Plasma processing apparatus and substrate processing system

Abstract

The present invention suppresses the occurrence of conveyance failure due to an edge ring being obliquely lifted from a substrate support part by a lifter.　This plasma processing apparatus comprises: a processing container configured to be depressurizable; an electrostatic chuck which is provided in the processing container, has a substrate support surface and a ring support surface provided so as to surround the substrate support surface, and is provided with an electrode below the ring support surface; a power supply that applies a DC voltage to the electrode; a lifter that raises and lowers an edge ring with respect to the ring support surface by an actuator; a gas supply unit that supplies a gas into the processing container; a plasma generation unit that generates plasma from the gas supplied into the processing container; and a control unit. After a substrate subjected to plasma processing is unloaded from the processing container, the control unit performs control so as to perform the following, in this order: (a) controlling the power supply to stop application of the voltage to the electrode, and controlling the plasma generation unit to generate first plasma and neutralize the charge from the edge ring on the ring support surface; (b) controlling the lifter to bring the lifter into contact with the lower surface of the edge ring, and controlling the plasma generation unit to generate second plasma and neutralize the charge from the edge ring; and (c) controlling the lifter to raise the edge ring to a position higher than the height position of the edge ring in (b), and controlling the plasma generation unit to generate third plasma and neutralize the charge from the edge ring.

Description

Plasma processing apparatus and substrate processing system

[0001] This disclosure relates to a plasma processing apparatus and a substrate processing system.

[0002] Patent Document 1 discloses a substrate processing system comprising a plasma processing apparatus, a vacuum transfer device connected to the plasma processing apparatus and having a transfer robot for transporting substrates and edge rings, and a control device. The plasma processing apparatus includes a processing container configured to be vacuum-reduced, and a substrate support stand provided inside the processing container, which includes a substrate mounting surface, a ring mounting surface on which edge rings are placed so as to surround the substrate mounting surface, and an electrostatic chuck provided on the ring mounting surface with electrodes for adsorbing edge rings. The plasma processing apparatus further includes a lifting mechanism for raising and lowering edge rings relative to the ring mounting surface, a gas supply unit for supplying gas into the processing container, and a plasma generation unit for generating plasma inside the processing container. The control device controls the following steps (a) to (d) to be executed in this order. Step (a) is a step in which a voltage of first polarity is applied to the electrodes that have been plasma-treated. (b) Step is a step to de-staticize the edge ring, in which gas is supplied into the processing container from the gas supply unit, and a voltage of a second polarity different from the first polarity applied to the electrode in step (a) is applied to the electrode, and after a predetermined time has elapsed, the application of voltage to the electrode is stopped. (c) Step is a step to separate the edge ring from the ring mounting surface using a lifting mechanism. (d) Step is a step to transport the edge ring from inside the processing container to the de-icing transport device using a transport robot.

[0003] International Publication No. 2024 / 71074

[0004] The technology disclosed herein suppresses transport failures caused by misalignment of the edge ring relative to the lifter or the edge ring falling from the lifter.

[0005] One aspect of the present disclosure is a plasma processing apparatus comprising: a processing vessel configured to be able to reduce pressure; an electrostatic chuck provided within the processing vessel and having a substrate support surface and a ring support surface provided so as to surround the substrate support surface, with electrodes provided below the ring support surface; a power supply for applying a DC voltage to the electrodes; a lifter for raising and lowering the edge ring with respect to the ring support surface by an actuator; a gas supply unit for supplying gas into the processing vessel; a plasma generation unit for generating plasma from the gas supplied into the processing vessel; and a control unit, wherein after the plasma-treated substrate is removed from the processing vessel, the control unit performs the following: The system is controlled to perform the following actions in this order: (a) control the power supply to stop the application of voltage to the electrodes, control the plasma generation unit to generate a first plasma and discharge the edge ring on the ring support surface; (b) control the lifter to bring it into contact with the lower surface of the edge ring, control the plasma generation unit to generate a second plasma and discharge the edge ring; and (c) control the lifter to raise the edge ring to a position higher than the height of the edge ring in (b), and control the plasma generation unit to generate a third plasma and discharge the edge ring.

[0006] According to this disclosure, it is possible to suppress transport failures caused by misalignment of the edge ring relative to the lifter or the edge ring falling from the lifter.

[0007] This is a plan view showing the schematic configuration of the plasma processing system as a substrate processing system according to this embodiment. This is a longitudinal cross-sectional view showing the schematic configuration of the processing module. This is a longitudinal end view showing an enlarged portion of the processing module. This is an enlarged cross-sectional view of a portion of the processing module that is different from Figure 3, relating to the circumferential direction of the wafer support base. This is a flowchart of Example 1 of a processing sequence, which includes a sequence for removing the edge ring from the processing module, executed by the plasma processing system of Figure 1. This is an explanatory diagram of the state of the processing module and the state of voltage application to the electrodes when the steps included in Example 1 of the processing sequence are executed. This is an explanatory diagram of the state of the processing module and the state of voltage application to the electrodes when the steps included in Example 1 of the processing sequence are executed. This is an explanatory diagram of the state of the processing module and the state of voltage application to the electrodes when the steps included in Example 1 of the processing sequence are executed. This is a schematic diagram showing an example of the charged state around the edge ring. This is an explanatory diagram of the state of the processing module and the state of voltage application to the electrodes when the steps included in Example 1 of the processing sequence are executed. This is a schematic diagram showing an example of the charged state around the edge ring. This is an explanatory diagram of the state of the processing module and the state of voltage application to the electrodes when the steps included in Example 1 of the processing sequence are executed. This is a schematic diagram showing an example of the charged state around the edge ring. This is an explanatory diagram of the state of the processing module and the voltage applied to the electrodes when the process included in Example 1 of the processing sequence is executed. This is a flowchart of Example 2 of the processing sequence, which includes the sequence for removing the edge ring from the processing module, executed by the plasma processing system of Figure 1. This is an explanatory diagram of the state of the processing module and the voltage applied to the electrodes when the static discharge process of the edge ring E included in Example 2 of the processing sequence is executed. This is a partially enlarged view illustrating an example of a wafer support configured to support a covering ring in addition to the edge ring.

[0008] The plasma processing apparatus and substrate processing system according to this embodiment will be described below with reference to the drawings. In this specification and the drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant explanations will be omitted.

[0009] <Plasma Processing System> Figure 1 is a plan view showing a schematic configuration of the plasma processing system as a substrate processing system according to this embodiment. In the plasma processing system 1 of Figure 1, a semiconductor wafer (hereinafter referred to as "wafer") W is processed as a substrate, and specifically, substrate processing such as etching using plasma, i.e., plasma processing, is performed on the wafer W.

[0010] The plasma processing system 1 has an atmospheric section 10 and a depressurization section 11, and these atmospheric section 10 and depressurization section 11 are integrally connected via load lock modules 20 and 21. The atmospheric section 10 includes an atmospheric module that performs a desired processing on the wafer W under atmospheric pressure. The depressurization section 11 includes a depressurization module that performs a desired processing on the wafer W under a reduced pressure atmosphere (vacuum atmosphere).

[0011] The load lock modules 20 and 21 are provided to connect the loader module 30, which is included in the atmospheric pressure section 10, and the transfer module 50, which is included in the reduced pressure section 11, via gate valves (not shown). The load lock modules 20 and 21 are configured to temporarily hold the wafer W. The load lock modules 20 and 21 are also configured to switch between an atmospheric pressure atmosphere and a reduced pressure atmosphere inside.

[0012] The atmospheric section 10 includes a loader module 30 equipped with a transport mechanism 40 (described later) and a load port 32 on which a hoop 31 is placed. The hoop 31 is capable of storing multiple wafers W. The loader module 30 may also be connected to an orienter module (not shown) for adjusting the horizontal orientation of the wafers W, a buffer module (not shown) for temporarily storing multiple wafers W, and the like.

[0013] The loader module 30 has a rectangular housing, and the inside of the housing is maintained at atmospheric pressure. Multiple load ports 32, for example, five, are arranged side by side on one side that forms the long side of the loader module 30 housing. Load lock modules 20 and 21 are arranged side by side on the other side that forms the long side of the loader module 30 housing.

[0014] Inside the housing of the loader module 30 is a transport mechanism 40 configured to hold and transport wafers W. The transport mechanism 40 includes a transport arm 41 that supports the wafers W during transport, a turntable 42 that rotatably supports the transport arm 41, and a base 43 on which the turntable 42 is mounted. Inside the loader module 30 is a guide rail 44 that extends in the longitudinal direction of the loader module 30. The base 43 is mounted on the guide rail 44, and the transport mechanism 40 is configured to move along the guide rail 44.

[0015] The depressurization unit 11 includes a transfer module 50 as a depressurization transport device, a processing module 60 as a plasma processing device, and a storage module 61 as a storage unit. The interiors of the transfer module 50 and the processing module 60 (specifically, the interiors of the depressurization transport chamber 51 and the chamber 100 described later) are maintained in a depressurized atmosphere, and the interior of the storage module 61 is also maintained in a depressurized atmosphere. For one transfer module 50, there are multiple processing modules 60, for example, six, and multiple storage modules 61, for example, two. The number and arrangement of the processing modules 60 are not limited to this embodiment and can be set arbitrarily, as long as at least one processing module equipped with a wafer support base described later is provided. Similarly, the number and arrangement of the storage modules 61 are not limited to this embodiment and can be set arbitrarily, for example, at least one is provided.

[0016] The transfer module 50 is configured to transport wafers W inside. The transfer module 50 is also configured to transport edge rings E, which will be described later, inside. The transfer module 50 includes a reduced pressure transport chamber 51 having a housing that is polygonal in plan view (a quadrilateral in plan view in the illustrated example), and the reduced pressure transport chamber 51 is connected to load lock modules 20 and 21.

[0017] The transfer module 50 transports the wafer W loaded into the load lock module 20 to a processing module 60, and also unloads the wafer W, which has undergone the desired plasma processing in the processing module 60, to the load lock module 21. In addition, the transfer module 50 may transport the edge ring E in the storage module 61 to a processing module 60, and may also unload the edge ring E in the processing module 60 to the storage module 61.

[0018] The processing module 60 performs a desired plasma treatment, such as etching, on the wafer W transported from the transfer module 50. The processing module 60 is connected to the transfer module 50 via a gate valve 62. The specific configuration of the processing module 60 will be described later.

[0019] The storage module 61 houses the edge ring E. The storage module 61 is also connected to the transfer module 50 via a gate valve 63.

[0020] A transfer robot 70 is provided inside the reduced-pressure transfer chamber 51 of the transfer module 50. The transfer robot 70 is configured to hold and transfer the wafer W. The transfer robot 70 is also configured to hold and transfer the edge ring E.

[0021] This transport robot 70 has a transport arm 71 that is configured to rotate, extend and retract, and move up and down while holding a wafer W. The tip of the transport arm 71 is branched into two forks 72, 72 which serve as holding parts. Each of the forks 72, 72 is configured to hold the wafer W and edge ring E to be transported.

