JPH058271B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applicable to a parallel plate electrode type plasma etching apparatus, a reactive ion etching apparatus or a plasma etching apparatus.
This relates to chemical processing equipment such as CVD equipment.

Conventional structure and its problems Dry etching equipment used in plasma etching method and reactive ion etching method, plasma CVD (Chemical Vapor
Deposition devices and puttering devices are used as manufacturing devices for various products such as thin film sensors and semiconductor components.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A plasma reaction apparatus as a conventional chemical processing apparatus will be described below with reference to the drawings.

Figure 1 shows a conventional plasma CVD apparatus.

1 is a vacuum container made of stainless steel that can maintain a vacuum, 2 is a nozzle for introducing gas into the vacuum container 1, 3 is a vacuum pump for evacuating the inside of the vacuum container 1, and 4 is a frequency 13.56MHz high frequency power is supplied, and the load electrode has a disc shape.
5 is a power supply component for supplying high frequency power to the load electrode 4, 6 is a high frequency power supply with a frequency of 13.56MHz,
7 is a matching tuner for adjusting the matching state of the high frequency power load path; 8 is an insulating component made of Teflon for preventing contact and insulating the vacuum container 1 and the power supply component 5; 9 is a load electrode It is placed at a distance of about 40 mm from the surface of 4.
The sample stand is made of stainless steel and has a disk-like shape that can hold the workpiece, and has a heater inside to heat the workpiece. 10 is the workpiece. This is a sample whose material is silicon single crystal.

Here, the vacuum container 1 and the sample stage 9 are grounded.

Plasma silicon nitride film (hereinafter referred to as
The operation of forming a SiN film (abbreviated as SiN film) on the sample 10 will be described below.

First, the pressure inside the vacuum container 1 is evacuated to 3×10 ^-3 Torr or less using the vacuum pump 3, and then nitrogen (hereinafter abbreviated as N ₂ ) gas is passed through the nozzle 2 at a flow rate of 160 SCCM to pump the inside of the vacuum container 1. and adjust the vacuum pumping speed to reduce the pressure inside the vacuum container 1 to 0.3Toor.
to hold.

Further, the heater built into the sample stage 9 is adjusted to maintain the surface temperature of the sample 10 at about 250°C. Next, pass the monosilane (hereinafter referred to as
SiH ₄ ), ammonia (NH ₃ hereafter) gas, and N ₂ gas were introduced into the vacuum vessel 1 at a mixing ratio of 6:7:45 and a mixed gas flow rate of 160 sccM, and at a vacuum pumping speed. is adjusted to maintain the pressure inside the vacuum vessel 1 at 0.3 Torr. Here, a SiN film is formed on the surface of the sample 10 by supplying high frequency power to the load electrode 4 and turning the mixed gas into plasma.

However, in the above configuration, gas plasma is generated not only in the space between the load electrode 4 and the sample stage 9 necessary for processing the sample 10, but also in the space between the power supply component 5 and the inner wall of the vacuum vessel 1. occurs continuously or intermittently depending on the pressure setting conditions or the high-frequency power load electrode value. Therefore, the load state of the high-frequency power acting on the space between the load electrode 4 and the sample stage 9, that is, the matching state of the power load changes, and the state of the gas plasma changes continuously or continuously during plasma processing of the sample 10. As a result, the rate at which the thin film is formed on the surface of the sample 10 and the quality of the formed film become unstable.Furthermore, it is difficult to process the sample 10 with good reproducibility in view of variations in the thickness of the formed thin film. It is difficult to do so.

In this way, conventional plasma CVD equipment
When processing the sample 10 , plasma is generated continuously or intermittently in the space between the power supply component 5 and the inner wall of the vacuum container 1 . This method has the disadvantage that it is difficult to generate the desired stable plasma.

Purpose of the Invention In view of the above-mentioned drawbacks, the present invention aims to prevent plasma from being generated in the space between the power supply part and the inner wall of the vacuum container when plasma processing a sample using a parallel plate electrode type plasma chemical processing apparatus. The present invention provides a chemical processing apparatus capable of generating stable plasma in a space between a load electrode and a sample stage and plasma processing a sample with good reproducibility.

