional view. The plasma processing device (10) shown in Fig. 1 is a capacity-coupled parallel plate plasma etching device. The plasma processing device (10) is equipped with a processing vessel (12) having a substantially cylindrical shape. The processing vessel (12) is made of, for example, aluminum. In addition, the surface of the processing vessel (12) is subjected to anodizing treatment.

Inside the processing vessel (12), a mounting table (16) is provided. The mounting table (16) has an electrostatic chuck (18) and a base (20). The upper surface of the electrostatic chuck (18) is a mounting surface on which a target object to be processed is mounted. In the present embodiment, a wafer W is mounted on the upper surface of the electrostatic chuck (18) as the target object to be processed. The base (20) has an approximately disc shape, and its main part is made of a conductive metal such as, for example, aluminum. The base (20) constitutes a lower electrode. The base (20) is supported by a support member (14). The support member (14) is a cylindrical member extending from the bottom of the processing vessel (12).

The first high-frequency power supply HFS is electrically connected to the base (20) via the matching device MU1. The first high-frequency power supply HFS is a power supply that generates high-frequency power for plasma generation, and generates high-frequency power of a frequency of 27 to 100 MHz, and in one example, 40 MHz. As a result, plasma is generated directly above the base (20). The matching device MU1 has a circuit for matching the output impedance of the first high-frequency power supply HFS and the input impedance of the load side (base (20) side).

In addition, a second high-frequency power supply LFS is electrically connected to the base (20) via a matching device MU2. The second high-frequency power supply LFS generates high-frequency power (high-frequency bias power) for attracting ions to the wafer W, and supplies the high-frequency bias power to the base (20). As a result, a bias potential is generated in the base (20). The frequency of the high-frequency bias power is a frequency within a range of 400 kHz to 13.56 MHz, and is 3 MHz in one example. The matching device MU2 has a circuit for matching the output impedance of the second high-frequency power supply LFS and the input impedance of the load side (base (20) side).

On the base (20), an electrostatic chuck (18) is provided. The electrostatic chuck (18) holds the wafer W by sucking the wafer W by electrostatic force such as Coulomb force. The electrostatic chuck (18) has an electrode E1 for electrostatic suction provided inside the ceramic main body. A DC power supply (22) is electrically connected to the electrode E1 via a switch SW1. The suction force for holding the wafer W depends on the value of the DC voltage applied from the DC power supply (22).

In addition, a focus ring FR is arranged around the wafer W on the electrostatic chuck (18). The focus ring FR is provided to improve the uniformity of plasma processing. The focus ring FR is composed of a material appropriately selected depending on the plasma processing to be performed. For example, the focus ring FR is composed of silicon or quartz.

Inside the expectation (20), a refrigerant path (24) is formed. Refrigerant is supplied to the refrigerant path (24) from a chiller unit provided outside the processing vessel (12) through a pipe (26a). The refrigerant supplied to the refrigerant path (24) returns to the chiller unit through a pipe (26b).

Inside the processing vessel (12), an upper electrode (30) is provided. The upper electrode (30) is positioned above the mounting base (16) and is positioned opposite to the base (20). The base (20) and the upper electrode (30) are provided approximately parallel to each other.

The upper electrode (30) is supported on the upper part of the processing vessel (12) via an insulating shielding member (32). The upper electrode (30) has an electrode plate (34) and an electrode support (36). The electrode plate (34) faces the processing space S and has a plurality of gas discharge holes (34a) formed therein. The electrode plate (34) is made of a low-resistance conductor or semiconductor with little Joule heat. The upper electrode (30) is capable of controlling the temperature. For example, the upper electrode (30) is provided with a temperature control mechanism such as a heater (not shown), and the temperature can be controlled.

The electrode support (36) freely supports the electrode plate (34) in a detachable manner. The electrode support (36) is made of a conductive material such as, for example, aluminum. A gas diffusion chamber (36a) is provided inside the electrode support (36). In the electrode support (36), a plurality of gas flow holes (36b) communicating with gas discharge holes (34a) extend downward from the gas diffusion chamber (36a). In addition, a gas inlet (36c) for introducing a processing gas to the gas diffusion chamber (36a) is formed in the electrode support (36). A gas supply pipe (38) is connected to the gas inlet (36c).

A gas source group (40) is connected to a gas supply pipe (38) via a valve group (42) and a flow controller group (44). The valve group (42) has a plurality of opening/closing valves. The flow controller group (44) has a plurality of flow controllers called mass flow controllers. In addition, the gas source group (40) has gas sources for a plurality of types of gases required for plasma processing. The plurality of gas sources of the gas source group (40) are connected to the gas supply pipe (38) via corresponding opening/closing valves and corresponding mass flow controllers.

In the plasma processing device (10), one or more gases from one or more gas sources selected from among a plurality of gas sources of a gas source group (40) are supplied to a gas supply pipe (38). The gas supplied to the gas supply pipe (38) reaches a gas diffusion chamber (36a) and is discharged into a processing space S through a gas flow hole (36b) and a gas discharge hole (34a).

In addition, as shown in Fig. 1, the plasma processing device (10) further has a grounding conductor (12a). The grounding conductor (12a) is a grounding conductor having a substantially cylindrical shape, and is provided to extend upward from the side wall of the processing vessel (12) above the height position of the upper electrode (30).

In addition, in the plasma processing device (10), a sediment shield (46) is freely provided to be attached and detached along the inner wall of the processing vessel (12). In addition, the sediment shield (46) is also provided on the outer periphery of the support member (14). The sediment shield (46) prevents etching by-products (sediments) from attaching to the processing vessel (12), and is configured by coating ceramics such as Y2O3 on aluminum material. The sediment shield (46) is configured to enable temperature control. For example, the sediment shield (46) is provided with a temperature control mechanism such as a heater (not shown), and the temperature can be controlled.

On the bottom side of the processing vessel (12), an exhaust plate (48) is provided between the support member (14) and the inner wall of the processing vessel (12). The exhaust plate (48) is configured by, for example, coating aluminum with ceramics such as Y2O3. The processing vessel (12) is provided with an exhaust port (12e) at the bottom of the exhaust plate (48). An exhaust device (50) is connected to the exhaust port (12e) via an exhaust pipe (52). The exhaust device (50) has a vacuum pump such as a turbo molecular pump. The exhaust device (50) depressurizes the inside of the processing vessel (12) to a desired vacuum level when performing plasma processing. In addition, a wafer W loading/unloading port (12g) is provided on the side wall of the processing vessel (12). The loading/unloading port (12g) can be opened/closed by a gate valve (54).

The plasma processing device (10) configured as described above has its operation comprehensively controlled by a control unit (100). The control unit (100) is, for example, a computer and controls each part of the plasma processing device (10). The operation of the plasma processing device (10) is comprehensively controlled by the control unit (100).

[Composition of the payload]

Next, the mounting stand (16) will be described in detail. Fig. 2 is a plan view showing a mounting stand related to the embodiment. As described above, the mounting stand (16) has an electrostatic chuck (18) and a base (20). The electrostatic chuck (18) is formed of ceramic, and has a top surface as a mounting area (18a) for mounting a wafer W and a focus ring FR. The mounting area (18a) is a substantially circular area in a plan view. As shown in Fig. 1, the electrostatic chuck (18) is provided with an electrode E1 for electrostatic adsorption in an area where the wafer W is placed. The electrode E1 is connected to a DC power supply (22) via a switch SW1.

In addition, as shown in Fig. 1, a plurality of heaters HT are provided below the electrode E1 in the mounting area (18a). The mounting area (18a) is divided into a plurality of divided areas (75), and a heater HT is provided in each divided area (75). For example, as shown in Fig. 2, the mounting area (18a) is divided into a circular divided area (75a) in the center (center portion) and three annular divided areas (75b to 75d) (middle portion, edge portion, focus ring portion). A heater HT is provided in each of the divided areas (75a to 75d). A wafer W is placed in the divided areas (75a to 75c). A focus ring FR is placed in the divided area (75d). In this embodiment, a case is explained as an example in which the temperature is controlled by dividing the surface of the mounting plate (16) into four divided areas (75a to 75d), but the number of divided areas (75) is not limited to four, and may be two or three, or may be five or more.

The heater HT is individually connected to the heater power HP shown in Fig. 1 via wiring not shown. The heater power HP supplies individually adjusted power to each heater HT under control from the control unit (100). As a result, the heat generated by each heater HT is individually controlled, and the temperatures of multiple partition areas within the mounting area (18a) are individually adjusted.

The heater power HP is provided with a power detection unit PD that detects the power supply supplied to each heater HT. In addition, the power detection unit PD may be provided separately from the heater power HP in a wiring through which power flows from the heater power HP to each heater HT. The power detection unit PD detects the power supply supplied to each heater HT. For example, the power detection unit PD detects the amount of power [W] as the power supply supplied to each heater HT. The heater HT generates heat according to the amount of power. Therefore, the amount of power supplied to the heater HT represents the heater power. The power detection unit PD notifies the control unit (100) of power data representing the detected power supply to each heater HT.

In addition, the mounting plate (16) is provided with a temperature sensor (not shown) capable of detecting the temperature of the heater HT in each of the divided areas (75) of the mounting area (18a). The temperature sensor may be a device that measures the temperature separately from the heater HT. In addition, the temperature sensor may be a device that is arranged in a wiring through which electric power flows to the heater HT and detects the temperature by utilizing the property that the electric resistance increases as the temperature rises. The sensor value detected by each temperature sensor is sent to the temperature measuring device TD. The temperature measuring device TD measures the temperature of each divided area (75) of the mounting area (18a) from each sensor value. The temperature measuring device TD notifies the control unit (100) of temperature data indicating the temperature of each divided area (75) of the mounting area (18a).

In addition, it is also acceptable for a heating gas, such as He gas, to be supplied between the upper surface of the electrostatic chuck (18) and the back surface of the wafer W by a heating gas supply device and a gas supply line that are not shown in the city.

[Control unit configuration]

Next, the control unit (100) will be described in detail. Fig. 3 is a block diagram showing a schematic configuration of a control unit that controls a plasma processing device related to the embodiment. The control unit (100) is provided with an external interface (101), a process controller (102), a user interface (103), and a memory unit (104).

The external interface (101) is capable of communicating with each part of the plasma processing device (10) and inputs and outputs various data. For example, power data indicating the power supply to each heater HT from the power detection unit PD is input to the external interface (101). In addition, temperature data indicating the temperature of each partition area (75) of the mounting area (18a) is input to the external interface (101) from the temperature measuring device TD. In addition, the external interface (101) outputs control data for controlling the power supply to each heater HT to the heater power supply HP.

The process controller (102) is equipped with a CPU (Central Processing Unit) and controls each part of the plasma processing device (10).

The user interface (103) is composed of a keyboard through which a process manager inputs commands to manage the plasma processing device (10), a display that visualizes and displays the operating status of the plasma processing device (10), etc.