[0022] In the transfer module 50, the transport arm 71 receives the wafer W held in the load lock module 20 and transports it to the processing module 60. In addition, the transport arm 71 receives the wafer W after the desired processing has been performed in the processing module 60 and transports it to the load lock module 21.

[0023] Furthermore, in the transfer module 50, the transport arm 71 may receive the edge ring E from the storage module 61 and transport it to the processing module 60. Also, in the transfer module 50, the transport arm 71 may receive the edge ring E from the processing module 60 and transport it to the storage module 61.

[0024] Furthermore, the plasma processing system 1 has one or more control devices 80. In one embodiment, the control device 80 processes computer-executable commands that cause the plasma processing system 1 to perform the various processes described herein. The control device 80 may be configured to control each of the other elements of the plasma processing system 1 so that the plasma processing system 1 performs the various processes described herein. In one embodiment, some or all of the control device 80 may be included in the other elements of the plasma processing system 1. The control device 80 may include, for example, a computer 90. The computer 90 may include, for example, a processing unit (CPU: Central Processing Unit) 91, a storage unit 92, and a communication interface 93. The processing unit 91 may be configured to perform various control operations and calculations based on a program stored in the storage unit 92. The storage unit 92 may include RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), or a combination thereof. The communication interface 93 may communicate with the other elements of the plasma processing system 1 via a communication line such as a LAN (Local Area Network).

[0025] The control device 80 may also function as the control unit of the processing module 60, which is a plasma processing apparatus. In one embodiment, the control unit of the processing module 60 processes computer-executable commands that cause the processing module 60 to perform various processes described herein. The control unit of the processing module 60 may be configured to control each of the other elements of the processing module 60 so that the processing module 60 performs the various processes described herein. In one embodiment, some or all of the control unit of the processing module 60 may be included in the other elements of the processing module 60. The processing module 60 may include a computer, for example, similar to the control device 80. This computer may include, for example, a processing unit (CPU), a storage unit, and a communication interface. The processing unit may be configured to perform various control operations and calculations based on a program stored in the storage unit. The storage unit may include RAM, ROM, HDD, SSD, or a combination thereof. The communication interface may communicate with the other elements of the processing module 60 via a communication line such as a LAN.

[0026] <Wafer Processing with Plasma Processing System 1> Next, an example of wafer processing using the plasma processing system 1 configured as described above will be explained.

[0027] First, the transport mechanism 40 removes the wafer W from the desired hoop 31 and loads it into the load lock module 20. Next, the load lock module 20 is sealed and the pressure is reduced. After that, the inside of the load lock module 20 and the inside of the transfer module 50 are connected.

[0028] Next, the wafer W is held by the transport robot 70 and transported from the load lock module 20 to the transfer module 50.

[0029] Next, the gate valve 62 corresponding to the desired processing module 60 is opened, and the wafer W is loaded into the desired processing module 60 by the transport robot 70. After that, the gate valve 62 is closed, and the desired processing is performed on the wafer W in the processing module 60. The processing performed on the wafer W in this processing module 60 will be described later.

[0030] Next, the gate valve 62 is opened, and the wafer W is unloaded from the processing module 60 by the transport robot 70. After that, the gate valve 62 is closed.

[0031] Next, the transport robot 70 loads the wafer W into the load lock module 21. Once the wafer W is loaded into the load lock module 21, the inside of the load lock module 21 is sealed and then opened to the atmosphere. After that, the inside of the load lock module 21 and the inside of the loader module 30 are connected.

[0032] Next, the wafer W is held by the transport mechanism 40 and returned to the desired hoop 31 via the load lock module 21 and loader module 30 for storage. This completes the wafer processing using the plasma processing system 1.

[0033] <Processing Module 60> Next, the processing module 60 will be described using Figures 2 to 4. Figure 2 is a longitudinal cross-sectional view showing an outline of the configuration of the processing module 60. Figure 3 is a longitudinal end view showing an enlarged portion of the processing module 60. Figure 4 is an enlarged cross-sectional view of a portion of the processing module 60 that is different from Figure 3 and relates to the circumferential direction of the wafer support base 101, which will be described later.

[0034] As shown in Figure 2, the processing module 60 includes a chamber 100 as a processing container, a gas supply unit 140, an RF (Radio Frequency) power supply unit 150, and an exhaust system 160. The processing module 60 also includes a voltage application unit 120 (see Figure 3) and a gas supply unit 130 (see Figure 4). Furthermore, the processing module 60 includes a wafer support base 101 and an upper electrode 102 as substrate support bases.

[0035] Chamber 100 is configured to allow for reduced pressure inside, defining a processing space 100s where plasma is generated. The chamber 100 also contains a wafer support 101 and the like. For example, aluminum can be used as the material for chamber 100. Chamber 100 is connected to ground potential.

[0036] The wafer support 101 is located, for example, in the lower region of the chamber 100. The upper electrode 102 is located above the wafer support 101 and may function as part of the ceiling of the chamber 100.

[0037] The wafer support base 101 is configured to support the wafer W. In one embodiment, the wafer support base 101 includes a lower electrode 103, an electrostatic chuck 104, a support body 105, an insulator 106, a lifter 107, and a lifter 108. The wafer support base 101 is also configured to support the edge ring E. The wafer support base 101 may or may not include the edge ring E as a component.

[0038] The lower electrode 103 is made of a conductive material such as aluminum. In one embodiment, a flow path 109 for a temperature-controlled fluid is formed inside the lower electrode 103. The temperature-controlled fluid is supplied to the flow path 109 from a chiller unit (not shown) located outside the chamber 100. The temperature-controlled fluid supplied to the flow path 109 is returned to the chiller unit. By circulating, for example, a low-temperature brine as the temperature-controlled fluid in the flow path 109, the wafer support 101 (specifically, the electrostatic chuck 104), the wafer W, or the edge ring E can be cooled to a predetermined temperature. By circulating, for example, a high-temperature brine as the temperature-controlled fluid in the flow path 109, the wafer support 101 (specifically, the electrostatic chuck 104), the wafer W, or the edge ring E can be heated to a predetermined temperature. The flow path 109 can function as at least part of a cooling section that cools the edge ring E.

[0039] Furthermore, when a temperature adjustment mechanism is provided on the wafer support table 101, the form of the temperature adjustment mechanism is not limited to the above-described flow path 109, and may be in other forms such as a resistance heating type heater, for example. In addition, the member in which the temperature adjustment mechanism is disposed in the wafer support table 101 is not limited to the lower electrode 103, and may be another member.

[0040] The electrostatic chuck 104 is a member configured to be capable of electrostatically adsorbing at least the edge ring E, and is provided on the lower electrode 103. In addition, the electrostatic chuck 104 may be configured to be capable of electrostatically adsorbing the wafer W as well. In one embodiment, the central portion of the electrostatic chuck 104 constitutes a substrate mounting portion. Furthermore, in one embodiment, the electrostatic chuck 104 is formed such that the upper surface of the central portion is higher than the upper surface of the peripheral portion. In one embodiment, the electrostatic chuck 104 supports the wafer W on the upper surface 104a of the central portion thereof, and supports the edge ring E on the upper surface 104b of the peripheral portion thereof. That is, in one embodiment, the upper surface 104a of the central portion of the electrostatic chuck 104 serves as a wafer support surface serving as a substrate support surface for supporting the wafer W, and the upper surface 104b of the peripheral portion of the electrostatic chuck 104 serves as a ring support surface provided so as to surround the wafer support surface and support the edge ring E.

[0041] The edge ring E is an annular member in plan view disposed so as to surround the wafer W, and specifically, it is an annular member in plan view disposed so as to surround the wafer W mounted on the electrostatic chuck 104. The edge ring E is used to obtain good and uniform plasma processing results between the central portion and the peripheral portion of the wafer W, and is also referred to as a focus ring. In one embodiment, the edge ring E is disposed so as to surround the central portion of the electrostatic chuck 104 where the upper surface is higher than the peripheral portion. The edge ring E is formed in an annular shape in a plan view. The material of the edge ring E includes Si, SiO ２ or the like is used.

[0042] An electrode 110 for electrostatically attracting a wafer W to an upper surface 104a of a central portion of an electrostatic chuck 104 may be provided at the central portion. Further, at a peripheral edge portion of the electrostatic chuck 104, an electrode 111 for electrostatically attracting an edge ring E to an upper surface 104b of the peripheral edge portion is provided below the upper surface 104b. The electrode 111 is, for example, a bipolar type including a pair of electrodes 111a and 111b formed at mutually different positions. The electrode 111a is provided on the central portion side, that is, the inner side of the electrostatic chuck 104, and the electrode 111b is provided on the outer side. The electrostatic chuck 104 has a configuration in which the electrodes 110 and 111 are sandwiched between insulating members made of, for example, an insulating material.

[0043] As shown in FIG. 3, a voltage applying unit 120 is connected to the electrode 111 so that an electric force (specifically, for example, Coulomb force) for electrostatically attracting the edge ring E is generated in the electrode 111. When the electrode 111 is of a bipolar type, it is configured such that either voltages of different polarities or voltages of the same polarity can be selectively applied from the voltage applying unit 120 to the pair of electrodes 111a and 111b.

[0044] The voltage applying unit 120 includes, for example, two DC power supplies 121a and 121b serving as power supplies that apply a DC voltage to the electrode 111, and two switches 122a and 122b. The DC power supply 121a is connected to the electrode 111a via the switch 122a, and selectively applies a positive voltage or a negative voltage for electrostatically attracting the edge ring E to the electrode 111a. The DC power supply 121b is connected to the electrode 111b via the switch 122b, and selectively applies a positive voltage or a negative voltage for electrostatically attracting the edge ring E to the electrode 111b.

[0045] The voltage applying unit 120 may include a DC power supply 121c and a switch 122c. The DC power supply 121c is connected to the electrode 110 via the switch 122c, and applies a voltage for electrostatically attracting the wafer W to the electrode 110.

[0046] In this embodiment, the central part of the electrostatic chuck 104 on which the electrode 110 is provided and the peripheral part on which the electrode 111 is provided are integrated, but these central and peripheral parts may be separate. Also, in this embodiment, the electrode 111 for adsorbing and holding the edge ring E is a bipolar type, but it may be a unipolar type.

[0047] Furthermore, the central part of the electrostatic chuck 104 is formed to have a smaller diameter than the diameter of the wafer W, for example, so that the peripheral edge of the wafer W supported by the upper surface 104a of the central part of the electrostatic chuck 104 protrudes from the central part of the electrostatic chuck 104. The edge ring E has a step formed on its upper part, and the upper surface of the outer circumference is formed to be higher than the upper surface of the inner circumference. The inner circumference of the edge ring E is formed to fit underneath the peripheral edge of the wafer W that protrudes from the central part of the electrostatic chuck 104. In other words, the inner diameter of the edge ring E is formed to be smaller than the outer diameter of the wafer W.

[0048] The support 105 is a member formed in an annular shape in plan view using an insulating material such as quartz, and is arranged to surround the lower electrode 103 and the electrostatic chuck 104.

