Plasma processing apparatus and plasma processing method

Abstract

To start plasma processing after confirming that a substrate is adsorbed to an electrostatic chuck.SOLUTION: A plasma processing apparatus comprises an electrostatic chuck, a first switch, a second switch, and a control unit. The electrostatic chuck adsorbs a substrate which is subjected to plasma processing, with voltage applied to an internal electrode. The first switch is provided in wiring between an electric power source and the electrode. The second switch is provided in wiring between a detector and the electrode. The control unit controls the first switch and the second switch into a closed state, causes the electric power source to output first voltage and, when the first voltage is detected by the detector, determines that the first switch and the second switch are in the closed state. After it is determined that the first switch and the second switch are in the closed state, the control unit controls the first switch and the second switch into an open state and starts substrate processing using plasma while controlling the electrode into a floating state.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] Various aspects and embodiments of the present disclosure relate to plasma processing apparatuses and methods. [Background technology]

[0002] For example, Patent Document 1 listed below discloses a plasma processing apparatus in which a switch is provided between an electrode provided on an electrostatic chuck that attracts and holds a substrate to be processed and a DC power supply that applies a DC voltage to the electrode. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-46997 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a plasma processing apparatus and a plasma processing method that are capable of starting plasma processing after confirming that a substrate is attracted to an electrostatic chuck. [Means for solving the problem]

[0005] One aspect of the present disclosure is a plasma processing apparatus including an electrostatic chuck, a first switch, a second switch, and a control unit. The electrostatic chuck is provided in a chamber, has an electrode therein, and adsorbs a substrate to be processed using plasma by a voltage applied to the electrode. The first switch is provided on a wiring between a power source that supplies a voltage to the electrode and the electrode. The second switch is provided on a wiring between a detector that detects the voltage of the electrode and the electrode. The control unit controls the first switch and the second switch to a closed state, controls the power source so that a first voltage of a predetermined magnitude is output from the power source, and executes a first determination process of determining that the first switch and the second switch are in a closed state when the first voltage is detected by the detector. In addition, after it is determined that the first switch and the second switch are in a closed state, the control unit starts processing of the substrate using plasma in a state in which the electrodes are controlled to a floating state by controlling the first switch and the second switch to an open state. Effect of the Invention

[0006] According to various aspects and embodiments of the present disclosure, plasma processing can be started after it is confirmed that the substrate is attracted to the electrostatic chuck. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating an example of a plasma processing system according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a flow chart illustrating an example of a plasma processing method according to an embodiment of the present disclosure. [Diagram 3] FIG. 3 is a flowchart illustrating an example of a plasma processing method according to an embodiment of the present disclosure. [Figure 4] FIG. 4 is a time chart showing an example of a control procedure. [Diagram 5] FIG. 5 is a diagram showing an example of the states of the first switch and the second switch. [Figure 6]FIG. 6 is a diagram showing an example of the states of the first switch and the second switch. [Figure 7] FIG. 7 is a diagram showing an example of the states of the first switch and the second switch. [Figure 8] FIG. 8 is a time chart showing another example of the control procedure. [Figure 9] FIG. 9 is a time chart showing another example of the control procedure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, embodiments of the disclosed plasma processing apparatus and plasma processing method will be described in detail with reference to the drawings. Note that the disclosed plasma processing apparatus and plasma processing method are not limited to the following embodiments.

[0009] However, if a switch provided in a wiring between an electrode in an electrostatic chuck and a power supply that applies a voltage to the electrode fails and remains open, a desired voltage is not applied to the electrode. If a desired voltage is not applied to the electrode, a desired electrostatic force is not generated in the electrode, and the substrate is not attracted to the electrostatic chuck. As a result, when the substrate is processed using plasma, the substrate may move relative to the electrostatic chuck, and the accuracy of the substrate processing may decrease.

[0010] Therefore, the present disclosure provides a technique that allows plasma processing to be started after it is confirmed that a substrate is attracted to an electrostatic chuck.

[0011] [Configuration of Plasma Processing System 100] An example of the configuration of the plasma processing system 100 will be described below. FIG. 1 is a diagram illustrating an example of the plasma processing system 100 according to an embodiment of the present disclosure. The plasma processing system 100 includes a capacitively coupled plasma processing device 1 and a control unit 2. The plasma processing device 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, and an exhaust system 40. The plasma processing device 1 also includes a substrate support unit 11 and a gas introduction unit. The gas introduction unit is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas introduction unit includes a shower head 13. The substrate support unit 11 is disposed in the plasma processing chamber 10. The shower head 13 is disposed above the substrate support unit 11. In an embodiment, the shower head 13 constitutes at least a part of a ceiling of the plasma processing chamber 10.

