JPH10146751A - Chemical mechanical polishing equipment - Google Patents

Abstract

(57) [PROBLEMS] To provide a chemical mechanical polishing apparatus capable of rapidly performing highly accurate and stable polishing of substrates such as various wafers under respective optimum polishing conditions. SOLUTION: Optimal polishing conditions (for example, types of polishing pads and polishing slurries, numerical values such as the number of rotations of each drive system, a sequence of a polishing process, etc.) corresponding to information recorded on various kinds of substrates are previously stored in advance. The information of the substrate W carried in for polishing is read by the information reading means 31, and based on the polishing conditions corresponding to the information, the polishing using different types of polishing pads is performed. A head assembly H composed of the head 10 and the brush head 20, a plurality of kinds of supply means 45 for different types of polishing slurry, a switching means 30 for polishing slurry and the like, and various drive systems are set and controlled to execute chemical mechanical polishing. I do. The polishing conditions are appropriately changed according to the measurement result of the polishing state such as the thickness of the substrate by the measuring means 41.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a chemical mechanical polishing apparatus for polishing a substrate such as a wafer with high precision.

[0002]

2. Description of the Related Art In recent years, in semiconductor devices, ultra-miniaturization and higher steps have been advanced, and with this, Si, GaAs
A semiconductor wafer of s, InP or the like, or a quartz or glass substrate having a plurality of island-shaped semiconductor regions formed on its surface is used, all of which are used to form wiring and insulating regions patterned by photolithography. In addition, a flat surface is required, and the surface is an insulating film, a metal film, or a mixed surface thereof. As a processing means for flattening a substrate such as a wafer with high precision, a chemical mechanical polishing (CMP) method is known.

As an apparatus for performing chemical mechanical polishing (CMP), an apparatus as shown in FIG. 6 is used. This type of chemical mechanical polishing apparatus includes a rotary table 101 on which a polishing pad 102 is attached, A substrate to be polished is provided with a member to be polished 103 for detachably holding a substrate 104 such as a wafer as a member to be polished on a lower surface, and a polishing slurry supply nozzle 106 for supplying a polishing slurry (abrasive) 107 on a polishing pad. While rotating the rotary table 101 while pressing the polishing pad 102 so as to apply a predetermined processing pressure by bringing the 104 into contact with the polishing pad 102,
The member to be polished 103 is also rotated or linearly moved, and at the same time, chemical mechanical polishing is performed while supplying a polishing slurry between the polishing pad 102 and the substrate 104.

A polishing pad used for chemical mechanical polishing is made of a material such as nonwoven fabric or polyurethane foam, or a material having a different hardness or surface roughness. The polishing slurry contains fine particles. Liquid, and silica (SiO ₂ ), alumina (A
l ₂ O ₃ ), manganese oxide (MnO ₂ ), cerium oxide (CeO) and the like.
H, KOH, NH ₄ OH, H ₂ O _{2 and the} like are used. These polishing slurries are appropriately selected and used according to the surface to be polished of the substrate.For example, in polishing a silicon semiconductor surface, a silica-dispersed sodium hydroxide solution is used, and the silicon surface reacts with NaOH. Creates a product Na ₂ SiO ₃ layer, removes it by mechanical polishing with silica and a polishing pad, and exposes a new silicon surface to promote the reaction, thereby flattening the semiconductor surface with high precision Is what you do. Thus, a silica-dispersed sodium hydroxide solution is used for polishing a silicon semiconductor surface, a silica-dispersed potassium hydroxide solution is used for polishing an interlayer insulating film, and an alumina or manganese oxide is used for polishing a metal film such as tungsten. Dispersed aqueous hydrogen peroxide is suitable.

[0005]

However, the above-mentioned conventional chemical mechanical polishing apparatus has the following unsolved problems.

Since the turntable on which the polishing pad is integrally attached has a significantly larger diameter than the substrate, the entire polishing apparatus including the turntable becomes large, and the turntable on which the polishing pad is attached is rotated at high speed. Vibrations occur and the surface to be polished of the substrate, which is the member to be polished, cannot be polished with high precision, so that the rotating table cannot be rotated at a high speed. As a result, the polishing speed can be improved. Can not. In addition, it is difficult to remove foreign substances such as polishing debris during polishing and to detect the film thickness and surface shape of the polished surface of the substrate, and it is not possible to perform stable chemical mechanical polishing for a long time. Was.

