JP2024104577A - Substrate processing method and substrate processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate processing method that can heat a substrate to an even prescribed temperature by electrostatically attracting the substrate over the entire surface thereof without causing damage or misalignment of the substrate Sw in a relatively large size.

SOLUTION: A substrate Sw is installed on a surface of a chuck plate 52 heated to a prescribed temperature in a vacuum chamber, the voltage is applied to electrodes 53a-53d and the substrate is electrostatically attracted to the surface of the chuck plate. The voltage applied to the electrodes necessary for electrostatically attracting the substrate to the surface of the chuck plate over the entire surface thereof is the attraction voltage. When the temperature difference between the chuck plate and the substrate before the substrate is electrostatically attracted to the surface of the chuck plate exceeds a preset range, the attraction voltage is applied in a pulsed form for a predetermined time.

SELECTED DRAWING: Figure 3

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a substrate processing method and substrate processing apparatus, and more specifically, to a substrate processing method and substrate processing apparatus in which a substrate to be processed is placed on the surface of a chuck plate heated to a predetermined temperature in a vacuum chamber in a vacuum atmosphere, and when a voltage is applied to an electrode to electrostatically attract the substrate to the surface of the chuck plate, the substrate to be processed is electrostatically attracted over its entire surface and heated to a uniform temperature as quickly as possible.

The manufacturing process of semiconductor devices includes a process of performing various processes such as film formation and dry etching on one side of a substrate to be processed (hereinafter referred to as "substrate") such as a silicon wafer or silicon carbide wafer, and such processes are performed in a vacuum chamber of a vacuum processing device in which a vacuum atmosphere is formed. A stage with an electrostatic chuck is usually provided in the vacuum chamber. Then, after placing the substrate on the surface of a chuck plate that constitutes the electrostatic chuck, a voltage is applied to an adhesion electrode attached to the chuck plate to electrostatically adhere the substrate to the surface of the chuck plate, and various processes are performed while the substrate is positioned and held. In some processing steps, a heating means such as a hot plate is attached to the stage, and the substrate is heated and controlled to a predetermined temperature (e.g., 300°C) by thermal conduction from the chuck plate while processing is performed.

Here, some substrates (before processing) may be warped or distorted when placed on the surface of the chuck plate. For this reason, a substrate processing method is known in which, when electrostatically adsorbing a substrate, the voltage applied to the electrodes is increased stepwise while a rectangular pulse voltage is applied to electrostatically adsorb the substrate over its entire surface, and the substrate is then heated to a predetermined temperature (see, for example, Patent Document 1). If the substrate is heated after being electrostatically adsorbed in this way, there is a problem that it takes a long time before processing can begin in the vacuum chamber. Therefore, it is conceivable to apply the above-mentioned conventional example in which the chuck plate is heated to a predetermined temperature in advance, and when the substrate is placed on the surface of the heated chuck plate and electrostatically adsorbed, the voltage applied to the electrodes is increased stepwise while a rectangular pulse voltage is applied.

In this method, when the substrate size is small (e.g., 8 inches), the substrate can be electrostatically attracted and heated evenly over its entire surface, but when the substrate size is large (e.g., φ12 inches), it has been found that this may cause damage to the substrate or misalignment. The inventors of the present application have conducted extensive research and have discovered the following. That is, when the chucking voltage at the beginning of chucking is relatively low, most of the substrate is not electrostatically attracted due to the large influence of substrate deformation, and the substrate temperature rise rate per unit time is slow. When the chucking voltage is increased, the portion of the substrate that is electrostatically attracted increases and the substrate also rises in temperature, but at this time, depending on the temperature difference between the chuck plate and the substrate before the substrate is electrostatically attracted to the surface of the chuck plate, large temperature unevenness is instantly generated within the substrate surface, which may cause damage to the substrate or the substrate to bounce on the chuck plate and become misaligned.