In the memory (104), a control program (software) for implementing various processes executed in the plasma processing device (10) under the control of the process controller (102), a recipe in which processing condition data, etc. are stored, are stored. In addition, in the memory (104), parameters related to the device or process for performing the plasma processing, etc. are stored. In addition, the control program, recipe, and parameters may be stored in a computer-readable computer recording medium (e.g., a hard disk, an optical disk such as a DVD, a flexible disk, a semiconductor memory, etc.). In addition, the control program, recipe, and parameters may be stored in another device and may be read out and used online, for example, through a dedicated line.

The process controller (102) has an internal memory for storing programs or data, reads the control program stored in the memory unit (104), and executes the processing of the read control program. The process controller (102) functions as various processing units by operating the control program. For example, the process controller (102) has the functions of a heater control unit (102a), a first acquisition unit (102b), a second acquisition unit (102c), a set temperature calculation unit (102d), a monitoring unit (102e), an alarm unit (102f), and a correction unit (102g). In addition, in this embodiment, a case where the process controller (102) functions as various processing units is described as an example, but is not limited to this. For example, the functions of the heater control unit (102a), the first acquisition unit (102b), the second acquisition unit (102c), the set temperature calculation unit (102d), the monitoring unit (102e), the alarm unit (102f), and the correction unit (102g) may be distributed and realized by multiple controllers.

However, in plasma processing, the progress of processing changes depending on the temperature of the wafer W. For example, in plasma etching, the etching progress speed changes depending on the temperature of the wafer W. Therefore, in the plasma processing device (10), it is conceivable to control the temperature of the wafer W to a target temperature by each heater HT.

However, in plasma processing, there is heat input from the plasma to the wafer W. For this reason, the plasma processing device (10) may not be able to precisely control the temperature of the wafer W during plasma processing to the target temperature.

Hereinafter, a flow of energy affecting the temperature of a wafer W will be described. FIG. 4 is a diagram schematically showing the flow of energy affecting the temperature of a wafer. In FIG. 4, a wafer W and a mounting table (16) including an electrostatic chuck (ESC) (18) are shown in a simplified manner. The example of FIG. 4 shows the flow of energy affecting the temperature of a wafer W for one partition area (75) of a mounting area (18a) of an electrostatic chuck (18). The mounting table (16) has an electrostatic chuck (18) and a base (20). The electrostatic chuck (18) and the base (20) are bonded by an adhesive layer (19). A heater HT is provided inside the mounting area (18a) of the electrostatic chuck (18). A coolant path (24) through which a coolant flows is formed inside the base (20).

The heater HT generates heat and its temperature rises according to the power supply supplied from the heater power HP. In Fig. 4, the power supply supplied to the heater HT is expressed as heater power Ph. In the heater HT, the heat generation amount (heat flux) qh per unit area is generated by dividing the heater power Ph by the area A of the area where the heater HT of the electrostatic chuck (18) is provided.

In the plasma processing device (10), when the temperature of internal parts of the processing vessel (12), such as the upper electrode (30) or the sediment shield (46), is controlled, radiant heat is generated from the internal parts. For example, when the temperature of the upper electrode (30) or the sediment shield (46) is controlled to a high temperature in order to suppress adhesion of sediment, radiant heat is input to the wafer W from the upper electrode (30) or the sediment shield (46). In Fig. 4, the radiant heat qr from the upper electrode (30) or the sediment shield (46) to the wafer W is expressed.

In addition, when plasma treatment is performed, the wafer W receives heat from the plasma. In Fig. 4, the amount of heat input from the plasma to the wafer W is expressed as the heat flux qp from the plasma per unit area, which is calculated by dividing the amount of heat input by the area of the wafer W. The temperature of the wafer W increases due to the heat input of the heat flux qp from the plasma or the heat input of the radiant heat qr.

The heat input by radiant heat is proportional to the temperature of the internal parts of the processing vessel (12). For example, the heat input by radiant heat is proportional to the temperature of the upper electrode (30) or the sediment shield (46). It is known that the heat input from the plasma is mainly proportional to the product of the amount of ions in the plasma irradiated to the wafer W and the bias potential for drawing the ions in the plasma into the wafer W. The amount of ions in the plasma irradiated to the wafer W is proportional to the electron density of the plasma. The electron density of the plasma is proportional to the power of the first high-frequency power from the first high-frequency power source HFS applied in generating the plasma. In addition, the electron density of the plasma depends on the pressure inside the processing vessel (12). The bias potential for drawing the ions in the plasma into the wafer W is proportional to the power of the second high-frequency power from the second high-frequency power source LFS applied in generating the bias potential. In addition, the bias potential for drawing ions in the plasma to the wafer W depends on the pressure inside the processing vessel (12). In addition, when the second high-frequency power is not applied to the mounting table (16), ions are drawn to the mounting table by the potential difference between the plasma potential (plasma potential) generated when plasma is generated and the mounting table (16).

In addition, heat input from the plasma includes heating by luminescence of the plasma, irradiation of the wafer W by electrons or radicals in the plasma, and surface reaction on the wafer W by ions and radicals. These components also depend on the power of the high-frequency power source and the pressure within the processing vessel (12). Heat input from the plasma also depends on device parameters related to plasma generation, such as the distance between the mounting table (16) and the upper electrode (30) and the type of gas supplied to the processing space S.

The heat transferred to the wafer W is transferred to the electrostatic chuck (18). Here, not all of the heat of the wafer W is transferred to the electrostatic chuck (18), but heat is transferred to the electrostatic chuck (18) depending on the difficulty of heat transfer, such as the degree of contact between the wafer W and the electrostatic chuck (18). The difficulty of heat transfer, that is, the thermal resistance, is inversely proportional to the cross-sectional area with respect to the direction of heat transfer. Therefore, in Fig. 4, the difficulty of heat transfer from the wafer W to the surface of the electrostatic chuck (18) is expressed as the thermal resistance RthㆍA per unit area between the wafer W and the surface of the electrostatic chuck (18). In addition, A is the area of the region (divided region (75)) where the heater HT is provided. Rth is the thermal resistance in the entire region where the heater HT is provided. In addition, in Fig. 4, the amount of heat input from the wafer W to the surface of the electrostatic chuck (18) is expressed as the heat flux q per unit area from the wafer W to the surface of the electrostatic chuck (18). In addition, the thermal resistance RthㆍA depends on the surface condition of the electrostatic chuck (18), the value of the DC voltage applied from the DC power supply (22) to hold the wafer W, and the pressure of the heat transfer gas supplied between the upper surface of the electrostatic chuck (18) and the back surface of the wafer W. In addition, the thermal resistance RthㆍA also depends on other device parameters involved in thermal resistance or thermal conductivity.

The heat transferred to the surface of the electrostatic chuck (18) increases the temperature of the electrostatic chuck (18) and is also transferred to the heater HT. In Fig. 4, the amount of heat input from the surface of the electrostatic chuck (18) to the heater HT is expressed as the heat flux qc per unit area from the surface of the electrostatic chuck (18) to the heater HT.

Meanwhile, the base (20) is cooled by the coolant flowing in the coolant path (24) and cools the electrostatic chuck (18) with which it is in contact. At this time, in Fig. 4, the amount of heat loss from the back surface of the electrostatic chuck (18) to the base (20) through the adhesive layer (19) is expressed as the heat flux qsus per unit area from the back surface of the electrostatic chuck (18) to the base (20). As a result, the heater HT is cooled by the heat loss and the temperature is lowered.

When the temperature of the heater HT is controlled to be constant, at the position of the heater HT, the sum of the amount of heat input to the heater HT and the amount of heat generated from the heater HT and the amount of heat loss from the heater HT become the same. For example, in an unignited state where the plasma is not ignited, the sum of the amount of heat of the radiant heat qr and the amount of heat generated from the heater HT and the amount of heat loss from the heater HT become the same. Fig. 5A is a diagram schematically showing the flow of energy in an unignited state. In the example of Fig. 5A, "100" of heat is lost from the heater HT by cooling from the base (20). "1" of heat is transferred to the wafer W by the radiant heat. When the temperatures of the wafer W and the electrostatic chuck (18) are in a substantially constant and stable state, the heat transferred to the wafer W is transferred as is to the electrostatic chuck (18). The amount of heat "1" input to the wafer W is input to the heater HT through the electrostatic chuck (18). When the temperature of the heater HT is controlled to be constant, the amount of heat "99" is generated in the heater HT by the heater power Ph from the heater power HP.

Meanwhile, for example, in the ignition state where plasma is ignited, heat is input to the heater HT from the plasma via the electrostatic chuck (18). Fig. 5b is a diagram schematically showing the flow of energy in the ignition state. Here, the ignition state has a transient state and a steady state. The transient state is, for example, a state where the heat input to the wafer W or the electrostatic chuck (18) is greater than the heat loss, and the temperature of the wafer W or the electrostatic chuck (18) tends to rise over time. The steady state is a state where the heat input and heat loss to the wafer W or the electrostatic chuck (18) are the same, and the temperature of the wafer W or the electrostatic chuck (18) does not tend to rise over time, and the temperature becomes approximately constant.

In the example of Fig. 5b, "100" amount of heat is lost from the heater HT by cooling from the expectation (20). In the case of the ignition state, the temperature of the wafer W rises due to heat input from the plasma until it becomes a steady state. Heat is transferred from the wafer W to the heater HT through the electrostatic chuck (18). As described above, when the temperature of the heater HT is controlled to be constant, the amount of heat input to the heater HT and the amount of heat lost from the heater HT become the same. The amount of heat required for the heater HT to maintain the temperature of the heater HT constant decreases. For this reason, the power supplied to the heater HT decreases.

For example, in the example of the "transient state" in Fig. 5b, "80" heat is transferred from the plasma to the wafer W. In addition, "1" heat is transferred to the wafer W by radiant heat. The heat transferred to the wafer W is transferred to the electrostatic chuck (18). In addition, when the temperature of the wafer W is not in a normal state, some of the heat transferred to the wafer W acts to increase the temperature of the wafer W. The amount of heat acting to increase the temperature of the wafer W depends on the heat capacity of the wafer W. Therefore, among the "81" heat transferred to the wafer W, "61" heat is transferred from the wafer W to the surface of the electrostatic chuck (18). The heat transferred to the surface of the electrostatic chuck (18) is transferred to the heater HT. In addition, when the temperature of the electrostatic chuck (18) is not in a normal state, some of the heat transferred to the surface of the electrostatic chuck (18) acts to increase the temperature of the electrostatic chuck (18). The amount of heat that acts to increase the temperature of the electrostatic chuck (18) depends on the heat capacity of the electrostatic chuck (18). Therefore, among the “61” amounts of heat transferred to the surface of the electrostatic chuck (18), “41” amounts of heat are transferred to the heater HT. Therefore, when the temperature of the heater HT is controlled to be constant, “59” amounts of heat are supplied to the heater HT by the heater power Ph from the heater power HP.

In addition, in the example of the "normal state" in Fig. 5b, "80" heat is transferred from the plasma to the wafer W. In addition, "1" heat is transferred to the wafer W by radiant heat. The heat transferred to the wafer W is transferred to the electrostatic chuck (18). In addition, when the temperature of the wafer W is in a normal state, the wafer W has the same heat input and output. Therefore, "81" heat transferred from the plasma to the wafer W is transferred from the wafer W to the surface of the electrostatic chuck (18). The heat transferred to the surface of the electrostatic chuck (18) is transferred to the heater HT. When the temperature of the electrostatic chuck (18) is in a normal state, the electrostatic chuck (18) has the same heat input and output. Therefore, "81" heat transferred to the surface of the electrostatic chuck (18) is transferred to the heater HT. For this reason, when the temperature of the heater HT is controlled to be constant, a heat amount of "19" is supplied to the heater HT by the heater power Ph from the heater power HP.