In addition, in order to perform efficient polishing when a substrate such as a wafer is chemically and mechanically polished, the polishing slurry and polishing pad to be used should be changed depending on the surface material and condition of the substrate. In the above polishing apparatus, the polishing slurry, the polishing pad, and the polishing conditions cannot be changed immediately according to the surface material and condition of the substrate, and the polishing rate and the productivity cannot be improved.

In view of the foregoing, the present invention has been made in view of the above-mentioned unresolved problems of the related art, and has been made so that optimum polishing conditions respectively corresponding to various substrates can be appropriately selected and reproduced. It is another object of the present invention to provide a chemical mechanical polishing apparatus which has stable properties and can perform high-precision chemical mechanical polishing.

[0009]

In order to achieve the above object, a chemical mechanical polishing apparatus according to the present invention abuts on a surface to be polished of a member to be polished and a predetermined processing pressure is applied to the surface to be polished. The polishing slurry is supplied in a chemical mechanical polishing apparatus that performs polishing by revolving and rotating the polishing surface of the polishing head and rotating or swinging the surface to be polished while supplying the polishing slurry between the polishing surface and the polishing surface of the polishing head. A plurality of polishing heads each having a supply passage to be supplied, a plurality of polishing slurry supply means for respectively supplying a plurality of polishing slurries, and any one of the plurality of polishing slurry supply means being a supply passage for the polishing head. Switching means for selectively communicating any one of the information, information reading means for reading information recorded in advance on the member to be polished, and measuring means for measuring a polishing state of the member to be polished; Further, a memory means including a table memory storing optimum polishing conditions respectively corresponding to various types of polished members, and an optimal polishing condition based on information of the polished members read by the information reading means. A setting means for setting polishing conditions and the like, and a measurement result of the polishing condition by the measuring means is compared with a target value corresponding to a preset polishing condition, and the polishing conditions and the like are corrected and set as necessary. Control means for controlling the polishing head, the polishing slurry supply means, the switching means and the like in response to commands from the comparison / correction change means and the polishing condition etc. setting means and / or the command from the comparison / correction change means. And a control system having:

Further, the present invention provides a chemical mechanical polishing apparatus for polishing between a surface to be polished of a member to be polished and a polishing surface of a polishing head abutted while applying a predetermined processing pressure to the surface to be polished. In a chemical mechanical polishing apparatus that performs polishing by revolving and rotating the polishing surface of the polishing head and rotating or swinging the surface to be polished while supplying the slurry, a plurality of polishing heads each having a supply passage for supplying the polishing slurry are provided. A first drive system for revolving and rotating each of the polishing heads, and further applying pressure; a polished member holding unit; and a second drive system for rotating and swinging the polished member holding unit. A plurality of polishing slurry supply means for respectively supplying a plurality of polishing slurries; and selectively connecting any one of the plurality of polishing slurry supply means to any of the supply passages of the polishing head. Switching means for causing the workpiece to be polished, information reading means for reading information recorded in advance on the workpiece, and measuring means for measuring a polishing state of the workpiece, and further corresponding to various types of workpieces. A memory unit including a table memory storing optimal polishing conditions; a polishing condition setting unit for setting optimal polishing conditions based on information on a member to be polished read by the information reading unit; A comparison / correction changing means for comparing and judging the measurement result of the polishing status with a target value corresponding to a preset polishing condition, correcting and setting the polishing condition and the like as necessary, and setting the polishing condition and the like. And / or the polishing head, the polishing slurry supply means, the switching means, the first drive system, Characterized in that it comprises a control system and a control means for controlling said second driving system, etc., respectively.

In the chemical mechanical polishing apparatus according to the present invention, the information recorded on the member to be polished read by the information reading means relates to an ID number of a substrate such as a wafer or a surface material such as an insulating film or a metal film. Preferably, the information is information, and the measuring means for measuring the polishing state of the member to be polished preferably measures the film thickness or surface shape of the member to be polished.

Further, in the chemical mechanical polishing apparatus of the present invention, the type of polishing pad to be mounted on the polishing head,
The type and particle size of the particles of the polishing slurry, the type and pH of the dispersion of the polishing slurry, the relationship between the polishing pad and the polishing slurry, the number of revolutions in the first drive system, the number of revolutions and the pressing force,
It is preferable that an appropriate combination of the number of rotations and the swing in the second drive system and / or the sequence of the polishing process be set in accordance with each of the various members to be polished.

