Substrate adsorption state detection method and substrate processing apparatus

Abstract

A substrate suction state detection method for detecting the suction state of a substrate and a substrate processing apparatus are provided. [Solution] In a substrate processing apparatus including an electrostatic chuck having a dielectric layer with a mounting surface on which a substrate is placed and a chuck electrode embedded in the dielectric layer, and a chuck power supply that applies an attraction voltage to the chuck electrode, a substrate attraction state detection method for detecting an attraction state of the substrate attracted and held by the electrostatic chuck includes the steps of: detecting a change in voltage over time of the attraction voltage from a first applied state to a second applied state; determining whether a voltage change in the reverse direction has temporarily occurred during the time change of the voltage; and, if it is determined that the voltage change in the reverse direction has occurred, determining that the attraction state of the substrate has changed from the first attraction state to the second attraction state.

Description

[Technical Field]

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

[0002] Patent Document 1 describes a mounting table mechanism that includes an electrostatic chuck provided with a chuck electrode, a DC high-voltage power supply connected via a power supply line to apply a DC voltage that generates an electrostatic force to the chuck electrode, and a chuck switch unit that is interposed midway along the power supply line and closes when adsorbing a workpiece, and that when the chuck switch unit is switched from open to closed, the potential of the chuck electrode increases, and when the chuck switch unit is switched from closed to open, the potential of the chuck electrode decreases (see FIG. 4 in particular). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-4009 Summary of the Invention [Problem to be solved by the invention]

[0004] In one aspect, the present disclosure provides a substrate suction state detection method for detecting a suction state of a substrate, and a substrate processing apparatus. [Means for solving the problem]

[0005] In order to solve the above-described problems, according to one aspect, there is provided a substrate attraction state detection method for a substrate processing apparatus including an electrostatic chuck having a dielectric layer having a mounting surface on which a substrate is to be mounted and a chuck electrode embedded in the dielectric layer, and a chuck power supply that applies an attraction voltage to the chuck electrode, the method including: detecting a change in the attraction voltage over time from a first applied state to a second applied state; determining whether a voltage change in the reverse direction has temporarily occurred during the change in the voltage over time; and determining, when it is determined that the voltage change in the reverse direction has occurred, that the attraction state of the substrate has changed from the first attraction state to the second attraction state. [Effects of the Invention]

[0006] According to one aspect, the present disclosure can provide a substrate suction state detection method for detecting a suction state of a substrate, and a substrate processing apparatus. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic vertical cross-sectional view showing an example of a substrate processing apparatus. [Figure 2] FIG. 2 is a diagram showing an example of an equivalent circuit for an attraction voltage of an electrostatic chuck. [Figure 3] 10 is an example of a flowchart showing a process during suction of a substrate. [Figure 4] 10 is an example of a graph showing the change over time in the clamping voltage when the substrate is clamped. [Figure 5] 10 is an example of a graph showing a decrease in the clamping voltage. [Figure 6] 10 is an example of a flowchart showing a process when a substrate is removed. [Figure 7] 10 is an example of a graph showing the change in attraction voltage over time when a substrate is detached. [Figure 8] 10 is an example of a graph showing an increase in the attraction voltage. 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 equipment] An example of the substrate processing apparatus 1 will be described with reference to Fig. 1. Fig. 1 is a schematic vertical cross-sectional view showing the example of the substrate processing apparatus 1.

[0010] The substrate processing apparatus 1 is an apparatus that performs a predetermined substrate processing based on a processing recipe or the like on a substrate G that is placed on the mounting surface 30 of the mounting table 3 and attracted and held by an electrostatic chuck 32. The substrate processing apparatus 1 may be, for example, a film forming apparatus that performs a film forming process on the substrate G, an etching apparatus that performs an etching process on the substrate G, or a heat treatment apparatus that performs a heat treatment (annealing process, etc.) on the substrate G, and the processing performed on the substrate is not limited thereto. Furthermore, the substrate G to be processed is typically a glass substrate used in the manufacture of flat panel displays, but is not limited thereto and may be, for example, a semiconductor wafer.

[0011] The substrate processing apparatus 1 includes a processing chamber 2, a mounting table 3, a chuck power supply 4, and a controller 5. The substrate processing apparatus 1 may also include a gas supply unit that supplies a processing gas into the processing chamber 2, a plasma generation unit that generates plasma of the processing gas in the processing chamber 2, a gas exhaust unit (pressure adjustment unit) that exhausts gas from the processing chamber 2, and the like (none of which are shown).