[0049] A gas discharge hole (not shown) may be formed on the upper surface 104a of the central part of the electrostatic chuck 104 to discharge heat transfer gas into the gap between the back surface of the placed wafer W and the wafer W. Heat transfer gas is supplied from a gas supply unit (not shown) through this gas discharge hole. The gas supply unit may include one or more gas sources and one or more pressure controllers. In one embodiment, the gas supply unit is configured to supply heat transfer gas from a gas source to the gas supply hole via a pressure controller.

[0050] Furthermore, as shown in Figure 4, gas discharge holes 104c are formed on the upper surface 104b of the peripheral edge of the electrostatic chuck 104. Specifically, one end of the gas discharge holes 104c is open on the upper surface 104b of the peripheral edge of the electrostatic chuck 104. For example, multiple gas discharge holes 104c are provided along the circumferential direction of the electrostatic chuck 104. The gas discharge holes 104c supply a heat transfer gas, such as helium gas, to the gap between the back surface of the edge ring E, which is placed on the upper surface 104b of the peripheral edge of the electrostatic chuck 104, and the upper surface 104b. The end of the gas discharge hole 104c opposite to the upper surface 104b of the peripheral edge is connected to a gas supply unit 130 via piping 133. The gas supply unit 130 may include one or more gas sources 131 and one or more flow controllers 132. In one embodiment, the gas supply unit 130 is configured to supply, for example, heat transfer gas from a gas source 131 to a gas discharge port 104c via a flow controller 132. Each flow controller 132 may include, for example, a mass flow controller or a pressure-controlled flow controller. The gas discharge port 104c and piping 133 can function as at least part of a supply path that supplies gas between the upper surface 104b of the peripheral edge of the electrostatic chuck 104 that constitutes the ring support surface and the back surface of the edge ring E.

[0051] Furthermore, the end of the gas discharge hole 104c opposite to the upper surface 104b of the peripheral edge is connected to the exhaust system 160 via piping 161. This allows exhaust to be performed around the upper surface 104b of the peripheral edge of the electrostatic chuck 104 via the gas discharge hole 104c. In other words, the gas discharge hole 104c can function as an exhaust hole that exhausts around the ring support surface, including the upper surface 104b of the peripheral edge of the electrostatic chuck 104. Therefore, in one embodiment, the gas discharge hole 104c and piping 161 can function as at least part of an exhaust passage that exhausts between the upper surface 104b of the peripheral edge of the electrostatic chuck 104, which is the ring support surface, and the back surface of the edge ring E. In addition, the piping 133 may be provided with a switching valve 135 for switching the supply of heat transfer gas by the gas supply unit 130 on and off. Similarly, the piping 161 may be provided with a switching valve 162 for switching between running and stopping the exhaust of the area around the upper surface 104b of the peripheral portion by the exhaust system 160.

[0052] Furthermore, a groove 104d that is recessed downward may be formed on the upper surface 104b of the peripheral edge of the electrostatic chuck 104, in an annular shape in plan view (specifically, a circular shape in plan view). A gas discharge hole 104c may be formed in the groove 104d. Specifically, one end of the gas discharge hole 104c may be open in the groove 104d.

[0053] The insulator 106 in Figure 2 is a cylindrical member made of ceramic or the like, and supports the support 105. The insulator 106 is formed to have an outer diameter equivalent to the outer diameter of the support 105, and supports the peripheral edge of the support 105.

[0054] The lifter 107 is a member that raises and lowers the wafer W relative to the upper surface 104a of the central part of the electrostatic chuck 104, and is formed in a columnar shape using, for example, ceramic as the material. When the lifter 107 is raised, its upper end protrudes from the upper surface 104a, enabling it to support the wafer W. This lifter 107 allows the wafer W to be transferred between the wafer support base 101 and the transfer arm 71 of the transfer robot 70. Three or more lifters 107 are provided along the circumferential direction of the electrostatic chuck 104, spaced apart from each other, and are arranged to extend in the vertical direction.

[0055] The lifter 107 is driven by an actuator 112. The actuator 112 includes, for example, a support member 113 that supports a plurality of lifters 107, and a drive unit 114 that generates a driving force to raise and lower the support member 113 and raise and lower the plurality of lifters 107. The drive unit 114 has, for example, a motor (not shown) as a drive source that generates the driving force.

[0056] The lifter 107 is inserted through a through hole 115 whose upper end opens in the upper surface 104a of the central part of the electrostatic chuck 104. The through hole 115 is formed, for example, to extend downward from the upper surface 104a of the central part of the electrostatic chuck 104 to the bottom surface of the lower electrode 103.

[0057] The lifter 108 is a lifting member that raises and lowers the edge ring E relative to the upper surface 104b of the peripheral edge of the electrostatic chuck 104 by the actuator 116 described later, and is formed from a material such as ceramic. The lifter 108 is formed in a columnar shape except for the upper end (i.e., the tip), and the upper end is formed in a hemispherical shape. In one embodiment, when the lifter 108 is raised, its upper end is configured to protrude from the upper surface 105a of the support 105. Three or more lifters 108 are provided along the circumferential direction of the electrostatic chuck 104, spaced apart from each other, and are provided to extend in the vertical direction.

[0058] The lifter 108 is driven by an actuator 116. The actuator 116 has, for example, a support member 117 provided for each lifter 108 that supports the lifter 108 so that it can move horizontally. The support member 117 has, for example, a thrust bearing to support the lifter 108 so that it can move horizontally. The actuator 116 also has a drive unit 118 that generates a driving force to raise and lower the support member 117 and raise and lower the lifter 108. The drive unit 118 has, for example, a motor (not shown) as a drive source that generates the above driving force.

[0059] In one embodiment, the lifter 108 is inserted through a through hole 119 whose upper end opens in the upper surface 105a of the support 105. The through hole 119 is formed, for example, to penetrate the support 105 in the vertical direction.

[0060] The lifter 108 described above allows the edge ring E to be transferred between the wafer support base 101 and the transport arm 71 of the transport robot 70. The lifter 108 and actuator 116 also constitute a lifting mechanism that raises and lowers the edge ring E relative to the ring support surface.

[0061] The edge ring E may have recesses E1 on its lower surface at positions corresponding to each of the lifters 108, for positioning relative to the lifters 108 having the upper end portion as described above. The recesses E1 have a flared shape that widens downwards. If the edge ring E is misaligned with respect to the lifters 108 immediately after handing over to the lifters 108, the edge ring E moves relative to the lifters 108 so that the upper end portion of each lifter 108 slides along the concave surface forming the recess E1. Therefore, the edge ring E can be positioned relative to the lifters 108.

[0062] The upper electrode 102 also functions as a gas supply unit, or showerhead, supplying one or more gases from the gas supply unit 140 into the chamber 100. In one embodiment, the upper electrode 102 has a gas inlet 102a, a gas diffusion chamber 102b, and a plurality of gas outlets 102c. The gas inlet 102a is in fluid communication with, for example, the gas supply unit 140 and the gas diffusion chamber 102b. The plurality of gas outlets 102c are in fluid communication with the gas diffusion chamber 102b and the inside of the chamber 100. In one embodiment, the upper electrode 102 is configured to supply one or more gases, such as processing gases, into the chamber 100 from the gas inlet 102a through the gas diffusion chamber 102b and the plurality of gas outlets 102c.

[0063] The gas supply unit 140 may include one or more gas sources 141 and one or more flow controllers 142. In one embodiment, the gas supply unit 140 is configured to supply, for example, one or more gases from the corresponding gas sources 141 to the gas inlet 102a via the corresponding flow controllers 142. Each flow controller 142 may include, for example, a mass flow controller or a pressure-controlled flow controller. Furthermore, the gas supply unit 140 may include one or more flow modulation devices that modulate or pulse the flow rates of one or more gases.

[0064] The RF power supply unit 150 is configured to supply RF power, for example, one or more RF signals, to one or more electrodes, such as the lower electrode 103, the upper electrode 102, or both the lower electrode 103 and the upper electrode 102. This generates plasma from one or more processing gases supplied into the chamber 100, i.e., the processing space 100s. Therefore, the RF power supply unit 150 can function as at least part of a plasma generation unit that generates plasma from gases supplied into the chamber 100. Specifically, the plasma generation unit is configured to generate plasma from one or more gases supplied in the chamber 100. The RF power supply unit 150 includes, for example, two RF generation units 151a, 151b and two matching circuits 152a, 152b. In one embodiment, the RF power supply unit 150 is configured to supply a first RF signal from the first RF generation unit 151a to the lower electrode 103 via the first matching circuit 152a. For example, the first RF signal may have a frequency in the range of 27 MHz to 100 MHz.

[0065] In one embodiment, the RF power supply unit 150 is configured to supply a second RF signal from the second RF generation unit 151b to the lower electrode 103 via the second matching circuit 152b. For example, the second RF signal may have a frequency in the range of 400 kHz to 13.56 MHz. Alternatively, a DC (Direct Current) pulse generation unit may be used instead of the second RF generation unit 151b.

[0066] Furthermore, although not shown in the figures, other embodiments are possible in this disclosure. For example, in an alternative embodiment, the RF power supply unit 150 may be configured to supply a first RF signal from an RF generation unit to the lower electrode 103, a second RF signal from another RF generation unit to the lower electrode 103, and a third RF signal from yet another RF generation unit to the lower electrode 103. In addition, in another alternative embodiment, a DC voltage may be applied to the upper electrode 102.

[0067] Furthermore, in various embodiments, the amplitude of one or more RF signals (i.e., a first RF signal, a second RF signal, etc.) may be pulsed or modulated. Amplitude modulation may include pulsing the RF signal amplitude between an ON state and an OFF state, or between two or more different ON states.

[0068] The exhaust system 160 may be connected to, for example, an exhaust port 100e located at the bottom of the chamber 100. The exhaust system 160 may include a pressure valve and a vacuum pump. The vacuum pump may include a turbomolecular pump, a roughing pump, or a combination thereof.

[0069] <Example of Processing Sequence 1> Next, an example of a processing sequence, including the sequence for removing the edge ring E from the processing module 60, executed by the plasma processing system 1, will be described using Figures 5 to 14. Figure 5 is a flowchart of Example 1 of the processing sequence. Figures 6 to 8, 10, 12, and 14 are explanatory diagrams of the state of the processing module 60 and the state of voltage application to the electrode 111 when the steps included in Example 1 of the processing sequence are executed, respectively. In Figures 6 to 8, 10, 12, and 14, open valves are shown in white, closed valves in black, and piping with gas flow is shown with thick lines. Also, in Figures 6 to 8, 10, 12, and 14, the gas discharge port 104c when exhaust has been performed through the gas discharge port 104c is shown in black, the gas discharge port 104c when heat transfer gas is present inside is shown in gray, and the gas discharge port 104c in other states is shown in white. Figures 9, 11, and 13 are schematic diagrams showing examples of the charge state around the edge ring E.

