JPH10107134A - Electrostatic suction device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize temperature distribution necessary for keeping plane uniformity of a sample to be processed. SOLUTION: A control part 9 allows a wafer to be sucked electrostatically to an electrostatic suction table and supplies a helium gas to cooling discs 3a, 3b and 3c from a helium gas supply part 8 through a gas supply pipe 14. The control part 9 activates driving motors 6a, 6b and 6c for elevation according to the temperature distribution data of wafer measured by a temperature sensor 10 and the position data from an encoder 7, so as to control the position and area of the cooling discs 3a, 3b and 3c which are brought into contact with the rear surface of the wafer. Thus, the wafer can be controlled at desired temperature distribution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic attraction device, and more particularly, to an electrostatic attraction device for performing a process by electrostatically attracting a sample such as a semiconductor substrate onto a processing table.

[0002]

2. Description of the Related Art Conventionally, an electrostatic chuck (Electrostatic Chuck) has been used as an electrostatic chucking device for holding a sample by electrostatic force when performing a predetermined process on the sample.
uck) was used. In this electrostatic chuck, an electrostatic layer is provided on a sample stage, a voltage is applied between the sample stage and a sample to be processed (eg, a wafer), and the wafer is attracted by Coulomb force generated between the two. It is a mechanism to do. Such an electrostatic chuck is used for a sample table, a transfer system, and the like for holding a wafer and controlling a temperature.

[0003] For example, in a semiconductor manufacturing apparatus or the like,
In the process of manufacturing a circuit pattern for forming a high-density integrated circuit on a wafer, dry etching or CV
D (Chemical Vapor Deposition system) processing or the like is performed. At this time, the wafer is fixed on the sample table by the above-mentioned electrostatic chuck. It is desirable that the etch rate in such a dry etching process and the deposition rate by the CVD process are uniform over at least one wafer surface, but it is very difficult to maintain in-plane uniformity due to changes in processing conditions. Was.

In view of the above, a conventional electrostatic attraction device has been proposed in which a wafer is attracted and fixed, and a heat transfer means for controlling the temperature of the wafer is arranged on a wafer mounting surface (actual flat plate). 3-73453).

Further, in the conventional electrostatic attraction device, in order to obtain the above-mentioned uniformity of the etching rate and the deposition rate in the wafer surface, the control is performed by changing the electrode interval, the set pressure of the gas, and the like.

[0006]

However, in such a conventional electrostatic attraction device, the wafer is electrostatically attracted by the electrostatic attraction electrode, and the heat is placed on the wafer mounting surface. The wafer was cooled by a helium gas supply device as a transfer means so as to equalize the in-plane temperature of the wafer. However, since the wafer lift pins for lifting the wafer are arranged at the center of the sample table, the wafer is compared with other parts. In addition, the cooling efficiency is poor, and the in-plane temperature of the wafer is likely to be non-uniform, so that there is a problem that it is difficult to make the etch rate or the deposit uniform.

For example, in the case of plasma etching or plasma CVD, the concentration of plasma density increases the etch rate and deposition rate only in the central portion of the wafer, deteriorating in-plane uniformity and burning the resist. Was.

In this case, if the above-described non-uniform temperature distribution in the wafer surface and the degree of plasma density concentration are known in advance, the etch rate and the deposition rate in the wafer surface are made uniform according to these conditions. The electrode spacing may be set as described above, or the gas pressure may be set to a predetermined pressure. However, since uniforming conditions vary depending on processing contents and processing conditions, it has been extremely difficult to always uniform the etching rate, the deposition rate, and the like in the wafer surface.

Therefore, the present invention is intended to realize a temperature distribution state necessary to maintain the in-plane uniformity of a sample to be processed even when the processing content and processing conditions for the sample to be processed change. By driving the divided heat exchanging section contacting the sample to be processed by the heat exchanging section driving means, the sample to be processed can have a desired temperature distribution, and the in-plane uniformity of the sample to be processed can be improved. It is an object of the present invention to provide an electrostatic attraction device that can obtain the following.