[0012] The processing chamber 2 defines a processing space therein for processing the substrate G. A mounting table 3 for holding the substrate G in a substantially horizontal position is provided in the processing chamber 2. The mounting table 3 includes a base 31 and an electrostatic chuck 32.

[0013] The base 31 is made of, for example, a conductive material and supports the electrostatic chuck 32. The base 31 may function as a lower electrode. The base 31 may be grounded or may be configured to receive a bias voltage. The substrate processing apparatus 1 may be provided with an upper electrode (e.g., a shower head that supplies a processing gas into the processing chamber 2) facing the mounting table 3, which serves as the lower electrode. The substrate processing apparatus 1 may be configured to generate plasma of the processing gas in the processing chamber 2 by supplying high-frequency power to the lower electrode or the upper electrode. The substrate processing apparatus 1 may be provided with a window member made of a dielectric or metal facing the mounting table 3 and an inductively coupled antenna facing the mounting table 3 across the window member.

[0014] An electrostatic chuck 32 is provided on the base 31. The electrostatic chuck 32 has a dielectric layer 32a having a mounting surface 30 on which a substrate G is placed, and a chuck electrode 32b embedded inside the dielectric layer 32a. The upper surface of the electrostatic chuck 32 has the mounting surface 30 on which the substrate G is placed.

[0015] Although the chuck electrode 32b is described as a monopolar electrode, the present invention is not limited to this and may be a bipolar electrode.

[0016] The chuck power supply 4 is connected to the chuck electrode 32b via a power supply line and applies an attraction voltage to the chuck electrode 32b to attract and hold the substrate G. The chuck power supply 4 also includes a power supply unit 41, a switching unit 42, and a voltage detection unit 43.

[0017] The power supply unit 41 is connected to the chuck electrode 32b via a power supply line. The power supply unit 41 generates an attraction voltage to be applied to the chuck electrode 32b, and applies the generated attraction voltage to the chuck electrode 32b.

[0018] The switching unit 42 switches the attracting voltage applied from the power supply unit 41 to the chuck electrode 32b. For example, when attracting the substrate G to the electrostatic chuck 32, the switching unit 42 sets the attracting voltage applied from the power supply unit 41 to the chuck electrode 32b to a predetermined holding voltage. Furthermore, when desorbing the substrate G from the electrostatic chuck 32, the switching unit 42 sets the attracting voltage applied from the power supply unit 41 to the chuck electrode 32b to 0 V. Note that the holding voltage is a value set in a process recipe or the like to reliably attract the substrate G to the electrostatic chuck 32, and is not necessarily the minimum voltage value required to attract the substrate G.

[0019] The following description will be given assuming that the holding voltage applied from the power supply unit 41 to the chuck electrode 32b is a positive voltage. The holding voltage is not limited to a positive voltage and may be set to a negative voltage. In this case, in the control described below, an increase in the attraction voltage may refer to an increase in the attraction voltage in a negative direction, in other words, an increase in the absolute value of the attraction voltage with a negative polarity. Furthermore, a decrease in the attraction voltage may refer to a decrease in the attraction voltage in a negative direction, in other words, an increase in the absolute value of the attraction voltage with a negative polarity.

[0020] The switching unit 42 may be configured to switch the attraction voltage applied from the power supply unit 41 to the chuck electrode 32b between a preset holding voltage and 0V.

[0021] The configuration of the switching unit 42 is not limited to this. The switching unit 42 may be configured to switch between connecting the chuck electrode 32b to the power supply unit 41 and connecting it to the ground potential. That is, the switching unit 42 switches the connection between the power supply unit 41 and the chuck electrode 32b, thereby setting the attracting voltage applied to the chuck electrode 32b to the holding voltage. The switching unit 42 also disconnects the power supply unit 41 from the chuck electrode 32b and switches the connection between the chuck electrode 32b and the ground potential, thereby setting the attracting voltage applied to the chuck electrode 32b to the ground potential. Note that the ground potential is assumed to be 0 V.

[0022] The voltage detection unit 43 is configured to be able to detect the chucking voltage of the chuck electrode 32b.

[0023] The control unit 5 controls the operation of each component of the substrate processing apparatus 1, such as the chuck power supply 4, gas supply unit, plasma generation unit, gas exhaust unit, etc. The control unit 5 has a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory). The CPU executes a predetermined process in accordance with a recipe (process recipe) stored in the storage area of ​​the RAM or ROM.