As shown in FIG. 5a and FIG. 5b, the power supplied to the heater HT is lower in the ignition state than in the non-ignition state. In addition, in the ignition state, the power supplied to the heater HT is lowered until it becomes a normal state.

In addition, as shown in FIGS. 5A and 5B, when the temperature of the heater HT is controlled to be constant, even in any of the "unignited state", "transient state", and "steady state", "100" of heat is lost from the heater HT by cooling from the base (20). That is, the heat flux qsus per unit area from the heater HT to the refrigerant supplied to the refrigerant path (24) formed inside the base (20) is always constant, and the temperature gradient from the heater HT to the refrigerant is also always constant. Therefore, the temperature sensor used to control the temperature of the heater HT to be constant does not necessarily need to be installed directly on the heater HT. For example, if the temperature difference between the heater HT and the temperature sensor is always constant, such as between the back of the electrostatic chuck (18), inside the adhesive layer (19), inside the base (20), and between the heater HT and the coolant, the temperature difference (ΔT) between the temperature sensor and the heater HT is calculated using the thermal conductivity, thermal resistance, etc. of the material between the heater HT and the temperature sensor, and by adding the temperature difference (ΔT) to the temperature value detected by the temperature sensor, it is possible to output the temperature of the heater HT, and control the actual temperature of the heater HT to be constant.

Fig. 6 is a diagram showing an example of changes in the temperature of the wafer and the power supplied to the heater. Fig. 6 (a) shows a change in the temperature of the wafer W. Fig. 6 (b) shows a change in the power supplied to the heater HT. The example of Fig. 6 shows an example of the results of measuring the temperature of the wafer W and the power supplied to the heater HT by controlling the temperature of the heater HT to be constant and igniting the plasma from a non-ignited state where the plasma is not ignited. The temperature of the wafer W was measured using a temperature measurement wafer such as Etch Temp sold by KLA-Tencor. This temperature measurement wafer is expensive. Therefore, in mass production sites, if a temperature measurement wafer is used to adjust the temperature of each heater HT of the plasma processing device (10), the cost increases. In addition, in mass production sites, if a temperature measurement wafer is used to adjust the temperature of each heater HT of the plasma processing device (10), productivity decreases.

Period T1 of Fig. 6 is an unignited state in which plasma is not ignited. In period T1, the power supplied to the heater HT is constant. Period T2 of Fig. 6 is an ignited state in which plasma is ignited, and is a transient state. In period T2, the power supplied to the heater HT decreases. Furthermore, in period T2, the temperature of the wafer W rises to a constant temperature. Period T3 of Fig. 6 is an ignited state in which plasma is ignited. In period T3, the temperature of the wafer W is constant and in a steady state. When the electrostatic chuck (18) also becomes a steady state, the power supplied to the heater HT becomes approximately constant, and the fluctuation of the decreasing tendency becomes stable. Period T4 of Fig. 6 is an unignited state in which plasma is eliminated. In period T4, since there is no heat input from the plasma to the wafer W, the temperature of the wafer W decreases, and the power supplied to the heater HT increases.

The tendency of the decrease in the power supply to the heater HT in the transient state shown in the period T2 of Fig. 6 varies depending on the amount of heat input from the plasma to the wafer W, the thermal resistance between the wafer W and the surface of the electrostatic chuck (18), etc.

Fig. 7 is a diagram schematically showing the flow of energy in the ignition state. Also, Fig. 7 is an example of a transient state. Also, since the heat input of radiant heat has a small influence, it is omitted. For example, in Fig. 7, in the example of "heat input: small, thermal resistance: small", "80" amount of heat is transferred from the plasma to the wafer W. Of the "80" amount of heat transferred from the plasma to the wafer W, "60" amount of heat is transferred from the wafer W to the surface of the electrostatic chuck (18). And, of the "60" amount of heat transferred to the surface of the electrostatic chuck (18), "40" amount of heat is transferred to the heater HT. For example, when the temperature of the heater HT is controlled to be constant, "60" amount of heat is supplied to the heater HT from the heater power supply HP by the heater power Ph.

In addition, in the example of "heat input: large, thermal resistance: small" in Fig. 7, "100" amount of heat is transferred from the plasma to the wafer W. Of the "100" amount of heat transferred from the plasma to the wafer W, "80" amount of heat is transferred from the wafer W to the surface of the electrostatic chuck (18). And, of the "80" amount of heat transferred to the surface of the electrostatic chuck (18), "60" amount of heat is transferred to the heater HT. For example, when the temperature of the heater HT is controlled to be constant, "40" amount of heat is supplied to the heater HT from the heater power HP by the heater power Ph.

In addition, in the example of "heat input: small, thermal resistance: large" in Fig. 7, "80" amount of heat is transferred from the plasma to the wafer W. Of the "80" amount of heat transferred from the plasma to the wafer W, "40" amount of heat is transferred from the wafer W to the surface of the electrostatic chuck (18). Of the "40" amount of heat transferred to the surface of the electrostatic chuck (18), "20" amount of heat is transferred to the heater HT. For example, when the temperature of the heater HT is controlled to be constant, "80" amount of heat is supplied to the heater HT by the heater power Ph from the heater power HP.

In this way, when the temperature of the heater HT is controlled to be constant, the heater power Ph changes depending on the heat input from the plasma to the wafer W or the thermal resistance between the wafer W and the surface of the electrostatic chuck (18). Therefore, the tendency of the decrease in the power supplied to the heater HT in the period T2 shown in Fig. 6 (b) changes depending on the heat input from the plasma to the wafer W or the thermal resistance between the wafer W and the surface of the electrostatic chuck (18). Therefore, the graph of the power supplied to the heater HT in the period T2 can be modeled using the heat input from the plasma to the wafer W or the thermal resistance between the wafer W and the surface of the electrostatic chuck (18) as parameters. That is, the change in the power supplied to the heater HT in the period T2 can be modeled by an operational formula using the heat input from the plasma to the wafer W or the thermal resistance between the wafer W and the surface of the electrostatic chuck (18) as parameters.

In this embodiment, the change in the power supply to the heater HT in the period T2, as shown in Fig. 6 (b), is modeled as an equation per unit area. For example, the amount of heat generated qh from the heater HT per unit area when there is a heat flux from the plasma can be expressed as in the following equation (2). The amount of heat generated qh0 from the heater HT per unit area in the steady state when there is no heat flux from the plasma can be expressed as in the following equation (3). The thermal resistance RthcㆍA per unit area between the surface of the electrostatic chuck (18) and the heater can be expressed as in the following equation (4). When the heat flux qp and the thermal resistance RthㆍA are parameters, and a1, a2, a3, λ1, λ2, τ1, and τ2 are expressed as in the following equations (5)-(11), the amount of heat generated qh can be expressed as in the following equation (1).

[Mathematical Formula 1]

Here,

Ph is the heater power [W] when there is heat flux from the plasma.

Ph0 is the heater power [W] at steady state when there is no heat flux from the plasma.

qh is the heat generation from the heater HT per unit area [W/㎡] when there is a heat flux from the plasma.

qh0 is the heat generation per unit area from the heater HT in steady state when there is no heat flux from the plasma [W/㎡].

qp is the heat flux per unit area from the plasma to the wafer W [W/m2].

RthㆍA is the thermal resistance per unit area [Kㆍ㎡/W] between the wafer W and the surface of the electrostatic chuck (18).

RthcㆍA is the thermal resistance per unit area [Kㆍ㎡/W] between the surface of the electrostatic chuck (18) and the heater.

A is the area [㎡] of the partition area (75) where the heater HT is provided.

ρw is the density of wafer W [kg/㎥].

Cw is the heat capacity per unit area of the wafer W [J/Kㆍ㎡].

zw is the thickness of the wafer W [m].

ρc is the density [kg/㎥] of the ceramic constituting the electrostatic chuck (18).

Cc is the heat capacity per unit area [J/Kㆍ㎡] of the ceramic constituting the electrostatic chuck (18).

zc is the distance [m] from the surface of the electrostatic chuck (18) to the heater HT.

κc is the thermal conductivity [W/Kㆍm] of the ceramic constituting the electrostatic chuck (18).

t is the time elapsed since ignition of the plasma [sec].

For a1 shown in equation (5), 1/a1 is a time constant representing the difficulty of warming up the wafer W. In addition, for a2 shown in equation (6), 1/a2 is a time constant representing the difficulty of heat penetration into and warming up of the electrostatic chuck (18). In addition, for a3 shown in equation (7), 1/a3 is a time constant representing the difficulty of heat penetration into and warming up of the electrostatic chuck (18).

The density ρw of the wafer W, the heat capacity Cw per unit area of the wafer W, and the thickness zw of the wafer W are each determined in advance from the actual configuration of the wafer W. The area A of the heater HT, the density ρc of the ceramic constituting the electrostatic chuck (18), and the heat capacity Cc per unit area of the ceramic constituting the electrostatic chuck (18) are each determined in advance from the actual configuration of the plasma processing device (10). The distance zc from the surface of the electrostatic chuck (18) to the heater HT, and the thermal conductivity κc of the ceramic constituting the electrostatic chuck (18) are also each determined in advance from the actual configuration of the plasma processing device (10). RthcㆍA is determined in advance from the thermal conductivity κc and the distance zc by Equation (4).

The heater power Ph when there is a heat flux from the plasma at each elapsed time t after igniting the plasma, and the heater power Ph0 in the steady state when there is no heat flux from the plasma, can be obtained by measurement using the plasma processing device (10). Then, as shown in Equation (2), by dividing the obtained heater power Ph by the area A of the heater HT, the heat generation amount qh from the heater HT per unit area when there is a heat flux from the plasma can be obtained. Furthermore, as shown in Equation (3), by dividing the obtained heater power Ph0 by the area A of the heater HT, the heat generation amount qh0 from the heater HT per unit area in the steady state when there is no heat flux from the plasma can be obtained.

And, the heat flux qp per unit area from the plasma to the wafer W and the thermal resistance RthㆍA per unit area between the wafer W and the surface of the electrostatic chuck (18) can be obtained by fitting equation (1) using the measurement results.