According to a second aspect of the present invention, the temperature of a plurality of points on the sample to be processed is measured by the sample temperature measuring means, and the control means drives the heat exchange section driving means in accordance with the measured temperature distribution. It is another object of the present invention to provide an electrostatic attraction device capable of providing a target sample with a desired temperature distribution.

According to a third aspect of the present invention, the vertical position of the heat exchange unit for each divided area is measured by the position measuring means.
By driving the heat exchanging unit driving means based on the measured vertical position of each heat exchanging unit, the heat exchanging unit divided into concentric multiple regions can have a desired position and area with respect to the sample to be processed. It is an object of the present invention to provide an electrostatic chuck capable of causing a sample to be processed to have a desired temperature distribution by being brought into contact with each other.

According to a fourth aspect of the present invention, when a semiconductor substrate as a sample to be processed is disposed in a vacuum vessel and dry etching or CVD is performed, the semiconductor substrate is electrostatically adsorbed and fixed. It is another object of the present invention to provide an electrostatic chuck capable of obtaining in-plane uniformity of a semiconductor substrate by controlling the temperature distribution.

[0013]

According to a first aspect of the present invention, there is provided an electrostatic attraction device for mounting a sample to be processed on a sample table and adsorbing the sample by electrostatic force, and A temperature controller for performing temperature control on the sample to be electrostatically adsorbed, wherein the sample stage is divided into multiple concentric regions around the adsorption position of the sample to be processed. A heat exchange section of the temperature control means for controlling the temperature by performing heat exchange on the sample to be processed for each of the divided areas is provided, and a heat exchange section for each of the divided areas is provided for the sample to be processed. The object is achieved by providing a heat exchange unit driving unit that is driven separately in the direction perpendicular to the mounting surface.

Here, as the sample to be processed, for example, there is a wafer such as a silicon substrate used for a semiconductor device.
Of course, the sample to be processed can be made of any material other than the wafer, as long as it can be electrostatically attracted by the action of Coulomb force and is subjected to a constant process while controlling the temperature.
It is not limited to the shape and the like.

The concentric multiplex area means a plurality of areas extending in a ring from a predetermined center position. Here, a sample table on which a sample to be processed is placed is divided for each ring area. The shape of the annular region is not particularly limited, and may be a circle,
Oval, rectangular or triangular shapes are possible. For example,
The shape may be similar to the sample to be processed, but in consideration of the fact that heat conduction from the center position is radially transmitted at a constant speed, it is preferable that the sample is formed in a circular ring regardless of the shape of the sample to be processed.

The heat exchanging section controls the temperature by performing heat exchange by contacting with the sample to be processed. For example, helium gas (He) is provided near the surface of the sample stage on which the sample to be processed is placed. Helium cooling is performed while constantly circulating helium gas. Here, the heat exchange unit is provided for each of the divided multiple regions.

The heat exchange section driving means separately drives each sample stage divided into multiple regions and provided with the heat exchange section as described above in a direction perpendicular to the mounting surface. For example, in the case of a DC servo motor, when a given target value is given, each multiplex area is driven in a vertical direction by a predetermined amount based on the given target value, and controlled so as to converge on the target position. Is done.

According to the above configuration, the sample stage on which the sample to be processed is placed is divided into concentric multiple regions, and the heat exchange units arranged for each of the divided regions are heated by the heat exchange unit driving means. It is individually driven in the direction perpendicular to the mounting surface, and the temperature distribution of the sample to be processed can be changed as appropriate. As a result, even if the processing content and processing conditions of the sample to be processed change, the in-plane uniformity of the sample to be processed can be obtained by changing the temperature distribution of the sample to be processed according to those conditions.