[0024] The control unit 5 also includes an attraction state determination unit 51. The attraction state determination unit 51 records the change over time in the attraction voltage of the chuck electrode 32b detected by the voltage detection unit 43. Based on the recorded change over time in the attraction voltage of the chuck electrode 32b, the attraction state determination unit 51 determines whether the substrate G placed on the mounting surface 30 is in an attracted state where it is attracted to the electrostatic chuck 32, or whether the substrate G placed on the mounting surface 30 is in a detached state where it is detached from the electrostatic chuck 32 (a non-attracted state, an attraction-released state).

[0025] Here, an equivalent circuit of the chucking voltage applied from the chuck power supply 4 to the chucking electrode 32b of the electrostatic chuck 32 will be described with reference to Fig. 2. Fig. 2 is a diagram showing an example of an equivalent circuit for the chucking voltage of the electrostatic chuck 32.

[0026] As shown in FIG. 2, the equivalent circuit is a circuit in which the electromotive force E of the chuck power supply 4 (power supply unit 41), the resistance R of the circuit, and the capacitance C of a capacitor formed by the chuck electrode 32b and the substrate G placed on the mounting surface 30 as two electrodes are arranged in series.

[0027] Therefore, when the switching unit 42 switches the state in which the attracting voltage applied to the chuck electrode 32b is 0 V (ground potential) to the state in which the attracting voltage applied to the chuck electrode 32b is a holding voltage, and the application of the holding voltage from the chuck power supply 4 to the chuck electrode 32b begins, the attracting voltage of the chuck electrode 32b transiently increases with a time constant RC.

[0028] Similarly, when the switching unit 42 switches the state in which the attracting voltage applied to the chuck electrode 32b is the holding voltage to the state in which the attracting voltage applied to the chuck electrode 32b is 0 V (ground potential), and the application of the holding voltage from the chuck power supply 4 to the chuck electrode 32b is cut off (ended), the attracting voltage of the chuck electrode 32b transiently decreases with a time constant RC.

[0029] In a capacitor formed by the chuck electrode 32b and the substrate G, the relationship of the following formula (1) is satisfied using the charge Q stored in the capacitor, the capacitance C, and the voltage V (chucking voltage) of the chuck electrode 32b. Furthermore, the capacitance C satisfies the relationship of the following formula (2) using the dielectric constant ε, the area S, and the distance d between the chuck electrode 32b and the substrate G, which is the distance between the electrodes of the capacitor.

[0030] Q=CV (1) C=εS / d (2)

[0031] Furthermore, the distance d between the chuck electrode 32b and the substrate G changes before and after the substrate G is attracted and held. The distance between the chuck electrode 32b and the substrate G before the substrate G is attracted and held is defined as distance d1, and the distance between the chuck electrode 32b and the substrate G after the substrate G is attracted and held is defined as distance d2. The attraction voltage immediately before the substrate G is attracted and held is defined as voltage V1, and the attraction voltage immediately after the substrate G is attracted and held is defined as voltage V2. It is assumed that the charge Q is equal immediately before and immediately after the substrate G is attracted and held. The distances d1 and d2 and the voltages V1 and V2 satisfy the relationship of the following equation (3).

[0032] V2=(d2 / d1)V1 (3)

[0033] When the substrate G is adsorbed, the distance d2 after the substrate G is adsorbed and held is smaller than the distance d1 before the substrate G is adsorbed and held (d1 > d2). Therefore, the voltage V2 immediately after the substrate G is adsorbed and held is smaller than the voltage V1 immediately before the substrate G is adsorbed and held (V1 > V2). Thus, it is possible to detect that the substrate G is adsorbed and held by the electrostatic chuck 32 by detecting the decrease (reduction) in the voltage V of the chuck electrode 32b.

[0034] Similarly, when the substrate G is detached (when the adsorption and holding is released), the distance d4 after the substrate G is detached is larger than the distance d3 before the substrate G is detached (d3 < d4). Therefore, the voltage V4 immediately after the substrate G is detached is larger than the voltage V3 immediately before the substrate G is detached (V3 < V4). Thus, it is possible to detect that the substrate G is detached from the electrostatic chuck 32 by detecting the increase (increase) in the voltage V of the chuck electrode 32b. In Equation (3), d1, d2, V1, and V2 shall be read as d3, d4, V3, and V4, respectively. That is, the following relationship of Equation (4) is satisfied.