Also, in the steady state of Fig. 5b, the heat input from the plasma to the wafer W is increasing as heat input to the heater HT as it is from the unignited state shown in Fig. 5a. Therefore, the amount of heat input from the plasma to the wafer W may be calculated from the difference between the power supply in the unignited state shown in period T1 of Fig. 6 and the power supply in the steady state shown in period T3. For example, the heat flux qp per unit area from the plasma to the wafer W can be calculated from the difference between the heater power Ph0 when there is no heat flux from the plasma (unignited state) and the heater power Ph in the steady state shown in period T3, converted to a value per unit area, as in the following equation (12). In addition, the heat flux qp per unit area from the plasma to the wafer W can be calculated from the difference between the heat generation qh0 per unit area from the heater HT obtained from the heater power Ph0 when there is no heat flux from the plasma (unignited state) and the heat generation qh per unit area from the heater HT obtained from the heater power Ph in the steady state shown in the period T3, as in the following equation (12).

qp=(Ph0-Ph)/A=qh0-qh … (12)

In addition, the graph of the temperature of the wafer W in the period T2 shown in (a) of Fig. 6 can also be modeled using the heat input from the plasma to the wafer W or the thermal resistance between the wafer W and the surface of the electrostatic chuck (18) as parameters. In the present embodiment, the change in the temperature of the wafer W in the period T2 is modeled as an equation per unit area. For example, when the heat flux qp and the thermal resistance RthㆍA are used as parameters and a1, a2, a3, λ1, λ2, τ1, and τ2 shown in equations (5)-(11) are used, the temperature TW [℃] of the wafer W can be expressed as in the following equation (13).

[Mathematical formula 2]

Here,

TW is the temperature of wafer W [℃].

Th is the temperature [℃] of the heater HT, which is controlled constantly.

The temperature Th of the heater can actually be obtained from the conditions when the temperature of the wafer W is controlled to a constant level.

Using the measurement results, when the heat flux qp and the thermal resistance RthㆍA are obtained by fitting equation (1), the temperature TW of the wafer W can be calculated from equation (13).

If the elapsed time t is sufficiently longer than the time constants τ1 and τ2 shown in equations (10) and (11), equation (13) can be omitted as in equation (14) below. That is, if the temperature TW of the wafer W after transitioning to a steady state, which is the period T3 of Fig. 6, is used to calculate the temperature Th of the heater HT, which becomes the target temperature, equation (13) can be expressed as in equation (14).

[Mathematical Formula 3]

For example, by equation (14), the temperature TW of the wafer W can be obtained from the temperature Th of the heater, the heat flux qp, and the thermal resistances RthㆍA and RthcㆍA.

However, in the plasma processing device (10), the processing conditions of the plasma processing may change due to the occurrence of an abnormality or failure, changes over time, etc. For example, in the plasma processing device (10), the pressure inside the processing vessel (12), the power applied in the plasma processing, etc. may change due to the occurrence of an abnormality or failure, changes over time, etc. Examples of the processing conditions of the plasma processing include the power of the first high-frequency power from the first high-frequency power source HFS, and the power of the second high-frequency power from the second high-frequency power source LFS. In addition, examples of the processing conditions of the plasma processing include the pressure inside the processing vessel (12), the surface roughness of the mounting table (16), the pressure of the heat transfer gas, the back surface film thickness of the wafer W, the warpage of the wafer W, the temperature of the upper electrode (30), and the temperature of the sediment shield (46). In addition, the processing conditions of the plasma processing are not limited to these, and may be any conditions that change due to the occurrence of an abnormality or failure, changes over time, etc.

In the plasma processing device (10), when the processing conditions of the plasma processing change, the heat input from the plasma or the heat input due to radiant heat, the thermal resistance between the wafer W and the surface of the electrostatic chuck (18), etc. change, and the value related to the temperature of the mounting table (16) changes. As the value related to the temperature of the mounting table (16), for example, the amount of heat generated by the heater HT for maintaining the temperature of the mounting table (16) at a predetermined temperature in an unignited state, the thermal resistance between the wafer W and the mounting table (16), and the heat input that flows into the mounting table (16) from the plasma in an ignited state can be mentioned. In addition, the value related to the temperature of the mounting table (16) is not limited to these, and any value related to the temperature of the mounting table (16) may be used as long as it changes due to a change in the processing conditions of the plasma processing.

For example, in the plasma processing device (10), when the temperature of the upper electrode (30) or the temperature of the sediment shield (46) changes, the heat input of the radiant heat to the wafer W changes. As a result, the heater power Ph0 supplied to each heater HT in the non-ignition state changes, and the heat generation amount qh0 from the heater HT per unit area changes. The heat generation amount qh0 is obtained by dividing the heater power Ph0 by the area of each heater HT. Fig. 8A is a drawing showing an example of a change in the heat generation amount from the heater when the temperatures of the upper electrode and the sediment shield change. Fig. 8A shows a change in the heat generation amount qh0 from the heater HT due to the heater power Ph0 supplied to the heater HT provided in each of the divided areas (75) of the center portion (Center), the middle portion (Middle), the edge portion (Edge), and the focus ring portion (F/R) in the plasma non-ignition state. The solid line represents the change in the amount of heat generated qh0 from the heater HT when the temperature of the upper electrode (30) is changed from 40°C to 120°C. The dashed line represents the change in the amount of heat generated qh0 from the heater HT when the temperature of the sediment shield (46) is changed from 40°C to 120°C. In this way, when the temperature of the upper electrode (30) or the temperature of the sediment shield (46) increases, the amount of heat input to the wafer W increases, so the amount of heat generated qh0 from the heater HT decreases. In addition, as shown by the solid line and the dashed line, in the upper electrode (30) and the sediment shield (46), there is a difference in the change in temperature in each divided area (75) when the temperature changes. For example, the radiant heat from the upper electrode (30) is input from the upper portion of the mounting plate (16). For this reason, when the temperature of the upper electrode (30) changes, the heat generation amount qh0 from the heater HT changes significantly in areas near the center within the surface of the mounting base (16), such as the center portion and the middle portion. On the other hand, the radiant heat from the sediment shield (46) enters from the side of the mounting base (16). For this reason, when the temperature of the sediment shield (46) changes, the heat generation amount qh0 from the heater HT changes significantly in areas near the periphery within the surface of the mounting base (16), such as the edge portion and the focus ring portion. Therefore, it is possible to determine which temperature of the upper electrode (30) or the sediment shield (46) has changed from the change pattern of the heat generation amount qh0 from the heater HT of each divided region (75).

In addition, for example, in the plasma processing device (10), when the power of the first high-frequency power from the first high-frequency power source HFS or the power of the second high-frequency power from the second high-frequency power source LFS changes, the heat input from the plasma changes. Thereby, the heater power Ph supplied to each heater HT in a steady state where the plasma is ignited changes, and the heat generation amount qh from the heater HT per unit area changes. The heat generation amount qh is obtained by dividing the heater power Ph by the area of each heater HT. Fig. 8b is a drawing showing an example of a change in the heat generation amount from the heater when the first high-frequency power and the second high-frequency power change. Fig. 8b shows a change in the heat generation amount qh from the heater HT due to the heater power Ph supplied to the heater HT provided in each of the divided regions (75) of the center portion (Center), the middle portion (Middle), the edge portion (Edge), and the focus ring portion (F/R) in a steady state where the plasma is ignited. The solid line shows the change in the amount of heat generated qh from the heater HT when the power of the first high-frequency power is changed from 500 W to 1000 W. The dashed line shows the change in the amount of heat generated qh from the heater HT when the power of the second high-frequency power is changed from 500 W to 1000 W. In this way, when the power of the first high-frequency power or the power of the second high-frequency power increases, the amount of heat input from the plasma increases, so the amount of heat generated qh from the heater HT decreases. In addition, as shown by the solid line and the dashed line, there is a difference in temperature in each divided area (75) due to the change in power between the first high-frequency power and the second high-frequency power. For example, when the power of the first high-frequency power is changed, the amount of heat generated qh from the heater HT changes significantly in an area near the periphery within the surface of the mounting plate (16), such as a focus ring portion. Meanwhile, when the second high-frequency power changes, the amount of heat generated qh from the heater HT in the area near the center within the surface of the mounting base (16), such as the center portion, and near the periphery within the surface of the mounting base (16), such as the focus ring portion, changes significantly. Therefore, it is possible to determine which power, the first high-frequency power or the second high-frequency power, has changed from the change pattern of the amount of heat generated qh from the heater HT in each divided area (75).

In addition, for example, in the plasma processing device (10), when the pressure inside the processing vessel (12) changes, the heat input from the plasma changes. Thereby, the heater power Ph supplied to each heater HT in the steady state where the plasma is ignited changes, and the heat generation qh from the heater HT per unit area changes. The heat generation qh is obtained by dividing the heater power Ph by the area of each heater HT. Fig. 8C is a drawing showing an example of a change in the heat generation from the heater when the pressure inside the processing vessel changes. Fig. 8C shows a change in the heat generation qh from the heater HT supplied to each of the divided regions (75) of the center portion (Center), the middle portion (Middle), the edge portion (Edge), and the focus ring portion (F/R) in the steady state where the plasma is ignited. The solid line shows a change in the heat generation qh from the heater HT when the pressure inside the processing vessel (12) changes from 30 mTorr to 50 mTorr. In this way, when the pressure inside the processing vessel (12) increases, the heat input from the plasma decreases, so the heat generation qh from the heater HT increases. In addition, when the pressure inside the processing vessel (12) increases, the heat generation qh from the heater HT in the peripheral region within the surface of the mounting plate (16), such as the focus ring portion, changes significantly. Therefore, it is possible to determine whether the pressure inside the processing vessel (12) has changed from the change pattern of the heat generation qh from the heater HT in each divided region (75).

In addition, for example, in the plasma processing device (10), when the pressure of the heat transfer gas supplied between the upper surface of the electrostatic chuck (18) and the back surface of the wafer W changes, the thermal resistance between the wafer W and the surface of the electrostatic chuck (18) changes. In addition, in the plasma processing device (10), when the back surface film thickness of the wafer W changes, the thermal resistance between the wafer W and the surface of the electrostatic chuck (18) changes. Fig. 8d is a drawing showing an example of a change in thermal resistance when the pressure of the heat transfer gas and the back surface film thickness of the wafer W change. Fig. 8d shows a change in thermal resistance RthㆍA of each divided area (75) of the center portion (Center), the middle portion (Middle), the edge portion (Edge), and the focus ring portion (F/R). The solid line shows the change in thermal resistance when the pressure of the heat transfer gas supplied between the upper surface of the electrostatic chuck (18) and the back surface of the wafer W is changed from 10 Torr to 30 Torr. The dashed line shows the change in thermal resistance when the film thickness of the SiO2 layer on the back surface of the wafer W is changed from 0 nm to 1000 nm. In this way, when the pressure of the heat transfer gas or the film thickness on the back surface of the wafer W increases, the thermal resistance changes and the amount of heat input from the plasma changes. In addition, as shown by the solid line and the dashed line, there is a difference in the change in thermal resistance depending on the pressure of the heat transfer gas and the film thickness on the back surface of the wafer W. For example, when the pressure of the heat transfer gas changes, the thermal resistance of the area near the center of the wafer W, such as the center portion, changes significantly. On the other hand, when the film thickness on the back surface of the wafer W changes, the thermal resistance changes significantly over the entire area of the wafer W. Accordingly, it is possible to determine whether the pressure of the heat transfer gas or the film thickness on the back side of the wafer W has changed from the change pattern of the thermal resistance of each divided area (75).