[0070] First, as shown in Figure 5, plasma treatment is performed on the wafer W (step S1). Specifically, a voltage is applied to the electrode 111 of the electrostatic chuck 104, and with the edge ring E electrostatically attached to the ring support surface, plasma treatment is performed on the wafer W supported on the wafer support surface.

[0071] More specifically, for example, first, a wafer W held by the transport arm 71 of the transport robot 70 is loaded into the chamber 100, and the wafer W is supported by the upper surface (i.e., wafer support surface) 104a of the central part of the electrostatic chuck 104 through the raising and lowering of the lifter 107 and the withdrawal of the transport arm 71 from the chamber 100. Subsequently, a DC voltage is applied to the electrodes 110 of the electrostatic chuck 104 from the DC power supply 121c, thereby electrostatically attracting and holding the wafer W to the electrostatic chuck 104. After the wafer W is loaded, the inside of the chamber 100 is depressurized to a predetermined vacuum level by the exhaust system 160.

[0072] Next, a processing gas is supplied from the gas supply unit 140 to the processing space 100s via the upper electrode 102. Additionally, high-frequency power HF for plasma generation is supplied from the RF power supply unit 150 to the lower electrode 103, thereby exciting the processing gas and generating plasma. At this time, high-frequency power LF for ion pull-in may also be supplied from the RF power supply unit 150. Then, plasma processing such as etching is performed on the wafer W by the action of the generated plasma. During the plasma processing, heat transfer gas is discharged toward the bottom surface of the wafer W, which is held by the electrostatic chuck 104.

[0073] Furthermore, during the plasma treatment, continuing from before step S1, a DC voltage is applied to the electrodes 111 of the electrostatic chuck 104 from the DC power supplies 121a and 121b, and the edge ring E is electrostatically attracted to and held on the ring support surface including the upper surface 104b of the peripheral edge of the electrostatic chuck 104. At this time, for example as shown in Figure 6, a voltage of common polarity is applied to electrodes 111a and 111b, specifically a voltage of common positive polarity. In addition, during the plasma treatment, heat transfer gas supplied from the gas supply unit 130 is discharged through the gas discharge hole 104c into the gap between the ring support surface and the edge ring E.

[0074] When the plasma processing is completed, the supply of high-frequency power HF from the RF power supply unit 150 and the supply of processing gas from the gas supply unit 140 are stopped. If high-frequency power LF was being supplied during the plasma processing, the supply of said high-frequency power LF is also stopped. Next, the electrostatic adsorption of the wafer W by the electrostatic chuck 104 is stopped. The supply of heat transfer gas to the bottom surface of the wafer W is also stopped.

[0075] Furthermore, before step S1 described above is performed on the first wafer W after the edge ring E is supported on the ring support surface, for example, electrostatic adsorption treatment and adsorption stabilization treatment are performed.

[0076] In the electrostatic adsorption process, for example, a voltage is applied to the electrode 111 of the electrostatic chuck 104 when no wafer W is present in the chamber 100. Specifically, when no wafer W is present in the chamber 100 and the edge ring E is supported on the ring support surface including the upper surface 104b of the peripheral edge of the electrostatic chuck 104, the application of DC voltages from DC power supplies 121a and 121b is started, causing the edge ring E to be electrostatically adsorbed to and held on the ring support surface. At this time, for example, for a predetermined time elapsed from the start of the application of the DC voltage, voltages of different polarities are applied to the electrode 111a and electrode 111b, and after the predetermined time elapsed, a voltage of common polarity (specifically, a negative polarity voltage) is applied.

[0077] Furthermore, the edge ring E may be vacuum-adsorbed even before the application of the DC voltage begins. Specifically, the area around the ring support surface may be exhausted through the gas discharge hole 104c, which also functions as an exhaust hole. More specifically, the switching valve 182 may be opened, and the area around the upper surface 104b of the peripheral edge of the electrostatic chuck 104 and the upper surface 105a of the support 105 may be exhausted through the gas discharge hole 104c by the exhaust system 180. As a result, the edge ring E is vacuum-adsorbed to the ring support surface, including the upper surface 104b of the peripheral edge of the electrostatic chuck 104.

[0078] The adsorption stabilization process is performed after the electrostatic adsorption process and stabilizes the electrostatic adsorption of the edge ring E to the electrostatic chuck 104 using plasma. In the adsorption stabilization process, with the edge ring E electrostatically adsorbed to the ring support surface, a gas for adsorption stabilization is supplied from the gas supply unit 140 to the processing space 100s via the upper electrode 102. In addition, high-frequency power HF for plasma generation is supplied from the RF power supply unit 150 to the lower electrode 103, for example, thereby exciting the gas and generating plasma. Since charges (specifically ions, etc.) move from the generated plasma to the edge ring E, the charge amount of the edge ring E increases. As a result, the electrostatic adsorption force of the edge ring E to the electrostatic chuck 104 can be improved. The high-frequency power HF for plasma generation may also be supplied to the upper electrode 102. During the adsorption stabilization process, for example, a voltage of common polarity is applied to electrodes 111a and 111b immediately following the electrostatic adsorption process. Furthermore, the adsorption stabilization process may be performed with the dummy wafer W electrostatically adsorbed to the wafer support surface of the electrostatic chuck 104.

[0079] After step S1, the wafer W is transported from the chamber 100 to the transfer module 50 (step S2).

[0080] Specifically, for example, the wafer W is lifted by the lifter 107 and separated from the upper surface (i.e., wafer support surface) 104a of the central part of the electrostatic chuck 104. Next, the gate valve 62 is opened and the transfer arm 71 of the transfer robot 70 is inserted into the chamber 100. Subsequently, the lifter 107 is lowered and the wafer W is transferred from the lifter 107 to the transfer arm 71. Next, the transfer arm 71 is withdrawn from the chamber 100 and the wafer W is transported from the chamber 100 to the transfer module 50. After that, the gate valve 62 is closed.

[0081] Furthermore, after step S1, until step S1 for the next wafer W, or until the static discharge of the edge ring E in step S4 described later, the processing module 60 switches to idle mode, and in idle mode, a voltage of a predetermined polarity is applied to the electrode 111 of the electrostatic chuck 104 (step S3).

[0082] The polarity of the voltage applied to electrode 111 in idle mode (first polarity) is different from the polarity of the voltage applied to electrode 111 during plasma processing in step S1, for example. In step S3, that is, in idle mode, specifically, the polarity of the voltage applied to electrode 111 of the electrostatic chuck 104 is changed. For example, as shown in Figure 7, a negative polarity voltage, which has the same polarity as electrode 111a or electrode 111b but is the opposite polarity to that during plasma processing, is applied to electrode 111a or electrode 111b. The magnitude of the voltage applied to electrode 111 may also be changed from that during plasma processing.

[0083] Furthermore, in step S3, that is, in idle mode, the discharge of heat transfer gas through the gas discharge port 104c continues.

[0084] Note that step S2 and step S3 may be performed in either order. For example, the wafer W in step S2 may be removed during step S3, i.e., while in idle mode, or step S3 may be started after the wafer W is removed in step S2, meaning the processing module 60 may transition to idle mode.

[0085] Next, if plasma processing is to be performed on another wafer W, the sequence returns to step S1, but the edge ring E may also be removed. In this case, first, the DC power supplies 121a and 121b are controlled to apply a voltage with a different polarity from the voltage applied to the electrode 111, and the gas supply unit 140 is controlled to supply gas, thereby discharging static electricity from the edge ring E on the ring support surface (step S4).

[0086] Specifically, the gas supply unit 140 is controlled, and gas is supplied into the chamber 100 from the upper electrode 102. In addition, the DC power supplies 121a and 121b are controlled, and a voltage of a second polarity different from the first polarity applied to the electrode 111 in step S3 is applied to the electrode 111, and after a predetermined time has elapsed, the application of voltage to the electrode 111 is stopped.

[0087] More specifically, for example, first, a predetermined flow rate of static elimination gas is supplied from the gas supply unit 140 to the processing space 100s via the upper electrode 102, and at the same time, exhaust control by the exhaust system 160 is started to bring the chamber 100 to a target pressure. The static elimination gas is N ２ It includes at least one selected from the group consisting of gas, Ar gas, and oxygen-containing gas. The oxygen-containing gas is O ２ Gas, O ３ Gas, CO gas, CO ２ It includes at least one selected from the group consisting of gas and COS gas. For example, the predetermined flow rate is 100 sccm to 1000 sccm, and the target pressure is 100 mTorr to 1000 mTorr.

[0088] After a predetermined waiting time T1 has elapsed and the chamber 100 is filled with an atmosphere of static elimination gas, the application of a voltage with a different polarity to the electrode 111 than that used in the idle mode of step S3 is started, as shown in Figure 8. Specifically, a voltage with a common polarity and a positive polarity opposite to that used in the idle mode is applied to electrodes 111a and 111b. The magnitude of the voltage applied to the electrode 111 may be changed from that used in the idle mode of step S3, for example, between 1000V and 5000V. As an example, the absolute value of the voltage with the opposite polarity to that used in the idle mode applied in step S4 may be the same as or smaller than the absolute value of the voltage applied in the idle mode. The waiting time T1 is, for example, 15 seconds or more.

[0089] After the start of application, the application to the electrode 111 is stopped after a predetermined time T2 has elapsed. The predetermined time T2 is, for example, 0.5 seconds to 600 seconds, preferably 1 second to 60 seconds, and more preferably 2 seconds to 40 seconds. From the viewpoint of throughput, a shorter predetermined time T2 is preferable.

[0090] For example, after a predetermined time T3 (>T2) has elapsed since the start of applying a reverse polarity voltage to electrode 111, the supply of static elimination gas and the control of exhaust to reach the target pressure are also stopped.

[0091] In step S4, the switching valve 135 is closed, stopping the discharge of heat transfer gas through the gas discharge hole 104c into the gap between the ring support surface, including the upper surface 104b of the peripheral edge of the electrostatic chuck 104, and the edge ring E, while the switching valve 162 is opened. This starts the exhaust of the supply path, including the gas discharge hole 104c, by the exhaust system 160, i.e., the exhaust of the gap. When the application of the reverse polarity voltage is stopped, the exhaust through the gas discharge hole 104c is also stopped.

[0092] The charges removed in step S4 are specifically as follows. When a positive voltage is applied to at least one of the electrodes 111a and 111b during the electrostatic adsorption process described above or during the plasma treatment in step S2, the portion of the edge ring E facing the electrode 111 to which the positive voltage is applied becomes negatively charged, and electrons diffuse from that portion to the ring support surface including the upper surface 104b of the peripheral edge of the electrostatic chuck 104. As the plasma treatment is repeated, as shown in Figure 9, electrons accumulate on the ring support surface including the upper surface 104b of the peripheral edge of the electrostatic chuck 104. The accumulated electrons remain on the ring support surface of the electrostatic chuck 104 even when no voltage is applied to the electrode 111. As a result, the lower part of the edge ring E becomes positively charged, that is, positive charges are generated and remain on the lower part of the edge ring E, so that electrostatic balance is achieved at the interface between the edge ring E and the electrostatic chuck 104. Furthermore, when electrons diffuse to the ring support surface, electrons also diffuse to the upper surface of the lifter 108.