[0012] The plasma processing chamber 10 has a plasma processing space 10s defined by a showerhead 13, a sidewall 10a of the plasma processing chamber 10, and a substrate support 11. The plasma processing chamber 10 has at least one gas supply port for supplying at least one processing gas to the plasma processing space 10s and at least one gas exhaust port for exhausting gas from the plasma processing space 10s. The sidewall 10a is grounded. The showerhead 13 and the substrate support 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0013] The substrate support 11 includes a main body 111 and a ring assembly 112. The main body 111 has a substrate support surface 111a which is a central region for supporting the substrate W, and a ring support surface 111b which is an annular region for supporting the ring assembly 112. The substrate W is sometimes called a wafer. The ring support surface 111b of the main body 111 surrounds the substrate support surface 111a of the main body 111 in a plan view. The substrate W is disposed on the substrate support surface 111a of the main body 111, and the ring assembly 112 is disposed on the ring support surface 111b of the main body 111 so as to surround the substrate W on the substrate support surface 111a of the main body 111.

[0014] In one embodiment, the main body 111 includes an electrostatic chuck 1110 and a base 1111. The base 1111 includes a conductive member. The conductive member of the base 1111 functions as a lower electrode. The electrostatic chuck 1110 is disposed on the base 1111. The upper surface of the electrostatic chuck 1110 is a substrate support surface 111a. The electrostatic chuck 1110 is provided with an electrode 1110a. The electrode 1110a is connected to a variable DC power supply 115 via a wiring 113. The wiring 113 is provided with a first switch 114. When the first switch 114 is in a closed state, the electrode 1110a generates an electrostatic force on the substrate support surface 111a by a DC voltage applied from the variable DC power supply 115. As a result, the electrostatic chuck 1110 adsorbs the substrate W disposed on the substrate support surface 111a. When the substrate W is attracted to the electrostatic chuck 1110, a first voltage (hereinafter, may be referred to as an H voltage) of a predetermined magnitude is applied from the variable DC power supply 115 to the electrode 1110a.

[0015] In this embodiment, after the substrate W is attracted to the electrostatic chuck 1110, the first switch 114 is controlled to be in an open state, so that the electrode 1110a is brought into a floating state. In the floating state, the charge accumulated in the electrode 1110a until just before the electrode 1110a is brought into a floating state is maintained. Then, after the electrode 1110a is brought into a floating state, plasma processing is performed on the substrate W using plasma. By performing the plasma processing with the electrode 1110a in a floating state, excessive charging of the substrate W during the plasma processing is suppressed. In addition, by performing the plasma processing with the electrode 1110a in a floating state, excessive attracting force between the substrate W and the electrostatic chuck 1110 during the plasma processing is suppressed.

[0016] Further, the electrode 1110a is connected to the detector 118 via the wiring 116. The wiring 116 is provided with a second switch 117. When the second switch 117 is closed, the detector 118 detects the magnitude of the voltage of the electrode 1110a via the wiring 116. For example, the detector 118 detects the voltage of the electrode 1110a after the electrode 1110a is neutralized after the plasma processing on the substrate W is completed. When the magnitude of the voltage of the electrode 1110a detected by the detector 118 is a second voltage (hereinafter, may be referred to as an L voltage) lower than the first voltage, the control unit 2 determines that neutralization is completed and starts unloading the substrate W for which the plasma processing has been completed.

[0017] If the second switch 117 is not provided and the electrode 1110a and the detector 118 are constantly connected via the wiring 116, the charge accumulated in the electrode 1110a in the floating state will leak via the wiring 116 and the detector 118. If the charge accumulated in the electrode 1110a leaks via the wiring 116 and the detector 118, the charge accumulated in the electrode 1110a will decrease, and the adsorptive force between the substrate W and the electrostatic chuck 1110 will decrease during plasma processing. This makes it difficult to maintain the position of the substrate W at a predetermined position relative to the electrostatic chuck 1110.

[0018] Therefore, in this embodiment, a second switch 117 is provided on the wiring 116, and the second switch 117 is controlled to a closed state only when it is necessary to detect the voltage of the electrode 1110a. In particular, during plasma processing, the second switch 117 is controlled to an open state. This suppresses a decrease in the charge accumulated in the electrode 1110a in a floating state during plasma processing, and suppresses a decrease in the adsorptive force between the substrate W and the electrostatic chuck 1110. This makes it possible to maintain the position of the substrate W at a predetermined position relative to the electrostatic chuck 1110.