Returning to Fig. 3, the heater control unit (102a) controls the temperature of each heater HT. For example, the heater control unit (102a) outputs control data indicating the supply power to each heater HT to the heater power HP, and controls the supply power supplied from the heater power HP to each heater HT, thereby controlling the temperature of each heater HT.

During plasma processing, the heater control unit (102a) sets a target temperature for each heater HT. For example, in the heater control unit (102a), the target temperature of the wafer W for each divided area (75) of the mounting area (18a) is set as the target temperature of the heater HT for that divided area (75). This target temperature of the wafer W is, for example, a temperature at which the precision of plasma etching for the wafer W is the best.

The heater control unit (102a) controls the power supply to each heater HT so that each heater HT becomes the set temperature during plasma processing. For example, the heater control unit (102a) compares the temperature of each partition area (75) of the mounting area (18a) indicated by the temperature data input to the external interface (101) with the set temperature of each partition area (75) for each partition area (75). Using the comparison result, the heater control unit (102a) specifies the partition area (75) whose temperature is lower than the set temperature and the partition area (75) whose temperature is higher than the set temperature. The heater control unit (102a) outputs control data to the heater power HP that increases the power supply to the partition area (75) whose temperature is lower than the set temperature and decreases the power supply to the partition area (75) whose temperature is higher than the set temperature.

The first acquisition unit (102b) acquires change information (104a) indicating a change in the temperature of the mounting plate (16) when the processing conditions for plasma treatment change.

First, the first acquisition unit (102b) places the wafer W on the mounting table (16), performs plasma processing with processing parameters as processing conditions of plasma processing as standard conditions, and acquires a value regarding the temperature of the mounting table (16). The standard conditions are processing conditions for performing actual plasma processing on the wafer W in a production process for producing semiconductors, for example. The first acquisition unit (102b) performs plasma processing with processing conditions as standard conditions, and acquires a value regarding the temperature of the mounting table (16).

During plasma treatment, a target temperature for each heater HT is set in the heater control unit (102a). The heater control unit (102a) controls the power supplied to each heater HT so that each heater HT reaches the set temperature during plasma treatment.

The first acquisition unit (102b) performs plasma processing while controlling the power supply to each heater HT so that the temperature of each heater HT is constant by the heater control unit (102a), and acquires a value related to the temperature of the mounting plate (16). For example, the first acquisition unit (102b) measures the power supply to each heater HT in a non-ignited plasma state before the start of the plasma processing. In addition, the first acquisition unit (102b) measures the power supply to each heater HT in a transient state until the fluctuation of the tendency for the power supply to each heater HT to decrease after the plasma is ignited stabilizes. In addition, the first acquisition unit (102b) measures the power supply to each heater HT in a stable steady state after the plasma is ignited and the decrease in the power supply to each heater HT has disappeared. The power supplied to each heater HT in the non-ignition state may be measured at least once for each heater HT, and may be measured multiple times and the average value may be used as the power supplied in the non-ignition state. The power supplied to each heater HT in the transient state and the steady state may be measured twice or more. It is preferable that the measurement timing for measuring the power supplied includes a timing at which the power supplied tends to decrease greatly. Furthermore, when the number of measurements is small, the measurement timing is preferably spaced apart by a predetermined period or more. In the present embodiment, the first acquisition unit (102b) measures the power supplied to each heater HT at a predetermined cycle (for example, a 0.1 second cycle) during the period of plasma processing. Thereby, the power supplied to each heater HT in the transient state and the steady state is measured multiple times.

The first acquisition unit (102b) measures the power supplied to each heater HT in the non-ignition state, transient state, and steady state in a predetermined cycle.

The first acquisition unit (102b) calculates, for each heater HT, the amount of heat generated in the heater HT to maintain the temperature at a predetermined temperature in the non-ignition state. For example, the first acquisition unit (102b) calculates, for each heater HT, the heater power Ph0 in the non-ignition state from the power supplied to the heater HT in the non-ignition state.

In addition, the first acquisition unit (102b) calculates, for each heater HT, the thermal resistance between the wafer W and the mounting table (16), and the heat input flowing into the mounting table (16) from the plasma in the ignition state. For example, the first acquisition unit (102b) calculates, for each heater HT, the heat input from the plasma and the thermal resistance between the wafer W and the heater HT as parameters, and calculates the heat input and thermal resistance for each heater HT by fitting a calculation model that calculates the power supply in the transient state using the measured power supply in the non-ignition state and the transient state.

For example, the first acquisition unit (102b) obtains, for each heater HT, the heater power Ph0 of the non-ignition state for each elapsed time t. In addition, the first acquisition unit (102b) obtains, for each heater HT, the heater power Ph of the transient state for each elapsed time t. The first acquisition unit (102b) obtains, by dividing the obtained heater power Ph0 by the area of each heater HT, the heat generation amount qh0 from the heater HT per unit area of the non-ignition state for each elapsed time t. In addition, the first acquisition unit (102b) obtains, by dividing the obtained heater power Ph0 by the area of each heater HT, the heat generation amount qh from the heater HT per unit area of the transient state for each elapsed time t.

And, the first acquisition unit (102b) uses the above equations (1)-(11) as a calculation model to fit the heat generation amount qh and the heat generation amount qh0 for each elapsed time t for each heater HT, and calculates the heat flux qp and the thermal resistance RthㆍA that have the smallest error.

In addition, the first acquisition unit (102b) may calculate the heat input from the plasma to the wafer W from the difference between the supply power in the unignited state and the supply power in the normal state. For example, the first acquisition unit (102b) may calculate the heat flux qp by dividing the difference between the heater power Ph0 in the unignited state and the heater power Ph in the normal state by the area of each heater HT using equation (12).

Next, the first acquisition unit (102b) changes the processing parameters that are processing conditions of the plasma treatment. For example, the first acquisition unit (102b) changes one of the processing parameters, the power of the first high-frequency power, the power of the second high-frequency power, the pressure of the heat-conducting gas, the backside film thickness of the wafer W, the temperature of the upper electrode (30), and the temperature of the sediment shield (46). In addition, it is preferable to change the processing parameters one by one, but it is also possible to change multiple processing parameters at the same time.

The first acquisition unit (102b) places a new wafer W on the mounting table (16), performs plasma processing under changed processing conditions, and acquires a value regarding the temperature of the mounting table (16). For example, the first acquisition unit (102b) measures the power supplied to each heater HT in the non-ignition state, transient state, and steady state of the plasma processing while the heater control unit (102a) controls the power supplied to each heater HT so that the temperature of each heater HT becomes a constant set temperature.

The first acquisition unit (102b) calculates, for each heater HT, the heater power Ph0 in the unignited state as the amount of heat generated in the heater HT for maintaining the temperature at a predetermined temperature in the unignited state from the power supplied to the heater HT in the unignited state. In addition, the first acquisition unit (102b) performs fitting using the measured unignited state and transient state power supplies for the above-described calculation model, and calculates the heat input to the wafer W and the thermal resistance for each heater HT. In addition, the first acquisition unit (102b) may calculate the heat input to the wafer W from the plasma from the difference between the power supply in the unignited state and the power supply in the steady state.

The first acquisition unit (102b) changes the processing parameters, which are processing conditions for the plasma treatment, within a predetermined range, and acquires values related to the temperature of the mounting table (16). For example, the first acquisition unit (102b) changes the processing parameters, which are processing conditions for the plasma treatment, within a predetermined range, and calculates the heater power Ph0, the heat flux qp, and the thermal resistance Rth·A. Then, the first acquisition unit (102b) generates change information (104a) indicating changes in values related to the temperature of the mounting table (16) when the processing conditions for the plasma treatment have changed. For example, the first acquisition unit (102b) generates change information (104a) that records the change pattern of values related to the temperature of the mounting table (16) of each divided area (75) for each changed processing parameter, which is the processing condition for the plasma treatment. For example, the first acquisition unit (102b) generates change information (104a) that records a change pattern showing a change in the heater power Ph0, the heat flux qp, and the thermal resistance RthㆍA of each divided area (75) when the power of the first high-frequency power, the power of the second high-frequency power, the pressure of the heat-conducting gas, the back surface film thickness of the wafer W, the temperature of the upper electrode (30), and the temperature of the sediment shield (46) change. The change information (104a) may be such that the heater power Ph0, the heat flux qp, and the thermal resistance RthㆍA are memorized for each processing condition. In addition, the change information (104a) may be such that the heater power Ph0, the heat flux qp, and the thermal resistance RthㆍA under any one processing condition are used as a reference processing condition, and the difference in the heater power Ph0, the heat flux qp, and the thermal resistance RthㆍA between a processing condition that is different from the reference processing condition is memorized. The first acquisition unit (102b) stores the generated change information (104a) in the memory unit (104).

By this, the change information (104a) is stored in the memory unit (104). In addition, in this embodiment, a case is explained as an example in which the first acquisition unit (102b) performs plasma processing with changed processing conditions to acquire the change information (104a), but this is not limited thereto. The memory unit (104) may store change information (104a) prepared in advance or change information (104a) generated by another device.

However, as described above, the plasma processing device (10) may have changes in the processing conditions of the plasma processing due to occurrence of an abnormality or failure, changes over time, etc. Therefore, the plasma processing device (10) related to the embodiment monitors changes in the processing conditions of the plasma processing based on change information (104a) stored in the memory unit (104) when performing plasma processing on a wafer W in a production process for producing a semiconductor.

During plasma treatment, a target temperature for each heater HT is set in the heater control unit (102a). The heater control unit (102a) controls the power supplied to each heater HT so that each heater HT reaches the set temperature during plasma treatment.

The second acquisition unit (102c) performs plasma processing while the heater control unit (102a) controls the power supply to each heater HT so that the temperature of each heater HT becomes a constant set temperature, and acquires a value related to the temperature of the mounting plate (16). For example, the second acquisition unit (102c) measures the power supply to each heater HT in a non-ignited plasma state before the start of the plasma processing. In addition, the second acquisition unit (102c) measures the power supply to each heater HT in a transient state until the fluctuation of the tendency for the power supply to each heater HT to decrease after the plasma is ignited stabilizes. In addition, the second acquisition unit (102c) measures the power supply to each heater HT in a stable steady state after the plasma is ignited and the decrease in the power supply to each heater HT disappears. The power supplied to each heater HT in the non-ignition state may be measured at least once for each heater HT, and may be measured multiple times and the average value may be used as the power supplied in the non-ignition state. The power supplied to each heater HT in the transient state and the steady state may be measured twice or more. It is preferable that the measurement timing for measuring the power supplied includes a timing at which the power supplied tends to decrease greatly. Furthermore, when the number of measurements is small, the measurement timing is preferably spaced apart by a predetermined period or more. In the present embodiment, the second acquisition unit (102c) measures the power supplied to each heater HT at a predetermined cycle (for example, a cycle of 0.1 seconds) during the period of plasma processing. Thereby, the power supplied to each heater HT in the transient state and the steady state is measured multiple times.

The second acquisition unit (102c) measures the power supplied to each heater HT in the non-ignition state, the transient state, and the normal state for a predetermined cycle. For example, the second acquisition unit (102c) measures the power supplied to each heater HT in the non-ignition state, the transient state, and the normal state each time the wafer W is exchanged and the exchanged wafer W is mounted on the mounting stand (16) to perform plasma processing. In addition, for example, the second acquisition unit (102c) may measure the power supplied to each heater HT in the non-ignition state, the transient state, and the normal state for each plasma processing.