Further, in the chemical mechanical polishing apparatus of the present invention, it is desirable to provide a cleaning brush head together with a plurality of polishing heads, and to provide a plurality of polishing slurry supply units and a cleaning pure water or chemical supply unit. .

[0014]

In a chemical mechanical polishing of a substrate such as various wafers, the type of polishing pad to be used for polishing and the type of polishing slurry (particle type and its particle size, dispersion liquid) according to the surface material and condition of the substrate. Type, its pH, etc.), the relationship between the polishing pad and the polishing slurry, the drive system of the head assembly H (number of revolutions, the number of revolutions, and the pressing force), and the drive system (rotation speed) of the member-to-be-polished holding means E (rotary table). Optimum polishing conditions, such as the sequence of the polishing process, etc., are set in advance, and the information on the substrate to be polished is read by the reading means, so that the optimum polishing conditions corresponding to the substrate information are obtained. Can be set quickly and automatically, the optimal chemical-mechanical polishing of the substrate can be performed efficiently and stably, and highly accurate polishing with excellent flatness can be performed. Further, by measuring the polishing state with the measuring means, various polishing conditions can be corrected and changed according to the measurement result, and the sequence of the polishing process can be changed according to the measurement result, thereby performing stable polishing. And productivity can be improved.

[0015]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic side view illustrating the overall configuration of a chemical mechanical polishing apparatus according to the present invention, and FIG. 2 is an enlarged view of the head assembly. In FIG. 1 and FIG.
A member-to-be-polished holding means E is formed on a guide table 3 provided integrally therewith. The member-to-be-polished holding means E is movable along the guide table 3 in the X-axis direction and the Y-axis direction. And XY driving means (see FIG. 3) for moving the slider 4 in the X-axis direction and the Y-axis direction, respectively, and rotatably supported on the slider 4 via a rotary shaft 6. A rotatable table 5 provided rotatably, rotating means (see FIG. 3) connected to a rotary shaft 6 for rotating the rotatable table 5, and a rocking means for rocking the rotary table 5 (see FIG. 3). 3), the substrate W such as a wafer detachably held on the upper surface of the turntable 5 is moved in the X-axis direction and the Y-axis direction, and the substrate W is rotated and rocked during polishing. Like It is configured.

A plurality of polishing head assemblies Ha, Hb,... Are opposed to the member-to-be-polished holding means E above the base 1.
Hc and a brush head assembly Ho (hereinafter collectively referred to as a head assembly H) are supported by a support member 2 erected from a base 1 so as to be vertically movable.
The structure of the polishing head assembly Ha will be described with reference to FIG. 2. The polishing head assembly Ha is revolving drive means of a revolving drive / pressure unit 14a supported by the support member 2 so as to be vertically movable (see FIG. 3). Table 13a attached to a rotating shaft 15a connected to the
A polishing drive unit 12a for rotating the polishing head 10a and a rotation driving means (see FIG. 3) of the rotation drive unit 12a, and a polishing pad 11a is exchangeably mounted at a lower end thereof. Head 1
0a, and the polishing head 10a is driven by a revolving table 13a by a revolving drive means of a revolving drive / pressure unit 14a
And the rotation drive unit 12a
The polishing head 10a is vertically moved with respect to the support member 2 by the pressurizing means (see FIG. 3) of the revolving drive / pressurizing unit 14a. It is configured to be able to adjust the pressing force of the polishing head 10a on the substrate W held in the substrate.

The polishing head 10a and the rotation drive unit 12a are provided with a hole 19a for supplying the polishing slurry on the center axis thereof, and the hole 19a is further provided with a revolving table 13a, a rotating shaft 15a and a revolving drive / pressurization. Penetration pipe 1 provided along the central axis of unit 14a
7a through a conduit 18a, and the through tube 17a is connected to a polishing slurry / pure water switching means 30 (hereinafter, also simply referred to as a polishing slurry switching means) through a conduit 16a connected to the upper end thereof. Have been. Thus, in the polishing head assembly Ha, its conduit 16a,
The supply passage composed of the through pipe 17a, the conduit 18a and the hole 19a is communicated with a selected one of the polishing slurry supply means 45 by appropriately operating the switching means 30 for the polishing slurry or the like, and the polishing head 10a and the polishing pad A desired polishing slurry can be supplied to the center of the polishing pad 11a during chemical mechanical polishing.
The polishing slurry can be supplied directly and reliably to the contact surface between the substrate and the substrate W.