[0019] However, if the first switch 114 is in an open state and has a failure, even if the control unit 2 controls the first switch 114 to a closed state, the first switch 114 does not become in a closed state. Hereinafter, a state of the switch that remains in an open state despite being controlled to a closed state is described as an open failure. If the first switch 114 has an open failure, no voltage is applied to the electrode 1110a, and the substrate W is not attracted to the electrostatic chuck 1110. In order for the substrate W to be attracted to the electrostatic chuck 1110, it is necessary to confirm that the first switch 114 does not have an open failure, and if the first switch 114 has an open failure, it is necessary to take measures such as stopping the plasma processing. Therefore, in this embodiment, it is confirmed that the first switch 114 does not have an open failure before the plasma processing is started.

[0020] Moreover, when the first switch 114 is in a closed state and has a failure, even if the control unit 2 controls the first switch 114 to an open state, the first switch 114 does not become an open state. Hereinafter, a state of the switch that remains in a closed state despite being controlled to an open state is described as a closed failure. When the first switch 114 is in a closed failure, the electrode 1110a cannot be brought into a floating state, and the substrate W may become excessively charged during plasma processing, or an excessive adsorption force may occur between the substrate W and the electrostatic chuck 1110. When an excessive adsorption force occurs between the substrate W and the electrostatic chuck 1110, particles are generated due to friction between the substrate W and the electrostatic chuck 1110. When the substrate W becomes excessively charged, particles are likely to adhere to the substrate W. Therefore, it is necessary to confirm that the first switch 114 is not in a closed failure. Then, when the first switch 114 is in a closed failure, it is necessary to take measures such as stopping the plasma processing. Therefore, in this embodiment, it is confirmed that the first switch 114 is not in a closed failure.

[0021] The ring assembly 112 includes one or more annular members. At least one of the one or more annular members is an edge ring. Although not shown, the substrate support 11 may include a temperature adjustment module configured to adjust at least one of the electrostatic chuck 1110, the ring assembly 112, and the substrate W to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow path, or a combination thereof. A heat transfer fluid such as brine or gas flows through the flow path. The substrate support 11 may also include a heat transfer gas supply unit configured to supply a heat transfer gas between the substrate W and the substrate support surface 111a.

[0022] 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 a conductive member. The conductive member of the shower head 13 functions as an upper electrode. In addition to the shower head 13, the gas introduction unit may include one or more side gas injectors (SGIs) attached to one or more openings formed in the side wall 10a.

[0023] 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 corresponding gas source 21 through a corresponding 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.

[0024] The power source 30 includes an RF (Radio Frequency) 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 provide at least one RF signal, such as a source RF signal and a bias RF signal, to a conductive member of the substrate support 11, a conductive member of the showerhead 13, or both. This causes a plasma to be formed from at least one processing gas provided to the plasma processing space 10s. Thus, the RF power source 31 may 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. Also, by providing a bias RF signal to the conductive member of the substrate support 11, a bias potential is generated on the substrate W, and ion components in the formed plasma can be attracted to the substrate W.

[0025] 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 a conductive member of the substrate support 11, a conductive member of the showerhead 13, or both via at least one impedance matching circuit, and is configured to generate a source RF signal for plasma generation. The source RF signal may be referred to as a source RF power. In one embodiment, the source RF signal has a signal with a frequency in the range of 13 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 the conductive member of the substrate support 11, the conductive member of the showerhead 13, or both.

[0026] The second RF generator 31b is coupled to the conductive member of the substrate support 11 via at least one impedance matching circuit and configured to generate a bias RF signal. The bias RF signal may be referred to as a bias RF power. In one embodiment, the bias RF signal has a lower frequency than the source RF signal. In one embodiment, the bias RF signal has a signal with a frequency in the range of 400 kHz to 13.56 MHz. In one embodiment, the second RF generator 31b may be configured to generate multiple bias RF signals with different frequencies. The generated one or more bias RF signals are provided to the conductive member of the substrate support 11. Also, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0027] The power supply 30 may also include a direct current (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 a conductive member of the substrate support 11 and configured to generate a first DC signal. The generated first DC signal is applied to the conductive member of the substrate support 11. In other embodiments, the first DC signal may be applied to another electrode, such as the electrode 1110a in the electrostatic chuck 1110. In one embodiment, the second DC generator 32b is connected to a conductive member of the showerhead 13 and configured to generate a second DC signal. The generated second DC signal is applied to the conductive member of the showerhead 13. In various embodiments, at least one of the first and second DC signals may be pulsed. The first DC generating unit 32a and the second DC generating unit 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.

[0028] 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.