JP 2001-152335 A

The present invention was made based on the above findings, and its objective is to provide a substrate processing method and substrate processing apparatus that can electrostatically adsorb a substrate to be processed over its entire surface as quickly as possible and heat it uniformly to a predetermined temperature without damaging or misaligning the substrate, even when the substrate size is relatively large.

In order to solve the above problems, the present invention provides a substrate processing method including the steps of placing a substrate on the surface of a chuck plate heated to a predetermined temperature in a vacuum chamber and applying a voltage to an electrode to electrostatically attract the substrate to the surface of the chuck plate, the method further including the step of applying a pulsed attracting voltage for a predetermined period of time when the temperature difference between the chuck plate and the substrate before electrostatically attracting the substrate to the surface of the chuck plate exceeds a preset range.

According to the present invention, instead of increasing the voltage applied to the electrode stepwise as in the above-mentioned conventional example, an adhesion voltage is applied to the electrode from the beginning, i.e., a voltage that allows the substrate to be forcibly attracted to the surface of the chuck plate by electrostatic force over its entire surface. Then, only when the temperature difference between the chuck plate and the substrate to be processed is large (for example, when the temperature difference is 200°C or higher), the adhesion voltage is applied in pulses at the beginning of adhesion by appropriately setting the frequency and the application time of the adhesion voltage within one pulse. It has been confirmed that this makes it possible to electrostatically attract the substrate to be processed over its entire surface as quickly as possible and heat it to a uniform predetermined temperature while suppressing the occurrence of large temperature unevenness within the substrate surface, even when the substrate size is relatively large.

In the present invention, it is preferable to further include a step of applying a pulsed reverse voltage equivalent to the chucking voltage with the same period and application time when releasing the electrostatic chucking of the substrate to be processed after electrostatically chucking the substrate to the chuck plate. This makes it possible to prevent the substrate from bouncing off the chuck plate and becoming displaced when the electrostatic chucking of the substrate to be processed is released in order to remove the processed substrate from the stage after the processing step has been performed in the vacuum chamber.

In the present invention, when the chuck plate is a ceramic plate made of PBN (Pyrolytic Boron Nitride), a pair of electrodes is embedded in the chuck plate, and a DC chucking voltage is applied between the pair of electrodes, if the chucking voltage is in the range of 0.4 kV to 0.6 kV, the frequency when the chucking voltage is applied in a pulsed manner may be set to a range of 0.25 Hz to 10 Hz, and the application time of the chucking voltage in one pulse may be set to 2.2 seconds or less. On the other hand, if the chucking voltage is 0.6 kV or more, the frequency when the chucking voltage is applied in a pulsed manner may be set to a range of 0.2 Hz to 20 Hz, and the application time of the chucking voltage in one pulse may be set to 1.8 seconds or less.

In order to solve the above problem, the present invention provides a substrate processing apparatus that includes a chuck plate arranged in a vacuum chamber on which a substrate to be processed is placed, a chuck power supply that applies a voltage to an electrode attached to the chuck plate, and a heating means that heats the chuck plate to a predetermined temperature, and that applies a voltage to the electrode after the substrate to be processed is placed on the surface of the heated chuck plate so that the substrate to be processed is electrostatically attracted to the surface of the chuck plate. The apparatus further includes a measuring means that measures the temperature difference between the chuck plate and the substrate to be processed before the substrate to be processed is electrostatically attracted to the surface of the chuck plate, and when the temperature difference measured by the measuring means exceeds a preset range, the voltage applied to the electrode required to electrostatically attract the substrate to the surface of the chuck plate over its entire surface is set as the attraction voltage, and the attraction voltage is applied in pulses by the chuck power supply for a predetermined period of time.

1 is a schematic cross-sectional view of a sputtering apparatus including a substrate processing apparatus capable of carrying out a substrate processing method according to an embodiment of the present invention; 2 is a cross-sectional view taken along line II-II of FIG. 6 is a graph showing the relationship between the voltage applied to the electrodes and the temperature change of the substrate.