In this case, for example, as described in claim 2, the electrostatic adsorption device measures the temperature distribution by the temperature distribution measuring means for measuring the temperature distribution of the sample to be processed and the temperature distribution measuring means. Controlling the temperature distribution of the sample to be processed by driving the heat exchanging unit driving means in accordance with the temperature distribution state and changing the position and area where the heat exchange unit for each of the divided regions abuts on the sample to be processed. Control means for performing the operation.

Here, the temperature distribution measuring means may use a contact-type temperature sensor for measuring the temperature of each part by contacting each point of the sample to be processed placed on the sample stage. The temperature distribution state of the sample to be processed may be measured in a non-contact manner by using a thermography technique for displaying an image of the temperature distribution by imaging the sample to be processed.

The control means drives the heat exchanging section driving means based on the temperature distribution state measured by the temperature distribution measuring means, and determines the position and area of the heat exchange section for each divided area in contact with the sample to be processed. By changing the temperature, the sample to be processed is controlled to have a desired temperature distribution. For example, the control means may be a CPU (Central Processing Unit) or a ROM
(Read Only Memory), RAM (Random Access Memor)
y) etc., and dry etching and CV
The heat exchange unit driving means is controlled so as to have a temperature distribution for equalizing an etching rate and a deposition rate in a wafer surface as a sample to be processed according to processing contents such as the D processing and processing conditions. When the temperature near the center of the wafer is high, the cooling efficiency is increased by raising the heat exchange section (divided sample stage) near the center and bringing it into contact with the back side of the wafer. When the temperature near the outer periphery of the wafer is low, the cooling is stopped by lowering the heat exchange unit near the outer periphery to separate from the back surface of the wafer.

According to the above configuration, the temperature distribution of the sample to be processed is measured by the temperature distribution measuring means, and the heat exchange section driving means can be driven by the control means based on the measured temperature distribution state. As a result, since the control is performed while feeding back the temperature distribution state of the sample to be processed, the temperature can be accurately controlled so as to have a desired temperature distribution, and in-plane uniformity in the processing result of the sample to be processed is obtained. be able to.

Further, for example, as set forth in claim 3, the electrostatic suction device further includes a position measuring means for measuring a vertical position of each of the divided areas of the heat exchange section, The heat exchange unit driving unit may be driven based on the vertical position of each of the heat exchange units measured by the measurement unit.

Here, the position measuring means measures the vertical position of the heat exchange section provided for each of the divided areas. For example, the position measuring means uses a photoelectric sensor or the like for each of the divided areas of the sample table. The position in the vertical direction may be measured, or the position relative to the reference position may be measured using an encoder that measures the amount of drive of the heat exchange section drive means.

According to the above configuration, the vertical position of the heat exchange section for each divided area is measured by the position measurement section, and the heat exchange section drive section is operated based on the measured vertical position of each heat exchange section. Can be driven. As a result, the heat exchange section divided into concentric multiple regions is accurately brought into contact with the sample to be processed at a desired position and area, and the temperature distribution of the sample to be processed can be accurately controlled. .

Further, for example, as set forth in claim 4, in the electrostatic chuck, a semiconductor substrate as the sample to be processed is disposed in a vacuum vessel, and the semiconductor substrate is subjected to dry etching and CVD. May be fixed by electrostatic attraction when performing the above.

According to the above structure, a semiconductor substrate is disposed in a vacuum vessel as a sample to be processed, and the semiconductor substrate is electrostatically attracted when performing a dry etching process, a CVD process, or the like. Since the semiconductor substrate inside can be controlled to have a desired temperature distribution, in-plane uniformity of the etching rate and the deposition rate of the semiconductor substrate can be obtained.

[0028]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. It should be noted that the embodiments described below are preferred embodiments of the present invention, and therefore, various technically preferable limitations are added. However, the scope of the present invention is not limited to the following description. The embodiments are not limited to these embodiments unless otherwise specified.

FIGS. 1 to 3 show an electrostatic chuck to which an embodiment of the electrostatic chuck of the present invention is applied.