[0029] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various steps described in this disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform 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, for example, a computer 2a. The computer 2a may include, for example, a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The processing unit 2a1 may be configured to perform various control operations based on a program stored in the storage unit 2a2. The processing unit 2a1 may include a central processing unit (CPU). 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 communicates with the plasma processing apparatus 1 via a communication line such as a local area network (LAN).

[0030] [Plasma treatment method] 2 and 3 are flow charts showing an example of a plasma processing method according to an embodiment of the present disclosure. Each process illustrated in Fig. 2 and Fig. 3 is realized by the control unit 2 controlling each part of the plasma processing apparatus 1. The following description will be given with reference to the time chart illustrated in Fig. 4.

[0031] 2 and 3, in an initial state (period (a1) illustrated in FIG. 4), the first switch 114 is controlled to a closed state, the second switch 117 is controlled to an open state, and an L voltage is output from the variable DC power supply 115. Therefore, as shown in period (a1) illustrated in FIG. 4, the voltage of the electrode 1110a in the electrostatic chuck 1110 is an L voltage, and the voltage detected by the detector 118 is also an L voltage. In the example of FIG. 4, the closed state of each switch is described as "ON" and the open state is described as "OFF."

[0032] First, the control unit 2 controls a transfer device (not shown) to start loading the substrate W into the plasma processing chamber 10 (S100).

[0033] Next, the control unit 2 controls the output voltage of the variable DC power supply 115 to be the H voltage (S101). The process of step S101 is an example of step a). As a result, the output voltage from the variable DC power supply 115 becomes the H voltage during the period (a2) illustrated in FIG. 4. Here, if the first switch 114 is in a closed state, the voltage of the electrode 1110a in the electrostatic chuck 1110 becomes the H voltage during the period (a2) illustrated in FIG. 4, and the voltage detected by the detector 118 becomes the L voltage. On the other hand, if the first switch 114 is in an open state, the voltage of the electrode 1110a remains at the L voltage during the period (a2) illustrated in FIG. 4, and the voltage detected by the detector 118 also remains at the L voltage.

[0034] Next, the control unit 2 determines whether the voltage detected by the detector 118 is an L voltage or not (S102). Even if the first switch 114 is controlled to a closed state and the second switch 117 is controlled to an open state, if the first switch 114 and the second switch 117 are in a closed state, for example, as shown in Fig. 5, the voltage detected by the detector 118 is an H voltage. In the example of Fig. 5, the second switch 117 is in a closed state even though it is controlled to an open state, and therefore the second switch 117 is in a closed fault state.

[0035] If the voltage detected by detector 118 is the H voltage (S102: No), the second switch 117 has a closed failure, and the plasma processing method illustrated in FIGS. 2 and 3 ends without starting plasma processing.

[0036] On the other hand, if the voltage detected by the detector 118 is the L voltage (S102: Yes), the control unit 2 controls the second switch 117 to the closed state (S103). As a result, the second switch 117 is controlled to the closed state during the period (a3) ​​illustrated in FIG. 4. The process of step S103 is an example of process b). Even if the voltage detected by the detector 118 is the L voltage in step S102, the first switch 114 may have an open failure, as shown in FIG. 6, for example. Alternatively, even if the voltage detected by the detector 118 is the L voltage, the first switch 114 may have an open failure and the second switch 117 may have a close failure, as shown in FIG. 7, for example.

[0037] Next, the control unit 2 determines whether the voltage detected by the detector 118 is the H voltage (S104). If the voltage detected by the detector 118 is the L voltage (S104: No), at least one of the first switch 114 and the second switch 117 has an open failure. Therefore, the plasma processing method illustrated in FIGS. 2 and 3 ends without starting the plasma processing.

[0038] On the other hand, if the voltage detected by the detector 118 is the H voltage (S104: Yes), the first switch 114 and the second switch 117 are in the closed state as controlled by the control unit 2 during the period (a3) ​​illustrated in FIG. 4. This confirms that the first switch 114 and the second switch 117 are not at least in an open state. If the first switch 114 is not in an open state, the voltage output from the variable DC power supply 115 is applied to the electrode 1110a via the first switch 114, and the substrate W is attracted to the electrostatic chuck 1110. By confirming that the first switch 114 is not at least in an open state, it is possible to confirm that the substrate W is attracted to the electrostatic chuck 1110. Therefore, after it is confirmed that the substrate W is attracted to the electrostatic chuck 1110, the plasma processing can be started. The processing in step S104 is an example of a first determination processing and a process c).

[0039] Next, the control unit 2 controls the second switch 117 to be in the open state (S105). In step S105, the second switch 117 is controlled to be in the open state during a period (a4) illustrated in FIG.