[0093] The charges removed in step S4 are specifically, for example, the positive charges on the edge ring E and the electrons on the ring support surface of the electrostatic chuck 104. In step S4, the positive charges accumulated at the bottom of the edge ring E flow through the edge ring E and the static elimination gas to the ground potential to which the chamber 100 is connected, and the edge ring E is statically eliminated. In addition, the application of a positive voltage, which is the opposite polarity as described above, in step S4 promotes the removal of electrons accumulated on the electrostatic chuck 104 via the electrode 111.

[0094] Step S4 is intended to weaken the electrostatic clamping force (hereinafter sometimes referred to as "residual clamping force") of the edge ring E to the ring support surface of the electrostatic chuck 104, which is caused by the residual charge on the edge ring E and the residual charge on the electrostatic chuck 104.

[0095] However, in cases where time cannot be secured for step S4, even if step S4 is performed, the electrostatic attraction force may not be sufficiently weakened. Specifically, electric charge tends to remain on the ring support surface of the electrostatic chuck 104 that is not exposed to the static elimination gas, and the electrostatic attraction force caused by the remaining charge may not be sufficiently weakened. In such cases, when the lifter 108 raises the edge ring E against the electrostatic attraction force from the ring support surface of the electrostatic chuck 104, the position of the edge ring E relative to the lifter 108 may shift, or the edge ring E may fall from the lifter 108. In this case, the transport arm 71 of the transport robot 70 may not be able to receive the edge ring E from the lifter 108 at the appropriate position, or it may not be able to transfer the edge ring E from the lifter 108 to the transport arm 71 of the transport robot 70. As a result, the transport robot 70 may not be able to transport the edge ring E.

[0096] Therefore, steps S5 and S6 below are performed.

[0097] After step S4, the lifter 108 is controlled to come into contact with the lower surface of the edge ring E, the plasma generation unit is controlled to generate a first plasma, and the edge ring E is discharged (step S5). In step S5, the state in which the lifter 108 comes into contact with the lower surface of the edge ring E is a state in which there is an electrostatic attraction force of the edge ring E to the ring support surface due to the charge remaining on the edge ring E and the ring support surface after step S4. Specifically, the above contact state is a state in which there is an electrostatic attraction force of the edge ring E to the ring support surface due to the charge remaining on the edge ring E and the ring support surface after step S4, and the edge ring E, which has been raised by the lifter 108, is separated from the ring support surface. In the above contact state, the edge ring E is discharged by the first plasma. Specifically, in step S5, with the lifter 108 raised so that at least a part of the edge ring E is separated from the ring support surface of the electrostatic chuck 104, the edge ring E and the ring support surface are discharged by the first plasma.

[0098] More specifically, for example, first, as shown in Figure 10, with the application of voltage to electrodes 111a and 111b stopped, all lifters 108 are raised, and the edge ring E is transferred from the ring support surface, including the upper surface 104b of the peripheral edge of the electrostatic chuck 104, to the lifter 108 that has passed through the insertion hole 119. Thereafter, the raising continues until all lifters 108 reach a first height, and the edge ring E is separated from the ring support surface. When the lifters 108 have risen to the first height, the separation distance L1 of the lower surface of the edge ring E from the ring support surface is 0.1 mm or more and 1 mm or less, preferably 0.2 mm or more and 0.5 mm or less. Specifically, the first height is the height at which the separation distance L1 is 0.1 mm or more and 1 mm or less, preferably 0.2 mm or more and 0.5 mm or less, when the edge ring E and the electrostatic chuck 104 are not charged. If the above separation distance L1 exceeds 1 mm, the load on the lifter 108 will increase, potentially causing an error. Also, by setting the above separation distance L1 to at least 0.1 mm, the charge can be more easily removed from the edge ring E.

[0099] Furthermore, even when all the lifters 108 have risen to the first height and the entire edge ring E is separated from the ring support surface of the electrostatic chuck 104, an electrostatic attraction force of the edge ring E to the ring support surface of the electrostatic chuck 104 exists due to residual charges on the ring support surface of the electrostatic chuck 104.

[0100] After the lifter 108 rises to the first height, a predetermined flow rate of static elimination gas is supplied from the gas supply unit 140 to the processing space 100s via the upper electrode 102, and the exhaust control by the exhaust system 160 to bring the chamber 100 to a target pressure is initiated. For example, the predetermined flow rate is 100 sccm to 1000 sccm, and the target pressure is 100 mTorr to 1000 mTorr.

[0101] After a predetermined waiting time T4 has elapsed and the chamber 100 is filled with the atmosphere of the static elimination gas, high-frequency power HF for plasma generation is supplied from the RF power supply unit 150 to the lower electrode 103, for example, thereby generating the static elimination gas plasma as the first plasma. Although an example has been shown in which the high-frequency power HF for plasma generation is supplied to the lower electrode 103, it is not limited to this and may also be supplied to the upper electrode 102.

[0102] After plasma generation begins, once a predetermined time T5 has elapsed, the supply of high-frequency power HF from the RF power supply unit 150, the supply of static elimination gas via the upper electrode 102, and the control of exhaust to reach the target pressure are stopped. The application of voltage to electrodes 111a and 111b remains stopped. Also, in step S5, as in step S4, exhaust may be performed via the gas discharge port 104c instead of discharging heat transfer gas via the gas discharge port 104c.

[0103] In step S5, the edge ring E is discharged by the plasma generated as described above. Specifically, the charge removed from the edge ring E in step S5 is as follows: Depending on the electrons remaining on the ring support surface of the electrostatic chuck 104, a positive charge is generated again on the lower part of the edge ring E when the edge ring E is separated from the ring support surface. In addition, a positive charge is generated in the part of the lower part of the edge ring E that is in contact with the lifter 108 due to contact charging with the upper surface of the lifter 108 where electrons are present.

[0104] The charge removed from the edge ring E in step S5 is specifically the positive charge generated on the edge ring E as described above and the positive charge that could not be completely removed from the edge ring E in step S4. In step S5, the positive charge at the bottom of the edge ring E flows through the edge ring E and the plasma of the static elimination gas to the ground potential to which the chamber 100 is connected, as shown in Figure 11, and the edge ring E is statically eliminated.

[0105] In step S5, the ring support surface of the electrostatic chuck 104 is also partially discharged by the plasma. Specifically, the charge on the ring support surface of the electrostatic chuck 104 that is removed in step S5 is, for example, electrons that remained on the ring support surface after step S4. In step S5, these electrons flow to the ground potential to which the chamber 100 is connected, for example, through the plasma present between the ring support surface and the lower surface of the edge ring E and the plasma above the edge ring E, thereby dischargeing the ring support surface. Note that electrons remaining on the ring support surface can also be removed via the electrode 111.

[0106] Furthermore, in step S5, the plasma also removes the charge (specifically, electrons, for example) from the upper surface of the lifter 108. These electrons are also removed by flowing to the ground potential to which the chamber 100 is connected, for example, through the plasma present between the ring support surface and the lower surface of the edge ring E and the plasma above the edge ring E.

[0107] After step S5, the lifter 108 is controlled to raise the edge ring E to a position higher than the height position of the edge ring E in step S4, the plasma generation unit is controlled to generate a second plasma and the edge ring E is discharged (step S6).

[0108] Specifically, for example, as shown in Figure 12, first, with the application of voltage to electrodes 111a and 111b stopped, all lifters 108 supporting the edge ring E are raised to a second height higher than the first height. When the lifters 108 are raised to the second height, the distance L2 from the ring support surface of the lower surface of the edge ring E is longer than L1 and 5 mm or less, preferably 1 mm or less. Specifically, the second height is the height at which the distance L2 is longer than L1 and 5 mm or less, preferably 1 mm or less, when the edge ring E and electrostatic chuck 104 are not charged. If the distance L2 exceeds 5 mm, the load on the lifters 108 due to recharging of the edge ring E will increase, which may cause an error. In addition, making the distance L2 longer than L1 makes it easier to remove charge from the edge ring E and the ring support surface.

[0109] Furthermore, even when all the lifters 108 have risen to the second height and the entire edge ring E is separated from the ring support surface of the electrostatic chuck 104, an electrostatic attraction force of the edge ring E to the ring support surface of the electrostatic chuck 104 exists due to residual charges on the ring support surface of the electrostatic chuck 104.

[0110] After the lifter 108 rises to the second height, the supply of static elimination gas at a predetermined flow rate from the gas supply unit 140 to the processing space 100s via the upper electrode 102 is started, and the exhaust control by the exhaust system 160 to bring the chamber 100 to a target pressure is started. For example, the predetermined flow rate is 100 sccm to 1000 sccm, and the target pressure is 100 mTorr to 1000 mTorr.

[0111] After a predetermined waiting time T6 has elapsed and the chamber 100 is filled with the atmosphere of the static elimination gas, high-frequency power HF for plasma generation is supplied from the RF power supply unit 150 to the lower electrode 103, for example, thereby generating a plasma of the static elimination gas as a second plasma. Although an example has been shown in which high-frequency power HF for plasma generation is supplied to the lower electrode 103, it is not limited to this and may also be supplied to the upper electrode 102.

[0112] After plasma generation begins, once a predetermined time T7 has elapsed, the supply of high-frequency power HF from the RF power supply unit 150, the supply of static elimination gas via the upper electrode 102, and the control of exhaust to reach the target pressure are stopped. The application of voltage to electrodes 111a and 111b remains stopped. Also, in step S6, as in step S4, exhaust may be performed via the gas discharge port 104c instead of discharging heat transfer gas via the gas discharge port 104c.

[0113] In step S6, the plasma generated as described above discharges the edge ring E and also discharges the ring support surface of the electrostatic chuck 104. Specifically, the charge removed from the edge ring E in step S6 is the positive charge that could not be completely removed from the edge ring E in step S5. In step S6, the positive charge in the edge ring E flows through the plasma of the discharge gas to the ground potential to which the chamber 100 is connected, as shown in Figure 13, and the edge ring E is discharged.

[0114] Furthermore, the charge on the ring support surface of the electrostatic chuck 104 that is removed in step S6 is specifically, for example, electrons that remained on the ring support surface after step S5. In step S6, the electrons remaining on the ring support surface flow to the ground potential to which the chamber 100 is connected, for example, through the plasma present between the ring support surface and the lower surface of the edge ring E and the plasma above the edge ring E, thereby de-staticizing the ring support surface. In step S6, the gap between the ring support surface and the lower surface of the edge ring E is larger than in step S5, and the plasma can easily penetrate this gap, so the de-staticization of the ring support surface by plasma is performed more efficiently than in step S5. In step S6, as in step S5, electrons remaining on the ring support surface can also be removed via the electrode 111.

[0115] Then, the edge ring E is transported from the chamber 100 to the transfer module 50 by the transport robot 70 (step S7). Specifically, after the lifter 108 supporting the edge ring E is raised from step S6, the edge ring E is transported from the chamber 100 to the transfer module 50 by the transport robot 70.

