Plasma processing apparatus and program

Abstract

To sense the reduction in substrate-sucking power at an appropriate timing.SOLUTION: A plasma processing device comprises: an electrostatic chuck 1111 which sucks a substrate W by a voltage supplied to an electrostatic electrode 1111b; a relay circuit 51 disposed on a feeder line 52 between a DC power source 50 for voltage supply and the electrostatic electrode, and serving to turn ON / OFF voltage supply to the electrostatic electrode; a plasma generating part; and a control part. The control part performs steps of: supplying a voltage to the electrostatic electrode; causing a substrate to be sucked to an upper face of the electrostatic chuck; turning off the voltage supply to the electrostatic electrode by the relay circuit to bring the electrostatic electrode into a floating condition after the voltage supplied to the electrostatic electrode is stabilized; starting a plasma treatment on the substrate sucked to the electrostatic chuck after the voltage supplied to the electrostatic electrode is stabilized; and after start of the substrate treatment, turning on voltage supply to the electrostatic electrode by the relay circuit to gain a current running through the feeder line during the voltage supply to the electrostatic electrode, and making determination on a condition of sucking the substrate on the basis of the current.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a plasma processing apparatus and a program. [Background technology]

[0002] For example, Patent Document 1 proposes that after a substrate is attracted and held by an electrostatic chuck, gas is introduced into the gap between the electrostatic chuck plate and the substrate, and the pressure in the gap is monitored to detect poor attraction of the substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-87480 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique that can detect a decrease in the chucking force of a substrate at an appropriate time. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, there is provided an electrostatic chuck that is housed in a plasma processing chamber, has an electrostatic electrode, and attracts a substrate by a voltage supplied to the electrostatic electrode; a DC power source that supplies a voltage to the electrostatic electrode; a relay circuit that is disposed in a power supply line between the DC power source and the electrostatic electrode and turns on and off the supply of voltage to the electrostatic electrode; a plasma generating unit that generates plasma inside the plasma processing chamber; and a controller, wherein the controller (a) supplies a voltage to the electrostatic electrode to attract a substrate to an upper surface of the electrostatic chuck, and (b) controls the voltage supplied to the electrostatic electrode. (c) after the voltage supplied to the electrostatic electrode has stabilized, turning off the supply of voltage to the electrostatic electrode by the relay circuit to bring the electrostatic electrode into a floating state; (d) after the processing of the substrate has started, turning on the supply of voltage to the electrostatic electrode by the relay circuit to obtain a current flowing through the power supply line when a voltage is supplied to the electrostatic electrode; and (e) determining an attraction state of the substrate based on the current. Effect of the Invention

[0006] According to one aspect, a decrease in the chucking force of the substrate can be detected at an appropriate timing. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing an example of a plasma processing apparatus according to an embodiment. [Diagram 2] FIG. 13 is a diagram showing an example of an equivalent circuit when a substrate is attracted to the substrate; [Diagram 3] FIG. 2 is a diagram showing an example of an equivalent circuit during plasma processing according to an embodiment. [Figure 4] FIG. 4 is a diagram showing an example of the number of times of use and the change over time of insulation resistance value of a relay circuit according to an embodiment. [Diagram 5] 6A and 6B are diagrams for explaining a method for monitoring a decrease in an adsorptive force over time according to an embodiment. [Figure 6]5A and 5B are diagrams illustrating an example of a floating time, a leakage charge amount, a charge leakage rate, and a He gas leakage amount of a relay circuit according to an embodiment. [Figure 7] 4 is a flowchart showing an example of a monitoring method according to the first embodiment. [Figure 8] 10 is a flowchart showing an example of a monitoring method according to the second embodiment. [Figure 9] 13 is a flowchart showing an example of a monitoring method according to the third embodiment. [Figure 10] 13 is a flowchart showing an example of a monitoring method according to the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment 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 duplicated descriptions may be omitted.

[0009] In this specification, deviations in directions such as parallel, right angles, orthogonal, horizontal, vertical, up / down, left / right, etc., are permitted to the extent that they do not impair the effects of each embodiment. The shape of the corners is not limited to right angles and may be rounded in an arch shape. Parallel, right angles, orthogonal, horizontal, vertical, circular, and coincident may include approximately parallel, approximately right angles, approximately orthogonal, approximately horizontal, approximately vertical, approximately circular, and approximately coincident.

[0010] [Plasma processing equipment] An example of the configuration of a plasma processing apparatus will be described below. Fig. 1 is a diagram for explaining an example of the configuration of a capacitively coupled plasma processing apparatus.

[0011] The plasma processing apparatus 1 is a capacitively coupled plasma processing apparatus and includes a control unit 2. The plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power source 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support 11 and a gas inlet. The gas inlet is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas inlet includes a shower head 13. The substrate support 11 is disposed in the plasma processing chamber 10. The shower head 13 is disposed above the substrate support 11. In one embodiment, the shower head 13 forms at least a part of a ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the shower head 13, a sidewall 10a of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 has at least one gas inlet for supplying at least one processing gas to the plasma processing space 10s and at least one gas outlet for exhausting gas from the plasma processing space. The plasma processing chamber 10 is grounded. The showerhead 13 and the substrate support 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0012] The substrate support 11 includes a main body 111 and a ring assembly 112. The main body 111 has a central region 111a for supporting the substrate W and an annular region 111b for supporting the ring assembly 112. A wafer is an example of the substrate W. The annular region 111b of the main body 111 surrounds the central region 111a of the main body 111 in a plan view. The substrate W is disposed on the central region 111a of the main body 111, and the ring assembly 112 is disposed on the annular region 111b of the main body 111 so as to surround the substrate W on the central region 111a of the main body 111. Therefore, the central region 111a is also called a substrate support surface for supporting the substrate W, and the annular region 111b is also called a ring support surface for supporting the ring assembly 112.