[0035] V4 = (d4 / d3)V3 (4)

[0036] [Processing during substrate adsorption] The processing during the adsorption of the substrate G will be described using FIGS. 3 to 5. FIG. 3 is an example of a flowchart showing the processing during the adsorption of the substrate G. FIG. 4 is an example of a graph showing the time change of the adsorption voltage during the adsorption of the substrate G. FIG. 5 is an example of a graph showing the time when the adsorption voltage decreases. Hereinafter, the state before changing the application state of the adsorption voltage to the chuck electrode 32b is referred to as the first application state, and the state after the change is referred to as the second application state. Also, the adsorption state of the substrate G to the electrostatic chuck 32 in the first application state is referred to as the first adsorption state, and the adsorption state of the substrate G to the electrostatic chuck 32 in the second application state is referred to as the second adsorption state.

[0037] 3, the switching unit 42 sets the attracting voltage applied to the chuck electrode 32b to 0 V (ground potential) as a first applied state. The substrate G is in a non-attracted state as the first attracted state, in which it is not attracted and held by the electrostatic chuck 32.

[0038] In step S101, an attraction voltage is applied to the chuck electrode 32b (attraction voltage ON). Here, the control unit 5 controls the switching unit 42 of the chuck power supply 4 to set the second application state, in which the attraction voltage applied to the chuck electrode 32b is set to a holding voltage. This starts application of the attraction voltage from the chuck power supply 4 to the chuck electrode 32b in order to apply the holding voltage to the chuck electrode 32b.

[0039] When the power supply unit 41 starts to apply the attracting voltage to the chuck electrode 32b, the attracting voltage of the chuck electrode 32b increases transiently as shown in the graph of FIG.

[0040] In step S102, the clamping voltage is detected. Here, the voltage detection unit 43 detects the clamping voltage of the chuck electrode 32b. The detected clamping voltage value is transmitted to the clamping state determination unit 51 of the control unit 5. The clamping state determination unit 51 records the change over time in the clamping voltage of the chuck electrode 32b detected by the voltage detection unit 43.

[0041] In step S103, the attraction state determination unit 51 determines whether a drop (decrease) in the attraction voltage has been detected. Here, the attraction state determination unit 51 determines whether a drop (decrease) in the attraction voltage has been detected based on a change over time in the attraction voltage of the chuck electrode 32b detected by the voltage detection unit 43.

[0042] 5, the clamping voltage of the chuck electrode 32b is detected at a cycle of 100 msec. During the process of increasing the clamping voltage, if the voltage change amount ΔV between the previous clamping voltage and the current clamping voltage decreases by a value equal to or greater than a predetermined threshold voltage VC1, it is determined that a drop (decrease) in the clamping voltage has been detected.

[0043] For example, when a decrease (decrease) in the clamping voltage is detected (YES in S103), as shown in the voltage decrease change 150 in Fig. 4, the control unit 5 proceeds to step S104. In step S104, the clamping state determination unit 51 determines that the substrate G placed on the mounting surface 30 is in a second clamping state in which the substrate G is clamped to the electrostatic chuck 32. Then, the control unit 5 proceeds to step S107.

[0044] On the other hand, if a drop (decrease) in the attraction voltage has not been detected (S103: NO), the control unit 5 proceeds to step S105. In step S105, the attraction state determination unit 51 determines whether a predetermined time (e.g., 5 seconds) has elapsed since the application of the attraction voltage started (see S101). If the predetermined time has not elapsed (S105: NO), the control unit 5 returns to step S102.

[0045] On the other hand, if it is determined that the predetermined time has elapsed (S105 YES), the control unit 5 proceeds to step S106. In step S106, the attraction state determination unit 51 determines that the substrate G placed on the mounting surface 30 is in a second attraction state where the substrate G is attracted to the electrostatic chuck 32. Then, the control unit 5 proceeds to step S107.

[0046] In step S107, the following process is performed after the substrate G is attracted and held. For example, a back surface gas (heat transfer gas, such as He gas) is supplied to the gap between the back surface of the substrate G and the mounting surface 30 of the mounting table 3.

[0047] 4, when application of the holding voltage to the chuck electrode 32b begins (S101), the attraction voltage of the chuck electrode 32b transiently increases from 0 V (ground potential) to the holding voltage. Then, as the substrate G is attracted and held by the electrostatic chuck 32, the distance d between the chuck electrode 32b and the substrate G decreases, and the attraction voltage of the chuck electrode 32b temporarily drops (voltage drop change 150). That is, at the timing when the substrate G is attracted and held, the attraction voltage temporarily changes in the opposite direction (decreasing direction) to the transient change direction (increasing direction) of the attraction voltage. Thereafter, the attraction voltage of the chuck electrode 32b transiently increases again to the holding voltage.