FIG. 1 is a plan view of the electrostatic chuck table 2 of the electrostatic chuck 1 according to the present embodiment. FIG. 2 is a cross-sectional view of the electrostatic chuck table 2 taken along line AA of FIG. FIG. 4 is a view showing another configuration cross section of the electrostatic chuck 1 accompanying the following. 1 and 2, an electrostatic chuck 1 includes an electrostatic chuck 2, a cooling board 3a, 3b, 3c, a wafer lift pin 4, a lower electrode 5,
It comprises a lifting drive motor 6a, 6b, 6c, an encoder 7, a helium gas supply unit 8, a control unit 9, a temperature sensor 10, a DC power supply 11, a capacitor 12, a high frequency power supply 13, a gas supply pipe 14, and the like.

The electrostatic chuck 2 has a dielectric layer (electrodes for suction) provided on a mounting surface (not shown) on which a wafer is mounted (the upper surface of the electrostatic chuck 2). This is an electrostatic attraction means for applying a predetermined voltage between the wafer and the wafer to generate a Coulomb force between the two and attracting and fixing the wafer on a mounting surface on which a wafer as a sample to be processed is mounted. Since the electrostatic chuck table 2 in FIG. 2 intersects cooling plates 3a, 3b, 3c, which will be described later, in the figure, it is shown here by a dashed line transparent line.

The cooling plates 3a, 3b, 3c are slid in the direction of gravity (vertical direction in FIG. 2) according to the shape of the concentric multiple through-holes formed in the electrostatic chuck table 2 described above. It is a heat exchange section as a temperature control means which is divided so as to be movable. The heat exchanging section is provided with a helium gas (He) supplied from a helium gas supply section 8 to be described later through a gas supply pipe 14 for cooling (not shown) disposed near a contact surface that comes into contact with the wafer back side. By being guided by a pipe and circulating the same, the wafer and the cooling boards 3a, 3
Heat is exchanged at the contact surfaces b and 3c. Cooling boards 3a, 3b,
As shown in FIG. 1, the structure of 3c is composed of multiple concentric circular regions when viewed in a direction perpendicular to the wafer mounting surface. Is divided into four. The annular regions (3a, 3b, 3c) having the same diameter are configured so that they can be individually driven in the direction of gravity by lifting drive motors 6a, 6b, 6c, which will be described later, as one unit. 2).

The wafer lift pins 4 are provided at the center of the electrostatic chuck 2, and are composed of four pins that support the wafer and can move up and down. When the wafer lift pins 4 place the wafer on the electrostatic chucking table 2 by a wafer loader or the like that transports the wafer or move the wafer from the electrostatic chucking table 2 to another place, the wafer lift pins 4 lift the wafer to facilitate delivery. It is to be.

The lower electrode 5 performs wafer processing such as plasma etching and plasma CVD by applying a high-frequency voltage supplied from a high-frequency power supply 13 described later.

The lifting drive motors 6a, 6b, 6c are heat exchange section drive means for individually moving up and down a plurality of cooling boards 3a, 3b, 3c formed of concentric multiple annular regions. Here, a DC servomotor is used, and when a predetermined target value is given, drive control is performed so as to converge to a position corresponding to the target value.

The encoder 7 measures the position of the heat exchanging section of the cooling boards 3a, 3b, 3c by measuring the amount of drive of the DC servo motors, which are the above-described elevation drive motors 6a, 6b, 6c. Means. For example, in a state where each cooling board is arranged at a predetermined reference position, the value of the encoder is reset, and the amount of driving from the reference position is measured by the encoder 7, so that each cooling board 3a, 3b, 3
The relative position in the vertical direction at c can be grasped.

The helium gas supply section 8 circulates and supplies helium gas (He) for cooling to each of the cooling boards 3a, 3b, 3c through a gas supply pipe 14 to perform helium cooling. Make up part.