[0116] More specifically, as shown in Figure 14, for example, all the lifters 108 are raised to a transfer height higher than the second height. Then, the gate valve 62 is opened and the transfer arm 71 of the transfer robot 70 is inserted into the chamber 100. Next, the transfer arm 71 is moved between the edge ring E supported by the lifters 108 and the electrostatic chuck 104. Subsequently, all the lifters 108 are lowered and the edge ring E is transferred to the transfer arm 71. Next, the transfer arm 71 is withdrawn from the chamber 100 and the edge ring E is transported from the chamber 100 to the transfer module 50. After that, the gate valve 62 is closed. This completes the processing sequence, including the removal sequence of the edge ring E.

[0117] <Main effects of Example 1 of Processing Sequence> In Example 1 of Processing Sequence, in steps S5 and S6, the edge ring E is raised in stages while the plasma of the static elimination gas is used to eliminate static electricity from the edge ring E and the ring support surface of the electrostatic chuck 104. Therefore, according to Example 1 of Processing Sequence, when the edge ring E is supported and raised by the lifter 108, the electrostatic attraction force between the charge in the edge ring E and the charge on the ring support surface of the electrostatic chuck 104 can prevent the edge ring E from shifting relative to the lifter 108 or from falling off the lifter 108. As a result, it is possible to prevent the transfer robot 70 from being unable to transport the edge ring E.

[0118] Furthermore, in example 1 of the processing sequence, in step S4, the edge ring E supported on the ring support surface is electrostatically neutralized while exhausting the supply path including the gas discharge hole 104c, which also serves as an exhaust hole, without discharging the heat transfer gas through the gas discharge hole 104c, that is, while exhausting the gap between the edge ring E and the ring support surface. In contrast, if the edge ring E supported on the ring support surface is electrostatically neutralized while discharging the heat transfer gas through the gas discharge hole 104c, the edge ring E may detach forcefully from the electrostatic chuck 104 when the electrostatic attraction force of the edge ring E weakens, causing the position of the edge ring E on the electrostatic chuck 104 to shift, and making it impossible to recover the edge ring E via the lifter 108. In contrast, as described above, by applying a reverse polarity voltage to the electrode 111 while exhausting without discharging the heat transfer gas, it is possible to suppress the forceful detachment of the edge ring E from the electrostatic chuck 104.

[0119] Furthermore, in example 1 of the processing sequence, during the idle mode in step S3, voltages with the same polarity as the plasma processing in step S1 are applied to electrodes 111a and 111b, but with the opposite polarity. In contrast, if the same polarity voltage as during plasma processing is applied to electrodes 111a and 111b during the idle mode, the charge on the electrostatic chuck 104 side of the edge ring E will move to the electrostatic chuck 104. As a result, the degree of charge on the electrostatic chuck 104 side of the edge ring E will decrease, and the adsorption force of the edge ring E by the electrostatic chuck 104 may weaken. In contrast, as described above, by applying a voltage with a common polarity as the plasma processing in step S1 to electrodes 111a and 111b during the idle mode, the movement of charge from the electrostatic chuck 104 side of the edge ring E to the electrostatic chuck 104 can be suppressed. Therefore, when plasma processing is performed continuously, it is possible to prevent the adsorption force of the edge ring E by the electrostatic chuck 104 from gradually weakening.

[0120] <Example of Processing Sequence 2> Figure 15 is a flowchart of Example 2 of a processing sequence, which includes the sequence for removing the edge ring E from the processing module 60. Figure 16 is an explanatory diagram of the state of the processing module 60 and the state of voltage application to the electrode 111 when the static discharge step of the edge ring E included in Example 2 of the processing sequence is executed.

[0121] In the aforementioned Example 1 of the processing sequence, in step S4, the edge ring E was statically removed while no plasma was being generated in the chamber 100. In contrast, in this example, as shown in Figure 15, after steps S1 to S3 of the aforementioned Example 1 of the processing sequence are performed in order, step S11 is performed instead of step S4.

[0122] In step S11, the DC power supplies 121a and 121b are controlled to stop the application of voltage to the electrode 111, the plasma control unit is controlled to generate plasma, and the edge ring E on the ring support surface is discharged.

[0123] Specifically, for example, the DC power supplies 121a and 121b are controlled, and the application of the first polarity voltage to the electrode 111, which was performed in step S3, is stopped. Also, as shown in Figure 16, with no wafer W present in the chamber 100 and the edge ring E supported on the ring support surface including the upper surface 104b of the peripheral edge of the electrostatic chuck 104, the supply of static elimination gas at a predetermined flow rate from the gas supply unit 140 to the processing space 100s via the upper electrode 102 is started. At the same time, the exhaust control by the exhaust system 160 to bring the chamber 100 to a target pressure is started. For example, the predetermined flow rate is 100 sccm to 1000 sccm, and the target pressure is 100 mTorr to 1000 mTorr.

[0124] After a predetermined waiting time T8 has elapsed and the chamber 100 is filled with the atmosphere of static elimination gas, high-frequency power HF for plasma generation is supplied from the RF power supply unit 150 to the lower electrode 103, for example, thereby generating a plasma of static elimination gas. Although an example has been shown in which high-frequency power HF for plasma generation is supplied to the lower electrode 103, it is not limited to this and may also be supplied to the upper electrode 102.

[0125] After the application starts, once a predetermined time T9 has elapsed, the supply of high-frequency power HF from the RF power supply unit 150, the supply of static elimination gas via the upper electrode 102, and the control of exhaust to reach the target pressure are stopped. Also, in this step S11, as in step S4, exhaust is performed via the gas discharge port 104c without the discharge of heat transfer gas through the gas discharge port 104c.

[0126] After step S11, the steps from step S5 onwards of Example 1 of the processing sequence are performed.

[0127] In this example, as in Example 1 of the processing sequence, it is possible to suppress misalignment of the edge ring E relative to the lifter 108 and transport failures caused by the edge ring E falling from the lifter 108.

[0128] <Modifications of Processing Sequence Examples 1 and 2> Unlike Processing Sequence Examples 1 and 2, static electricity removal of the edge ring E may be performed while discharging heat transfer gas through the gas discharge hole 104c, without exhausting the gap between the edge ring E and the ring support surface through the gas discharge hole 104c.

[0129] In the above example, during the plasma treatment in step S1, the electrode 111 was subjected to the same polarity as the second polarity applied to the electrode 111 of the electrostatic chuck 104 during the static elimination process of the edge ring E in step S4. However, the electrode 111 may be subjected to the same polarity as the second polarity. Furthermore, unlike the above example, voltages of different polarities may be applied to electrodes 111a and 111b during the plasma treatment in step S1, a voltage of a common polarity may be applied during the idle mode in step S3, and a voltage of a common polarity but opposite to the polarity of the idle mode in step S3 may be applied during the static elimination of the edge ring E in step S4. Specifically, during the plasma treatment in step S1, either a positive polarity voltage or a negative polarity voltage may be applied to electrode 111a and the other to electrode 111b. Furthermore, in the idle mode of step S3, a common positive or negative voltage may be applied to both electrodes 111a and 111b, and in the static elimination of the edge ring E in step S4, a common voltage with the opposite polarity to that of step S3 may be applied to both electrodes 111a and 111b. Additionally, in the plasma processing of step S1, a voltage with a common polarity may be applied to electrodes 111a and 111b, in the idle mode of step S3, voltages with different polarities may be applied, and in the static elimination of the edge ring E in step S4, voltages with different polarities and the opposite polarity to that of the idle mode of step S3 may be applied. Specifically, in the plasma treatment of step S1, a common positive or negative voltage is applied to both electrodes 111a and 111b; in the idle mode of step S3, either a positive or negative voltage is applied to electrode 111a and the other to electrode 111b; and in the static elimination of the edge ring E of step S4, a voltage with the opposite polarity to that applied in the idle mode of step S3 may be applied to electrodes 111a and 111b, respectively. Furthermore, in all of the plasma treatment of step S1, the idle mode of step S3, and the static elimination of the edge ring E of step S4, a voltage with a common polarity is applied to both electrodes 111a and 111b, while the polarity of the applied voltage may be different between the plasma treatment of step S1 and the idle mode of step S3 and the static elimination of the edge ring E of step S4.Specifically, in the plasma treatment of step S1, a common positive or negative voltage is applied to both electrodes 111a and 111b; in the idle mode of step S3, a common voltage with the same polarity as in step S1 is applied to both electrodes 111a and 111b; and in the static elimination of the edge ring E of step S4, a common voltage with a different polarity than in step S1 may be applied to both electrodes 111a and 111b.

[0130] Furthermore, unlike the above examples, in at least one of step S5 and step S6, a voltage may be applied to the electrode 111 of the electrostatic chuck 104, similar to step S4.

[0131] Unlike the above example, in steps S5 and S6, when raising the lifter 108, the supply of static elimination gas via the upper electrode 102 and the control of exhaust to reach the target pressure may be continued. For example, the supply of static elimination gas via the upper electrode 102 and the control of exhaust to reach the target pressure may be continued from the start in step S4 until the plasma generation is completed in step S6. In this case, plasma generation may be carried out continuously from the start of generation in step S4 until completion in step S6, or it may be carried out only when the lifter 108 is raised.

[0132] When examples 1 and 2 of the processing sequence are executed, during the period after step S6 and before step S7, a step may be performed in which, with the lifter 108 supporting the edge ring E raised from step S6, reaction products adhering to the edge ring E and the ring support surface of the electrostatic chuck 104 are removed by plasma of the cleaning gas. In other words, a step of cleaning the edge ring E and the ring support surface may be performed.

[0133] In this cleaning process, specifically, with the wafer W not placed on the electrostatic chuck 104 and the application of voltage to electrodes 111a and 111b stopped, all lifters 108 supporting the edge ring E are raised to a cleaning height higher than the second height and lower than the transfer height. Subsequently, a predetermined flow rate of cleaning gas is supplied from the gas supply unit 140 to the processing space 100s via the upper electrode 102, and the exhaust control by the exhaust system 160 to bring the chamber 100 to a target pressure is initiated. The cleaning gas is, for example, the oxygen-containing gas mentioned above. For example, the predetermined flow rate is 100 sccm to 1000 sccm, and the target pressure is 100 mTorr to 1000 mTorr.

[0134] After a predetermined waiting time T10 has elapsed and the chamber 100 is filled with the cleaning gas atmosphere, high-frequency power HF for plasma generation is supplied from the RF power supply unit 150 to the lower electrode 103, for example, thereby generating a plasma of the cleaning gas. Although an example has been shown in which high-frequency power HF for plasma generation is supplied to the lower electrode 103, it is not limited to this and may also be supplied to the upper electrode 102.

[0135] After the application starts, once a predetermined time T11 has elapsed, the supply of high-frequency power HF from the RF power supply unit 150, the supply of cleaning gas via the upper electrode 102, and the control of exhaust to reach the target pressure are stopped.