The second acquisition unit (102c) calculates, for each heater HT, the amount of heat generated by the heater HT to maintain the temperature at a predetermined temperature in the non-ignition state. For example, the second acquisition unit (102c) calculates, for each heater HT, the heater power Ph0 in the non-ignition state from the power supplied to the heater HT in the non-ignition state.

In addition, the second acquisition unit (102c) calculates, for each heater HT, the thermal resistance between the wafer W and the mounting table (16), and the heat input flowing into the mounting table (16) from the plasma in the ignition state. For example, the second acquisition unit (102c) calculates, for each heater HT, the heat input and the thermal resistance by performing fitting using the measured unignited state and transient state supply power for the above-described calculation model.

For example, the second acquisition unit (102c) obtains the heater power Ph0 of the non-ignition state for each heater HT at each elapsed time t. In addition, the second acquisition unit (102c) obtains the heater power Ph of the transient state for each heater HT at each elapsed time t. The second acquisition unit (102c) obtains the heat generation amount qh0 from the heater HT per unit area of the non-ignition state for each elapsed time t by dividing the obtained heater power Ph0 by the area of each heater HT. In addition, the second acquisition unit (102c) obtains the heat generation amount qh from the heater HT per unit area of the transient state for each elapsed time t by dividing the obtained heater power Ph0 by the area of each heater HT.

And, the second acquisition unit (102c) uses the above equations (1)-(11) as a calculation model to fit the heat generation amount qh and the heat generation amount qh0 for each elapsed time t for each heater HT, and calculates the heat flux qp and the thermal resistance RthㆍA with the smallest error.

In addition, the second acquisition unit (102c) may calculate the heat input from the plasma to the wafer W from the difference between the supply power in the unignited state and the supply power in the normal state. For example, the first acquisition unit (102b) may calculate the heat flux qp by dividing the difference between the heater power Ph0 in the unignited state and the heater power Ph in the normal state by the area of each heater HT using equation (12).

The second acquisition unit (102c) calculates the heater power Ph0, heat flux qp, and thermal resistance RthㆍA in the non-ignition state for a predetermined cycle. For example, the second acquisition unit (102c) calculates the heater power Ph0, heat flux qp, and thermal resistance RthㆍA in the non-ignition state by using the supplied power in the non-ignition state, transient state, and steady state measured while the wafer W is mounted on the mounting stand (16) each time the wafer W is exchanged.

The set temperature calculating unit (102d) calculates the set temperature of the heater HT at which the wafer W becomes the target temperature, using the calculated heat input and thermal resistance for each heater HT. For example, the set temperature calculating unit (102d) substitutes the calculated heat flux qp and the thermal resistance RthㆍA for each heater HT into equations (5), (6), and (13), and calculates the temperature Th of the heater HT from equation (13) using a1, a2, a3, λ1, λ2, τ1, and τ2 shown in equations (5)-(11). For example, the set temperature calculating unit (102d) calculates the temperature Th of the heater HT by setting the elapsed time t to a predetermined value that is large enough to be regarded as a steady state. The calculated temperature Th of the heater HT is the temperature of the heater HT at which the temperature of the wafer W becomes the target temperature. Also, the temperature Th of the heater HT may be obtained from equation (14).

In addition, the set temperature calculation unit (102d) may calculate the temperature TW of the wafer W at the current temperature T of the heater HT for each heater from Equation (13). For example, the set temperature calculation unit (102d) calculates the temperature TW of the wafer W when the elapsed time t is a predetermined value that is large enough to be regarded as a steady state at the current temperature T of the heater HT. Next, the set temperature calculation unit (102d) calculates the difference ΔTW between the calculated temperature TW and the target temperature. Then, the set temperature calculation unit (102d) may calculate the temperature obtained by subtracting the difference ΔTW from the current temperature T of the heater HT as the temperature Th of the heater HT at which the temperature of the wafer W becomes the target temperature.

The set temperature calculation unit (102d) corrects the set temperature of each heater HT of the heater control unit (102a) to the temperature of the heater HT at which the temperature of the wafer W becomes the target temperature.

The set temperature calculating unit (102d) calculates the temperature of the heater HT at which the temperature of the wafer W becomes the target temperature for a predetermined cycle, and modifies the set temperature of each heater HT. For example, the set temperature calculating unit (102d) calculates the temperature of the heater HT at which the temperature of the wafer W becomes the target temperature every time the wafer W is exchanged, and modifies the set temperature of each heater HT. In addition, for example, the set temperature calculating unit (102d) may calculate the temperature of the heater HT at which the temperature of the wafer W becomes the target temperature for each plasma treatment, and modifies the set temperature of each heater HT.

By this, the plasma processing device (10) related to the present embodiment can precisely control the temperature of the wafer W during plasma processing to the target temperature.

However, as described above, the plasma processing device (10) may have processing conditions for plasma processing that change due to occurrence of an abnormality or failure or changes over time.

Therefore, the monitoring unit (102e) monitors changes in the processing conditions of the plasma processing from changes in the values related to the temperature of the mounting plate (16) acquired by the second acquisition unit based on the change information (104a). For example, the monitoring unit (102e) stores, in a predetermined cycle, the heater power Ph0, the heat flux qp, and the thermal resistance RthㆍA of each heater HT in the non-ignition state, which are calculated by the second acquisition unit. Then, the monitoring unit (102e) monitors whether a change in any one of the change patterns stored in the change information (104a) has occurred in the heater power Ph0, the heat flux qp, and the thermal resistance RthㆍA of each heater HT. For example, the monitoring unit (102e) compares the heater power Ph0, the heat flux qp, and the thermal resistance RthㆍA of each heater HT, which are respectively calculated from the first wafer W and the most recent wafer W. And, the monitoring unit (102e) obtains the change in heater power Ph0, heat flux qp, and thermal resistance RthㆍA for each heater HT of the first wafer W and the most recent wafer W. The monitoring unit (102e) determines whether the change in heater power Ph0, heat flux qp, and thermal resistance RthㆍA for each heater HT corresponds to a change in any one of the change patterns stored in the change information (104a). For example, the monitoring unit (102e) determines whether a change greater than a predetermined tolerance has occurred in any one of the heater power Ph0, heat flux qp, and thermal resistance RthㆍA for each heater HT. If a change greater than the predetermined tolerance has occurred, the monitoring unit (102e) compares the change pattern in the heater power Ph0, heat flux qp, and thermal resistance RthㆍA for each heater HT with the change pattern stored in the change information (104a) to specify a change pattern that is similar to a predetermined or higher. For example, the monitoring unit (102e) specifies a change pattern in which, as a result of the comparison, the difference in each divided area (75) is within an allowable value in any one of the heater power Ph0, the heat flux qp, and the thermal resistance RthㆍA. In addition, the monitoring unit (102e) may specify a plurality of change patterns. In addition, when a plurality of change patterns are specified, the monitoring unit (102e) may specify one change pattern with the smallest difference. The monitoring unit (102e) specifies the processing parameter that was being changed in a specific change pattern as the processing condition of the changed plasma processing.

The alarm unit (102f) issues an alarm when a change greater than or equal to a predetermined value is detected in the processing conditions of the plasma processing as a result of the monitoring of the monitoring unit (102e). For example, the alarm unit (102f) issues an alarm when a change greater than or equal to a predetermined value occurs in any one of the heater power Ph0, the heat flux qp, and the thermal resistance RthㆍA of each heater HT as a result of the monitoring of the monitoring unit (102e). In addition, the alarm unit (102f) issues an alarm that notifies the processing parameter specified by the monitoring unit (102e) as the processing condition of the changed plasma processing. When a plurality of change patterns are specified, the alarm unit (102f) issues an alarm that notifies the processing parameter that was being changed in each of the change patterns as the processing condition of the changed plasma processing. The alarm may be in any manner as long as it can notify an abnormality to a process manager or a manager of the plasma processing device (10). For example, the alarm unit (102f) displays a message notifying an abnormality on the user interface (103).

By this, the plasma processing device (10) related to the present embodiment can notify the occurrence of an abnormality when the processing conditions of the plasma processing change due to the occurrence of an abnormality or a failure or a change over time. In addition, the plasma processing device (10) can notify the processing parameter that has become abnormal. By this, the process manager or the manager of the plasma processing device (10) can be notified of the occurrence of an abnormality or a failure or a change over time. In addition, the process manager or the manager of the plasma processing device (10) can estimate the part requiring maintenance from the known processing parameters, and can quickly recover the plasma processing device (10).

The correction unit (102g) corrects the processing conditions of the plasma treatment to eliminate the change in the detected processing conditions when a change greater than a predetermined value is detected in the processing conditions of the plasma treatment as a result of the monitoring of the monitoring unit (102e). For example, the correction unit (102g) corrects the value of the processing parameter specified by the monitoring unit (102e) by the amount of change.

By this, the plasma processing device (10) related to the present embodiment can automatically correct the changed processing conditions back to the original state when the processing conditions of the plasma processing change due to the occurrence of an abnormality or failure or changes over time.

[Processing Flow]

Next, the flow of processing performed by the plasma processing device (10) related to the present embodiment will be described. First, the flow of the generation processing in which the plasma processing device (10) generates change information (104a) will be described. Fig. 9 is a flowchart showing an example of the flow of the generation processing related to the embodiment. This generation processing is performed at a predetermined timing, for example, at a timing when a predetermined operation for instructing the start of the generation processing is performed on the user interface (103).

The heater control unit (102a) controls the power supply to each heater HT so that each heater HT reaches the set temperature (step S10).

The first acquisition unit (102b) performs plasma treatment using the treatment parameters as the treatment conditions for plasma treatment as standard conditions, and acquires a value related to the temperature of the mounting table (16) (step S11).

The first acquisition unit (102b) determines whether plasma treatment has been performed under all processing conditions in which each processing parameter has been changed within a predetermined range (step S12). If plasma treatment has been performed under all processing conditions (step S12: Yes), the process proceeds to step S15 described below.

Meanwhile, if plasma treatment is not performed under all processing conditions (step S12: No), the first acquisition unit (102b) changes the processing conditions to processing conditions that have not yet been performed (step S13). The first acquisition unit (102b) performs plasma treatment under the changed processing conditions, acquires a value related to the temperature of the mounting table (16) (step S14), and then proceeds to step S12 described above.

The first acquisition unit (102b) generates change information (104a) that indicates a change in the temperature of the mounting base (16) when the processing conditions change from the temperature of the mounting base (16) in each acquired processing condition (step S15). The first acquisition unit (102b) stores the generated change information (104a) in the memory unit (104) (step S16) and ends the processing.

Next, the flow of monitoring processing for monitoring the occurrence of an abnormality in the plasma processing device (10) is described. Fig. 10 is a flowchart showing an example of the flow of monitoring processing related to the embodiment. This monitoring processing is executed at a predetermined timing, for example, at the timing of starting plasma processing of a production process for producing semiconductors.