The control unit 9 comprises a CPU, a ROM, a RAM, and the like.
b, 6c, an encoder 7, a helium gas supply unit 8, and a temperature sensor 10 to be described later, which collect various data, send control commands, and control the whole electrostatic adsorption device. The ROM of the control unit 9 stores a system program of the electrostatic chuck device, a temperature distribution control program of the wafer, and the like, and also stores system data and various data necessary for executing each of these programs. I have. The RAM is used as a work memory of the CPU. The CPU controls each part of the electrostatic suction device according to the present embodiment based on a program in the ROM to cause the wafer to be electrostatically sucked on the electrostatic suction table 2 and to adjust the wafer to a desired temperature distribution. Control so that

The temperature sensor 10 is a temperature distribution measuring means for measuring the temperature distribution of the wafer. Here, a thermistor, which is a contact-type temperature sensor, is used, but the temperature distribution of the wafer is measured using various contact-type or non-contact-type temperature sensors such as a thermocouple, an IC temperature sensor, and a radiation thermometer. Is also good.

The DC power supply 11 is a power supply for generating a Coulomb force for attracting the wafer onto the electrostatic attraction table 2 and constitutes a part of the electrostatic attraction means.

The capacitor 12 is arranged between the positive side of the DC power supply 11 and the high frequency power supply 13.

The high-frequency power supply 13 supplies a high-frequency voltage to the lower electrode 5 and is used as a power supply for generating plasma when the wafer is subjected to plasma etching or plasma CVD.

Next, the operation will be described. In the electrostatic chuck 1 according to the present embodiment, when dry etching or CVD processing is performed on a wafer in a vacuum vessel, the processing is performed while the wafer is suction-fixed on the electrostatic suction table 2. When performing a dry etching process or a CVD process on a wafer, it is necessary to make the etching rate and the deposition rate in the wafer surface uniform, but in order to achieve this, uniformity of the temperature distribution in the wafer surface is required. ing. For this reason,
The electrostatic chuck 1 according to the present embodiment is characterized in that the temperature distribution of a wafer being processed can always be controlled uniformly while the wafer is fixed by suction.

First, a wafer to be processed is transported by using a wafer loader (not shown), and is transferred to the electrostatic chuck table 2 shown in FIGS.
Absorb and fix on top. In this case, the wafer lift pins 4
After the wafer is loaded by the wafer loader in the raised state and the wafer loader is retracted, the wafer lift pins 4
Is lowered, and the wafer is placed on the electrostatic attraction table 2. At this time, a DC voltage from the DC power supply 11 is applied to the dielectric layer on the electrostatic chucking table 2, and the wafer is moved by the Coulomb force generated between the electrostatic chucking table 2 and the wafer. Is fixed by suction. FIG. 2 shows a state in which the wafer lift pins 4 and the cooling boards 3a, 3b, 3c protrude above the electrostatic chucking table 2. In this case, the position is lower than the upper surface position of the electrostatic chucking table 2.

Next, the operation of controlling the temperature distribution of the wafer will be described. As described above, the wafer adsorbed on the electrostatic chuck 2 has a gas temperature distribution unevenly distributed in the vacuum vessel and the temperature distribution in the wafer surface is not necessarily uniform due to heat conduction from the electrostatic chuck 2. If not happen. If plasma etching or plasma CVD is performed in this state, the wafer is processed at an etching rate or a deposition rate corresponding to a difference in wafer temperature, so that in-plane uniformity cannot be obtained and the yield of integrated circuits to be manufactured is reduced. It may be worse.

For this reason, in the electrostatic chuck 1 according to the present embodiment, the cooling plates 3a, 3b, 3c as a heat exchange portion composed of multiple concentric annular regions from below the electrostatic chuck table 2 can be moved up and down. The upper end surfaces of the cooling boards 3a, 3b, 3c are brought into contact with the back surface of the wafer, and heat exchange is performed on the contact surface, thereby controlling the temperature distribution of the wafer.