[0013] In one embodiment, the main body 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes a conductive member. The conductive member of the base 1110 may function as a lower electrode. The electrostatic chuck 1111 is disposed on the base 1110. The electrostatic chuck 1111 includes a ceramic member 1111a and an electrostatic electrode 1111b disposed within the ceramic member 1111a. The ceramic member 1111a has a central region 111a. In one embodiment, the ceramic member 1111a also has an annular region 111b. Note that other members surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member, may have the annular region 111b. In this case, the ring assembly 112 may be disposed on the annular electrostatic chuck or the annular insulating member, or may be disposed on both the electrostatic chuck 1111 and the annular insulating member. Also, at least one RF / DC electrode coupled to a radio frequency (RF) power source 31 and / or a direct current (DC) power source 32 described later may be disposed in the ceramic member 1111a. In this case, the at least one RF / DC electrode functions as a lower electrode. When a bias RF signal and / or a DC signal described later is supplied to the at least one RF / DC electrode, the RF / DC electrode is also called a bias electrode. Note that the conductive member of the base 1110 and the at least one RF / DC electrode may function as a plurality of lower electrodes. Also, the electrostatic electrode 1111b may function as a lower electrode. Thus, the substrate support 11 includes at least one lower electrode.

[0014] The ring assembly 112 includes one or more annular members. In one embodiment, the one or more annular members include one or more edge rings and at least one cover ring. The edge rings are formed of a conductive or insulating material, and the cover rings are formed of an insulating material.

[0015] The substrate support 11 may also include a temperature adjustment module configured to adjust at least one of the electrostatic chuck 1111, the ring assembly 112, and the substrate to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow passage 1110a, or a combination thereof. A heat transfer fluid such as brine or gas flows through the flow passage 1110a. In one embodiment, the flow passage 1110a is formed in the base 1110, and one or more heaters are disposed in the ceramic member 1111a of the electrostatic chuck 1111. The substrate support 11 may also include a heat transfer gas supply unit configured to supply a heat transfer gas to a gap between the back surface of the substrate W and the central region 111a. For example, the heat transfer gas supply unit supplies He gas, which is an example of a heat transfer gas, to the gap between the back surface of the substrate W and the central region 111a from a heat transfer gas supply line 57 that penetrates the main body 111.

[0016] The shower head 13 is configured to introduce at least one processing gas from the gas supply unit 20 into the plasma processing space 10s. The shower head 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and multiple gas inlets 13c. The processing gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the multiple gas inlets 13c. The shower head 13 also includes at least one upper electrode. Note that the gas introduction unit may include, in addition to the shower head 13, one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 10a.

[0017] The gas supply 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply 20 is configured to supply at least one process gas from a respective gas source 21 through a respective flow controller 22 to the showerhead 13. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply 20 may include one or more flow modulation devices to modulate or pulse a flow rate of the at least one process gas.

[0018] The power source 30 includes an RF power source 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power source 31 is configured to supply at least one RF signal (RF power) to at least one lower electrode and / or at least one upper electrode. This causes a plasma to be formed from at least one processing gas supplied to the plasma processing space 10s. Thus, the RF power source 31 can function as at least a part of a plasma generating unit configured to generate a plasma from one or more processing gases in the plasma processing chamber 10. In addition, a bias potential is generated on the substrate W by supplying a bias RF signal to the at least one lower electrode, and ion components in the formed plasma can be attracted to the substrate W.

[0019] In one embodiment, the RF power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating unit 31a is coupled to at least one lower electrode and / or at least one upper electrode via at least one impedance matching circuit, and is configured to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 10 MHz to 150 MHz. In one embodiment, the first RF generating unit 31a may be configured to generate a plurality of source RF signals having different frequencies. The generated one or more source RF signals are supplied to at least one lower electrode and / or at least one upper electrode.

[0020] The second RF generating unit 31b is coupled to at least one lower electrode via at least one impedance matching circuit and configured to generate a bias RF signal (bias RF power). The frequency of the bias RF signal may be the same as or different from the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency lower than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 100 kHz to 60 MHz. In one embodiment, the second RF generating unit 31b may be configured to generate a plurality of bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to at least one lower electrode. Also, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0021] The power supply 30 may also include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generator 32a and a second DC generator 32b. In one embodiment, the first DC generator 32a is connected to at least one lower electrode and configured to generate a first DC signal. The generated first bias DC signal is applied to the at least one lower electrode. In one embodiment, the second DC generator 32b is connected to at least one upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to the at least one upper electrode.

[0022] In various embodiments, at least one of the first and second DC signals may be pulsed. In this case, a sequence of voltage pulses is applied to at least one lower electrode and / or at least one upper electrode. The voltage pulses may have a rectangular, trapezoidal, triangular or combination thereof pulse waveform. In one embodiment, a waveform generator for generating a sequence of voltage pulses from the DC signal is connected between the first DC generator 32a and at least one lower electrode. Thus, the first DC generator 32a and the waveform generator constitute a voltage pulse generator. When the second DC generator 32b and the waveform generator constitute a voltage pulse generator, the voltage pulse generator is connected to at least one upper electrode. The voltage pulses may have a positive polarity or a negative polarity. Also, the sequence of voltage pulses may include one or more positive polarity voltage pulses and one or more negative polarity voltage pulses in one period. The first and second DC generating units 32a, 32b may be provided in addition to the RF power supply 31, or the first DC generating unit 32a may be provided in place of the second RF generating unit 31b.

[0023] The exhaust system 40 may be connected to, for example, a gas exhaust port 10e provided at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure in the plasma processing space 10s is adjusted by the pressure regulating valve. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0024] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to execute various steps described in the present disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to execute various steps described herein. In one embodiment, a part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 may include a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The control unit 2 is realized, for example, by a computer 2a. The processing unit 2a1 may be configured to perform various control operations by reading a program from the storage unit 2a2 and executing the read program. This program may be stored in the storage unit 2a2 in advance, or may be acquired via a medium when necessary. The acquired program is stored in the storage unit 2a2 and is read from the storage unit 2a2 by the processing unit 2a1 and executed. The medium may be various storage media readable by the computer 2a, or may be a communication line connected to the communication interface 2a3. The processing unit 2a1 may be a CPU (Central Processing Unit). The storage unit 2a2 may include a random access memory (RAM), a read only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a local area network (LAN).

[0025] [Substrate adsorption processing] Before the substrate W is subjected to plasma processing, the substrate is subjected to adsorption processing. The substrate W is carried into the plasma processing chamber 10 and placed on the upper surface of the electrostatic chuck 1111. Gas is supplied from the gas supply unit 20 into the plasma processing space 10s via the shower head 13, and an RF signal is supplied from the RF power supply 31 to the conductive member of the substrate support unit 11, the conductive member of the shower head 13, or both. Note that plasma is generated in the plasma processing space 10s by an inert gas such as argon gas supplied into the plasma processing space 10s during the substrate adsorption processing.