Below, with reference to the drawings, an embodiment of the substrate processing method and substrate processing apparatus of the present invention will be described using as an example a silicon wafer with a diameter of 12 inches (hereinafter referred to as "substrate Sw") as the substrate to be processed, a bipolar electrode for suction, and a processing process in which a film is formed by sputtering in a vacuum atmosphere.

Referring to FIG. 1, the sputtering apparatus Sm equipped with the substrate processing apparatus of this embodiment has a vacuum chamber 1 capable of forming a vacuum atmosphere. A cathode unit 2 is detachably attached to the top opening of the vacuum chamber 1. The cathode unit 2 is composed of a target 21 and a magnet unit 22 arranged above the target 21. The target 21 is made of known materials such as aluminum, copper, titanium, and alumina depending on the film to be formed on the surface of the substrate Sw. The target 21 is attached to the backing plate 21a and is attached to the top of the vacuum chamber 1 with its sputtering surface 21b facing downward via an insulator 31 that also serves as a vacuum seal provided on the upper wall of the vacuum chamber 1.

The target 21 is connected to an output 21d from a sputtering power supply 21c, which is composed of a DC power supply or an AC power supply depending on the target type, and, for example, DC power with a negative potential or high-frequency power (AC power) of a predetermined frequency is input depending on the target type. The magnet unit 22 has a known closed magnetic field or cusp magnetic field structure that generates a magnetic field in the space below the sputtering surface 21b of the target 21, captures electrons ionized below the sputtering surface 21b during sputtering, and efficiently ionizes sputter particles scattered from the target 21. A gas pipe 41 is connected to the side wall of the vacuum chamber 1, and sputtering gas whose flow rate is controlled via a mass flow controller (not shown) is introduced into the vacuum chamber 1. The sputtering gas includes not only rare gases such as argon gas introduced into the vacuum chamber 1 when forming plasma, but also reactive gases such as oxygen gas and nitrogen gas. An exhaust port 42 is also provided in the side wall of the vacuum chamber 1, and an exhaust pipe 43 is connected to the exhaust port 42, which leads to a vacuum pump such as a turbomolecular pump or rotary pump (not shown), and the vacuum chamber 1 is evacuated at a constant speed. When forming a film by sputtering, the vacuum chamber 1 is maintained at a predetermined pressure with sputtering gas introduced. A stage 5 that constitutes the substrate processing apparatus of this embodiment is disposed at the bottom of the vacuum chamber 1, facing the target 21. In addition, in FIG. 1, reference numerals 61 and 62 denote adhesion prevention plates.

Referring also to FIG. 2, the stage 5 has a base 51 made of metal (e.g., SUS) with a cylindrical outline, which is installed via an insulator 32 provided at the bottom of the vacuum chamber 1, and a chuck plate 52 provided on the upper surface of the base 51. Although not shown or described, the base 51 has a refrigerant circulation path for circulating a refrigerant supplied from a chiller unit not shown, so that the base 51 can be selectively cooled when controlling the substrate Sw to a predetermined temperature range. The chuck plate 52 is a ceramic plate made of PBN and has an outer diameter slightly smaller than the upper surface of the base 51. A pair of positive and negative electrodes 53a to 53d for electrostatically adsorbing the substrate Sw by electrostatic force are also embedded in the chuck plate 52. Each pair of electrodes 53a to 53d is made of a metal plate with a predetermined area, and is connected to chuck power sources 55a and 55b via power cables 54a and 54b, respectively. The chuck power supplies 55a and 55b can be well known and, although not specifically shown or described, are equipped with a voltage control circuit that can apply a DC voltage in a predetermined range with an arbitrary waveform to each pair of electrodes 53a to 53d, and a reverse voltage application circuit that applies a reverse voltage to each pair of electrodes 53a to 53d. The chucking voltage is experimentally determined in advance and is set to a voltage (e.g., 0.4 kV to 1 kV) that can forcibly chucking a warped or distorted φ12 inch substrate Sw over its entire surface with electrostatic force.