[0040] Next, the control unit 2 determines whether the voltage detected by the detector 118 is the L voltage (S106). If the voltage detected by the detector 118 is the H voltage (S106: No), the second switch 117 has a close failure, and the plasma processing method illustrated in Fig. 2 and Fig. 3 ends without starting the plasma processing. This makes it possible to prevent the charge accumulated in the electrode 1110a in a floating state from leaking through the wiring 116 and the detector 118 during the plasma processing, and thus to prevent a decrease in the adsorptive force between the substrate W and the electrostatic chuck 1110.

[0041] On the other hand, if the voltage detected by the detector 118 is the L voltage (S106: Yes), it is confirmed in step S104 that the first switch 114 does not have an open fault, and therefore it is confirmed that the second switch 117 does not have a close fault. The process of step S106 is an example of a second determination process.

[0042] Next, the control unit 2 controls the first switch 114 to be in an open state (S107). In step S107, the first switch 114 is controlled to be in an open state during a period (a5) illustrated in FIG. 4. When the first switch 114 is in an open state, the electrode 1110a of the electrostatic chuck 1110 is in a floating state. Note that the processes of steps S101 to S107 are performed while the substrate W is being loaded before plasma processing.

[0043] Next, the control unit 2 performs plasma processing on the substrate W (S108). In step S108, the plasma processing is performed during a period (a6) illustrated in FIG. 4. Then, the plasma processing ends during a period (a7) illustrated in FIG. The processing in step S108 is an example of process d).

[0044] Next, the control unit 2 controls the first switch 114 to the closed state (S109). Since it is confirmed in step S104 that the first switch 114 does not have an open failure, in step S109, the first switch 114 is in the closed state during the period (a8) illustrated in FIG.

[0045] Next, the control unit 2 controls the output voltage of the variable DC power supply 115 to the L voltage (S110). In step S110, the output voltage of the variable DC power supply 115 is controlled to the L voltage during the period (a9) illustrated in FIG. 4. This causes the charge accumulated in the electrode 1110a to flow through the variable DC power supply 115, and the electrode 1110a is neutralized. In this embodiment, when the electrode 1110a is neutralized, the voltage of the electrode 1110a becomes the L voltage, which is the same as the output voltage of the variable DC power supply 115.

[0046] Next, the control unit 2 controls the second switch 117 to a closed state (S111). In step S111, the second switch 117 is controlled to a closed state during the period (a10) illustrated in FIG. 4. In step S104, it is confirmed that the first switch 114 and the second switch 117 do not have an open failure. Therefore, during the period (a10), the second switch 117 is controlled to a closed state, and the detector 118 can detect the voltage of the electrode 1110a.

[0047] In addition, the life of the switch is longer when the switching is performed under a low applied voltage condition. During the period (a9) to (a10) illustrated in Fig. 4, the second switch 117 is switched from the open state to the closed state, and at that time, the voltage of the wiring 116 on which the second switch 117 is provided is the L voltage. This can extend the life of the second switch 117.

[0048] Next, the control unit 2 judges whether the voltage detected by the detector 118 is the L voltage or not (S112 in FIG. 3). The process of step S112 is an example of a third judgment process. If the voltage detected by the detector 118 is the H voltage (S112: No), the electrode 1110a has not been sufficiently neutralized. If the electrode 1110a has not been sufficiently neutralized, the substrate W may jump up or crack when the processed substrate W is separated from the electrostatic chuck 1110 by a lift pin or the like (not shown). Therefore, the control unit 2 stops carrying out the substrate W after the plasma processing, and ends the plasma processing method exemplified in FIG. 2 and FIG. 3.

[0049] On the other hand, if the voltage detected by the detector 118 is the L voltage (S112: Yes), the electrode 1110a has been sufficiently neutralized, so the control unit 2 starts unloading the substrate W after the plasma processing (S113). In step S113, the control unit 2 controls a drive unit (not shown) that drives the lift pins so as to lift the substrate W by the lift pins.

[0050] Next, the control unit 2 controls the first switch 114 and the second switch 117 to be in the open state (S114). In step S114, the first switch 114 and the second switch 117 are controlled to be in the open state during the period (a11) illustrated in FIG.

[0051] Next, the control unit 2 controls the output voltage of the variable DC power supply 115 to the H voltage (S115). In step S115, the output voltage of the variable DC power supply 115 is controlled to the H voltage during the period (a12) illustrated in FIG.

[0052] Next, the control unit 2 controls the second switch 117 to a closed state (S116). In step S116, the second switch 117 is controlled to a closed state during the period (a13) illustrated in Fig. 4. Since it is confirmed in step S104 that the second switch 117 does not have an open failure, the second switch 117 is controlled to a closed state during the period (a13), and the detector 118 can detect the voltage of the electrode 1110a.