[0026] In this state, the suction process is performed, and the substrate W is attracted to the substrate support surface 111a. Fig. 2 shows an example of an equivalent circuit when attracting a substrate. As shown in Fig. 2, in the suction process, a voltage is applied from the DC power supply 50 to the electrostatic electrode 1111b, and a closed circuit is formed via plasma. Between the substrate W and the electrostatic electrode 1111b, a capacitance component 115 of capacitance C0 exists due to the dielectric electrostatic chuck 1111. The charge Q0 is the charge accumulated in the capacitance component 115 at this time, and is expressed as Q0=C0V0.

[0027] The substrate W has a self-bias V that is more negative when the bias RF signal voltage is negative than when the bias RF signal voltage is positive, depending on the RF signal, mainly the bias RF signal. dc0 The self-bias V dc0 If is too large, the ions are attracted strongly and the substrate W may be damaged during the adsorption process. dc0 A weak plasma is generated.

[0028] If the voltage during attraction supplied from the DC power supply 50 to the electrostatic electrode 1111b is V0, the electrostatic force F0 generated between the substrate W and the electrostatic electrode 1111b by the capacitance component 115 is calculated by the self-bias V dc0 is negligibly small compared to V0. For this reason, it is expressed, for example, as the following equation (1). F0 = k(C0V0 / r) 2 (1)

[0029] In formula (1), k is a constant, and r is the distance between the back surface of the substrate W and the electrostatic electrode 1111b. The voltage V0 supplied to the electrostatic electrode 1111b is a DC voltage during adsorption that is preset so that the electrostatic force F0 has a predetermined magnitude.

[0030] When a processing gas is supplied after the substrate W is attracted, and plasma processing is performed on the substrate W using a plasma of the processing gas that is stronger than that during the attraction, as shown in FIG. 3, the self-bias Vdc0 Self-bias V larger than dc1 Furthermore, when plasma processing of the substrate W is started, the adsorption state between the substrate W and the substrate support surface 111a changes under the influence of the plasma, and the capacitance of the capacitance component 115 between the substrate W and the electrostatic electrode 1111b changes from C0 to C1. Furthermore, when plasma processing of the substrate W is started, the temperature of the substrate W and the state of the surface of the electrostatic chuck 1111 change under the influence of the plasma, and the state of the contact surface between the substrate W and the substrate support surface 111a changes. As a result, the capacitance component 116 of the capacitance C2 and the resistance value R c A resistance component 117 is generated.

[0031] The charge Q1 accumulated in the capacitance component 115 and the charge Q2 accumulated in the capacitance component 116 are expressed, for example, by the following formula (2). Note that the capacitance C1 of the capacitance component 115 during plasma processing is approximately the same as the capacitance C0 of the capacitance component 115 during adsorption processing. Q1+Q2=C1(V0+V dc1 )+C2(V0+V dc1 ) · · · (2)

[0032] Here, the charge Q0 accumulated in the capacitance component 115 during the adsorption process is C0V0. Therefore, referring to the above formula (2), during the plasma process, the self-bias V dc1 Due to this effect, charges Q1 and Q2 larger than the charge Q0 accumulated during the adsorption process are accumulated on the substrate W. This makes it easier for particles generated in the plasma processing space 10s to be attracted to the substrate W during the plasma processing.

[0033] Moreover, the electrostatic force F generated between the substrate W and the electrostatic electrode 1111b by the capacitance components 115 and 116 is expressed, for example, by the following formula (3). F=F1+F2 =k(C1(V0+V dc1 ) / r) 2 +k(C2(V0+V dc1 ) / r) 2 (3)

[0034] Here, since the capacitance C2 of the capacitance component 116 is negligibly small compared to the capacitance C1 of the capacitance component 115, the electrostatic force F generated between the substrate W and the electrostatic electrode 1111b can be approximated by, for example, the following equation (4). F≒k(C1(V0+V dc1 ) / r) 2 (4)

[0035] Comparing the above formula (4) with the above formula (1), the electrostatic force F during plasma processing of the substrate W after attraction is calculated by the self-bias V dc1 Due to the influence of the self-bias V, the electrostatic force F is larger than the electrostatic force F0 during the adsorption process. Therefore, it is considered that the adsorption force between the substrate W and the electrostatic electrode 1111b (electrostatic chuck 1111) becomes excessively large during the plasma processing of the substrate W. dc1 Since varies depending on the plasma processing state, the self-bias V dc1 It is difficult to accurately set the voltage V0 taking these factors into account in advance.

[0036] When the adhesion force between the substrate W and the electrostatic chuck 1111 becomes excessive, the friction force between the substrate W and the substrate support surface 111a increases. As a result, the amount of particles generated by friction between the substrate W and the substrate support surface 111a increases due to the difference in thermal expansion coefficient between the substrate W and the substrate support surface 111a. In addition, when the operating temperature of the electrostatic chuck 1111 increases, the adhesion force increases, and the amount of particles generated further increases. Furthermore, when the adhesion force between the substrate W and the substrate support surface 111a becomes excessive, the substrate W may jump up or crack when the substrate W after plasma processing is separated from the substrate support surface 111a by a lift pin or the like.

[0037] Therefore, in the adsorption process according to this embodiment, the supply of voltage to the electrostatic electrode 1111b is turned on and off by a relay circuit 51 disposed on a power supply line 52 between the electrostatic electrode 1111b and the DC power supply 50. When a switch 51a of the relay circuit 51 is turned on (connected state), the DC power supply 50 is connected to the electrostatic electrode 1111b, and a DC voltage V0 of a preset magnitude is supplied from the DC power supply 50 to the electrostatic electrode 1111b via the relay circuit 51 and the power supply line 52. As a result, the substrate W is adsorbed to the electrostatic chuck 1111.

[0038] After the voltage supplied to the electrostatic electrode 1111b of the electrostatic chuck 1111 in the adsorption process is stabilized, the switch 51a of the relay circuit 51 is turned off (open state) and plasma processing is performed. An example of an equivalent circuit during plasma processing according to an embodiment is shown in Fig. 3. When the switch 51a is turned off, the electrostatic electrode 1111b is in a floating state.