[0136] As described above, the plasma from the cleaning gas removes reaction products adhering to the edge ring E. Therefore, it is possible to suppress the adverse effects of the reaction products when the edge ring E is removed. In addition, the plasma from the cleaning gas can remove at least the reaction products adhering to the ring support surface of the electrostatic chuck 104.

[0137] Furthermore, a DC voltage may be supplied to the lower electrode 103 for plasma generation of the cleaning gas.

[0138] <Modifications of the Plasma Processing Apparatus> In the above example, exhaust through the gas discharge port 104c, which also serves as an exhaust port, and exhaust from inside the chamber 100, i.e., the processing space 100s, were performed by a common exhaust system 160. However, these may be performed by different exhaust systems. Alternatively, the exhaust port and the gas discharge port 104c may be provided separately. That is, an exhaust passage including the exhaust port and a supply passage including the gas discharge port 104c may be provided separately.

[0139] In addition to the edge ring E, a covering ring may be placed on the wafer support base used in plasma processing equipment so as to cover the outer surface of the edge ring. The technology of this disclosure can also be applied in this case.

[0140] Figure 17 is a partially enlarged view illustrating an example of a wafer support configured to support a covering ring CA in addition to an edge ring EA. Below, the wafer support 101A in Figure 17 will be described, focusing on the differences between it and the wafer support 101 shown in Figure 2, etc.

[0141] The wafer support base 101A in Figure 17, like the wafer support base 101 shown in Figure 2, includes an electrostatic chuck 104, an insulator 106, and a lifter 107, as well as a lower electrode 103A, a support body 105A, and a lifter 108A. The wafer support base 101A is configured to support both the edge ring EA and the covering ring CA.

[0142] The lower outer periphery of the lower electrode 103A and the upper inner periphery of the support 105A are formed to overlap in a plan view. Furthermore, the lower electrode 103A and the support 105A are provided with through holes 119A through which the lifter 108A is inserted. The through holes 119A are formed to extend downward from the upper surface 105Aa of the inner periphery of the support 105A to the bottom surface of the lower outer periphery of the lower electrode 103A.

[0143] The electrostatic chuck 104 is positioned to rest on the lower electrode 103A. The edge ring EA is supported on the upper surface 104b of the peripheral edge of the electrostatic chuck 104, and the covering ring CA is supported on the upper surface 105Aa of the support 105A. The upper surface 105Aa of the support 105A and the upper surface of the lower electrode 103A are approximately at the same height.

[0144] The edge ring EA is formed with a larger outer diameter than the electrostatic chuck 104. Therefore, when the edge ring EA is supported on the upper surface 104b of the peripheral edge of the electrostatic chuck 104, the peripheral edge of the edge ring EA protrudes from the peripheral edge of the electrostatic chuck 104.

[0145] The covering CA is a component positioned to cover the outer surface of the edge ring EA. Like the edge ring EA, the covering CA is also formed in an annular shape in plan view. In one embodiment, the covering CA has a convex portion CA1 at its bottom that protrudes radially inward.

[0146] Furthermore, the covering CA has through holes CA2 at positions corresponding to each of the lifters 108A through which the lifters 108A are inserted. The through holes CA2 penetrate from the bottom surface of the covering CA to the edge ring EA. The through holes CA2 are provided in the portion of the covering CA that overlaps with the inner circumference of the covering CA and the peripheral edge of the edge ring EA in a plan view (specifically, for example, the convex portion CA1).

[0147] The lifter 108A is configured to protrude from the upper surface 105Aa of the inner circumference of the support 105A, and its protrusion amount from the upper surface 105Aa can be adjusted by raising and lowering it. Specifically, the lifter 108A is configured to protrude from a position on the upper surface 105Aa of the inner circumference of the support 105A where it overlaps with the edge ring EA and the covering ring CA in a plan view. The insertion hole 119A through which the lifter 108A is inserted is formed at a position where it overlaps with the edge ring EA and the covering ring CA in a plan view.

[0148] The lifters 108A are arranged in groups of three or more, spaced apart from each other, along the circumferential direction of the electrostatic chuck 104, similar to the lifter 108 in Figure 3. Furthermore, the lifters 108A have a first engaging portion 108Aa and a second engaging portion 108Ab.

[0149] The first engaging portion 108Aa is formed by the upper part of the lifter 108A. The first engaging portion 108Aa is formed in a columnar shape except for the upper end (i.e., the tip), and the upper end is formed in a hemispherical shape. This first engaging portion 108Aa protrudes upward from the through hole CA2 of the covering CA and engages with the edge ring E. When the lifter 108A is raised, the first engaging portion 108Aa passes through the through hole CA2 of the covering CA and comes into contact with the bottom surface of the edge ring EA, thereby supporting the edge ring EA from the bottom surface.

[0150] The second engaging portion 108Ab is located below the first engaging portion 108Aa and engages with the covering CA. The second engaging portion 108Ab does not pass through the through hole CA2 of the covering CA, but abuts against the bottom surface of the covering CA, thereby supporting the covering CA from the bottom surface. The second engaging portion 108Ab is also connected to the base end side of the first engaging portion 108Aa along the axial direction of the lifter 108A. The second engaging portion 108Ab also has a projection 108Ac that protrudes outward from the outer circumference of the first engaging portion 108Aa at the position where it is connected to the first engaging portion 108Aa.

[0151] The specific shapes of the first engaging portion 108Aa, the second engaging portion 108Ab, and the protruding portion 108Ac are not particularly limited. For example, the first engaging portion 108Aa, the second engaging portion 108Ab, and the protruding portion 108Ac may each be cylindrical members and be coaxial with one another.

[0152] The aforementioned actuator 116 raises and lowers the lifter 108A, in which the covering CA is engaged with the second engaging portion 108Ab, thereby raising and lowering the covering CA. The actuator 116 also raises and lowers the lifter 108A, in which the edge ring E is engaged with the first engaging portion 108Aa, thereby raising and lowering the edge ring E.

[0153] When this wafer support stand 101A is used, the removal of the edge ring EA may be performed by the edge ring EA alone, or it may be performed simultaneously with the removal of the covering ring CA.

[0154] When removing the edge ring EA by itself, the steps of separating the edge ring EA from the ring support surface using a lifting mechanism including the lifter 108A and transporting the edge ring EA to the transfer module 50 are performed, for example, as follows.

[0155] In the step of separating the edge ring EA from the ring support surface, for example, all the lifters 108 are raised. As a result, the edge ring E is transferred from the ring support surface, including the upper surface 104b of the peripheral edge of the electrostatic chuck 104, to the first engaging portion 108Aa of the lifter 108, which has passed through the insertion hole 119A and the through hole CA2 of the covering ring CA. This raising of the lifter 108A is performed to the extent that the covering ring CA is not transferred to the second engaging portion 108Ab of the lifter 108A, and is performed until the top of the first engaging portion 108Aa reaches a predetermined height. The predetermined height here is the height at which the transport arm 71 does not interfere with the edge ring E and the covering ring CA when the transport arm 71 is inserted and removed between the covering ring CA placed on the support 105A and the edge ring EA supported by the first engaging portion 108Aa.

[0156] In the process of transporting the edge ring EA to the transfer module 50, for example, first, a transport arm 71 is inserted into the chamber 100 via an inlet / outlet (not shown). Then, the transport arm 71 is moved between the covering CA placed on the support 105A and the edge ring EA supported by the first engaging portion 108Aa of the lifter 108A.

[0157] Next, all the lifters 108 are lowered, and the edge ring EA is transferred from the first engaging portion 108Aa of the lifter 108A to the transport arm 71. Subsequently, the transport arm 71 is withdrawn from the chamber 100, and the edge ring E is transported to the transfer module 50. The transported edge ring E is then placed into the storage module 61.

[0158] On the other hand, when the edge ring EA is removed at the same time as the covering CA, the steps of separating the edge ring EA from the ring support surface using a lifting mechanism including the lifter 108A and transporting the edge ring EA to the transfer module 50 are carried out, for example, as follows.

[0159] In the step of separating the edge ring EA from the ring support surface, for example, all the lifters 108 are raised. As a result, the edge ring EA is transferred from the ring support surface, including the upper surface 104b of the peripheral edge of the electrostatic chuck 104, to the first engaging portion 108Aa of the lifter 108, which has passed through the insertion hole 119A and the through hole CA2 of the covering ring CA. Subsequently, all the lifters 108A continue to rise, and the covering ring CA is transferred from the upper surface 105Aa of the support 105A to the second engaging portion 108Ab of the lifter 108A. At this time, the lifter 108A is raised until the top of the second engaging portion 108Ab reaches a predetermined height. The predetermined height here is such that when the transport arm 71 is inserted into or removed from the upper surface 104a of the central part of the electrostatic chuck 104 and the covering CA supported by the second engaging portion 108Ab, the transport arm 71 does not interfere with the covering CA or the like.

[0160] In the process of transporting the edge ring EA to the transfer module 50, for example, first, a transport arm 71 is inserted into the chamber 100 via an inlet / outlet (not shown). Then, the transport arm 71 is moved between the upper surface 104a of the central part of the electrostatic chuck 104 and the covering ring CA supported by the second engaging portion 108Ab of the lifter 108A.

[0161] Next, all the lifters 108A are lowered, and the covering CA is transferred from the second engaging portion 108Ab of the lifter 108A to the transport arm 71. After that, all the lifters 108A continue to lower, and the edge ring EA is transferred from the first engaging portion 108Aa of the lifter 108A to the covering CA supported by the transport arm 71. Subsequently, the transport arm 71 is withdrawn from the chamber 100, and the covering CA supporting the edge ring EA is transported to the transfer module 50. The transported covering CA supporting the edge ring EA is then transported into the storage module 61.

[0162] The edge ring EA may also be provided with a recess similar to the recess E1 of the edge ring E shown in Figure 2, etc.

[0163] Furthermore, even when the wafer support stand 101A shown in Figure 14 is used, a groove similar to groove 104d may be provided on the upper surface of the peripheral edge of the electrostatic chuck.

[0164] The embodiments disclosed herein should be considered in all respects as illustrative and not restrictive. The embodiments described above may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims. For example, the constituent elements of the embodiments described above can be combined in any way. Such any combination will naturally yield the functions and effects of each constituent element in the combination, as well as other functions and effects that will be apparent to those skilled in the art from the description herein.

[0165] Furthermore, the effects described herein are merely descriptive or illustrative and not limiting. In other words, the technology relating to this disclosure may produce other effects that are obvious to those skilled in the art from the description herein, in addition to or instead of the effects described herein.