[0048] 3, the attracting state of the substrate G can be determined (S104) by detecting a drop (decrease) in the attracting voltage of the chuck electrode 32b (S103 YES). This allows the next process (S107) to be executed before the attracting voltage reaches the holding voltage (see FIG. 4). That is, the waiting time for the attracting process can be shortened, and the processing efficiency of the substrate processing apparatus 1 can be improved.

[0049] Furthermore, when a predetermined time has elapsed that is set as a time sufficient for the substrate G to be attracted to the electrostatic chuck 32 (YES in S105), the attracting state of the substrate G can also be determined (S106).

[0050] [Processing when removing the substrate] The process when the substrate G is detached will be described with reference to Figs. 6 to 8. Fig. 6 is an example of a flowchart showing the process when the substrate G is detached. Fig. 7 is an example of a graph showing the change in the clamping voltage over time when the substrate G is detached. Fig. 8 is an example of a graph showing the rise of the clamping voltage.

[0051] 6, the switching unit 42 sets the attracting voltage applied to the chuck electrode 32b as the holding voltage, which is the first application state. The substrate G is attracted and held by the electrostatic chuck 32, which is the first attracting state.

[0052] In step S201, the attracting voltage applied to the chuck electrode 32b is set to 0 V (ground potential) (attracting voltage OFF). Here, the control unit 5 controls the switching unit 42 of the chuck power supply 4 to set the attracting voltage applied to the chuck electrode 32b to 0 V (ground potential) as the second application state. This cuts off (terminates) the application of the holding voltage from the chuck power supply 4 to the chuck electrode 32b, and discharges the charge accumulated in the chuck electrode 32b.

[0053] When the application of the attracting voltage from the power supply unit 41 to the chuck electrode 32b is cut off (ended), the attracting voltage of the chuck electrode 32b transiently decreases as shown in the graph of FIG.

[0054] In step S202, the clamping voltage is detected. Here, the voltage detection unit 43 detects the clamping voltage of the chuck electrode 32b. The detected clamping voltage value is transmitted to the clamping state determination unit 51 of the control unit 5. The clamping state determination unit 51 records the change over time in the clamping voltage of the chuck electrode 32b detected by the voltage detection unit 43.

[0055] In step S203, the attraction state determination unit 51 determines whether or not an increase in the attraction voltage has been detected. Here, the attraction state determination unit 51 determines whether or not an increase in the attraction voltage has been detected based on a change over time in the attraction voltage of the chuck electrode 32b detected by the voltage detection unit 43.

[0056] 8, the clamping voltage of the chuck electrode 32b is detected at a cycle of 100 msec. During the process of decreasing the clamping voltage, if the voltage change amount ΔV between the previous clamping voltage and the current clamping voltage increases by a value equal to or greater than a predetermined threshold voltage VC2, it is determined that an increase in the clamping voltage has been detected. Note that the threshold voltage VC2 may be the same value as the threshold voltage VC1 (see FIG. 5) or may be a different value.

[0057] For example, when an increase (increase) in the clamping voltage is detected (YES in S203), as shown in the voltage increase change 250 in Fig. 7, the control unit 5 proceeds to step S204. In step S204, the clamping state determination unit 51 determines that the substrate G placed on the mounting surface 30 is in a second clamping state, that is, a detached state in which the substrate G is detached from the electrostatic chuck 32. Then, the control unit 5 proceeds to step S207.

[0058] On the other hand, if an increase (increase) in the attraction voltage has not been detected (S203: NO), the control unit 5 proceeds to step S205. In step S205, the attraction state determination unit 51 determines whether the attraction voltage is equal to or lower than a predetermined voltage (e.g., 100 V). If the attraction voltage is not equal to or lower than the predetermined voltage (S205: NO), the control unit 5 returns to step S202.

[0059] On the other hand, if it is determined that the voltage is equal to or lower than the predetermined voltage (YES in S205), the control unit 5 proceeds to step S206. In step S206, the attraction state determination unit 51 determines that the substrate G placed on the mounting surface 30 is in a second attraction state, that is, a detached state in which the substrate G is detached from the electrostatic chuck 32. Then, the control unit 5 proceeds to step S207.