The other plurality of polishing head assemblies Hb and Hc also have the same structure as the polishing head assembly Ha, and the same members have the same reference numerals with alphabetical letters b and c, respectively. To display.

On the other hand, the brush head assembly Ho has a brush 21 attached to the lower end of the brush head 20, but the other configuration is the same as the revolving drive / pressing unit 24 similar to the polishing head assemblies Ha, Hb and Hc. , A rotating shaft 25, a revolution table 23, and a rotation drive unit 22,
It is driven similarly to the polishing head assembly Ha and the like. Further, the brush head assembly Ho is provided with a hole 29 for supplying pure water or a chemical for cleaning, a through pipe 27 and conduits 26 and 28, similarly to the through pipe and conduit of the polishing head assembly Ha and the like. Thus, a supply passage is formed, and is connected to a switching means 30 for polishing slurry or the like.

The supply of the polishing slurry and the pure water (or the chemical) is performed by a plurality of supply means 45 having a plurality of slurry supply sources and a supply source of the pure water or the chemical for cleaning. Is connected to a switching means 30 such as a polishing slurry through a set of conduits 46. As the polishing slurry, it is necessary to select and use the optimum polishing slurry according to the type of the substrate to be polished. Therefore, by operating the switching means 30 according to the type of the substrate, the supply path 45 of the specified polishing slurry or pure water is communicated with the supply path of the specified head assembly H, and the optimum supply path 45 is provided. It is configured so that polishing slurry or pure water can be supplied to a polishing point.

The base 1 has information (for example, ID numbers or information on surface materials such as metal films and interlayer insulating films) recorded in a substrate W or a substrate cassette accommodating a plurality of substrates. And a reading stage 32 for reading the information. Before supplying the substrate W to be polished to the turntable 5, the information reading means 31 reads substrate information recorded on the substrate W or the like placed on the reading stage 32 and controls the information to be described later. Transmit to the system 50.

Further, a transfer robot hand 35 having a support leg 34 is provided on the base 1, and the transfer robot hand 35 is moved from a substrate cassette loaded near the base 1 into the transfer robot hand 35. Each of the accommodated substrates W is taken out and transported to the reading stage 32, and the substrate W that has been read is transferred from the reading stage 32 to the rotary table 5.
To the rotary table 5, and transports the polished substrate W from the rotary table 5 so as to be stored in a substrate cassette. The individual substrates W can be taken out from the mounted substrate cassette and transported to the rotary table 5.

A measuring means 41 for electrically or optically detecting and measuring a polishing state such as a film thickness or a surface shape of the substrate is supported by a support portion 42 erected on the base 1. It is provided so as to be able to move facing the location. The measuring means 41 is connected to a control system 50 described later, and transmits the measurement result to the control system 50. An operation panel 44 provided with a display monitor and input means connected to the control system 50 is attached to the support member 2.

Next, a control device of a chemical mechanical polishing (CMP) apparatus having the above-described configuration will be described with reference to FIG.

Information recorded on the substrate W or a substrate cassette accommodating a plurality of substrates W (for example, ID numbers or information on surface materials such as metal films and interlayer insulating films).
A control system 50 connected to an information reading means 31 for reading the data and a measuring means 41 for measuring the polishing state (film thickness or surface shape, etc.) of the substrate W has a table memory 51 in a memory 52, and the table memory 51 Includes various data optimal for polishing corresponding to each of the substrate information of the substrate W, for example, the type of polishing pad to be used for polishing, the type of polishing slurry (the type of particle and its particle size, the type of dispersion liquid) And its pH, etc.), the relationship between the polishing pad and the polishing slurry, the drive system of the head assembly H (number of revolutions, number of revolutions and pressing force), and the drive system of the member-to-be-polished holding means E (rotary table) (number of rotations and swinging). ), And optimal polishing conditions such as an optimal polishing process sequence according to the type of the substrate W are set and stored in advance. Note that various data and the like of these optimal polishing conditions set in the table memory 51 are optimal values respectively obtained for various substrates based on theoretical or past experience or experiments. It is composed.