More specifically, the electrostatic chuck 2 shown in FIG.
Temperature sensor 10 comprising a thermistor disposed thereon
By (a, b, c), the temperature from the vicinity of the center of the wafer to the outer peripheral direction is measured, and the measured temperature data is sequentially input to the control unit 9.

The lifting drive motors 6a, 6b, 6c
Is for individually moving the cooling boards 3a, 3b, 3c up and down in the direction of gravity. Here, the cooling boards 3a, 3
A position where the upper end surfaces of b and 3c are evenly in contact with the back surface of the wafer sucked on the electrostatic chuck table 2 is set as a reference position, and the encoder 7 is reset when each of the cooling boards 3a, 3b and 3c comes to this position. . When the wafer is placed on the electrostatic chuck 2, the cooling platen 3 is positioned higher than the upper surface of the electrostatic chuck 2.
The control unit 9 controls so that the upper end surfaces of a, 3b, and 3c move to the lower positions.

Further, the control unit 9 controls each of the cooling boards 3a, 3
Helium gas is circulated and supplied from the helium gas supply unit 8 via the gas supply pipe 14 in order to helium cool b and 3c.

The controller 9 controls the temperature distribution based on the measured temperature data of each part of the wafer from the temperature sensor 10 (a, b, c) so that the temperature in the wafer surface becomes uniform. . FIGS. 3A to 3C show the cooling board 3.
FIG. 4 is a diagram illustrating a state in which the temperature distribution of the wafer 20 is controlled by individually moving a, 3b, and 3c up and down. Note that the up and down arrows shown in FIG. 3 are marks indicating a state in which heat exchange is being performed, and that the larger the number of arrows, the higher the heat exchange efficiency, and the smaller the number of arrows, the lower the heat exchange efficiency. Means.

FIG. 3A shows an electrostatic chuck table 2 (not shown).
2 shows a state in which the cooling boards 3a, 3b, 3c are driven to the reference position of the encoder 7 by the lifting drive motors 6a, 6b, 6c with respect to the wafer 20 suction-fixed. That is, in a state where the upper end surfaces of the cooling boards 3a, 3b, 3c are evenly in contact with the back side of the wafer 20, heat is being exchanged by all the cooling boards. In the state shown in FIG. 3A, the cooling efficiency is the highest, and when the temperature of the wafer 20 is uniformly rising as a whole, the control unit 9 controls the cooling boards 3a, 3b, 3c to this position. , So as to lower the temperature of the wafer as a whole.

FIG. 3B shows an electrostatic chuck table 2 (not shown).
The cooling platen 3a is set at a reference position, the cooling platen 3b is set at a position slightly lower than the reference position, and the cooling platen 3c is set at a position lower than the cooling platen 3b by the drive motors 6a, 6b, 6c for raising and lowering the wafer 20 sucked and fixed on the cooling platen 3b. Is also controlled by the control unit 9 so as to be at a lower position. At this time, the control operation by the control unit 9 allows the position of the elevation drive motors 6a, 6b, 6c to be accurately controlled by the value of the encoder 7. Cooling boards 3a, 3b, 3c shown in FIG.
Is a case where the heat exchange (cooling) efficiency is high at the center of the wafer 20 and the heat exchange efficiency decreases toward the outer periphery. Accordingly, when the temperature of the central portion of the wafer 20 is high and the temperature is low toward the peripheral portion, the driving is controlled as shown in FIG. 3B.