Between the base 51 and the chuck plate 52, a hot plate 56 made of, for example, aluminum nitride is interposed. A heating means 56a such as an electric heater is incorporated in the hot plate 56, and the electric heater can be energized to heat the plate to a predetermined temperature range (for example, 100°C to 500°C). In this case, the heater can be built into the chuck plate 52 to integrally form the chuck plate 52 and the hot plate 56. A temperature sensor 57 as a measuring means such as a thermocouple is also incorporated in the hot plate 56, and the temperature measuring part (not shown) of the temperature sensor 57 can be abutted against the underside of the chuck plate 52 to measure the temperature of the chuck plate 52. Although not specifically shown or described, a substrate lift mechanism having a known structure is provided on the stage 5, allowing the substrate Sw to be transferred between the stage 5 and a transport robot (not shown). The sputtering apparatus Sm includes a control unit CU equipped with a microcomputer, a memory element, a sequencer, etc., and the control unit CU controls the operation of each component, such as the sputtering power supply 21c, the chuck power supplies 55a, 55b, the mass flow controller, and the vacuum pump. As will be described in detail later, the control unit CU is also a component of the substrate processing apparatus of this embodiment, and also controls the application of voltage to each pair of electrodes 53a to 53d of the chuck power supplies 55a, 55b in response to an input from a temperature sensor 57. The substrate processing method of this embodiment will be described below using the sputtering apparatus Sm as an example to form a predetermined film on the underside of a substrate Sw.

Prior to placing the substrate Sw on the stage 5 in the vacuum chamber 1 in a vacuum atmosphere, the heating means 56a is operated to heat the hot plate 56 and the chuck plate 52 to a predetermined temperature according to the temperature of the substrate Sw to be heated during film formation. When the temperature of the chuck plate 52 measured by the temperature sensor 57 reaches a predetermined value, the substrate Sw is placed on the stage 5 by the transport robot and the substrate lift mechanism. At this time, the temperature of the substrate Sw before film formation is input to the control unit CU. The temperature of the substrate Sw may be measured by a temperature sensor (not shown) just before placing the substrate Sw on the stage 5, and this measured temperature may be input to the control unit CU. Then, the control unit CU determines whether the temperature difference between this input temperature and the temperature measured by the temperature sensor 57 is equal to or greater than a predetermined value, and if it is lower than the predetermined value (e.g., 200°C), a constant DC voltage is continuously applied to each pair of electrodes 53a to 53d by the chuck power sources 55a and 55b. The chucking voltage at this time is set to the voltage (e.g., 0.4 kV to 1 kV) required to electrostatically chuck the substrate Sw over its entire surface, as described above. The upper limit of the chucking voltage is set appropriately according to the design values of the chuck power supplies 55a and 55b. As a result, the substrate Sw is electrostatically chucked over its entire surface to the chuck plate 52 and heated to a uniform predetermined temperature.

On the other hand, when the temperature difference is equal to or greater than a predetermined value, the control unit CU applies a DC voltage equivalent to the above in a pulsed manner to the electrodes 53a to 53d by the chuck power supplies 55a and 55b for a predetermined time from the start of voltage application, as shown in FIG. 3. If the chucking voltage is in the range of 0.4 kV to 0.6 kV, the frequency when the chucking voltage is applied in a pulsed manner is set to a range of 0.25 Hz to 10 Hz, and the application time of the chucking voltage in one pulse is set to 2.2 seconds or less, and if the chucking voltage is 0.6 kV or more, the frequency when the chucking voltage is applied in a pulsed manner is set to a range of 0.2 Hz to 20 Hz, and the application time of the chucking voltage in one pulse is set to 1.8 seconds or less. The time for applying the chucking voltage in a pulsed manner is set appropriately according to, for example, the range of temperature unevenness in the surface of the substrate Sw. As a result, as shown by the solid line in Figure 3, the substrate Sw can be electrostatically attracted over its entire surface as quickly as possible and heated to a uniform predetermined temperature while suppressing a rapid temperature rise in the substrate Sw and preventing large temperature variations. After a predetermined time has elapsed, the control unit CU determines that the substrate Sw has been heated to the predetermined temperature, and the target 21 is sputtered by a known method to form a predetermined thin film on the surface of the substrate Sw.