[0039] The voltage of the electrostatic electrode 1111b during plasma processing is V a Then, the voltage V a is expressed, for example, as the following equation (5). V a =V0-V dc1 (5)

[0040] An electrostatic force F' generated between the substrate W and the electrostatic electrode 1111b by the capacitance components 115 and 116 in the state of FIG. 3 is expressed, for example, by the following formula (6). F'=k(C1(V a +V dc1 ) / r) 2 +k(C2(V a +V dc1 ) / r) 2 (6)

[0041] Here, since the capacitance C2 of the capacitive component 116 is negligibly small compared to the capacitance C1 of the capacitive component 115, the electrostatic force F' generated between the substrate W and the electrostatic electrode 1111b can be approximated by, for example, the following equation (7). F'≒k(C1(V a+V dc1 ) / r) 2 =k(C1V0 / r) 2 (7)

[0042] The capacitance C1 of the capacitance component 115 is almost the same as the capacitance C0 of the capacitance component 115 during the adsorption process. Therefore, referring to the above formulas (1) and (7), even during the plasma process, the substrate W has a self-bias V dc1 Regardless of the magnitude of F0, an electrostatic force F' equivalent to the electrostatic force F0 generated between the substrate W and the electrostatic electrode 1111b during the suction process is generated.

[0043] In this manner, in this embodiment, the switch 51a of the relay circuit 51 is turned off during plasma processing, and the electrostatic electrode 1111b is brought into a floating state, thereby suppressing the generation of excessive electrostatic force between the substrate W and the electrode 1111h during plasma processing. This suppresses an increase in the frictional force between the substrate W and the substrate supporting surface 111a, and suppresses the generation of particles due to friction between the substrate W and the substrate supporting surface 111a.

[0044] However, it was found that the chucking force of the substrate W decreases while the electrostatic electrode 1111b is in a floating state. Fig. 4 is a diagram showing an example of the number of uses of the relay circuit 51 according to one embodiment and the change over time in insulation resistance value. The relay circuit 51 has a relay box 51b formed from an insulator (see Fig. 3). The number of uses of the relay on the horizontal axis of Fig. 4 is the number of times the relay circuit 51 is turned on and off, and the relay insulation resistance value on the vertical axis is the resistance value of the insulator forming the relay box 51b.

[0045] 4, a phenomenon is seen in which the insulation resistance value of relay box 51b decreases as the number of times relay circuit 51 is used increases. This means that the more the relay circuit 51 is used, the more the relay box 51b deteriorates, the weaker the insulation of relay box 51b becomes, and the electric charge flows directly from relay box 51b to the ground side due to the potential difference between relay box 51b and ground. This causes electric charge to leak between the substrate W and electrostatic electrode 1111b, and the suction force, which is the attractive force generated between the substrate W and electrostatic electrode 1111b, decreases.

[0046] When the chucking force falls below the lower limit for maintaining the chucking of the substrate W, the pressure of the back surface of the substrate W caused by the He gas supplied to the back surface of the substrate W may cause the substrate W to bounce and be damaged. For this reason, a method for monitoring the chucking force has been proposed. For example, there is a method for measuring the amount of leakage of the He gas supplied to the back surface of the substrate W, and determining that the chucking force has decreased when the amount of leakage exceeds a threshold value. However, in this method, when the pressure between the back surface of the substrate W and the electrostatic chuck 1111 becomes larger than the chucking force due to the supply of the He gas, the amount of leakage of the He gas increases rapidly. As a result, the risk of the substrate W bouncing and being damaged may not be avoided. That is, it is important to detect the decrease in the chucking force generated between the substrate W and the electrostatic electrode 1111b before the amount of leakage of the He gas increases rapidly.

[0047] Therefore, in this embodiment, by monitoring the current flowing through the power supply line 52, the deterioration state of the relay circuit 51 can be determined based on the amount or rate of charge leakage, and thereby the attracting state of the substrate W can be determined and a decrease in the attracting force generated between the substrate W and the electrostatic electrode 1111b can be detected. Based on the detection result, it becomes possible to take necessary measures, such as stopping the processing of the substrate W before the attracting force decreases to the extent that the substrate W is splashed and damaged.

[0048] [Method for monitoring changes in adhesion force over time] Next, a method for monitoring the change over time of the attractive force in the sequence of the attractive process, the substrate process, and the static electricity removal process according to this embodiment will be described with reference to Fig. 5. Fig. 5 is a diagram for explaining a method for monitoring the usage state of the relay circuit 51 according to one embodiment and the decrease over time of the attractive force.

[0049] 5, the process is performed in the order of (1) preparation process (period T1) and adsorption process (period T2), (2) substrate process (period T3), and (3) static electricity removal process (period T4). At this time, the measurement result of the current i flowing through the power supply line 52 measured by the ammeter A and the voltage V output from the DC power supply 50 measured by the voltmeter V are shown in FIG. p 5 shows an example of the measurement results. (a) to (c) at the bottom of FIG. 5 show ammeter A and voltage V that measure the on and off states of relay circuit 51 and the current i during (1) preparation processing and adsorption processing, (2) substrate processing, and (3) static elimination processing. p The arrangement of the voltmeter V for measuring is shown.

[0050] (1) Preparation and adsorption treatment A period T1 is a preparation period for the adsorption process, during which an RF signal is supplied from the RF power source 31 to the conductive member of the substrate support 11, the conductive member of the shower head 13, or both. Also, an inert gas such as argon gas is supplied from the gas supply unit 20 into the plasma processing space 10s. This generates a plasma of the inert gas in the plasma processing space 10s.

[0051] In the adsorption process in the period T2, the DC power supply 50 is turned on at time t0. At this time, the relay circuit 51 is on (see FIG. 5(a)), and a DC voltage V p During the periods T1 and T2, no He gas is supplied to the rear surface of the substrate W.

[0052] At this time, the voltage changes from 0 to V p, a DC current i flows through the power supply line 52 connecting the DC power supply 50 and the electrostatic electrode 1111b. The ammeter A measures the current i and monitors the change in the current i. In the example of FIG. 5, the current i measured by the ammeter A flows instantaneously from time t0 to time t1 and becomes zero after time t1. At this time, the amount of adsorption charge indicating the degree of the adsorption force generated between the electrostatic electrode 1111b and the substrate W is calculated by integrating the current i flowing from time t0 to time t1. The amount of adsorption charge is the amount of charge introduced into the electrostatic chuck 1111 between time t0 and time t1.

[0053] (2) Substrate processing After the voltage supplied to the electrostatic electrode 1111b becomes stable in period T2, substrate processing is performed in period T3. Period T3 is a period during which the substrate W is plasma-processed (also referred to as substrate processing), and an RF signal continues to be supplied from the RF power supply 31 to the conductive member of the substrate support 11, the conductive member of the shower head 13, or both. In addition, a processing gas is supplied from the gas supply unit 20 into the plasma processing space 10s. This generates plasma of the processing gas in the plasma processing space 10s.

[0054] During the substrate processing in period T3, while the DC power supply 50 is maintained in the on state, the relay circuit 51 is switched from the on state to the off state at time t2 (see FIG. 5(b)), and the relay circuit 51 enters a floating state. Also, at time t2, the supply of He gas to the rear surface of the substrate W is started. The supply of He gas is continued during period T3. During period T3, the current i measured by ammeter A is 0.

[0055] (3) Static electricity removal The period T4 is a period during which the charge removal process is performed. In the substrate T4, the RF power source 31 continues to supply an RF signal to the conductive member of the substrate support 11, the conductive member of the shower head 13, or both. In addition, an inert gas such as argon gas is supplied from the gas supply unit 20 into the plasma processing space 10s. This generates a plasma of the inert gas in the plasma processing space 10s.

[0056] While the DC power supply 50 is maintained in the on state, the relay circuit 51 is switched from the off state to the on state at time t3 (see FIG. 5(c)). In this manner, during the period T4, the switch 51a of the relay circuit 51 is connected to again supply the voltage V p At time t3, the supply of He gas to the rear surface of the substrate W is stopped, and the He gas pressure on the rear surface of the substrate W is reduced to 0 by evacuating the He gas therefrom. Then, the substrate W is peeled off from the electrostatic chuck 1111 and is unloaded from the plasma processing chamber 10.

[0057] When the relay circuit 51 is switched from the OFF state to the ON state at time t3, a current i flows through the power supply line 52. In the example of Fig. 5, the current i measured by the ammeter A flows instantaneously from time t3 to time t4, and becomes zero after time t4. The current i flowing here is the charge (amount of leakage charge) that leaked from the relay box 51b to the ground side in response to the deterioration of the relay box 51b while the relay circuit 51 was in a floating state during the period T3. In other words, the current i flowing here is the current that flowed through the power supply line 52 to compensate for the charge lost by the electrostatic electrode 1111b.

[0058] Therefore, the amount of leakage charge generated during the period T3 is calculated by integrating the current i flowing from time t3 to time t4. The amount of leakage charge is the amount of charge replenished to the electrostatic chuck 1111 between time t3 and time t4.

[0059] A method for monitoring the change in the adsorptive force over time is to use the amount of adsorptive charge introduced during adsorptive action as a reference charge amount, and calculate the ratio of the amount of leakage charge replenished during static neutralization to the reference charge amount, thereby calculating the amount of charge leakage relative to the reference charge amount. This makes it possible to monitor the decrease in adsorptive force over time and determine the adsorptive state of the substrate W. It is also possible to reduce differences between substrates W during this monitoring, and differences between the plasma processing apparatus 1. Hereinafter, the ratio of the amount of leakage charge to the amount of adsorptive charge (reference charge amount) is also referred to as the "charge leakage rate."

[0060] The integral value of the current i is correlated with the maximum value of the current i. Therefore, as another method for monitoring the change over time in the chucking force, the amount of charge leakage may be calculated by calculating the ratio of the maximum value of the current i measured during static elimination to the maximum value of the current i measured during chucking. This also makes it possible to monitor the decrease over time in the chucking force and determine the chucking state of the substrate W, and also to reduce the difference between the substrates W and the machine difference of the plasma processing apparatus 1 during this monitoring. Hereinafter, the ratio of the maximum value of the current i measured during static elimination to the maximum value of the current i measured during chucking is also referred to as the "current leakage rate."

[0061] As another method for monitoring the change over time in the attracting force, the integral value of the current i measured during the charge removal or the maximum value of the current i measured during the charge removal may be used as the "amount of leakage charge." This also makes it possible to monitor the decrease over time in the attracting force and determine the attracting state of the substrate W.

[0062] FIG. 6(a) shows the leakage charge amount versus the floating time of the relay circuit 51 on the horizontal axis, with the integral value of the current i measured during charge removal as the leakage charge amount, on the vertical axis. FIG. 6(b) shows the charge leakage rate versus the floating time of the relay circuit 51 on the horizontal axis. The floating time is the time during which the switch 51a of the relay circuit 51 is in the OFF state, and in the case of processing multiple substrates, it is the total time during which the switch 51a is in the OFF state when multiple substrates are processed sequentially. In both of FIG. 6(a) and (b), the leakage charge amount and the charge leakage rate increase in proportion to the floating time of the relay circuit 51, and the time-dependent change in the decrease in the chucking force of the electrostatic chuck 1111 can be monitored. Note that the measurement accuracy of the charge leakage rate is slightly higher than that of the leakage charge amount.

[0063] On the other hand, Fig. 6(c) shows the amount of He gas leakage on the vertical axis versus the floating time of the relay circuit 51 on the horizontal axis. As shown in A of Fig. 6(c), the amount of He gas leakage is the flow rate of He gas leaking from between the substrate W and the electrostatic chuck 1111, and is not proportional to the floating time, but increases suddenly at a certain point. Therefore, in the method of monitoring the amount of He gas leakage, it is not possible to detect a decrease in the chucking force of the substrate W at an appropriate timing before the substrate W bounces, and there is a risk that the substrate W will bounce and be damaged at the moment when the amount of He gas leakage increases suddenly.

[0064] 6(a)-(b) are set in advance as the lower limit for maintaining chucking, by setting the thresholds in Fig. 6(a)-(b) to values ​​before the substrate bounces due to leakage of He gas, corresponding to the leakage charge amount and the charge leakage rate. This makes it possible to determine the chucking state of the substrate W from the relationship between the leakage charge amount and the threshold. This makes it possible to detect a decrease in the chucking force of the substrate W at an appropriate timing before the amount of leakage of He gas increases and the substrate W bounces and is damaged. This makes it possible to determine the appropriate time to replace the relay circuit 51. Furthermore, it becomes possible to take appropriate measures, such as stopping substrate processing when the leakage charge amount exceeds the threshold in order to avoid chucking failure.

[0065] It is desirable to measure the current i every time the substrate W is plasma-processed (one by one). This prevents the substrate W from being damaged by bouncing. However, in an apparatus that processes substrates one by one, the current i may be measured every other substrate, or may be measured once per lot, or may be measured at other times. When calculating the charge leakage rate and the current leakage rate, it is essential to measure the current i at times t0 to t1 and t3 to t4 in FIG. 5. On the other hand, when calculating the "amount of leakage charge", it is essential to measure the current i at times t3 to t4 in FIG. 5, but it is not essential to measure the current i at times t0 to t1. The control unit 2 acquires the measured current i from the ammeter A.

[0066] In addition, in FIG. 5, the timing for measuring the leakage charge amount is after the substrate W is processed, but the timing is not limited to this and may be during the substrate W processing.

[0067] [Monitoring method] Next, the monitoring methods according to the first to fourth embodiments will be described with reference to Fig. 7 to Fig. 10. Fig. 7 to Fig. 10 are flow charts showing an example of the monitoring methods according to the first to fourth embodiments. The monitoring methods according to the first to fourth embodiments can be executed by the control unit 2.

[0068] First Embodiment 7 is a flowchart showing an example of a monitoring method according to the first embodiment. In this embodiment, a case will be described in which the relay circuit 51 is switched during processing of the substrate W, and the attraction state of the substrate is determined by calculating a charge leakage rate from a current i measured during processing of the substrate W and a current i measured at the time of attraction.

[0069] When this process is started, the control unit 2 controls the loading of the substrate W into the plasma processing chamber 10 and places it on the electrostatic chuck 1111 (step S1). Next, the control unit 2 supplies an RF signal (RF power) from the RF power source 31 to the conductive member of the substrate support 11, the conductive member of the shower head 13, or both (step S2). The control unit 2 also supplies an inert gas, such as argon gas, from the gas supply unit 20 into the plasma processing space 10s. This generates plasma of the inert gas in the plasma processing space 10s.

[0070] Next, the control unit 2 turns on the DC power supply 50 to supply a voltage to the electrostatic electrode 1111b, and adsorbs the substrate W onto the upper surface of the electrostatic chuck 1111 (step S3). By turning on the DC power supply 50, the voltage is increased from 0 to V p , whereby a DC current i flows through the power supply line 52 connecting the DC power supply 50 and the electrostatic electrode 1111b. The ammeter A measures the current i. The control unit 2 acquires the current i measured by the ammeter A, calculates the integral value of the current i, and sets it as the amount of adsorption charge (step S4).

[0071] After the voltage supplied to the electrostatic electrode 1111b becomes stable, the control unit 2 switches the relay circuit 51 from the on state to the off state, stops the supply of voltage to the electrostatic electrode 1111b, and sets the electrostatic electrode 1111b in a floating state (step S5). Next, the control unit 2 introduces He gas to the rear surface of the substrate W (step S6).

[0072] Next, the processing of the substrate W is started (step S7), and the processing of the substrate W shown in steps S7 to S11 is performed a preset number of times. The control unit 2 switches the relay circuit 51 from an off state to an on state during the processing of the substrate W (step S8), and the relay circuit 51 is brought into a connected state. This causes a voltage to be supplied from the DC power supply 50 to the electrostatic electrode 1111b. At this time, the ammeter A measures the current i flowing through the power supply line 52. The control unit 2 acquires the current i measured by the ammeter A, calculates the integral value of the current i as the amount of leakage charge, and calculates the ratio of the amount of leakage charge to the amount of adsorption charge to obtain the charge leakage rate (step S9).

[0073] Next, the control unit 2 determines whether the charge leakage rate is smaller than a threshold value (step S10). In step S10, if the control unit 2 determines that the charge leakage rate is equal to or greater than the threshold value, it stops the processing of the substrate W, displays a warning for replacing the relay circuit 51 (step S12), and ends this processing. If the control unit 2 determines that the charge leakage rate is smaller than the threshold value, it determines whether the processing of steps S7 to S11 has been repeated a set number of times (step S11). If the control unit 2 determines that the processing has not been repeated the set number of times, it returns to step S7 and continues the processing of the substrate W. In the repeated processing of steps S7 to S11, after the relay circuit 51 is switched from the OFF state to the ON state once in step S8, the relay circuit 51 is switched from the ON state to the OFF state before the processing of the next step S8 is performed.

[0074] In step S11, when the control unit 2 determines that the processes of steps S7 to S11 have been repeated a set number of times, it stops the supply of He gas and evacuates the rear surface of the substrate W to set the He gas pressure on the rear surface of the substrate W to 0 (step S13). Then, it performs a charge removal process and peels the substrate W from the electrostatic chuck 1111 (step S14). Next, the control unit 2 unloads the substrate W from the plasma processing chamber 10 (step S15) and ends this process.

[0075] In this embodiment, the charge leakage rate is calculated from the measurement result of the current, and the attraction state of the substrate W is judged based on the charge leakage rate. This makes it possible to monitor the decrease in the attraction force over time, detect the decrease in the attraction force of the substrate W at an appropriate timing, and judge the attraction state of the substrate W. Also, the difference between the substrates W and the machine difference of the plasma processing apparatus 1 during this monitoring can be reduced.

[0076] <Second embodiment> 8 is a flow chart showing an example of a monitoring method according to the second embodiment. In this embodiment, a case will be described in which the relay circuit 51 is switched after the substrate W is processed, and the charge leakage rate is calculated from the measured current i to determine the attraction state of the substrate. The same steps as those in the monitoring method according to the first embodiment are assigned the same step numbers, and duplicated explanations will be omitted.

[0077] When this process is started, the control unit 2 executes the processes of steps S1 to S7. As a result, the substrate W is processed. After the substrate W is processed, the control unit 2 switches the relay circuit 51 from the off state to the on state (step S21), and the relay circuit 51 is connected. As a result, a voltage is supplied from the DC power supply 50 to the electrostatic electrode 1111b. The ammeter A measures the current i flowing through the power supply line 52. The control unit 2 acquires the current i measured by the ammeter A, calculates the integral value of the current i as the amount of leakage charge, and calculates the ratio of the amount of leakage charge to the amount of adsorption charge calculated in step S4 to obtain the charge leakage rate (step S22).

[0078] Next, the control unit 2 stops the supply of He gas and evacuates the back surface of the substrate W (step S23). Next, the control unit 2 determines whether the charge leakage rate is smaller than a threshold value (step S10). If the control unit 2 determines that the charge leakage rate is equal to or greater than the threshold value, it stops the substrate W processing, displays a warning to replace the relay circuit 51 (step S12), and ends this processing. If the control unit 2 determines in step S10 that the charge leakage rate is smaller than a preset threshold value, it performs a charge removal process and peels the substrate W from the electrostatic chuck 1111 (step S14). Next, the control unit 2 unloads the substrate W from the plasma processing chamber 10 (step 15), and ends this processing.

[0079] In this embodiment, the charge leakage rate is calculated from the measurement result of the current, and the attraction state of the substrate W is judged based on the charge leakage rate. This makes it possible to monitor the decrease in the attraction force over time, detect the decrease in the attraction force of the substrate W at an appropriate timing, and judge the attraction state of the substrate W. Also, the difference between the substrates W and the machine difference of the plasma processing apparatus 1 during this monitoring can be reduced.

[0080] <Third embodiment> 9 is a flow chart showing an example of a monitoring method according to the third embodiment. In this embodiment, a case will be described in which the relay circuit 51 is switched during processing of the substrate W, and the amount of leakage charge is calculated from the measured current i to determine the attraction state of the substrate. The same steps as those in the monitoring methods according to the first and second embodiments are assigned the same step numbers, and duplicated explanations will be omitted.

[0081] When this process is started, the control unit 2 executes the processes of steps S1 to S3 and S5 to S8. In step S7, the process of the substrate W is started, and the process of the substrate W in steps S7, S8, S31, S32, and S11 is executed a preset number of times.

[0082] The processing of the substrate W is started (step S7), and during the processing of the substrate W, the relay circuit 51 is switched from the OFF state to the ON state (step S8), whereby a voltage is supplied from the DC power supply 50 to the electrostatic electrode 1111b. At this time, the ammeter A measures the current i flowing through the power supply line 52, and the control unit 2 acquires the current i measured by the ammeter A and calculates the integral value of the current i to be the amount of leakage charge (step S31). Next, the control unit 2 determines whether the amount of leakage charge is smaller than a threshold value (step S32).

[0083] If the control unit 2 determines that the amount of leakage charge is equal to or greater than the threshold, it stops the processing of the substrate W, displays a warning to replace the relay circuit 51 (step S12), and ends this processing. If the control unit 2 determines that the amount of leakage charge is smaller than the threshold in step S32, it determines whether the process has been repeated a set number of times (step S11). If the control unit 2 determines in step S32 that the process has not been repeated the set number of times, it returns to step S7 and continues the processing of the substrate W.

[0084] In step S11, if the control unit 2 determines that the processes of steps S7 to S11 have been repeated a set number of times, it evacuates the back surface of the substrate W, performs a discharge process, and removes the substrate W from the plasma processing chamber 10 (steps S13 to S15), thereby completing this process.

[0085] In this embodiment, the amount of leakage charge is calculated from the measurement result of the current, and the attraction state of the substrate W is determined based on the amount of leakage charge. This makes it possible to monitor the decrease in the attraction force over time, detect the decrease in the attraction force of the substrate W at an appropriate timing, and determine the attraction state of the substrate W.

[0086] <Fourth embodiment> 10 is a flow chart showing an example of a monitoring method according to the fourth embodiment. In this embodiment, a case will be described in which the relay circuit 51 is switched after the substrate W is processed, and the amount of leakage charge is calculated from the measured current i to determine the attraction state of the substrate. The same steps as those in the monitoring methods according to the first to third embodiments are given the same step numbers, and duplicated explanations will be omitted.

[0087] When this process is started, the control unit 2 executes the processes of steps S1 to S3 and S5 to S8. In step S7, the process of the substrate W is started, and during the process of the substrate W, the relay circuit 51 is switched from the OFF state to the ON state (step S8), whereby a voltage is supplied from the DC power supply 50 to the electrostatic electrode 1111b. At this time, the ammeter A measures the current i flowing through the power supply line 52. The control unit 2 acquires the current i measured by the ammeter A, calculates the integral value of the current i, and sets it as the amount of leakage charge (step S31). The control unit 2 stops the supply of He gas, and evacuates the rear surface of the substrate W (step S23). Next, the control unit 2 determines whether the amount of leakage charge is smaller than a threshold value (step S32).

[0088] If the control unit 2 determines that the amount of leakage charge is equal to or greater than the threshold, it stops the processing of the substrate W, displays a warning to replace the relay circuit 51 (step S12), and ends this processing. If the control unit 2 determines in step S32 that the amount of leakage charge is smaller than the threshold, it performs a charge removal processing, unloads the substrate W from the plasma processing chamber 10 (steps S14 to S15), and ends this processing.

[0089] In this embodiment, the amount of leakage charge is calculated from the measurement result of the current, and the attraction state of the substrate W is determined based on the amount of leakage charge. This makes it possible to monitor the decrease in the attraction force over time, detect the decrease in the attraction force of the substrate W at an appropriate timing, and determine the attraction state of the substrate W.

[0090] As described above, according to the monitoring method and plasma processing apparatus of this embodiment, a decrease in the chucking force of the substrate W can be detected at an appropriate timing.

[0091] In the monitoring methods of the first to fourth embodiments, in step S12, as an example of a warning, the processing of the substrate W is stopped and a warning to replace the relay circuit 51 is displayed, but this is not limited to this. For example, only a warning to replace may be displayed. Furthermore, together with the display of the warning to replace, instead of stopping the processing of the substrate W currently being processed, the processing of the substrate W to be processed next may be stopped.

[0092] The plasma processing apparatus according to each embodiment disclosed herein and the program for executing the monitoring method according to each embodiment should be considered as illustrative in all respects and not restrictive. Each embodiment can be modified and improved in various forms without departing from the scope and spirit of the appended claims. The matters described in the above embodiments can be configured in other ways as long as they are not inconsistent, and can be combined as long as they are not inconsistent.

[0093] The substrate W processing performed by the plasma processing apparatus of the present disclosure includes, for example, an etching process, a film formation process, etc. The plasma processing apparatus of the present disclosure can be applied to any of a single-wafer processing apparatus that processes substrates one by one, a batch processing apparatus that processes a plurality of substrates at once, and a semi-batch processing apparatus.

[0094] The monitoring method of each embodiment may be executed by the control unit 2 controlling the plasma processing apparatus 1 based on a program for executing the monitoring method. The program for executing the monitoring method of each embodiment may be stored in a storage unit 2a2 such as a ROM or RAM. The control unit 2 may be realized by a computer 2a that controls the operation of the monitoring method of each embodiment. In this case, the computer 2a reads out the program and executes the read program to operate the plasma processing apparatus 1 according to each embodiment to execute the monitoring method and detect a decrease in the chucking force of the substrate W. The program may be acquired via a recording medium. The acquired program may be stored in the storage unit 2a2. The computer 2a may read out the acquired program and execute the read program to operate the plasma processing apparatus 1 to execute the monitoring method.

[0095] The monitoring method in each embodiment may be executed not only by the control unit 2 but also by an information processing device capable of communicating with the plasma processing device 1 controlling the plasma processing device 1 with or without cooperation with the control unit 2. The information processing device executes the monitoring method by operating the plasma processing device 1 based on a program for executing the monitoring method, thereby detecting a decrease in the chucking force of the substrate W.

[0096] The information processing device may transmit and receive information via a communication interface 2a3 of the control unit 2 over a network (not shown), for example, and operate the plasma processing device 1 to execute the monitoring method. The information processing device may be any type of computer that can be connected to the control unit 2 or the plasma processing device 1 over a network (not shown), and may be, for example, a cloud computer. In addition, the program read by the information processing device may be stored in a storage area other than the storage unit 2a2, and may be, for example, a memory of a cloud computer. [Explanation of symbols]

[0097] 1. Plasma processing equipment 2. Control section 2a Computer 2a1 Processing section 2a2 Storage section 2a3 Communication Interface 10 Plasma Processing Chamber 11 Substrate support 13. Shower Head 21 Gas Source 20 Gas supply section 30 power supply 31 RF power supply 31a First RF generation unit 31b Second RF generation unit 32a First DC generation unit 32b Second DC generation section 50 DC power supply 51 Relay Circuit 111 Main body 112 Ring Assembly

Claims

1. an electrostatic chuck that is accommodated in the plasma processing chamber, has an electrostatic electrode, and attracts the substrate by a voltage supplied to the electrostatic electrode; A DC power source that supplies a voltage to the electrostatic electrode; a relay circuit disposed in a power supply line between the DC power source and the electrostatic electrode, for turning on and off the supply of voltage to the electrostatic electrode; a plasma generating unit for generating plasma within the plasma processing chamber; A control unit, The control unit is (a) supplying a voltage to the electrostatic electrode to attract a substrate to an upper surface of the electrostatic chuck; (b) after the voltage supplied to the electrostatic electrode has stabilized, the relay circuit cuts off the supply of voltage to the electrostatic electrode, thereby putting the electrostatic electrode into a floating state; (c) starting a process of the substrate attracted to the electrostatic chuck by plasma after the voltage supplied to the electrostatic electrode has stabilized; and (d) after starting the processing of the substrate, turning on the supply of voltage to the electrostatic electrode by the relay circuit and acquiring a current flowing through the power supply line when a voltage is supplied to the electrostatic electrode; (e) determining an attraction state of the substrate based on the current.

2. (f) acquiring a current flowing through the power supply line when a voltage is supplied to the electrostatic electrode in (a); (e) determining an attraction state of the substrate based on the current in (f) and the current in (e); The plasma processing apparatus according to claim 1 .

3. the step (e) calculates a current leakage rate indicated by a ratio of an integral value of the current acquired in the step (e) to an integral value of the current acquired in the step (f), and determines an attraction state of the substrate based on the current leakage rate. The plasma processing apparatus according to claim 2 .

4. the step (e) calculates a charge leakage rate indicated by a ratio of the maximum value of the current acquired in the step (e) to the maximum value of the current acquired in the step (f), and determines an attraction state of the substrate based on the charge leakage rate; The plasma processing apparatus according to claim 2 .

5. (e) determining an attraction state of the substrate based on an integral value of the current acquired in (e); The plasma processing apparatus according to claim 1 .

6. (e) determining an attraction state of the substrate based on the maximum value of the current acquired in (e); The plasma processing apparatus according to claim 1 .

7. The step (e) is performed during and / or after the processing of the substrate. The plasma processing apparatus according to claim 1 .

8. (e) stopping the processing of the substrate based on a result of the determination of the suction state of the substrate; The plasma processing apparatus according to claim 1 .

9. (e) displays a message to prompt replacement of the relay circuit based on a result of the determination of the suction state of the substrate. The plasma processing apparatus according to claim 1 .

10. an electrostatic chuck that is accommodated in the plasma processing chamber, has an electrostatic electrode, and attracts the substrate by a voltage supplied to the electrostatic electrode; A DC power source that supplies a voltage to the electrostatic electrode; a relay circuit disposed in a power supply line between the DC power source and the electrostatic electrode, for turning on and off the supply of voltage to the electrostatic electrode; a plasma generating unit for generating plasma within the plasma processing chamber; A program to be executed by an information processing device for controlling a plasma processing device having the (a) supplying a voltage to the electrostatic electrode to attract a substrate to an upper surface of the electrostatic chuck; (b) after the voltage supplied to the electrostatic electrode has stabilized, the relay circuit cuts off the supply of voltage to the electrostatic electrode, thereby putting the electrostatic electrode into a floating state; (c) starting a process of processing the substrate attracted to the electrostatic chuck by plasma after the voltage supplied to the electrostatic electrode has stabilized; and (d) after starting the processing of the substrate, turning on the supply of voltage to the electrostatic electrode by the relay circuit and acquiring a current flowing through the power supply line when a voltage is supplied to the electrostatic electrode; (e) determining an attraction state of the substrate based on the current; and A program for causing the information processing device to execute the above.

Images