FIG. 3C shows the electrostatic chuck table 2 (not shown).
The cooling plate 3c is set at a reference position, the cooling plate 3b is set at a position slightly lower than the reference position, and the cooling plate 3a is set at a lower position than the cooling plate 3b by the drive motors 6a, 6b, 6c for raising and lowering the wafer 20 sucked and fixed. Is also controlled by the control unit 9 so as to be at a lower position. At this time, the control operation by the control unit 9 can accurately control the position of the elevation drive motors 6a, 6b, 6c by the value of the encoder 7 as in FIG. 3B. The relationship between cooling boards 3a, 3b, 3c and wafer 20 shown in FIG.
In this case, the heat exchange efficiency is low at the center of the area, and the heat exchange (cooling) efficiency increases toward the outer periphery. Therefore, in this case, in the case of a temperature distribution situation in which the temperature at the outer peripheral portion of the wafer 20 is high and the temperature is lower toward the central portion,
Drive control is performed as shown in FIG.

Although not shown, other than the above,
Depending on the temperature distribution of the wafer 20, the cooling boards 3a and 3
c may be brought into contact with the back surface of the wafer 20 to increase the heat exchange (cooling) efficiency and lower the heat exchange efficiency by lowering only the cooling platen 3b, and vice versa. The heat exchange (cooling) efficiency may be increased by contacting the back surface, and the cooling boards 3a and 3c may be lowered to lower the heat exchange efficiency.

As described above, the control unit 9 controls the cooling boards 3a,
The cooling boards 3a, 3c are moved up and down in the direction of gravity by the drive motors 6a, 6b, 6c for lifting and lowering.
By changing the position and area where b, 3c abuts (or approaches) the back surface of the wafer 20, the heat exchange efficiency can be partially changed, and the temperature distribution of the wafer 20 is non-uniform. Can also be made uniform.

As described above, according to the above-described embodiment, the temperature distribution of the wafer is measured by the temperature sensor 10, and based on the measured temperature distribution, the control unit 9 controls the elevation drive motors 6 a, 6 b, 6 c. While driving the cooling board 3
Since the contact positions of a, 3b, and 3c with respect to the wafer are feedback-controlled, the temperature can be accurately controlled so that a desired temperature distribution is obtained in the wafer surface.

Further, according to the above-described embodiment, when a plasma etching process or a plasma CVD process is performed using a wafer having a uniform temperature distribution while applying a high-frequency voltage to the lower electrode 5 by the high-frequency power supply 13, Since the etching rate and the deposition rate are uniform, an integrated circuit having a good yield can be manufactured.

Although the invention made by the inventor has been specifically described based on the preferred embodiments, the invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the invention. It goes without saying that it is possible.

For example, in the above embodiment, the annular cooling plate composed of concentric circles for exchanging heat with the wafer has a triple structure (3a, 3b, 3c), but by further multiplexing, More detailed temperature distribution control can be performed. Further, the temperature control may be performed by using a multi-layered structure such as a rectangle other than a circle or a triangle, or by arranging and cooling each cooling board in a matrix.

Further, in the above embodiment, a contact-type thermistor is used as the temperature sensor 10 for measuring the temperature distribution of the wafer. However, the present invention is not limited to this, and other contact-type sensors or non-contact thermistors may be used. As a type sensor, for example, a radiation thermometer or the like may be used to measure the temperature distribution state.

Further, in the above embodiment, the positions of the cooling boards 3a, 3b, 3c are adjusted by the drive motors 6a, 6
When the drive is controlled by b and 6c, the control unit 9 performs the position control while watching the value of the encoder 7. However, the positions of the cooling boards 3a, 3b and 3c are patterned in advance,
By previously storing the target value of the DC servomotor in the RAM or ROM in the control unit 9, the control operation can be performed more quickly.

In the above embodiment, a contact-type thermistor is used as the temperature sensor 10 for measuring the temperature distribution of the wafer. However, the present invention is not limited to this, and other contact-type sensors or non-contact thermistors may be used. As a type sensor, for example, a radiation thermometer or the like may be used to measure the temperature distribution state.

In the above embodiment, the control is performed so as to make the temperature distribution of the wafer uniform. However, the present invention is not limited to this. For example, in contrast to the above embodiment, the etching rate and the deposition rate are partially changed. For this purpose, the temperature distribution may be consciously changed and controlled.