The heater control unit (102a) controls the power supply to each heater HT so that each heater HT reaches the set temperature (step S20).

The second acquisition unit (102c) acquires a value related to the temperature of the mounting plate (16) in a predetermined cycle during plasma treatment (step S21).

The monitoring unit (102e) monitors changes in processing conditions of plasma treatment from changes in values related to the temperature of the mounting plate (16) acquired by the second acquisition unit based on change information (104a) (step S22).

The alarm unit (102f) determines whether a change greater than or equal to a predetermined value is detected in the processing conditions of the plasma treatment as a result of the monitoring of the monitoring unit (102e) (step S23). If no change is detected (step S23: No), the process proceeds to step S26 described below.

Meanwhile, if a change is detected (step S23: yes), the alarm unit (102f) issues an alarm (step S24). The correction unit (102g) corrects the processing conditions of the plasma treatment to eliminate the detected change in the processing conditions (step S25).

The monitoring unit (102e) determines whether the plasma treatment of the production process is completely completed (step S26). If the plasma treatment of the production process is not completely completed (step S26: No), the process proceeds to step S21 described above.

Meanwhile, if the plasma treatment of the production process is completely completed (Step S26: Yes), the treatment is terminated.

In this way, the plasma processing device (10) related to the present embodiment has a memory unit (104), a second acquisition unit (102c), and a monitoring unit (102e). The memory unit (104) stores change information (104a) indicating a change in a value related to the temperature of the mounting table (16) when the processing conditions for plasma processing for a wafer W mounted on the mounting table (16) change. The second acquisition unit (102c) acquires a value related to the temperature of the mounting table (16) in a predetermined cycle. The monitoring unit (102e) monitors a change in the processing conditions for plasma processing from a change in the value related to the temperature of the mounting table (16) acquired by the second acquisition unit (102c) based on the change information (104a). Thereby, the plasma processing device (10) can detect the occurrence of an abnormality without arranging a sensor.

In addition, the plasma processing device (10) related to the present embodiment is provided with a heater HT capable of adjusting the temperature of a mounting surface on which a wafer W is mounted on a mounting table (16). The temperature of the mounting table is determined by at least one of the amount of heat generated by the heater HT for maintaining the temperature of the mounting table (16) at a predetermined temperature in an unignited state, the thermal resistance between the wafer W and the mounting table (16), and the amount of heat input from the plasma to the mounting table (16) in an ignited state. As a result, the plasma processing device (10) can detect the occurrence of an abnormality without arranging a sensor.

In addition, the second acquisition unit (102c) measures the supply power in the non-ignition state where the plasma is not ignited and in the transient state where the supply power to the heater HT is reduced after the plasma is ignited, while controlling the supply power to the heater HT so that the temperature of the heater HT is constant. Then, the second acquisition unit (102c) performs fitting using the measured non-ignition state and transient state supply power to a calculation model that calculates the supply power in the transient state using as parameters the heat input amount flowing into the mounting table (16) from the plasma and the thermal resistance between the wafer W and the mounting table (16), thereby calculating the heat input amount and the thermal resistance. Thereby, the plasma processing device (10) can acquire the heat input amount and the thermal resistance without arranging a sensor.

In addition, the second acquisition unit (102c) measures the supply power in a non-ignition state in which plasma is not ignited and a steady state in which plasma is ignited and the supply power to the heater HT is stable, while controlling the supply power to the heater HT so that the temperature of the heater HT is constant. The second acquisition unit (102c) calculates the heat input from the difference between the measured supply power in the non-ignition state and the steady state. Thereby, the plasma processing device (10) can acquire the heat input without arranging a sensor.

In addition, the second acquisition unit (102c) measures the supply power in the non-ignited state in which plasma is not ignited while controlling the supply power to the heater HT so that the temperature of the heater HT is constant. Then, the second acquisition unit (102c) calculates the amount of heat generated in the heater HT for maintaining the temperature of the mounting plate (16) at a predetermined temperature in the non-ignited state from the measured supply power in the non-ignited state. Thereby, the plasma processing device (10) can acquire the amount of heat generated in the heater HT without arranging a sensor.

In addition, the mounting plate (16) is divided into a plurality of partition areas (75) on which the wafer W is mounted, and a heater HT is provided in each partition area (75). The change information (104a) stores a change pattern of a value related to the temperature of the mounting plate (16) of each partition area (75) for each change in a processing parameter that is a processing condition for plasma processing. The second acquisition unit (102c) acquires a value related to the temperature of the mounting plate (16) of each partition area (75). The monitoring unit (102e) specifies the changed processing parameter from the change pattern of the value related to the temperature of the mounting plate (16) of each partition area (75) acquired by the second acquisition unit (102c) based on the change information (104a). Thereby, the plasma processing device (10) can specify the changed processing parameter without arranging a sensor.

In addition, the plasma processing device (10) further has an alarm unit (102f). The alarm unit (102f) issues an alarm when a change greater than or equal to a predetermined value is detected in the processing conditions of the plasma processing as a result of monitoring by the monitoring unit (102e). As a result, the plasma processing device (10) can issue an alarm when the processing conditions of the plasma processing have changed greater than or equal to a predetermined value.

In addition, the plasma processing device (10) further has a correction unit (102g). If a change greater than a predetermined value is detected in the processing conditions of the plasma processing as a result of monitoring by the monitoring unit (102e), the correction unit (102g) corrects the processing conditions of the plasma processing to eliminate the change in the processing conditions. Thereby, the plasma processing device (10) can automatically correct the changed processing conditions of the plasma processing.

Above, although the embodiment has been described, it should be considered that the embodiment disclosed this time is exemplary and not restrictive in all respects. In fact, the above-described embodiment can be implemented in various forms. In addition, the above-described embodiment may be omitted, substituted, or changed in various forms without departing from the scope and spirit of the claims.

For example, in the above embodiment, the case where plasma treatment is performed on a semiconductor wafer as a processing target is described as an example, but it is not limited to this. The processing target may be any object that affects the progress of plasma treatment depending on temperature.

In addition, in the above embodiment, the case where both the alarm by the alarm unit (102f) and the correction of the processing condition by the correction unit (102g) are performed is described as an example, but it is not limited to this. For example, the plasma processing device (10) may perform only one of the alarm by the alarm unit (102f) and the correction of the processing condition by the correction unit (102g).

In addition, in the above embodiment, as shown in Fig. 2, the case where the mounting area (18a) of the electrostatic chuck (18) is divided into four divided areas (75) at approximately equal intervals in the radial direction was explained as an example, but it is not limited to this. For example, the mounting area (18a) of the electrostatic chuck (18) may be divided into divided areas (75) with a large interval on the center side of the wafer W and a small interval on the outer side. Fig. 11A is a plan view showing a mounting table related to another embodiment. In Fig. 11A, the mounting area (18a) of the electrostatic chuck (18) is divided into a central circular divided area (75a) and four annular divided areas (75b to 75e). The wafer W is placed in the divided areas (75a to 75d). The focus ring FR is placed in the divided area (75e). In addition, the division area (75a) which is the center side of the wafer W is divided into a large width. The division areas (75b to 75d) which are the outer peripheral side of the wafer W are divided into a small width. In addition, the mounting area (18a) of the electrostatic chuck (18) may be divided in the circumferential direction. Fig. 11b is a plan view showing a mounting table related to another embodiment. In Fig. 11b, the mounting area (18a) is divided into a central circular division area (75) and a plurality of concentric annular division areas surrounding the circular division area (75). In addition, the annular division area is divided into a plurality of division areas (75) in the circumferential direction. In addition, the shape of the division area (75) may be other than a circular shape or an annular shape. Fig. 11c is a plan view showing a mounting table related to another embodiment. In Fig. 11c, the mounting area (18a) is divided into division areas (75) in a lattice shape.

In addition, in the above embodiment, the case where the temperature of the mounting table (16) is acquired for each divided area (75) that divides the mounting area (18a) of the electrostatic chuck (18) and the change in the processing condition of the plasma treatment is monitored is explained as an example, but it is not limited to this. For example, the plasma processing device (10) may acquire one value related to the temperature of the mounting table (16) in the entire mounting area (18a) of the electrostatic chuck (18) and monitor the change in the processing condition of the plasma treatment from the change in the acquired value. In addition, the plasma processing device (10) may acquire a value related to the temperature of the mounting table (16) for any one of the divided areas (75) and monitor the change in the processing condition of the plasma treatment from the change in the acquired value.

In addition, in the above embodiment, the case where plasma etching is performed as a plasma treatment is described as an example, but it is not limited to this. The plasma treatment may be any treatment that utilizes plasma and has an effect on the progress of the treatment depending on the temperature.

10: Plasma treatment device
16 : Mounting platform
18: Static Chuck
18a : Loading area
20 : Expectation
75 : Split area
100 : Control Unit
102 : Process Controller
102a : Heater control unit
102b: 1st Acquisition Department
102c: Second Acquisition Department
102d: Set temperature output section
102e : Surveillance Department
102f : Alarm Department
102g : Correction part
104 : Memory
104a : Change information
HP : Heater Power
HT : Heater
PD: Power Detection Unit
TD : Temperature Meter
W: Wafer

Claims (21)