Structure of the Invention The chemical processing apparatus of the present invention includes a vacuum container capable of maintaining a vacuum state, a nozzle for controlling and introducing a predetermined gas into the vacuum container, and a nozzle for evacuating the inside of the vacuum container. a vacuum evacuation device, a load electrode located in a vacuum container and to which a predetermined electric power is supplied, and an earth electrode placed a predetermined distance from the surface of the load electrode and grounded to earth;
A workpiece is placed on at least one of the load electrode or the earth electrode, gas plasma is generated in the space between the load electrode and the earth electrode, and power is supplied to the load electrode in order to process the workpiece. A power supply component that is a power supply source, and a power supply component that is located around the power supply component in a non-contact manner, one end surface is hermetically joined to the vacuum container, and the other end surface is insulated from the surface of the load electrode. It consists of a bellows that is airtightly joined to the gas atmosphere of the power supply component to atmospheric pressure, and prevents plasma from being generated in the space between the power supply component and the inner wall of the vacuum container. However, stable plasma can be generated in the space between the load electrode and the earth electrode, and the workpiece can be plasma-treated with good reproducibility.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2, 101 is a vacuum container made of stainless steel that can maintain a vacuum, 102 is a nozzle for introducing gas into the vacuum container 101, and 103 is a vacuum for evacuating the inside of the vacuum container 101. The exhaust device 104 is supplied with high frequency power with a frequency of 13.56 MHz, and has a disk-shaped load electrode.
105 is a power supply component for supplying high frequency power to the load electrode 104, and 106 is a frequency of 13.56MHz.
107 is a matching tuner for adjusting the matching state of the high frequency power load path;
108 is an insulating part made of Teflon to prevent contact between the vacuum container 101 and the power supply part 105 and to electrically insulate the same, and 109 is arranged at a distance of about 40 mm from the surface of the load electrode 104. , is made of stainless steel and has a disk-like shape, is capable of holding a workpiece, has a heater inside for heating the workpiece, and has an earth electrode that is grounded; 110 is the workpiece; The sample 111 is made of silicon single crystal, the material is Teflon, the shape is a disk, and the power supply part 105 and the sample 111 are made of Teflon.
Insulating ring hermetically joined through the ring, 1
12 is located around the power supply component in a non-contact manner, one end surface is hermetically joined to the vacuum container 101 by an O-ring, and the other end surface is hermetically connected to the surface of the insulating ring 111 and the O-ring. The bellows flange 113 which can be joined and which can bring the gas atmosphere of the power supply component 105 to atmospheric pressure is a bolt made of Teflon.

The operation of the chemical processing apparatus configured as described above will be described below, taking as an example the case where a plasma SiN film is formed on the surface of the sample 110.

First, the vacuum container 1 is
After evacuating the pressure inside 01 to below 3×10 ^-3 Torr, _N2 gas is pumped into nozzle 102 at a flow rate of 160SCCM.
is introduced into the vacuum container 101 through the
Hold at 0.35Torr.

In addition, the surface temperature of the sample 110 is adjusted to 250°C by adjusting the heater built in the earth electrode 109.
Keep it at a certain level. Next, after stopping the introduction of the N ₂ gas, the gas composition is adjusted through the nozzle 102.
A mixed gas of SiH ₄ , NH ₃ , and N ₂ with a composition ratio of 6:7:45 was mixed at a flow rate of 160 SCCM.
is introduced into the vacuum container 101, and the pressure inside the vacuum container 101 is adjusted to 0.35Toor by adjusting the evacuation speed.
to hold.

Next, the frequency is 13.56MHz from the high frequency power supply 106.
By supplying high-frequency power to the load electrode 104 through the matching tuner 107 and the power supply component 105, the mixed gas is turned into plasma, and a SiN film is formed on the surface of the sample 110.

That is, the mixed gas decomposes and reacts based on the following chemical reaction formula by plasma energy and thermal energy supplied from the surface of the sample 110 and the surface of the earth electrode 109, thereby forming a SiN film on the surface of the sample 110.

3SiH _(g) +4NH _3(g) plasma――――→ 250℃Si ₃ N _4(S) +12H _2(g) g: gas state s: solid state Here, the surrounding atmosphere of the power supply component 105 is as follows:
Since the pressure was at atmospheric pressure, no plasma was generated in the space between the surface of power supply component 105 and vacuum container 101 and bellows flange 112. Accordingly,
When processing the sample 110, stable plasma can be generated in the space between the load electrode 104 and the ground electrode 109, so SiN on the surface of the sample 110 is
The film formation rate and film quality are stabilized, and furthermore, the amount of variation in film thickness caused by instability of the plasma on the surface of the sample 110 can be greatly reduced, and the sample 110 can be processed with good reproducibility. Ta.