[0060] In step S207, the next process is performed after the substrate G is detached. For example, lift pins (not shown) provided on the mounting table 3 are raised to lift the substrate G from the mounting surface 30 of the mounting table 3.

[0061] 7, when the application of the holding voltage to the chuck electrode 32b is cut off (S201), the attraction voltage of the chuck electrode 32b transiently decreases from the holding voltage to 0 V (ground potential). Then, as the substrate G is released from the electrostatic chuck 32, the distance d between the chuck electrode 32b and the substrate G increases, and the attraction voltage of the chuck electrode 32b temporarily increases (voltage increase change 250). That is, with respect to the transient change direction (decreasing direction) of the attraction voltage, the attraction voltage temporarily changes in the opposite direction (increasing direction) at the timing when the substrate G is attracted and held. Thereafter, the attraction voltage of the chuck electrode 32b transiently decreases again to 0 V (ground potential).

[0062] 6, the release state of the substrate G can be determined (S204) by detecting an increase (increase) in the attracting voltage of the chuck electrode 32b (S203 YES). This allows the next process (S207) to be executed before the attracting voltage reaches a predetermined voltage (see FIG. 7). That is, the waiting time for the release process can be shortened, and the processing efficiency of the substrate processing apparatus 1 can be improved.

[0063] Furthermore, the detached state of the substrate G can also be determined (S206) when the charge on the chuck electrode 32b is discharged to a predetermined voltage or less (YES in S205).

[0064] 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]

[0065] G board 1. Substrate processing equipment 2. Processing vessel 3. Mounting table 4 Chuck power supply 5. Control section 30 Placement surface 31 Foundation 32 Electrostatic chuck 32a Dielectric layer 32b Chuck electrode 41 Power supply section 42 Switching section 43 Voltage detection section 51 Adsorption state determination unit 150 Voltage drop change 250 Voltage increase change

Claims

1. 1. A substrate attraction state detection method for a substrate processing apparatus including an electrostatic chuck having a dielectric layer having a mounting surface on which a substrate is placed and a chuck electrode embedded in the dielectric layer, and a chuck power supply that applies an attraction voltage to the chuck electrode, the method comprising: detecting a change in the attracting voltage over time from a first applied state to a second applied state; determining whether or not a temporary voltage change in the reverse direction has occurred during the time change of the voltage; determining that the attraction state of the substrate has changed from a first attraction state to a second attraction state when it is determined that the voltage change in the reverse direction has occurred; Substrate suction state detection method.

2. When the amount of voltage change in the reverse direction is equal to or greater than a predetermined threshold voltage, it is determined that the voltage change in the reverse direction has occurred.

2. The method for detecting a substrate suction state according to claim 1.

3. the first attracted state is a state in which the substrate is not attracted and held by the electrostatic chuck, the second attracting state is a state in which the substrate is attracted and held by the electrostatic chuck; 3. The method for detecting a substrate suction state according to claim 1.

4. the change in voltage over time is increasing, The voltage change in the reverse direction is a decrease.

4. The method for detecting a substrate suction state according to claim 3.

5. In the first application state, the attracting voltage applied to the chuck electrode is 0 V, In the second application state, the attraction voltage applied to the chuck electrode is a predetermined holding voltage.

4. The method for detecting a substrate suction state according to claim 3.

6. the first attracted state is a state in which the substrate is attracted and held by the electrostatic chuck, the second attracted state is a state in which the substrate is not attracted and held by the electrostatic chuck; 3. The method for detecting a substrate suction state according to claim 1.

7. The change in the voltage over time is a decrease, the voltage change in the reverse direction is an increase; 7. The method for detecting a substrate suction state according to claim 6.

8. the first application state is a state in which the attraction voltage applied to the chuck electrode is a preset holding voltage; In the second application state, the attracting voltage applied to the chuck electrode is 0 V.

7. The method for detecting a substrate suction state according to claim 6.

9. an electrostatic chuck including a dielectric layer having a mounting surface on which a substrate is placed and a chuck electrode embedded in the dielectric layer; a chuck power supply that applies a clamping voltage to the chuck electrode; a control unit, The control unit detecting a change in the attracting voltage over time from a first applied state to a second applied state; determining whether or not a temporary voltage change in the reverse direction has occurred during the time change of the voltage; and determining, when it is determined that the voltage change in the reverse direction has occurred, that the attraction state of the substrate has changed from a first attraction state to a second attraction state. Substrate processing equipment.

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