A memory unit that stores change information indicating a change in the temperature of the mounting platform when the processing conditions for plasma treatment for the object to be processed change on the mounting platform equipped with a heater capable of adjusting the temperature of the mounting surface on which the object to be processed is mounted;
An acquisition unit that acquires a temperature value of the above-mentioned mounting plate in a predetermined cycle;
A monitoring unit that monitors changes in processing conditions of plasma treatment from changes in values related to the temperature of the mounting base acquired by the acquiring unit based on the above change information.
Have,
The value related to the temperature of the above-mentioned mounting plate is at least one of the thermal resistance between the object to be processed and the mounting plate, and the amount of heat input from the plasma to the mounting plate in the ignition state in which the plasma is ignited.
The above acquisition unit controls the power supply to the heater so that the temperature of the heater is constant, measures the power supply in a non-ignition state where plasma is not ignited and in a transient state where the power supply to the heater decreases after igniting plasma, and calculates at least one of the heat input and the thermal resistance using the measured power supply in the non-ignition state and the transient state.
Plasma processing device.
In paragraph 1,
The above-mentioned mounting plate is divided into a plurality of partition areas on which the object to be processed is mounted, and the heater is provided in each partition area.
The above change information is a change pattern of the temperature of the mounting plate of each divided area is remembered for each change in the processing parameter that is the processing condition of the plasma treatment.
The above acquisition unit acquires a value related to the temperature of the mounting plate of each divided area,
The above monitoring unit, based on the change information, identifies the changed processing parameter from the change pattern of the temperature value of the mounting plate of each divided area acquired by the acquisition unit.
Plasma processing device.
In claim 1 or 2,
A plasma treatment device further having an alarm unit that issues an alarm when a change greater than a predetermined level in the treatment conditions of plasma treatment is detected as a result of monitoring by the above monitoring unit.
In claim 1 or 2,
A plasma processing device further having a correction unit that corrects the processing conditions of the plasma processing to eliminate the change in the processing conditions when a change in the processing conditions of the plasma processing exceeding a predetermined level is detected as a result of monitoring by the above-mentioned monitoring unit.
A process in which a heater capable of controlling the temperature of a mounting surface on which a processing object is mounted is provided, and a value related to the temperature of a mounting table on which the processing object is mounted and plasma processing is performed is acquired in a predetermined cycle; and
Based on change information indicating a change in a value related to the temperature of the mounting table when the processing conditions for plasma processing for the above-mentioned object change, a process is executed to monitor a change in the processing conditions for plasma processing from a change in the value related to the temperature of the mounting table that is acquired.
The value related to the temperature of the above-mentioned mounting plate is at least one of the thermal resistance between the object to be processed and the mounting plate, and the amount of heat input from the plasma to the mounting plate in the ignition state in which the plasma is ignited.
The above-mentioned acquiring process is characterized in that, while controlling the power supply to the heater so that the temperature of the heater is constant, the power supply in the non-ignition state where the plasma is not ignited and in the transient state where the power supply to the heater decreases after the plasma is ignited are measured, and at least one of the heat input and the thermal resistance is calculated using the measured power supply in the non-ignition state and the transient state.
How to monitor.
A program stored in a computer-readable storage medium, which causes the control unit to:
A process in which a heater capable of controlling the temperature of a mounting surface on which a processing object is mounted is provided, and a value related to the temperature of a mounting surface on which the processing object is mounted and plasma processing is performed is acquired in a predetermined cycle, and
Based on change information indicating a change in a value related to the temperature of the mounting table when the processing conditions for plasma processing for the above-mentioned object have changed, a process is executed to monitor a change in the processing conditions for plasma processing from a change in the value related to the temperature of the mounting table that is acquired.
The value regarding the temperature of the above-mentioned mounting plate is at least one of the thermal resistance between the object to be processed and the mounting plate and the heat input from the plasma to the mounting plate in the ignition state in which the plasma is ignited.
The above-mentioned acquiring process measures the supply power in a non-ignition state where plasma is not ignited and in a transient state where the supply power to the heater is reduced after igniting plasma while controlling the supply power to the heater so that the temperature of the heater is constant, and calculates at least one of the heat input and the thermal resistance using the measured supply power in the non-ignition state and the transient state.
A program stored on a computer-readable storage medium, characterized by:
A memory unit that stores change information indicating a change in the temperature of the mounting surface when the processing conditions for plasma treatment for the object to be processed are changed on the mounting surface equipped with a heater capable of adjusting the temperature of the mounting surface on which the object to be processed is mounted,
An acquisition unit that acquires a temperature value of the above-mentioned mounting plate in a predetermined cycle;
Based on the above change information, a monitoring unit is included that specifies the changed processing conditions from the change in the value related to the temperature of the mounting plate acquired by the acquisition unit.
The value regarding the temperature of the above-mentioned mounting plate is the heat input from the plasma to the mounting plate in the ignition state where the plasma is ignited.
The above acquisition unit controls the power supply to the heater so that the temperature of the heater is constant, measures the power supply in a non-ignition state where the plasma is not ignited and in a steady state where the power supply to the heater is stable by igniting the plasma, and calculates the heat input from the difference between the measured power supply in the non-ignition state and the steady state.
Plasma processing device.
In paragraph 7,
The above-mentioned mounting plate is divided into a plurality of partition areas on which the object to be processed is mounted, and the heater is provided in each partition area.
The above change information is a change pattern of the temperature of the mounting plate of each divided area is remembered for each change in the processing parameter that is the processing condition of the plasma treatment.
The above acquisition unit acquires a value related to the temperature of the mounting plate of each divided area,
The above monitoring unit, based on the change information, identifies the changed processing parameter from the change pattern of the temperature value of the mounting plate of each divided area acquired by the acquisition unit.
Plasma processing device.
In clause 7 or 8,
Plasma treatment further comprising an alarm unit that generates an alarm when a change greater than a predetermined level in the treatment conditions of plasma treatment is detected as a result of monitoring by the above monitoring unit.
In clause 7 or 8,
If a change in the processing conditions of the plasma treatment that is greater than or equal to a predetermined value is detected as a result of monitoring by the above monitoring unit, the system further includes a correction unit that corrects the processing conditions of the plasma treatment to offset the change in the processing conditions.
Plasma processing device.
A process in which a heater capable of controlling the temperature of a mounting surface on which a processing object is mounted is provided, and a value related to the temperature of a mounting table on which the processing object is mounted and plasma processing is performed is acquired in a predetermined cycle; and
Based on change information indicating a change in a value related to the temperature of the mounting table when the processing conditions for plasma processing for the above-mentioned object have changed, a process is executed to specify the changed processing conditions from the change in the value related to the temperature of the mounting table that is acquired.
The value regarding the temperature of the above-mentioned mounting plate is taken as the heat input from the plasma to the mounting plate in the ignition state where the plasma is ignited.
The above-mentioned acquisition process is characterized in that the power supply to the heater is controlled so that the temperature of the heater is constant, the power supply is measured in a non-ignition state where the plasma is not ignited and in a steady state where the power supply to the heater is stable by igniting the plasma, and the heat input is calculated from the difference between the measured power supply in the non-ignition state and the steady state.
How to monitor.
A program stored in a computer-readable storage medium, which causes the control unit to:
A process in which a heater capable of controlling the temperature of a mounting surface on which a processing object is mounted is provided, and a value related to the temperature of a mounting table on which the processing object is mounted and plasma processing is performed is acquired in a predetermined cycle; and
Based on change information indicating a change in a value related to the temperature of the mounting table when the processing conditions for plasma processing for the above-mentioned object have changed, a process is executed to specify the changed processing conditions from the change in the value related to the temperature of the mounting table that is acquired.
The value regarding the temperature of the above-mentioned mounting plate is the heat input from the plasma to the mounting plate in the ignition state where the plasma is ignited.
The above-mentioned acquisition process is characterized in that the power supply to the heater is controlled so that the temperature of the heater is constant, the power supply in the non-ignition state where the plasma is not ignited and the power supply in the steady state where the plasma is ignited and the power supply to the heater is stable are measured, and the heat input is calculated from the difference between the measured power supply in the non-ignition state and the steady state.
A program stored on a computer-readable storage medium.
A memory unit that stores change information indicating a change in the temperature of the mounting platform when the processing conditions for plasma treatment for the object to be processed are changed on the mounting platform equipped with a heater capable of adjusting the temperature of the mounting surface on which the object to be processed is mounted;
An acquisition unit that acquires a temperature value of the above-mentioned mounting plate in a predetermined cycle;
Based on the above change information, a monitoring unit is included that monitors changes in processing conditions of plasma processing from changes in values related to the temperature of the mounting platform acquired by the acquisition unit.
The value regarding the temperature of the above-mentioned mounting plate is the amount of heat generated by the heater to maintain the temperature of the above-mentioned mounting plate at a predetermined temperature in an unignited state where plasma is not ignited.
The above acquisition unit measures the supply power in a non-ignited state where plasma is not ignited while controlling the supply power to the heater so that the temperature of the heater is constant, and calculates the amount of heat generated by the heater to maintain the temperature of the mounting plate at a predetermined temperature in the non-ignited state from the measured supply power in the non-ignited state.
Plasma processing device.
In Article 13,
The above-mentioned mounting plate is divided into a plurality of partition areas on which the object to be processed is mounted, and the heater is provided in each partition area.
The above change information is a change pattern of the temperature of the mounting plate of each divided area is remembered for each change in the processing parameter that is the processing condition of the plasma treatment.
The above acquisition unit acquires a value related to the temperature of the mounting plate of each divided area,
The above monitoring unit, based on the change information, identifies the changed processing parameter from the change pattern of the temperature value of the mounting plate of each divided area acquired by the acquisition unit.
Plasma processing device.
In clause 13 or 14,
A plasma processing device further comprising an alarm unit that generates an alarm when a change greater than a predetermined level in the processing conditions of the plasma processing is detected as a result of monitoring by the monitoring unit.
In clause 13 or 14,
A plasma processing device further comprising a correction unit that corrects the processing conditions of the plasma processing to offset the change in the processing conditions when a change in the processing conditions of the plasma processing exceeding a predetermined level is detected as a result of monitoring by the above-mentioned monitoring unit.
In any one of paragraphs 2, 8 and 14,
The above-mentioned mounting plate is a plasma processing device in which a temperature sensor capable of detecting the temperature of the heater is provided for each of the above-mentioned divided areas.
In any one of paragraphs 2, 8 and 14,
The above-mentioned mounting plate is a plasma processing device having a central circular region as the divided region and a plurality of concentric annular regions surrounding the circular region.
A process in which a heater capable of controlling the temperature of a mounting surface on which a processing object is mounted is provided, and a value related to the temperature of a mounting table on which the processing object is mounted and plasma processing is performed is acquired in a predetermined cycle; and
Based on change information indicating a change in a value related to the temperature of the mounting table when the processing conditions for plasma processing for the above-mentioned object have changed, a process is executed to monitor a change in the processing conditions for plasma processing from a change in the value related to the temperature of the mounting table that is acquired.
The value regarding the temperature of the above-mentioned mounting plate is the amount of heat generated by the heater to maintain the temperature of the above-mentioned mounting plate at a predetermined temperature in an unignited state where plasma is not ignited.
The above-mentioned acquisition process is characterized in that it measures the supply power in an unignited state where plasma is not ignited while controlling the supply power to the heater so that the temperature of the heater is constant, and calculates the amount of heat generated by the heater to maintain the temperature of the mounting plate at a predetermined temperature in the unignited state from the measured supply power in the unignited state.
How to monitor.
A program stored in a computer-readable storage medium, which causes the control unit to:
A process in which a heater capable of controlling the temperature of a mounting surface on which a processing object is mounted is provided, and a value related to the temperature of a mounting surface on which the processing object is mounted and plasma processing is performed is acquired in a predetermined cycle; and
Based on change information indicating a change in a value related to the temperature of the mounting table when the processing conditions for plasma processing for the above-mentioned object have changed, a process is executed to monitor a change in the processing conditions for plasma processing from a change in the value related to the temperature of the mounting table that is acquired.
The value regarding the temperature of the above-mentioned mounting plate is the amount of heat generated by the heater to maintain the temperature of the above-mentioned mounting plate at a predetermined temperature in an unignited state where plasma is not ignited.
The above-mentioned acquisition process is characterized in that it measures the supply power in an unignited state where plasma is not ignited while controlling the supply power to the heater so that the temperature of the heater is constant, and calculates the amount of heat generated by the heater to maintain the temperature of the mounting plate at a predetermined temperature in the unignited state from the measured supply power in the unignited state.
A program stored on a computer-readable storage medium.
In paragraph 1,
The above-mentioned acquisition unit measures the supply power in a non-ignition state where plasma is not ignited and in a transient state where the supply power to the heater is reduced after igniting plasma while controlling the supply power to the heater so that the temperature of the heater is constant, and calculates the supply power in the transient state by using the measured supply power in the non-ignition state and the transient state as parameters for the heat input flowing into the mounting table from the plasma and the thermal resistance between the object to be processed and the mounting table, thereby calculating the heat input and the thermal resistance.
Plasma processing device.

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