[0064]

According to the first aspect of the present invention, even if the processing content and processing conditions for the sample to be processed change, it is necessary to maintain the in-plane uniformity of the sample to be processed. Since the temperature distribution state is realized, the sample to be processed can have a desired temperature distribution by driving the divided heat exchange unit that is in contact with the sample to be processed by the heat exchange unit driving unit,
In-plane uniformity of the sample to be processed can be obtained.

According to the second aspect of the present invention, the temperature of a plurality of points of the sample to be processed is measured by the sample temperature measuring means, and the control means is controlled by the heat exchange unit in accordance with the measured temperature distribution. Since the driving means is driven, the sample to be processed can have a desired temperature distribution.

According to the third aspect of the present invention, the vertical position of the heat exchanging unit for each divided area is measured by the position measuring means, and the measured vertical position of each heat exchanging unit is measured. Drives the heat exchange unit driving means based on
The heat exchange section divided into concentric multiple regions can be brought into contact with the sample to be processed at a desired position and area, and the sample to be processed can have a desired temperature distribution.

According to the electrostatic attraction device of the present invention, when a semiconductor substrate as a sample to be processed is placed in a vacuum vessel and dry etching or CVD is performed,
Since the semiconductor substrate is electrostatically attracted and fixed and the temperature distribution is controlled, in-plane uniformity of the semiconductor substrate can be obtained.

[Brief description of the drawings]

FIG. 1 is a plan view of an electrostatic chuck table of an electrostatic chuck according to an embodiment.

FIG. 2 is a diagram showing a cross section taken along line AA of the electrostatic chuck table of FIG. 1 and other configuration cross sections of the electrostatic chuck attached thereto.

FIG. 3 is a diagram illustrating a state in which a cooling board is individually moved up and down to control a temperature distribution of a wafer.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 electrostatic chuck 2 electrostatic chuck table 3 a, 3 b, 3 c cooling board 6 a, 6 b, 6 c lifting / lowering drive motor 7 encoder 8 helium gas supply unit 9 control unit 10 temperature sensor 11 DC power supply 14 gas supply pipe 20 wafer

Claims (4)

[Claims] 1. An electrostatic attraction means for mounting a sample to be processed on a sample table and adsorbing the sample by electrostatic force, and a temperature control for controlling the temperature of the sample electrostatically adsorbed on the sample table. Means, the sample stage is divided into multiple concentric regions around the adsorption position of the sample to be processed, and heat exchange is performed on the sample to be processed in each divided region. A heat exchange unit of the temperature control means for controlling the temperature by performing the heat exchange unit, wherein the heat exchange unit for separately driving the heat exchange units for each of the divided regions in a direction perpendicular to the mounting surface of the sample to be processed An electrostatic attraction device comprising a driving means. 2. The apparatus according to claim 1, wherein the electrostatic adsorption device includes: a temperature distribution measuring unit for measuring a temperature distribution of the sample to be processed; and a heat distribution unit driving unit according to a temperature distribution state measured by the temperature distribution measuring unit. And a control unit for controlling a temperature distribution of the sample to be processed by changing a position and an area where the heat exchange unit of each of the divided regions is in contact with the sample to be processed. The electrostatic attraction device according to claim 1. 3. The electrostatic chuck according to claim 1, further comprising: a position measuring unit for measuring a vertical position of each of the divided regions of the heat exchanging unit, wherein each of the heat exchanging units measured by the position measuring unit is measured. The electrostatic attraction device according to claim 1 or 2, wherein the heat exchanging unit driving means is driven based on the vertical position of the device. 4. The electrostatic chuck device according to claim 1, wherein the semiconductor substrate as the sample to be processed is disposed in a vacuum vessel, and the semiconductor substrate is electrostatically attracted and fixed when performing a dry etching process and a CVD process. The electrostatic attraction device according to any one of claims 1 to 3, wherein: