Substrate processing apparatus and state determination method

Abstract

To provide a substrate processing apparatus and a state determination method for determining a state of a substrate mounting table.SOLUTION: A substrate processing apparatus comprising: a substrate mounting table having an electrostatic chuck configured to electrostatically attract a substrate by applying a voltage to an electrode of the electrostatic chuck; lift pins configured to protrude from and retract into a substrate mounting surface of the substrate mounting table; a driving mechanism configured to move the lift pins up and down; an electrostatic capacitance detector configured to detect an electrostatic capacitance of the electrostatic chuck; and a controller configured to determine a state of the electrostatic chuck based on the electrostatic capacitance detected by the electrostatic capacitance detector.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a substrate processing apparatus and a state determination method. [Background technology]

[0002] Patent Document 1 discloses a vacuum processing apparatus in which a substrate is placed on an electrostatic chuck provided on a mounting table within a vacuum chamber, a chucking voltage is applied to a chuck electrode to electrostatically attract the substrate to the electrostatic chuck, and the substrate is processed. The vacuum processing apparatus includes: a power supply for applying a diagnostic voltage to the chuck electrode that is lower than the chucking voltage used during vacuum processing; a measurement unit for measuring electrical characteristics of the electrostatic chuck when the diagnostic voltage is applied to the chuck electrode and acquiring the measurement data; and a diagnosis unit for diagnosing whether the electrostatic chuck is usable or not, based on the measurement data acquired via the measurement unit and preset setting data. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-47564 Summary of the Invention [Problem to be solved by the invention]

[0004] One aspect of the present disclosure provides a substrate processing apparatus and a state determination method for determining the state of a substrate placing table. [Means for solving the problem]

[0005] In order to solve the above problem, according to one aspect, there is provided a substrate processing apparatus including: a substrate mounting table having an electrostatic chuck that electrostatically attracts a substrate by applying a voltage to an electrode of the electrostatic chuck; lift pins that can be protruded and retracted into a substrate mounting surface of the substrate mounting table; a drive mechanism that raises and lowers the lift pins; a capacitance detection unit that detects the capacitance of the electrostatic chuck; and a control unit that determines the state of the electrostatic chuck based on the capacitance detected by the capacitance detection unit. [Effects of the Invention]

[0006] According to one aspect of the present disclosure, it is possible to provide a substrate processing apparatus and a state determination method for determining the state of a substrate placing table. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional view illustrating an example of a substrate processing apparatus according to an embodiment of the present invention. [Figure 2] 10 is an example of a flowchart showing the operation of the substrate processing apparatus according to the present embodiment. [Figure 3] 5A to 5C are diagrams illustrating examples of states in which capacitance is measured. [Figure 4] 5A to 5C are enlarged cross-sectional views illustrating examples of states of the substrate mounting table in each state in which capacitance is measured. [Figure 5] An example of a capacitance graph. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant explanations may be omitted.

[0009] <Substrate processing apparatus 1> A substrate processing apparatus 1 according to this embodiment will be described with reference to Fig. 1. Fig. 1 is an example of a cross-sectional view showing the substrate processing apparatus 1 according to this embodiment. The substrate processing apparatus 1 is an apparatus that performs a desired substrate processing (e.g., film formation processing, etching processing, heat treatment, etc.) on a substrate W placed on a substrate mounting table 40. When the substrate processing apparatus 1 is a film formation apparatus, it may be any of an apparatus such as a CVD apparatus, an ALD apparatus, or a PVD apparatus.

[0010] 1, the substrate processing apparatus 1 includes a processing chamber 10, a substrate mounting table 40, a substrate lifting mechanism 50, and a controller 70. The substrate mounting table 40 and the substrate lifting mechanism 50 constitute a substrate mounting mechanism 60.

[0011] The processing vessel 10 is configured to accommodate a substrate W and maintain a vacuum inside. A mechanism for performing a desired process on the substrate W (e.g., a processing gas supply unit, a plasma generation unit, etc., neither of which are shown) is provided at the top of the processing vessel 10. An exhaust device 12 having a vacuum pump that can reduce the pressure inside the processing vessel 10 to a vacuum is connected to the bottom of the processing vessel 10. A loading / unloading port 13 for loading and unloading the substrate W is formed in the sidewall of the processing vessel 10. The loading / unloading port 13 is opened and closed by a gate valve 14. By opening the gate valve 14, the processing vessel 10 is connected to a vacuum transfer chamber (not shown) adjacent to the processing vessel 10, and the substrate W is loaded and unloaded by a transfer device (not shown) in the vacuum transfer chamber.

[0012] The substrate mounting table 40 is provided within the processing chamber 10, and its upper surface serves as a substrate mounting surface on which a substrate W is placed. The substrate mounting table 40 includes a plate-shaped main body 41 having a diameter slightly larger than that of the substrate W and made of a metal material, such as aluminum, and an electrostatic chuck 46 provided on the main body 41 for electrostatically attracting the substrate W. The electrostatic chuck 46 has an upper surface serving as the substrate mounting surface, and an electrode 46a embedded in a dielectric material. When a DC voltage is applied to the electrode 46a from a DC power supply 48, the substrate W placed on the substrate mounting surface is attracted by electrostatic force. The main body 41 is supported by a cylindrical support 47 extending downward from the center of its lower surface. The substrate mounting table 40 is configured to be heated or cooled by a temperature control mechanism (not shown). The substrate mounting table 40 may also be configured to be rotatable by a rotation mechanism (not shown).

[0013] The substrate processing apparatus 1 also includes a capacitance detector 49 that detects the capacitance of the electrostatic chuck 46. The detected capacitance varies depending on the state of the electrostatic chuck 46 (e.g., whether or not a substrate W is placed on the substrate placement surface, the thickness of the dielectric, contamination of the substrate placement surface, etc.), the contact / non-contact state between the lift pins 51 (described later) and the substrate W, and the state of power application to the electrode 46a (whether or not the substrate W is electrostatically attracted). The capacitance detector 49 is provided, for example, in the DC power supply 48. The capacitance detector 49 detects the capacitance of the electrostatic chuck 46. The electrostatic chuck 46 shown in FIG. 1 has bipolar electrodes 46a, and the capacitance detector 49 detects the capacitance between the bipolar electrodes 46a. Note that the electrostatic chuck 46 may have a monopolar electrode 46a. In this case, the capacitance detector 49 detects the capacitance between the monopolar electrode 46a and ground potential.

[0014] The substrate lifting mechanism 50 has a plurality of lift pins 51 for raising and lowering the substrate W, a support plate 52 that supports the lift pins 51, a lifting rod 53 that raises and lowers the support plate 52, a drive mechanism 54, and a bellows 57.

[0015] The plurality of lift pins 51 are inserted into holes 44 formed in the substrate mounting table 40 and are provided so as to be able to protrude and retract relative to the substrate mounting surface. The number and arrangement of the lift pins 51 are determined appropriately depending on the shape and size of the substrate W. The material of the lift pins 51 may be a conductor such as Ti or an insulator (dielectric) such as Al2O3. The support plate 52 is provided below the substrate mounting table 40 and is configured to support the plurality of lift pins 51 and move up and down together with the lift pins 51. One end of the lift rod 53 is fixed to the lower surface of the support plate 52 and extends downward, reaching the outside of the processing vessel 10 through an insertion hole 15 provided in the bottom wall of the processing vessel 10.

[0016] The drive mechanism 54 has a motor 55 and a ball screw mechanism 56. The motor 55 rotates a ball screw (not shown) of the ball screw mechanism 56, causing a moving member 59 guided by a guide member (not shown) to move up and down. The lower end of the lifting rod 53 is attached to the moving member 59, and by rotating the motor 55, the lifting rod 53 is raised and lowered via the ball screw mechanism 56 and the moving member 59, thereby raising and lowering the support plate 52 and the multiple lift pins 51. The motor 55 may be a servo motor or a stepping motor.

[0017] The tips of the lift pins 51 are moved between a lower end position (see FIGS. 4(a), 4(c), and 4(f)) where they are lower than the substrate mounting surface and recessed in the holes 44 of the substrate mounting table 40, and an upper end position (see FIG. 4(e)) that is above the substrate mounting surface of the substrate mounting table 40. A contact position (see FIGS. 4(b) and 4(d)) is included between the lower end position and the upper end position. The contact position is a position where the tips of the lift pins 51 come into contact with the substrate W placed on the substrate mounting surface of the substrate mounting table 40. The origin of the tips of the lift pins 51 is the lower end position, and the contact position is defined as a height position relative to the lower end position, which is the origin. The contact position can be adjusted by adjusting the lower end position, which is the origin.

[0018] The portion of the outer surface of the bottom wall of the processing vessel 10 corresponding to the insertion hole 15 is shielded by a shielding plate 58 having a hole through which the lifting rod 53 passes, and a bellows 57 is provided around the lifting rod 53 between the support plate 52 and the shielding plate 58. The bellows 57 shields the vacuum atmosphere inside the processing vessel 10 from the atmospheric atmosphere outside the processing vessel 10.

[0019] The control unit 70 controls each component of the substrate processing apparatus 1, such as the DC power supply 48, the exhaust device 12, and the drive mechanism 54. A part of the control unit 70 also functions as a control unit for the substrate mounting mechanism 60. The control unit 70 also receives the capacitance detected by the capacitance detection unit 49 and determines the state of the substrate mounting table 40.

[0020] <Operation of the substrate processing apparatus 1> An example of the operation of the substrate processing apparatus 1 according to this embodiment will be described with reference to Figs. 2 to 4. Fig. 2 is an example of a flowchart showing the operation of the substrate processing apparatus 1 according to this embodiment. Fig. 3 is an example of a diagram illustrating each state in which capacitance is measured. Fig. 4 is an example of a partially enlarged cross-sectional view illustrating the state of the substrate mounting table 40 in each state in which capacitance is measured.

[0021] In step S101, the substrate W is loaded into the processing chamber 10 and placed on the substrate mounting table 40. The control unit 70 opens the gate valve 14 and controls the transfer device (not shown) to place a pick (not shown) that holds the substrate W on the substrate mounting table 40. Next, the control unit 70 controls the drive mechanism 54 (motor 55) to raise the lift pins 51 to the upper end position. As a result, the substrate W supported by the pick of the transfer device is transferred to the lift pins 51. Next, the control unit 70 controls the transfer device (not shown) to retract the pick from the load / unload port 13 and closes the gate valve 14. Next, the control unit 70 controls the drive mechanism 54 (motor 55) to lower the lift pins 51 to the lower end position (origin position). As a result, the substrate W supported by the lift pins 51 is placed on the substrate mounting surface of the substrate mounting table 40.

[0022] In step S102, the capacitance is detected at the lower end position of the lift pin. The control unit 70 controls the drive mechanism 54 (motor 55) to lower the lift pin 51 to the lower end position (origin position) or to maintain the lower end position (origin position).

[0023] Fig. 3(a) shows the measurement state in step S102. Fig. 4(a) is an example of a partially enlarged cross-sectional view illustrating the state of the substrate mounting table 40 in step S102.

[0024] A substrate W is placed on the substrate placement surface of the substrate placement table 40 (Substrate: Present). The tips of the lift pins 51 are lower than the substrate placement surface of the substrate placement table 40 on which the substrate W is placed, and are positioned at a lower end position (Lift Pin State: Pin Lower) recessed in the holes 44 of the substrate placement table 40. In other words, there is no contact between the rear surface of the substrate W and the tips of the lift pins 51. The DC power supply 48 is not applying a voltage to the electrode 46a (Electrostatic adsorption: Off). The capacitance detection unit 49 measures the capacitance of the electrostatic chuck 46.

[0025] In step S103, the capacitance is detected at the lift pin contact position. The control unit 70 controls the drive mechanism 54 (motor 55) to raise the lift pins 51 to the contact position. Note that when the lift pins 51 are raised to the contact position, there may be a gap between the back surface of the substrate W and the substrate mounting surface of the electrostatic chuck 46.

[0026] Fig. 3(b) shows the measurement state in step S103. Fig. 4(b) is an example of a partially enlarged cross-sectional view illustrating the state of the substrate mounting table 40 in step S103.

[0027] A substrate W is placed on the substrate placement surface of the substrate placement table 40 (Substrate: Present). The tips of the lift pins 51 are positioned to contact the substrate W placed on the substrate placement table 40 (Lift Pin State: Pin Contact). That is, the rear surface of the substrate W and the tips of the lift pins 51 are in contact. The DC power supply 48 is not applying voltage to the electrode 46a (Electrostatic adsorption: Off). The capacitance detection unit 49 measures the capacitance of the electrostatic chuck 46. After the measurement, the control unit 70 controls the drive mechanism 54 (motor 55) to lower the lift pins 51 to the bottom position (origin position).

[0028] In step S104, the substrate W is electrostatically attracted. The control unit 70 controls the DC power supply 48 to apply a voltage to the electrode 46a. As a result, the substrate W is electrostatically attracted to the electrostatic chuck 46.

[0029] In step S105, substrate processing is started. For example, a desired process is performed on the surface of the substrate W by supplying a process gas into the processing vessel 10, generating plasma of the process gas in the processing vessel 10, or emitting sputtered particles in the processing vessel 10.

[0030] In step S106, the capacitance is detected at the lower end position of the lift pin. The control unit 70 controls the drive mechanism 54 (motor 55) to lower the lift pin 51 to the lower end position (origin position) or to maintain the lower end position (origin position).

[0031] Fig. 3(c) shows the measurement state in step S106. Fig. 4(c) is an example of a partially enlarged cross-sectional view illustrating the state of the substrate mounting table 40 in step S106.

[0032] A substrate W is placed on the substrate placement surface of the substrate placement table 40 (Substrate: Present). The tips of the lift pins 51 are lower than the substrate placement surface of the substrate placement table 40 on which the substrate W is placed, and are positioned at a lower end position (Lift Pin State: Pin Lower) recessed in the holes 44 of the substrate placement table 40. In other words, there is no contact between the rear surface of the substrate W and the tips of the lift pins 51. The DC power supply 48 is in a state in which a voltage is applied to the electrode 46a (Electrostatic adsorption: On). The capacitance detection unit 49 measures the capacitance of the electrostatic chuck 46.

[0033] In step S107, the substrate processing is completed.

[0034] In step S108, the capacitance is detected at the lift pin contact position. The control unit 70 controls the drive mechanism 54 (motor 55) to raise the lift pins 51 to the contact position. Note that when the lift pins 51 are raised to the contact position, there may be a certain gap between the back surface of the substrate W and the substrate mounting surface of the electrostatic chuck 46. Note that the force with which the drive mechanism 54 (motor 55) raises the lift pins 51 is greater than the force with which the electrostatic chuck 46 electrostatically attracts the substrate W, and the substrate W is separated from the substrate mounting surface of the electrostatic chuck 46 against the electrostatic attraction force.

[0035] Fig. 3(d) shows the measurement state in step S108. Fig. 4(d) is an example of a partially enlarged cross-sectional view illustrating the state of the substrate mounting table 40 in step S108.

[0036] A substrate W is placed on the substrate placement surface of the substrate placement table 40 (Substrate: Present). The tips of the lift pins 51 are positioned to contact the substrate W placed on the substrate placement table 40 (Lift Pin State: Pin Contact). That is, the rear surface of the substrate W and the tips of the lift pins 51 are in contact. The DC power supply 48 is in a state in which a voltage is applied to the electrode 46a (Electrostatic adsorption: On). The capacitance detection unit 49 measures the capacitance of the electrostatic chuck 46. After the measurement, the control unit 70 controls the drive mechanism 54 (motor 55) to lower the lift pins 51 to the bottom end position (origin position).

[0037] In step S109, the electrostatic attraction of the substrate W is released. The control unit 70 stops the application of voltage to the electrode 46a by the DC power supply 48. This causes the electrostatic attraction of the substrate W by the electrostatic chuck 46 to be released.

[0038] In step S110, the capacitance is detected at the upper end position of the lift pin. The control unit 70 controls the drive mechanism 54 (motor 55) to raise the lift pins 51 to the upper end position. At this time, the substrate W placed on the substrate placement surface of the substrate placement table 40 is lifted by the lift pins 51.

[0039] Fig. 3(e) shows the measurement state in step S110. Fig. 4(e) is an example of a partially enlarged cross-sectional view illustrating the state of the substrate mounting table 40 in step S110.

[0040] The tips of the lift pins 51 are positioned at an upper end position (lift pin state: Pin Upper) that is higher than the substrate mounting surface of the substrate mounting table 40 on which the substrate W is mounted. That is, the rear surface of the substrate W and the tips of the lift pins 51 are in contact with each other. The substrate W is supported by the lift pins 51, and no substrate W is mounted on the substrate mounting surface of the substrate mounting table 40 (substrate: absent). The DC power supply 48 is not applying a voltage to the electrode 46a (electrostatic adsorption: off). The electrostatic capacitance detection unit 49 measures the electrostatic capacitance of the electrostatic chuck 46.

[0041] In step S111, the substrate W is unloaded from the processing chamber 10. The control unit 70 opens the gate valve 14 and controls the transfer device (not shown) to place a pick (not shown) under the substrate W supported by the lift pins 51. Next, the control unit 70 controls the drive mechanism 54 (motor 55) to lower the lift pins 51 to the bottom end position (origin position). As a result, the substrate W supported by the lift pins 51 is transferred to the pick of the transfer device. Next, the control unit 70 controls the transfer device (not shown) to retract the pick holding the substrate W from the load / unload port 13, and closes the gate valve 14.

[0042] In step S112, the capacitance is detected at the lower end position of the lift pin. The control unit 70 controls the drive mechanism 54 (motor 55) to lower the lift pin 51 to the lower end position (origin position) or to maintain the lower end position (origin position).

[0043] Fig. 3(f) shows the measurement state in step S112. Fig. 4(f) is an example of a partially enlarged cross-sectional view illustrating the state of the substrate mounting table 40 in step S112.

[0044] A substrate W is placed on the substrate placement surface of the substrate placement table 40 (Substrate: Present). The tips of the lift pins 51 are lower than the substrate placement surface of the substrate placement table 40 on which the substrate W is placed, and are positioned at a lower end position (Lift Pin State: Pin Lower) recessed in the holes 44 of the substrate placement table 40. In other words, there is no contact between the rear surface of the substrate W and the tips of the lift pins 51. The DC power supply 48 is not applying a voltage to the electrode 46a (Electrostatic adsorption: Off). The capacitance detection unit 49 measures the capacitance of the electrostatic chuck 46.

[0045] In step S113, the control unit 70 determines whether maintenance is required for the substrate mounting table 40. Here, the state of the electrostatic chuck 46 of the substrate mounting table 40 is determined based on the capacitance detected in steps S102, S103, S106, S108, S110, and S112. The capacitance, which is one of the adsorption parameters of the electrostatic chuck 46, is quantified, and the determination is made based on whether the quantified capacitance is within a predetermined range.

[0046] Fig. 5 is an example of a graph of capacitance. Here, the processes of steps S101 to S112 were repeated to perform substrate processing on a plurality of substrates W, and the capacitance was measured. The vertical axis of the graph in Fig. 5 represents capacitance.

[0047] Reference numeral 501 is an example of a box and whisker plot of the capacitance detected in step S102. Reference numeral 502 is an example of a box and whisker plot of the capacitance detected in step S103. Reference numeral 503 is an example of a box and whisker plot of the capacitance detected in step S106. Reference numeral 504 is an example of a box and whisker plot of the capacitance detected in step S108. Reference numeral 505 is an example of a box and whisker plot of the capacitance detected in step S110. Reference numeral 506 is an example of a box and whisker plot of the capacitance detected in step S112.

[0048] Range 510 is the range of capacitance within which the electrostatic chuck 46 is determined to be normal when the substrate W is placed on the substrate mounting surface of the substrate mounting table 40 and is electrostatically attracted (S106), or when the substrate W is placed near the substrate mounting surface of the substrate mounting table 40 and is electrostatically attracted (S108).

[0049] Range 520 is the range of capacitance within which the electrostatic chuck 46 is determined to be normal when the substrate W is placed on the substrate mounting surface of the substrate mounting table 40 and is not electrostatically attracted (S102), or when the substrate W is placed near the substrate mounting surface of the substrate mounting table 40 and is not electrostatically attracted (S103).

[0050] Range 530 is the range of capacitance within which the electrostatic chuck 46 is determined to be normal when the substrate W is sufficiently separated from the substrate mounting surface of the substrate mounting table 40 and is not electrostatically attracted (S110, S112).

[0051] If the capacitance (501 to 506) detected in each step is within the corresponding capacitance range (510 to 530), the control unit 70 determines that the substrate mounting table 40 is normal. In other words, it determines that maintenance is not required.

[0052] On the other hand, if any of the capacitances (501 to 506) is outside the range of the corresponding capacitance (510 to 530), it is determined that maintenance of the substrate mounting table 40 is necessary.

[0053] Furthermore, if the capacitance measured in steps S102 and S103 is within range 520, it can be determined that the substrate W has been normally placed on the substrate placement surface. If the capacitance is outside range 520, it can be determined that the substrate W has not been normally placed on the substrate placement surface.

[0054] Furthermore, if the amount of change (difference) between the capacitance measured in step S103 and the capacitance measured in step S102 is equal to or greater than a predetermined threshold, it can be determined that the tips of the lift pins 51 are in contact with the substrate W. On the other hand, if the amount of change (difference) is less than the predetermined threshold, it can be determined that the tips of the lift pins 51 are not in contact with the substrate W.

[0055] Furthermore, if the amount of change (difference) between the capacitance measured in step S108 and the capacitance measured in step S106 is equal to or greater than a predetermined threshold, it can be determined that the tips of the lift pins 51 are in contact with the substrate W. On the other hand, if the amount of change (difference) is less than the predetermined threshold, it can be determined that the tips of the lift pins 51 are not in contact with the substrate W.

[0056] Furthermore, if the amount of change (difference) between the capacitance measured in step S110 and the capacitance measured in step S112 is equal to or greater than a predetermined threshold, it can be determined that the tips of the lift pins 51 are in contact with the substrate W. On the other hand, if the amount of change (difference) is less than the predetermined threshold, it can be determined that the tips of the lift pins 51 are not in contact with the substrate W.

[0057] Furthermore, if the capacitance measured in steps S106 and S108 is within the range 510, it can be determined that the substrate W is electrostatically attracted normally. If the capacitance is outside the range 510, it can be determined that the substrate W is not electrostatically attracted normally.

[0058] Furthermore, if the capacitance measured in steps S110 and S112 is within the range 530, it can be determined that the substrate W is normally separated from the substrate placing table. If the capacitance is outside the range 530, it can be determined that the substrate W is not normally separated from the substrate placing table.

[0059] For example, when the chucking force of the electrostatic chuck 46 decreases due to aging or the like of the substrate mounting table 40, the capacitances indicated by the reference numerals 503 and 504 decrease. When the capacitances indicated by the reference numerals 503 and 504 decrease below a range 510, it is determined that maintenance of the substrate mounting table 40 is necessary.

[0060] Furthermore, if the amount of change (difference) between the capacitance before electrostatic adsorption (S102, S103 in FIG. 2; see reference numerals 501, 502 in FIG. 5) and the capacitance after electrostatic adsorption (S106, S108 in FIG. 2; see reference numerals 503, 504 in FIG. 5) is equal to or greater than a predetermined threshold, it is determined that maintenance is unnecessary. On the other hand, if the amount of change (difference) is less than the predetermined threshold, it is determined that maintenance is necessary.

[0061] In addition, the control unit 70 may determine that the substrate W has been adsorbed normally if the amount of change (difference) is greater than or equal to a predetermined threshold, and may determine that the substrate W has not been adsorbed normally if the amount of change (difference) is less than the predetermined threshold.

[0062] Furthermore, if the amount of change (difference) between the capacitance in the electrostatically adsorbed state (S106, S108 in FIG. 2; see reference numerals 503, 504 in FIG. 5) and the capacitance in the state after the electrostatic adsorption is released (S110, S112 in FIG. 2; see reference numerals 505, 506 in FIG. 5) is equal to or greater than a predetermined threshold, it is determined that maintenance is unnecessary. On the other hand, if the amount of change (difference) is less than the predetermined threshold, it is determined that maintenance is necessary.

[0063] Furthermore, the control unit 70 may determine that the substrate W has been released from suction normally if the amount of change (difference) is greater than or equal to a predetermined threshold, and may determine that the substrate W has not been released from suction normally if the amount of change (difference) is less than the predetermined threshold.

[0064] Furthermore, if the amount of change (difference) between the capacitance when no substrate W is placed on the substrate mounting surface (S110, S112 in FIG. 2; see reference numerals 505, 506 in FIG. 5) and the capacitance when the substrate W is placed on the substrate mounting surface (S102, S103 in FIG. 2; see reference numerals 501, 502 in FIG. 5) is equal to or greater than a predetermined threshold, it is determined that maintenance is unnecessary. On the other hand, if the amount of change (difference) is less than the predetermined threshold, it is determined that maintenance is necessary.

[0065] Furthermore, the capacitance measured for each substrate W is stored as data (see, for example, the box-and-whisker plots indicated by the reference numerals 501 to 506) in the storage unit of the control unit 70. Based on changes in the stored data, it may be determined whether maintenance is necessary or not.

[0066] Here, a known maintenance method for the substrate mounting table 40 is to replace the substrate mounting table 40 at a predetermined maintenance interval unless there is an unexpected malfunction such as an initial defect, breakage, contamination, etc. In this maintenance method, the substrate mounting table 40 is replaced even if it is within the normal performance range.

[0067] In response to this, in the substrate processing apparatus 1, the control unit 70 determines whether maintenance of the substrate mounting table 40 is required based on the detected capacitance. This determines whether maintenance of the substrate mounting table 40 is required due to deterioration over time. Therefore, if the substrate mounting table 40 is within the normal performance range, the substrate mounting table 40 can be used continuously, and the predetermined maintenance cycle can be extended. In other words, downtime of the substrate processing apparatus 1 is reduced, and the operating rate of the substrate processing apparatus 1 is improved.

[0068] The substrate processing apparatus 1 has been described above, but the present disclosure is not limited to the above embodiments, and various modifications and improvements are possible within the scope of the gist of the present disclosure as described in the claims. [Explanation of symbols]

[0069] W substrate 1. Substrate processing equipment 10 Processing container 40 Board mounting table 46 Electrostatic Chuck 46a electrode 48 DC power supply 49 Capacitance detection unit 50 PCB lifting mechanism 51 Lift pin 54 Drive mechanism 55 Motor 60 Substrate placement mechanism 70 Control Unit

Claims

1. a substrate mounting table having an electrostatic chuck that electrostatically attracts a substrate by applying a voltage to an electrode of the electrostatic chuck; lift pins that can protrude and retract relative to a substrate mounting surface of the substrate mounting table; a drive mechanism for raising and lowering the lift pins; a capacitance detection unit that detects the capacitance of the electrostatic chuck; a control unit that determines a state of the electrostatic chuck based on the electrostatic capacitance detected by the electrostatic capacitance detection unit. Substrate processing equipment.

2. The control unit determining an attracting state of the substrate placed on the substrate mounting surface based on an electrostatic capacitance before a voltage is applied to the electrode of the electrostatic chuck and an electrostatic capacitance after a voltage is applied to the electrode of the electrostatic chuck; The substrate processing apparatus according to claim 1 .

3. The control unit determining an attracting state of the substrate placed on the substrate mounting surface based on a change in capacitance between before a voltage is applied to the electrode of the electrostatic chuck and after a voltage is applied to the electrode of the electrostatic chuck; The substrate processing apparatus according to claim 2 .

4. The control unit determining a state of the electrostatic chuck based on whether the detected capacitance is within a predetermined range; The substrate processing apparatus according to claim 1 .

5. 1. A method for determining a state of a substrate processing apparatus, comprising: a substrate mounting table having an electrostatic chuck that electrostatically attracts a substrate by applying a voltage to an electrode of the electrostatic chuck; lift pins that can be protruded and retracted into a substrate mounting surface of the substrate mounting table; a drive mechanism that raises and lowers the lift pins; and a capacitance detection unit that detects a capacitance of the electrostatic chuck, determining a state of the electrostatic chuck based on the electrostatic capacitance detected by the electrostatic capacitance detection unit; Status determination method.

Images