[0053] Next, the control unit 2 determines whether the voltage detected by the detector 118 is the L voltage (S117). If the voltage detected by the detector 118 is the H voltage (S117: No), the first switch 114 has a close failure, so the plasma processing for the next substrate W is stopped and the plasma processing method illustrated in FIGS. 2 and 3 is terminated.

[0054] On the other hand, if the voltage detected by the detector 118 is the L voltage (S117: Yes), it is confirmed in step S104 that the second switch 117 does not have an open fault, and therefore it is confirmed that the first switch 114 does not have a close fault. The process of step S117 is an example of a fourth determination process.

[0055] Next, the control unit 2 controls the second switch 117 to be in the open state (S118). In step S118, the second switch 117 is controlled to be in the open state during the period (a14) illustrated in FIG.

[0056] Next, the control unit 2 controls the output voltage of the variable DC power supply 115 to the L voltage (S119). In step S119, the output voltage of the variable DC power supply 115 is controlled to the L voltage during the period (a15) illustrated in FIG.

[0057] Next, the control unit 2 controls the first switch 114 to the closed state (S120). In step S120, the first switch 114 is controlled to the closed state during the period (a16) illustrated in FIG. 4. The processes of steps S114 to S120 are performed while the substrate W after the plasma processing is being unloaded. In the example of FIG. 4, the output voltage of the variable DC power supply 115 is switched from the H voltage to the L voltage during the period (a14) to (a15), and then the first switch 114 is switched from the open state to the closed state during the period (a15) to (a16). This can extend the life of the first switch 114.

[0058] Next, the control unit 2 determines whether or not to perform plasma processing on another substrate W (S121). If the plasma processing is to be performed on another substrate W (S121: Yes), the control unit 2 executes the processing shown in step S100 of Fig. 2 again. On the other hand, if the plasma processing is not to be performed on another substrate W (S121: No), the control unit 2 ends the plasma processing method illustrated in Figs. 2 and 3.

[0059] The first embodiment has been described above. As described above, the plasma processing apparatus 1 in this embodiment includes the electrostatic chuck 1110, the first switch 114, the second switch 117, and the control unit 2. The electrostatic chuck 1110 is provided in the plasma processing chamber 10, has an electrode 1110a therein, and adsorbs the substrate W to be processed using plasma by a voltage applied to the electrode 1110a. The first switch 114 is provided on the wiring 113 between the variable DC power supply 115 that supplies a voltage to the electrode 1110a and the electrode 1110a. The second switch 117 is provided on the wiring 116 between the detector 118 that detects the voltage of the electrode 1110a and the electrode 1110a. The control unit 2 controls the first switch 114 and the second switch 117 to a closed state, controls the variable DC power supply 115 so that a H voltage of a predetermined magnitude is output from the variable DC power supply 115, and executes a first determination process to determine that the first switch 114 and the second switch 117 are in a closed state when the H voltage is detected by the detector 118. After determining that the first switch 114 and the second switch 117 are controlled to a closed state, the control unit 2 controls the first switch 114 and the second switch 117 to an open state to control the electrode 1110a to a floating state and starts processing the substrate W using plasma. This makes it possible to start plasma processing after confirming that the substrate W is attracted to the electrostatic chuck 1110. It is also possible to confirm that the first switch 114 and the second switch 117 are not in an open state.

[0060] In the above embodiment, the control unit 2 executes a second determination process. In the second determination process, the first switch 114 is controlled to a closed state, the second switch 117 is controlled to an open state, the variable DC power supply 115 is controlled so that an H voltage is output from the variable DC power supply 115, and when an L voltage lower than the H voltage is detected by the detector 118, it is determined that the second switch 117 is in an open state. This makes it possible to confirm that the second switch 117 is not in a closed state.

[0061] In the above embodiment, the control unit 2 executes a third determination process. In the third determination process, after the processing of the substrate W using plasma is completed, the first switch 114 and the second switch 117 are controlled to be in a closed state, the variable DC power supply 115 is controlled to output an L voltage from the variable DC power supply 115, and when the L voltage is detected by the detector 118, it is determined that the neutralization of the electrode 1110a is completed. After it is determined that the neutralization of the electrode 1110a is completed, the control unit 2 controls the drive unit that drives the lift pins so that the lift pins lift the substrate W. This makes it possible to prevent the substrate W from jumping up or cracking after the plasma processing.

[0062] In the above embodiment, the control unit 2 executes a fourth determination process. In the fourth determination process, after the first switch 114 is controlled to a closed state and the variable DC power supply 115 is controlled so that an L voltage is output from the variable DC power supply 115, the first switch 114 is controlled to an open state, the second switch 117 is controlled to a closed state, and the variable DC power supply 115 is controlled so that an H voltage is output from the variable DC power supply 115, and when the L voltage is detected by the detector 118, it is determined that the first switch 114 is in an open state. This makes it possible to confirm that the first switch 114 is not in a closed state.

[0063] In the above embodiment, the control unit 2 executes the first determination process and the second determination process while the substrate W before being processed using plasma is being loaded into the plasma processing chamber 10. This makes it possible to improve the throughput of the process when performing plasma processing on a plurality of substrates W.

[0064] Moreover, in the above-described embodiment, the control unit 2 executes the fourth determination process while the substrate W after the plasma processing is unloaded from the plasma processing chamber 10. This makes it possible to improve the processing throughput when performing plasma processing on a plurality of substrates W.

[0065] The plasma processing method in the above embodiment includes steps a), b), c), and d). In step a), the variable DC power supply 115 is controlled to supply a voltage to the electrode 1110a provided inside the electrostatic chuck 1110 that attracts the substrate W to be processed by the plasma, so that the variable DC power supply 115 outputs an H voltage of a predetermined magnitude. In step b), the first switch 114 provided on the wiring 113 between the electrode 1110a and the variable DC power supply 115 and the second switch 117 provided on the wiring 116 between the electrode 1110a and the detector 118 that detects the voltage of the electrode 1110a are controlled to be in a closed state. In step c), when the detector 118 detects the H voltage, it is determined that the first switch 114 and the second switch 117 are in a closed state. In step d), after it is determined that the first switch 114 and the second switch 117 are in the closed state, the first switch 114 and the second switch 117 are controlled to the open state, and the electrode 1110a is controlled to the floating state, and then processing of the substrate W using plasma is started. This makes it possible to start the plasma processing after it is confirmed that the substrate W is attracted to the electrostatic chuck 1110. It is also possible to confirm that the first switch 114 and the second switch 117 are not in an open state.

[0066] [others] It should be noted that the technology disclosed in the present application is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist thereof.

[0067] For example, in the embodiment described above, in a period (a13) after the plasma processing is completed, the first switch 114 is controlled to an open state, the second switch 117 is controlled to a closed state, and the output voltage of the variable DC power supply 115 is controlled to an H voltage. Then, depending on whether or not the L voltage is detected by the detector 118, a close failure of the first switch 114 is determined. However, the disclosed technology is not limited to this.

[0068] FIG. 8 is a time chart showing another example of the control procedure. For example, as shown in FIG. 8, in a period (b1) following the period (a3), the second switch 117 is maintained in a closed state, and the output voltage of the variable DC power supply 115 is controlled to an L voltage. This removes electricity from the electrode 1110a. Then, in a period (b2), the first switch 114 is controlled to an open state, and in a period (b3), the output voltage of the variable DC power supply 115 is controlled to an H voltage again. Then, in the period (b3), a close failure of the first switch 114 may be determined depending on whether or not an L voltage is detected by the detector 118. This allows the close failure of the first switch 114 to be determined before the plasma processing is started, so that the electrode 1110a can be reliably controlled to a floating state in a period (a5) before the plasma processing is started. This prevents the substrate W from jumping up or cracking after the plasma processing.

[0069] During a period (b4) after it is determined whether or not the detector 118 has detected the L voltage, the second switch 117 is controlled to be open again. During a period (b5), the first switch 114 is controlled to be closed again, and the voltage output from the variable DC power supply 115 is applied to the electrode 1110a via the first switch 114. After it is confirmed that the electrode 1110a has been de-electrified during a period (a10), the second switch 117 is controlled to be open again during a period (b6), and the state returns to the initial state. The processes performed during the periods (b1) to (b5) are preferably performed while the substrate W is being loaded into the plasma processing chamber 10 before the plasma processing is performed.

[0070] In the above embodiment, the output voltage of the variable DC power supply 115 is controlled from an L voltage to an H voltage in the period (a2), and the second switch 117 is controlled from an open state to a closed state in the subsequent period (a3). However, the disclosed technology is not limited to this. For example, as shown in FIG. 9, the second switch 117 may be controlled from an open state to a closed state in the period (c2), and the output voltage of the variable DC power supply 115 may be controlled from an L voltage to an H voltage in the subsequent period (c3). This can extend the life of the second switch 117.

[0071] Furthermore, during the period (c5) illustrated in FIG. 9, the output voltage of the variable DC power supply 115 may be controlled from the H voltage to the L voltage, thereby maintaining the output voltage of the variable DC power supply 115 at the L voltage during the plasma processing.

[0072] 9, in a period (c8) after the plasma processing, the electrode 1110a is neutralized, and in a period (c9), the neutralization is confirmed by the detector 118. After the neutralization is confirmed, in a period (c10), the first switch 114 may be controlled to an open state while the second switch 117 is kept in a closed state, and in a period (c11), a close failure of the first switch 114 may be determined.

[0073] In the above embodiment, the plasma processing system 100 is described as performing processing using a capacitively coupled plasma (CCP) as an example of a plasma source, but the plasma source is not limited to this. Examples of plasma sources other than the capacitively coupled plasma include an inductively coupled plasma (ICP), a microwave excited surface wave plasma (SWP), an electron cyclotron resonance plasma (ECP), and a helicon wave excited plasma (HWP).

[0074] It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be construed as limiting. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0075] W substrate 100 Plasma Processing System 1. Plasma processing equipment 2. Control section 2a Computer 10 Plasma Processing Chamber 10s Plasma treatment space 11 Substrate support 111 Main body 111a Board support surface 111b Ring support surface 1110 Electrostatic Chuck 1110a electrode 1111 Foundation 112 Ring Assembly 113 Wiring 114 First Switch 115 Variable DC power supply 116 Wiring 117 Second Switch 118 Detector 20 Gas supply section 30 power supply 31 RF power supply 32 DC power supply 40 Exhaust system

Claims

1. an electrostatic chuck provided in the chamber, having an electrode therein, and attracting a substrate to be processed using plasma by a voltage applied to the electrode; a power source that supplies a voltage to the electrode, and a first switch provided in a wiring between the electrode and the power source; a detector for detecting a voltage of the electrode, and a second switch provided in a wiring between the electrode and the detector; Control unit and Equipped with The control unit is a first determination process is executed to control the first switch and the second switch to a closed state, to control the power source so that a first voltage of a predetermined magnitude is output from the power source, and to determine that the first switch and the second switch are in a closed state when the first voltage is detected by the detector; a plasma processing apparatus that, after it is determined that the first switch and the second switch are in a closed state, starts processing the substrate using plasma while controlling the first switch and the second switch to an open state and controlling the electrode to a floating state.

2. The control unit is 2. The plasma processing apparatus according to claim 1, further comprising: a second determination process for determining that the second switch is in an open state when the detector detects a second voltage lower than the first voltage, the second switch being controlled to a closed state and the second switch being controlled to an open state, and the power supply being controlled so that the first voltage is output from the power supply.

3. The control unit is a third determination process is executed to determine that the neutralization of the electrode is completed when the second voltage is detected by the detector, by controlling the first switch and the second switch to a closed state after the processing of the substrate using plasma is completed, and controlling the power source so that the second voltage is output from the power source after the processing of the substrate using plasma is completed; 3. The plasma processing apparatus according to claim 2, further comprising: a driving unit that drives the lift pins so as to lift the substrate by the lift pins after it is determined that the neutralization of the electrodes is completed.

4. The control unit is 4. The plasma processing apparatus according to claim 3, further comprising: a fourth determination process for controlling the first switch to a closed state, controlling the power supply so that the second voltage is output from the power supply, and then controlling the first switch to an open state, controlling the second switch to a closed state, and controlling the power supply so that the first voltage is output from the power supply; and determining that the first switch is in an open state when the second voltage is detected by the detector.

5. The control unit is The plasma processing apparatus according to claim 2 , wherein the first determination process and the second determination process are performed while the substrate is being carried into the chamber before being subjected to processing using plasma.

6. The control unit is The plasma processing apparatus according to claim 4 , wherein the fourth determination process is performed while the substrate is being unloaded from the chamber after the processing using plasma has been completed.

7. The control unit is The plasma processing apparatus according to claim 4 , wherein the fourth determination process is performed while the substrate is being carried into the chamber before being subjected to processing using plasma.

8. a) controlling a power supply that supplies a voltage to an electrode provided inside an electrostatic chuck that attracts a substrate to be processed by plasma so that the power supply outputs a first voltage of a predetermined magnitude; b) controlling a first switch provided in a wiring between the electrode and the power source and a second switch provided in a wiring between the electrode and a detector that detects a voltage of the electrode to a closed state; c) determining that the first switch and the second switch are in a closed state when the first voltage is detected by the detector; d) after it is determined that the first switch and the second switch are in a closed state, controlling the first switch and the second switch to an open state to control the electrode to a floating state, and starting a process of the substrate using plasma; A plasma processing method comprising:

Images