As described above, according to this embodiment, there is a vacuum container capable of maintaining a vacuum state, a vacuum evacuation device for controlling and introducing a predetermined gas into the vacuum container, and a A load electrode to which a predetermined power is supplied, a ground electrode that is placed a predetermined distance apart from the surface of the load electrode and is grounded, and a ground electrode that is connected to at least one of the load electrode or the ground electrode. a power supply component for arranging the workpiece, generating gas plasma in a space between the load electrode and the earth electrode, and supplying power to the load electrode in order to process the workpiece;
It is located in a non-contact manner around the power source, which is the power supply source, and the power supply components, and one end surface is hermetically connected to the vacuum container, and the other end surface is hermetically connected to the surface of the load electrode via an insulator. and a bellows that brings the gas atmosphere of the power supply component to atmospheric pressure.When forming a plasma CVD film on the surface of a sample, stable plasma can be generated in the space between the load electrode and the earth electrode. As a result, the formation speed of the plasma CVD film on the sample surface and the quality of the formed film, such as the refractive index, are stabilized, and the variation in film thickness due to instability of the plasma on the sample surface is stabilized. The amount can be reduced and samples can be processed with good reproducibility.

Note that since a bellows is used, the distance between the load electrode and the ground electrode can be easily changed. Therefore, when processing a sample, it is also possible to perform plasma processing in which the distance is changed continuously or intermittently during processing.

Effects of the Invention As described above, the chemical processing apparatus of the present invention includes a vacuum container that can maintain a vacuum state, a nozzle for controlling and introducing a predetermined gas into the vacuum container, and a vacuum container that maintains a vacuum state. A vacuum evacuation device for evacuation,
A load electrode located in a vacuum container and to which a predetermined power is supplied; a ground electrode placed a predetermined distance apart from the surface of the load electrode and grounded; and at least a load electrode or a ground electrode. A workpiece is placed on either side of the electrode, and
In order to generate gas plasma in the space between the load electrode and the earth electrode and process the workpiece, a power supply component for supplying power to the load electrode, a power source as a power supply source, and a power supply component are provided. It is located without contact with the surroundings, one end surface is hermetically connected to the vacuum container, the other end surface is hermetically connected to the surface of the load electrode via an insulator, and the gas atmosphere of the power supply component is kept at atmospheric pressure. By providing a bellows to prevent plasma from being generated in the space between the power supply parts and the inner wall of the vacuum container, stable plasma is generated in the space between the load electrode and the earth electrode. The workpiece can be processed with good reproducibility.
It is possible to treat plasma chemically and also
The distance between the load electrode and the ground electrode can be easily changed while maintaining the conditions that allow the above-mentioned effects to be exhibited, and the practical effects thereof are great.

In the above embodiments, the case of forming a plasma CVD film was taken as an example, but stable plasma can also be generated in the space between the load electrode and the earth electrode in plasma etching, reactive ion etching, sputtering, etc. The same effect as above can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of a conventional plasma reactor, and FIG. 2 is a front sectional view of a plasma reactor according to an embodiment of the present invention. 101... Vacuum container, 102... Nozzle, 10
3...Evacuation device, 104...Load electrode, 10
5... Power supply component, 106... Power supply, 109...
...Earth electrode, 112...Bellows.

Claims (1)

[Claims] 1. A vacuum container capable of maintaining a vacuum state, a nozzle for controlling and introducing a predetermined gas into the vacuum container, and a vacuum exhaust device for evacuating the inside of the vacuum container. , a load electrode located in a vacuum container and to which a predetermined power is supplied; a ground electrode disposed at a predetermined distance from the surface of the load electrode and grounded; at least a load electrode; A power supply for placing a workpiece on either side of the earth electrode, generating gas plasma in the space between the load electrode and the earth electrode, and supplying power to the load electrode for processing the workpiece. The component is located in a non-contact manner around the power supply, which is the power source, and the power supply component, and one end surface is airtightly connected to the vacuum container, and the other end surface is connected to the surface of the load electrode through an insulator. A chemical processing device consisting of a bellows that is joined to the gas atmosphere of the power supply component and brings the gas atmosphere of the power supply component to atmospheric pressure. 2. The chemical processing apparatus according to claim 1, wherein the bellows is a welded bellows or a molded bellows made of stainless steel. 3. The chemical processing apparatus according to claim 1, wherein the power source is a high frequency power source having a frequency of 13.56MHz. 4. The chemical processing apparatus according to claim 1, wherein the vacuum container is made of stainless steel, aluminum, or an aluminum alloy.