The control system 50 performs a table lookup based on the substrate information read by the information reading means 31, reads out the data of the appropriate optimum polishing conditions from the table memory 51, and assembles the head based on the data. A supply unit 45 for supplying the body H and the polishing slurry and the polishing slurry; a polishing condition setting unit 53 for setting various polishing conditions of the driving system; and a film thickness or a substrate W polished for a predetermined time set as appropriate. The measurement result of the polishing state of the substrate W by the measuring means 41 for measuring the surface shape and the like is compared with a target value corresponding to a preset condition, and the polishing condition and the like are determined as necessary according to the result of the comparison judgment. And a comparison / correction changing unit 55 for correcting and setting the polishing conditions.
Alternatively, in response to a command from the comparison / correction changing means 55, the head assembly H and the selection of the polishing slurry, the switching means 30 for the polishing slurry and the like, the driving system of the head assembly H, the driving system of the polished member holding means E, Polishing slurry supply means 4
5 is provided with a control means 54 for appropriately controlling the control unit 5. In addition, the control system 50 determines whether or not the predetermined polishing has been completed according to the measurement result of the measuring unit 41. If the predetermined polishing has not yet been reached, the control unit 50 stores the polishing again in the memory. It is configured to instruct to continue with the set polishing conditions or to proceed to the next polishing process.

First, a description will be given of an example in which a combination of a polishing pad and a polishing slurry is specified according to a substrate W having a different material or type on the surface to be polished.

First to third chemical mechanical polishing apparatuses
The polishing heads 10a, 10b, and 10c each have a different type of polishing pad Px, polishing pad Py, and polishing pad Pz as polishing pads, and the different types of polishing slurries include a polishing slurry Sa and a polishing slurry S.
b, polishing slurry Sc, polishing slurry Sd..., and pure water (or chemical) So for cleaning are prepared. The polishing pad has different types such as hardness and surface roughness. The polishing slurry S is specifically, for example, a silica-dispersed sodium hydroxide solution, For polishing the film, silica-dispersed potassium hydroxide solution is suitable, and for polishing a metal film such as tungsten, hydrogen peroxide solution of alumina or manganese oxide is suitable. Different types of fine particles, particle diameters, and pH values of liquids, etc., corresponding to the substrate W to be polished can be prepared as necessary. Also,
In the drive system of the head assembly H, the number of revolutions is 10
Up to 1000 rpm, rotation speed is 10 to 1000 rpm
And it is assumed that the pressure of the polishing head is set to be selected from those of about 100 to 500 g weight / cm ² .

Using the chemical mechanical polishing apparatus set as described above, the combination of the polishing pad and the polishing slurry and the driving system as the data of the optimum polishing conditions stored in the table memory 51 in accordance with the various substrates W. Are assumed to be set as shown in Table 1.

[0031]

[Table 1] (Wh, Wi... Indicate different pieces of substrate information recorded on the substrate W, and Kh, Ki... Indicate drive systems of the head assembly H (the number of rotations, the number of revolutions, and the pressure). And the drive system (rotational speed, swing) of the member-to-be-polished holding means (rotary table) means the specified polishing conditions, and the polishing time Th, Ti... Is performed to obtain a predetermined result.) The control system 5 in which such optimal polishing conditions are set is set.
0, when the substrate information is received from the information reading means 31 which has read the substrate information recorded on the substrate or the substrate cassette, a table lookup is performed according to the substrate information, and the data of the corresponding optimum polishing condition is stored in the table. Read from the memory 51. Then, the polishing condition setting means 53 of the control system 50 specifies the combination of the polishing head and the polishing slurry based on the read data, and the control means 54 operates the switching means 30 to specify the predetermined polishing slurry. In addition to controlling the supply to the finished polishing head, the driving system of the head assembly H, the driving system of the member-to-be-polished holding means E, and the like are controlled to match the respective polishing conditions.