When the film formation on the substrate Sw is completed, the chuck power supplies 55a and 55b apply a reverse voltage to each pair of electrodes 53a to 53d, and the electrostatic adsorption of the substrate Sw from the chuck plate 52 is released. In this case, the control unit CU applies a reverse voltage to the electrodes 53a to 53d by the chuck power supplies 55a and 55b according to the voltage application state during electrostatic adsorption. That is, when the temperature difference between the temperature of the substrate Sw and the temperature measured by the temperature sensor 57 is lower than a predetermined value and a constant DC voltage is continuously applied to the electrodes by the chuck power supplies 55a and 55b, an equivalent reverse voltage is continuously applied. On the other hand, when the temperature difference is equal to or greater than a predetermined value and a voltage is applied in a pulsed manner, a voltage equivalent to that applied to the electrodes 53a to 53d by the chuck power supplies 55a and 55b is applied in a pulsed manner with the same period and application time. It was confirmed that this can prevent the substrate Sw from bouncing on the chuck plate 52 and causing a positional shift when the electrostatic adsorption of the substrate Sw is released. When the electrostatic adsorption of the substrate Sw from the chuck plate 52 is released, the substrate Sw on which the film has been formed is transported from the stage 5 by the transport robot and substrate lift mechanism.

In order to confirm the above effects, the following experiment was carried out using the stage 5 of the sputtering device Sm shown in FIG. 1. That is, the substrate Sw was a silicon wafer with a diameter of 12 inches, and the voltage applied to each pair of electrodes 53a to 53d was set to 0.4 kV. Then, the heating means 56a was operated to heat the chuck plate 52 to a predetermined temperature, and then the substrate Sw was placed on the chuck plate 52 and heated while electrostatically adsorbing the substrate Sw. In sample 1, the substrate Sw was placed on the chuck plate 52 in a state where the temperature difference between the temperature of the substrate Sw and the temperature measured by the temperature sensor 57 was 200°C, and a voltage of 0.4 kV was continuously applied to each pair of electrodes 53a to 53d. The substrate Sw was electrostatically adsorbed over its entire surface and heated to a uniform predetermined temperature in a short time without causing damage or misalignment of the substrate Sw. In sample 2, when the substrate Sw was placed on the chuck plate 52 in a state where the temperature difference was 250° C., and a voltage of 0.4 kV was continuously applied to each pair of electrodes 53 a to 53 d, the substrate Sw bounced on the chuck plate 52 after a few seconds, causing a positional shift. Therefore, in sample 3, the frequency when the attracting voltage was applied in a pulsed manner was set to 1 Hz, and the application time of the attracting voltage in one pulse was set to 2.0 seconds, and after the substrate Sw was placed on the chuck plate 52 in a state where the temperature difference was 250° C., a voltage of 0.4 kV was applied in a pulsed manner to each pair of electrodes 53 a to 53 d for 60 seconds. As a result, no damage or positional shift of the substrate Sw was observed, and the temperatures of the center of the substrate Sw and two points on lines passing through the center of the substrate Sw and intersecting each other at right angles were measured, and the average temperature was 251.1° C., and the maximum temperature difference was 10° C., confirming that the substrate Sw could be electrostatically attracted over its entire surface and uniformly heated to a desired temperature. It has been confirmed that equivalent effects can be obtained if the frequency of the pulsed application of the attraction voltage is in the range of 0.25 Hz to 10 Hz and the application time of the attraction voltage within one pulse is 2.2 seconds or less. However, in order to electrostatically attract and heat the entire surface of the substrate Sw in a short time, it is preferable that the application time of the attraction voltage is 4 seconds or more.

Next, the voltage applied to each pair of electrodes 53a to 53d was set to 0.6 kV. Then, the heating means 56a was operated to heat the chuck plate 52 to a predetermined temperature, after which the substrate Sw was placed on the chuck plate 52 and heated while electrostatically adsorbing the substrate Sw. In sample 4, the substrate Sw was placed on the chuck plate 52 in a state where the temperature difference between the temperature of the substrate Sw and the temperature measured by the temperature sensor 57 was 350°C, and a voltage of 0.6 kV was continuously applied to each pair of electrodes 53a to 53d. As described above, after a lapse of about 10 seconds, the substrate Sw bounced on the chuck plate 52, causing it to shift position, and in some cases the substrate Sw was damaged. Therefore, in sample 5, the frequency when the attracting voltage was applied in a pulsed manner was set to 5 Hz, and the application time of the attracting voltage in one pulse was set to 1.2 seconds, and after the substrate Sw was placed on the chuck plate 52 in a state where the temperature difference was 350° C., a pulsed voltage of 0.6 kV was applied to each pair of electrodes 53 a to 53 d for 60 seconds. As a result, as in the above, no damage or displacement of the substrate Sw was observed, and the temperatures of the center of the substrate Sw and two points on the lines passing through the center of the substrate Sw and intersecting each other at right angles were measured, and the average temperature was 351.4° C. and the maximum temperature difference was 20° C., confirming that the substrate Sw could be electrostatically attracted over its entire surface and uniformly heated to a desired temperature. It was confirmed that the same effect could be obtained if the frequency when the attracting voltage was applied in a pulsed manner was in the range of 0.2 Hz to 20 Hz and the application time of the attracting voltage in one pulse was 1.8 seconds or less. However, in order to electrostatically attract and heat the entire surface of the substrate Sw in a short time, it is preferable that the attraction voltage be applied for 5 seconds or longer.

Next, in sample 5, when releasing the electrostatic adsorption of the substrate Sw from the chuck plate 52, a reverse voltage was applied to each pair of electrodes 53a to 53d by the chuck power supplies 55a and 55b. At this time, it was confirmed that when a reverse voltage equivalent to that applied to the electrodes 53a to 53d was continuously applied, the substrate Sw bounced on the chuck plate 52. On the other hand, when a reverse voltage equivalent to that applied to the electrodes 53a to 53d during adsorption was applied in pulses with the same period and application time, the substrate Sw did not bounce on the chuck plate 52 and did not become displaced, and it was confirmed that the electrostatic adsorption of the substrate Sw could be released satisfactorily.

As a reference experiment, the substrate Sw was placed on the chuck plate 52 with the temperature difference between the substrate Sw and the chuck plate 52 at 350°C, and a voltage of 0.2 kV was applied continuously for 30 seconds to each pair of electrodes 53a to 53d. The temperatures were measured at the center of the substrate Sw and at two points on a line that crosses the center of the substrate Sw at right angles. One measurement point rose to nearly 300°C, but the average temperature of the other measurement points was about 260°C, and the maximum temperature difference was 58°C. This shows that when the substrate size is large and the chucking voltage is relatively low, the substrate Sw is significantly affected by deformation, and most of it is not electrostatically chucked, resulting in large temperature unevenness. Then, when the chucking voltage was increased to 0.4 kV, even larger temperature unevenness occurred, which caused the substrate Sw to bounce on the chuck plate 52 and become misaligned.

Although the embodiment of the present invention has been described above, various modifications are possible without departing from the scope of the technical concept of the present invention. In the above embodiment, the processing step is a film formation process by a sputtering method, but the present invention can be applied to cases where other processes such as etching and CVD are performed while controlling the substrate temperature. In the above embodiment, a bipolar type electrostatic chuck is described as an example, but the present invention can also be applied to a monopolar type electrostatic chuck. Furthermore, in the above embodiment, the chuck plate is made of PBN, but the present invention can also be applied to a monopolar type electrostatic chuck. In addition, in the above embodiment, the chuck plate is made of PBN, but the present invention can also be applied to a ceramic plate such as alumina, aluminum nitride, or silicon nitride. In this case, the temperature difference, applied voltage, initial chucking start, frequency, and application time of the chucking voltage in one pulse when applied in a pulsed manner are appropriately set according to the material of the chuck plate. In particular, if another ceramic plate has an adhesive force equivalent to that of a PBN chuck plate, the temperature difference, initial chucking start, frequency, and application time of the chucking voltage in one pulse described in the above embodiment can be adopted in the applied voltage that generates an equivalent adhesive force.

1...vacuum chamber, 5...stage (component of vacuum processing device), 52...chuck plate, 53a-53d...electrodes for suction, 55a, 55b...chuck power supply (component of vacuum processing device), 56...hot plate (component of heating means), 57...temperature sensor (measuring means: component of vacuum processing device), Sw...substrate to be processed (substrate), Sm...sputtering device.

Claims (5)

1. A substrate processing method comprising the steps of placing a substrate on a surface of a chuck plate heated to a predetermined temperature in a vacuum chamber, and electrostatically attracting the substrate to the surface of the chuck plate by applying a voltage to an electrode,
a step of applying the attraction voltage in a pulsed manner for a predetermined period of time when a temperature difference between the chuck plate and the workpiece substrate before the workpiece substrate is electrostatically attracted to the surface of the chuck plate exceeds a predetermined range, the attraction voltage being defined as an attraction voltage applied to the electrodes required for electrostatically attracting the workpiece substrate over its entire surface onto the surface of the chuck plate, The substrate processing method further includes a step of applying a pulsed reverse voltage equivalent to the clamping voltage with the same period and application time when releasing the electrostatic clamping of the substrate to be processed after the substrate is electrostatically clamped to the chuck plate. 3. A substrate processing method according to claim 1, wherein the chuck plate is a ceramic plate made of PBN, a pair of electrodes are embedded in the chuck plate, and a DC attracting voltage is applied between the pair of electrodes, further comprising:
2. The substrate processing method according to claim 1, wherein the attracting voltage is set in a range of 0.4 kV to 0.6 kV, the attracting voltage is applied in a pulsed manner at a frequency in a range of 0.25 Hz to 10 Hz, and the application time of the attracting voltage in one pulse is set to 2.2 seconds or less. 3. The substrate processing method according to claim 1, wherein the chuck plate is a ceramic plate made of PBN, a pair of electrodes are embedded in the chuck plate, and a DC attracting voltage is applied between the pair of electrodes, further comprising:
2. The substrate processing method according to claim 1, wherein the attracting voltage is set to 0.6 kV or more, the attracting voltage is applied in a pulsed manner at a frequency in the range of 0.2 Hz to 20 Hz, and the application time of the attracting voltage in one pulse is set to 1.8 seconds or less. A substrate processing apparatus comprising: a chuck plate disposed in a vacuum chamber and on which a substrate to be processed is placed; a chuck power supply which applies a voltage to an electrode assembled to the chuck plate; and heating means which heats the chuck plate to a predetermined temperature, wherein after the substrate to be processed is placed on a surface of the heated chuck plate, a voltage is applied to the electrode to electrostatically attract the substrate to the surface of the chuck plate,
a measuring means for measuring a temperature difference between the chuck plate and the substrate before the substrate is electrostatically attracted to the surface of the chuck plate;
a chuck power supply that applies the attraction voltage in pulse form for a predetermined period of time to an electrode required for electrostatically attracting the workpiece substrate over its entire surface to the surface of the chuck plate when the temperature difference measured by the measuring means exceeds a predetermined range.

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