For example, when the substrate W (or substrate cassette) on which the substrate information Wi is recorded is carried in for polishing, the information reading means 31 reads the substrate information Wi,
The information is sent to the control system 50, and in the control system 50,
Data corresponding to the substrate information Wi is read from the table memory 51, and polishing conditions and the like are set according to the data. The second polishing head 10b on which the polishing pad Py is mounted is selectively set as the polishing head, and the polishing slurry Sa is selectively set as the polishing slurry. Then, the switching means 30 is operated to control so as to supply the polishing slurry Sa to the second polishing head 10b. Then, other polishing conditions Ki are instructed to the respective drive systems and are set to operate at predetermined values. On the other hand, the substrate W is loaded from the reading stage 32 to the turntable (member to be polished) 5 by the transfer robot hand 35. Then, the substrate W is moved to a position corresponding to the second polishing head 10b via the slider 4 together with the rotary table 5. Thereafter, the polishing head 10b is pressed against the substrate W at a set predetermined pressure, and each drive system is driven based on the set predetermined value.
The polishing slurry Sa is directly supplied to the center of the polishing head 10b, and the chemical mechanical polishing is performed.

Then, the substrate W on which the substrate information Wi is recorded
Then, when the substrate W having the substrate information Wn is carried in and the substrate is polished after the polishing of the polishing pad Pz, the polishing pad Pz is set based on the data corresponding to the substrate information Wn read by the information reading means 31. The combination of the mounted third polishing head 10c and the polishing slurry Sd is selected, and the polishing slurry S is supplied to the third polishing head 10c.
operating the switching means 30 so as to supply d, and thereafter, the polishing conditions Kn corresponding to the substrate information Wn are set,
Chemical mechanical polishing is performed under the optimum polishing conditions for the substrate W.

After the polishing of each substrate is completed, a combination of the brush head 20 and pure water So is employed to wash the substrate and the rotary table to remove foreign substances such as polishing slurry and polishing debris. The process can be performed, or only when the type of the substrate or the type of the polishing slurry is changed, the substrate or the rotary table is washed by the combination of the brush head 20 and the pure water So to remove the polishing slurry. It is also possible to remove and remove foreign matter such as polishing dust.

The polishing performed as described above is performed within each preset time. After the lapse of the time, the film thickness or surface shape of the substrate W is measured by the measuring means 41, and based on the measurement result. Comparison of control system 50
The correction changing means 55 determines whether or not the predetermined target value is within a permissible range, and if it is within the permissible range, the polishing is terminated. Note that an example of the allowable range is indicated by oblique lines in the table of FIG. 5 illustrating the relationship between the time and the polishing amount.

However, if the polishing time has not reached the allowable range even after the predetermined polishing time has elapsed due to the aging of the polishing pad and the drive system, the polishing is started again. Can take appropriate measures such as extending the polishing time. These correspondences are also stored in the table memory 5 in advance.
1 and can be manually input from the input means of the operation panel 44 as appropriate. Polishing is performed again based on data set in the table memory 51 in advance according to the degree of difference between the measurement result and the predetermined target value. The data on the re-polishing is stored in the table memory 5 of the control system 50.
1 is used instead of the data (the initial standard setting value).
Thereafter, similarly, after a predetermined period of time, a measurement inspection is performed to determine whether or not the polishing is within the allowable range.

As described above, when the polishing conditions such as the extension of the polishing time are corrected and changed according to the measurement result, the initial standard set values are stored in the memory so as to be corrected and changed.
Thereafter, polishing is performed based on the corrected data. That is, even if the polishing rate changes with the aging of the polishing pad or the like, the set value is automatically changed by the learning effect. By correcting and changing the data in this manner, it is possible to correct a change in polishing conditions due to aging of a polishing pad or the like, for example, and then when polishing the same type of substrate, polishing is performed based on the corrected and changed data. The polishing can be performed in a more appropriate state. When the polishing pad or the like is replaced with a new one, the initial polishing conditions (standard setting values) set in the table memory are adopted.

In the above description, the polishing control has been described by focusing on the combination of the polishing head and the polishing slurry. However, the data is stored in the table memory so as to control the sequence of the polishing process in accordance with the substrate information. You can also memorize it. For example, as an example of an optimal process sequence, in the first half of polishing, the polishing speed is given priority, the rotation speed is increased, the pressing force is increased, the polishing slurry is of high concentration or coarse grains, and the polishing pad is used as a polishing pad. Select a combination of polishing heads with high power, and in the latter half of polishing, set the pressing force low and prioritize flatness and uniformity based on the measurement result of the polishing state, and set the polishing slurry to low concentration or By using a combination of fine abrasive grains, a better polishing result can be obtained. Furthermore, at the time of intermediate switching,
By cleaning the remaining rough abrasive particles with pure water and a brush head and then proceeding to the next step, more effective polishing can be performed. In addition, polishing can be performed by combining different types of polishing slurries, and polishing can be performed even when substrates having different processes are mounted in one polishing apparatus. By storing such a sequence of various polishing processes in a table memory in correspondence with substrate information (ID number, information on surface material of the substrate, etc.), a more optimal polishing process can be quickly performed according to the substrate. Can be set.

Next, the flow of the polishing step in the present invention described above will be described with reference to the flowchart of FIG.

The information reading means 31 reads the substrate information of the substrate W (or the substrate cassette) conveyed on the reading stage 32 (step 1) and sends the information to the polishing condition setting means 53 of the control system 50. Polishing condition setting means 5
3 reads out the optimum polishing head and polishing slurry corresponding to the substrate information from the data stored in the table memory 51, and sets the polishing head and polishing slurry and switches the switching means (step 2). Subsequently, the set revolution speed, rotation speed, and pressing force of the drive system of the head assembly, and the speed and swing of the drive system of the member-to-be-polished holding means, or the processing sequence are respectively determined based on the data. And sets predetermined polishing conditions (steps 3 and 4). Then, polishing is performed under the set conditions (step 5). After a lapse of a predetermined time after the execution of the polishing, the thickness or surface shape of the substrate is measured by the measuring means 41 (Step 6), and the measurement result is compared with a target value corresponding to a preset polishing condition, It is determined whether or not the time is within the allowable range of the target value (step 7). If the film thickness or the surface shape has reached the allowable range of the target value, the polishing is terminated and the substrate is returned from the member-to-be-polished holding means. Is taken out (step 8).

On the other hand, it is compared whether the measurement results such as the film thickness or the surface shape are out of the allowable range of the target value and out of the upper limit of the allowable range (step 9). And stop polishing (Step 1)
0) If the measurement result does not reach the allowable range of the target value, the initial standard set value is corrected and changed according to the data of the table memory 51 set in advance or according to the input from the input means. Then, the polishing conditions are changed based on the corrected and changed data (the final value corrected and changed at this time is stored in the memory, and the corrected value is used as the initial standard setting value for the next polishing. ) Or the polishing conditions set in the latter half of the previously stored processing sequence (step 1).
1) Then, polishing is performed again (steps 2 to 5).
Then, after a predetermined period of re-polishing has elapsed, the substrate is measured by the measuring means (step 6) and compared with the allowable range of the target value (step 7). To end the polishing (step 8).

[0042]

Since the present invention is configured as described above, the optimal polishing conditions and the optimal polishing process sequence set in advance corresponding to the respective substrate information recorded on various substrates. Is quickly selected, and optimal polishing for various substrates can be automatically and efficiently performed stably, and highly accurate polishing with excellent flatness can be performed.

Further, it is possible to detect and measure the polishing state of the substrate at the time of polishing, correct and change various conditions according to the measurement result, and change the polishing process according to the measurement result to perform polishing. Polishing with even higher precision and excellent flatness can be performed, and furthermore, stable polishing including reproducibility can be performed, and productivity can be significantly improved.

[Brief description of the drawings]

FIG. 1 is a schematic side view illustrating the overall configuration of a chemical mechanical polishing apparatus according to the present invention.

FIG. 2 is an enlarged view of a head assembly in the chemical mechanical polishing apparatus of the present invention.

FIG. 3 is a block diagram of a control device in the chemical mechanical polishing apparatus of the present invention.

FIG. 4 is a flowchart for executing control in the chemical mechanical polishing apparatus.

FIG. 5 is a table illustrating a relationship between time and polishing amount and an allowable range.

FIG. 6 is a schematic perspective view showing an example of a conventional chemical mechanical polishing apparatus.

[Explanation of symbols]

 E Member to be polished holding means H Head assembly Ha, Hb, Hc Polishing head assembly Ho Brush head assembly S Polishing slurry W Substrate 1 Base 2 Supporting member 5 Rotary table 10 Polishing head 11 Polishing pad 12 Rotary drive unit 13 Revolution Table 14 Revolving drive / pressurizing unit 20 Brush head 30 Switching means such as polishing slurry 31 Information reading means 41 Measurement means 45 Supply means such as polishing slurry 50 Control system 51 Table memory 53 Polishing condition etc. setting means 54 Control means 55 Comparison / Correction change means

Claims (7)

[Claims] 1. A polishing slurry is supplied between a surface to be polished of a member to be polished and a polishing surface of a polishing head which is brought into contact with the surface to be polished while applying a predetermined processing pressure. In a chemical mechanical polishing apparatus that performs polishing by revolving and rotating a polishing surface and rotating or swinging a surface to be polished, a plurality of polishing heads each having a supply passage for supplying a polishing slurry, and a plurality of polishing slurries are respectively supplied. A plurality of polishing slurry supply means; a switching means for selectively communicating any one of the plurality of polishing slurry supply means with any of the supply passages of the polishing head; Information reading means for reading the information to be polished, and measuring means for measuring the polishing state of the member to be polished. Memory means including a stored table memory; polishing condition setting means for setting optimum polishing conditions based on information on a member to be polished read by the information reading means; and a polishing result measurement result by the measuring means Is compared with a target value corresponding to a preset polishing condition, and a comparison / correction change unit that corrects and sets the polishing condition and the like as necessary, and the polishing condition and the like setting unit and / or In response to the command of the comparison / correction change means,
A chemical mechanical polishing apparatus comprising: a control system having control means for controlling the polishing head, the polishing slurry supply means, the switching means, and the like. 2. A polishing head, wherein a polishing slurry is supplied between a surface to be polished of a member to be polished and a polishing surface of a polishing head which is brought into contact with the surface to be polished under a predetermined working pressure. In a chemical mechanical polishing apparatus that performs polishing by revolving and rotating a polishing surface and rotating or swinging a polished surface, a plurality of polishing heads each having a supply passage for supplying a polishing slurry, and revolving and rotating each of the polishing heads A first drive system for rotating and further applying pressure, a member-to-be-polished holding means, a second drive system for rotating and swinging the member-to-be-polished holding means, and a plurality of polishing slurries, respectively; A plurality of polishing slurry supply means, a switching means for selectively communicating any one of the plurality of polishing slurry supply means to any of the supply passages of the polishing head, An information reading unit for reading information recorded in advance on the polishing member; and a measuring unit for measuring a polishing state of the member to be polished. Further, optimal polishing conditions corresponding to various types of the member to be polished are stored. A memory means including a table memory; a polishing condition setting means for setting optimum polishing conditions based on information on a member to be polished read by the information reading means; and a measurement result of a polishing state by the measuring means set in advance. Comparison / correction changing means for comparing and judging with a target value corresponding to the polishing condition being set, and changing and setting the polishing condition and the like as necessary, and setting means for the polishing condition and the like and / or the comparison / correction In response to the command of the change means,
A chemical machine comprising a control system having the polishing head, the polishing slurry supply means, the switching means, and control means for controlling the first drive system, the second drive system, and the like, respectively. Polishing equipment. 3. The information pre-recorded on the member to be polished read by the information reading means is an ID number of a substrate such as a wafer or information on a surface material such as an insulating film or a metal film. Item 3. The chemical mechanical polishing apparatus according to Item 1 or 2. 4. The chemical according to claim 1, wherein the measuring means for measuring a polishing state of the member to be polished measures a film thickness or a surface shape of the member to be polished. Mechanical polishing equipment. 5. The optimum polishing conditions respectively corresponding to various types of members to be polished include the type of polishing pad mounted on the polishing head, the type and size of polishing slurry particles, the type of polishing slurry dispersion liquid, and the like. The pH, the relationship between the polishing pad and the polishing slurry, the number of revolutions in the drive system of the polishing head,
The method according to any one of claims 1 to 4, wherein an appropriate combination of the number of rotations and the pressing force and / or the sequence of the polishing process are set according to each of the various members to be polished. Chemical mechanical polishing equipment. 6. The optimum polishing conditions respectively corresponding to various types of members to be polished include the type of polishing pad to be mounted on the polishing head, the type and size of polishing slurry particles, the type of polishing slurry dispersion liquid, and the like. An appropriate combination of the pH, the relationship between the polishing pad and the polishing slurry, the number of revolutions in the first drive system, the number of revolutions and pressure, the number of revolutions and rocking in the second drive system, and / or the sequence of the polishing process The chemical mechanical polishing apparatus according to any one of claims 2 to 4, wherein is set according to each of various types of members to be polished. 7. A cleaning brush head is provided together with a plurality of polishing heads, and a supply of cleaning pure water or a chemical is provided together with a plurality of polishing slurry supply units. The chemical mechanical polishing apparatus according to claim 1.