[0166] The following configuration examples also fall within the technical scope of this disclosure: (1) A plasma processing apparatus comprising: a processing vessel configured to be able to reduce pressure; an electrostatic chuck provided in the processing vessel and having a substrate support surface and a ring support surface provided so as to surround the substrate support surface, with an electrode provided below the ring support surface; a power supply for applying a DC voltage to the electrode; a lifter for raising and lowering an edge ring with an actuator relative to the ring support surface; a gas supply unit for supplying gas into the processing vessel; a plasma generation unit for generating plasma from the gas supplied into the processing vessel; and a control unit, wherein after the plasma-treated substrate is removed from the processing vessel, the control unit: (a) controls the power supply to stop the application of voltage to the electrode, controls the plasma generation unit to generate a first plasma and discharge the edge ring on the ring support surface; (b) controls the lifter to bring the lifter into contact with the lower surface of the edge ring, controls the plasma generation unit to generate a second plasma and discharge the edge ring; (c) A plasma processing apparatus that controls the lifter to raise the edge ring to a position higher than the height position of the edge ring in (b), and controls the plasma generation unit to generate a third plasma and discharge the edge ring, in this order. (2) The plasma processing apparatus according to (1), wherein in (b), the state in which the lifter is in contact with the lower surface of the edge ring is a state in which there is an electrostatic attraction force of the edge ring to the ring support surface due to the charge remaining on the edge ring and the ring support surface after (a). (3) The plasma processing apparatus according to (1) or (2), wherein in (b), the distance between the lower surface of the edge ring and the ring support surface is 0.1 mm or more and 1 mm or less. (4) The plasma processing apparatus according to any one of (1) to (3), wherein in (c), the distance between the lower surface of the edge ring and the ring support surface is 5 mm or less.(5) The plasma processing apparatus according to (1), wherein in (b) above, the state where the lifter is in contact with the lower surface of the edge ring is a state where there is an electrostatic attraction force of the edge ring to the ring support surface due to charges remaining on the edge ring and the ring support surface after (a) above, and the edge ring lifted by the lifter is separated from the ring support surface. (6) The gas is N ２ gas, the plasma processing apparatus according to any one of (1) to (5) above, wherein the gas comprises at least one selected from the group consisting of Ar gas and oxygen-containing gas. (7) The plasma processing apparatus according to any one of (1) to (6) above, wherein the control unit further controls, after (c) in (d), the lifter supporting the edge ring to be lifted higher than that in (c), to remove reaction products attached to the edge ring and the ring support surface by plasma generated from cleaning gas supplied from the gas supply unit into the processing container. (8) The cleaning gas is O ２ gas, O ３ gas, CO gas, CO ２A plasma apparatus according to (7), comprising at least one selected from the group consisting of gas and COS gas. (9) A plasma apparatus according to any one of (1) to (8), further comprising a supply passage for supplying gas between the back surface of the edge ring and the ring support surface, wherein step (a) is performed while exhausting the supply passage. (10) A plasma apparatus according to any one of (1) to (9), further comprising a supply passage for supplying gas between the back surface of the edge ring and the ring support surface, and a groove provided on the ring support surface to which the supply passage is connected. (11) A plasma apparatus according to any one of (1) to (10), wherein the lower surface of the edge ring has a recess for accommodating the upper end of the lifter. (12) A plasma processing apparatus comprising: a processing vessel configured to be able to reduce pressure; an electrostatic chuck provided in the processing vessel and having a substrate support surface and a ring support surface provided so as to surround the substrate support surface, with an electrode provided below the ring support surface; a power supply for applying a DC voltage to the electrode; a lifter for raising and lowering an edge ring with an actuator relative to the ring support surface; a gas supply unit for supplying gas into the processing vessel; a plasma generation unit for generating plasma from the gas supplied into the processing vessel; and a control unit, wherein after the plasma-treated substrate is removed from the processing vessel, the control unit (a) controls the power supply to apply a voltage with a polarity different from the polarity of the voltage applied to the electrode, controls the gas supply unit to supply the gas and discharge the edge ring on the ring support surface; (b) controls the lifter to bring the lifter into contact with the lower surface of the edge ring, controls the plasma generation unit to generate a first plasma and discharge the edge ring. (c) A plasma processing apparatus that controls the lifter to raise the edge ring to a position higher than the height position of the edge ring in (b), and controls the plasma generation unit to generate a second plasma and discharge the edge ring, in this order.(13) A substrate processing system comprising: a plasma processing apparatus; a vacuum transfer apparatus connected to the plasma processing apparatus and having a transfer robot for transporting substrates and edge rings; and one or more control devices for controlling the plasma processing apparatus and the vacuum transfer apparatus, wherein the plasma processing apparatus comprises: a processing container configured to be able to reduce pressure; an electrostatic chuck provided inside the processing container and having a substrate support surface and a ring support surface provided so as to surround the substrate support surface, with electrodes provided below the ring support surface; a power supply for applying a DC voltage to the electrodes; a lifter for raising and lowering the edge ring with respect to the ring support surface by an actuator; a gas supply unit for supplying gas into the processing container; and a plasma generation unit for generating plasma from the gas supplied into the processing container, wherein after the plasma-processed substrate is removed from the processing container, the control device (a) controls the power supply to stop the application of voltage to the electrodes, controls the plasma generation unit to generate a first plasma and discharge the edge ring on the ring support surface, A substrate processing system that controls the following in this order: (b) controlling the lifter to bring it into contact with the lower surface of the edge ring, and controlling the plasma generation unit to generate a second plasma and discharge the edge ring; (c) controlling the lifter to raise the edge ring to a position higher than the height position of the edge ring in (b), and controlling the plasma generation unit to generate a third plasma and discharge the edge ring; and (d) controlling the lifter and the transport robot to transport the edge ring from the processing container to the reduced pressure transport device.

[0167] Furthermore, this application claims priority based on Japanese Patent Application No. 2025-039634, filed on 12 March 2025, and the entire contents of these Japanese Patent Applications are incorporated herein by reference.

[0168] 1 Plasma processing system 50 Transfer module 60 Processing module 70 Transport robot 80 Control unit 100 Chamber 101, 101A Wafer support 102 Upper electrode 104 Electrostatic chuck 104a Upper surface of central part (i.e., wafer mounting surface) 104b Upper surface of peripheral part 108, 108A Lifter 111 Electrode 111a Electrode 111b Electrode 116 Actuator 118 Drive unit 150 RF power supply unit E, EA Edge ring W Wafer

Claims

1. A plasma processing apparatus comprising: a processing vessel configured to be able to reduce pressure; an electrostatic chuck provided inside the processing vessel and having a substrate support surface and a ring support surface provided so as to surround the substrate support surface, with an electrode provided below the ring support surface; a power supply for applying a DC voltage to the electrode; a lifter for raising and lowering an edge ring with an actuator relative to the ring support surface; a gas supply unit for supplying gas into the processing vessel; a plasma generation unit for generating plasma from the gas supplied into the processing vessel; and a control unit, wherein after the plasma-treated substrate is removed from the processing vessel, the control unit (a) controls the power supply to stop the application of voltage to the electrode, controls the plasma generation unit to generate a first plasma and discharge the edge ring on the ring support surface; (b) controls the lifter to bring the lifter into contact with the lower surface of the edge ring, controls the plasma generation unit to generate a second plasma and discharge the edge ring. (c) A plasma processing apparatus that controls the lifter to raise the edge ring to a position higher than the height position of the edge ring in (b), and controls the plasma generation unit to generate a third plasma and discharge the edge ring, in this order.

2. The plasma processing apparatus according to claim 1, wherein, in (b) above, the state in which the lifter is in contact with the lower surface of the edge ring is a state in which an electrostatic attraction force of the edge ring to the ring support surface exists due to the charge remaining on the edge ring and the ring support surface after (a).

3. The plasma processing apparatus according to claim 2, wherein, in (b) above, the distance between the lower surface of the edge ring and the ring support surface is 0.1 mm or more and 1 mm or less.

4. The plasma processing apparatus according to claim 3, wherein, in (c) above, the distance between the lower surface of the edge ring and the ring support surface is 5 mm or less.

5. The plasma processing apparatus according to claim 1, wherein, in (b) above, the state in which the lifter is in contact with the lower surface of the edge ring is such that an electrostatic attraction force of the edge ring to the ring support surface exists due to the charge remaining on the edge ring and the ring support surface after (a), and the edge ring, which has been raised by the lifter, is separated from the ring support surface.

6. The gas is N ２ A plasma processing apparatus according to any one of claims 1 to 5, comprising at least one selected from the group consisting of gas, Ar gas, and oxygen-containing gas.

7. The plasma processing apparatus according to any one of claims 1 to 5, wherein the control unit further controls the lifter supporting the edge ring to be raised higher than at the time of (c) and to remove reaction products adhering to the edge ring and the ring support surface using plasma generated from the cleaning gas from the gas supply unit in the processing vessel.

8. The cleaning gas is O ２ Gas, O ３ Gas, CO gas, CO ２ The plasma processing apparatus according to claim 7, comprising at least one selected from the group consisting of gas and COS gas.

9. The plasma processing apparatus according to any one of claims 1 to 5, further comprising a supply passage for supplying gas between the back surface of the edge ring and the ring support surface, wherein step (a) is performed while exhausting the supply passage.

10. The plasma processing apparatus according to any one of claims 1 to 5, further comprising: a supply passage for supplying gas between the back surface of the edge ring and the ring support surface; and a groove provided on the ring support surface to which the supply passage is connected.

11. The plasma processing apparatus according to any one of claims 1 to 5, wherein the lower surface of the edge ring has a recess in which the upper end of the lifter fits.

12. A plasma processing apparatus comprising: a processing vessel configured to be able to reduce pressure; an electrostatic chuck provided inside the processing vessel and having a substrate support surface and a ring support surface provided so as to surround the substrate support surface, with an electrode provided below the ring support surface; a power supply for applying a DC voltage to the electrode; a lifter for raising and lowering an edge ring with an actuator relative to the ring support surface; a gas supply unit for supplying gas into the processing vessel; a plasma generation unit for generating plasma from the gas supplied into the processing vessel; and a control unit, wherein after the plasma-treated substrate is removed from the processing vessel, the control unit (a) controls the power supply to apply a voltage with a polarity different from the polarity of the voltage applied to the electrode, controls the gas supply unit to supply the gas and discharge the edge ring on the ring support surface; (b) controls the lifter to bring the lifter into contact with the lower surface of the edge ring, controls the plasma generation unit to generate a first plasma and discharge the edge ring. (c) A plasma processing apparatus that controls the lifter to raise the edge ring to a position higher than the height position of the edge ring in (b), and controls the plasma generation unit to generate a second plasma and discharge the edge ring, in this order.

13. A substrate processing system comprising: a plasma processing apparatus; a vacuum transfer apparatus connected to the plasma processing apparatus and having a transfer robot for transporting substrates and edge rings; and one or more control devices for controlling the plasma processing apparatus and the vacuum transfer apparatus, wherein the plasma processing apparatus comprises: a processing container configured to be able to reduce pressure; an electrostatic chuck provided inside the processing container and having a substrate support surface and a ring support surface provided so as to surround the substrate support surface, with electrodes provided below the ring support surface; a power supply for applying a DC voltage to the electrodes; a lifter for raising and lowering the edge ring with respect to the ring support surface by an actuator; a gas supply unit for supplying gas into the processing container; and a plasma generation unit for generating plasma from the gas supplied into the processing container, wherein after the plasma-processed substrate is removed from the processing container, the control device (a) controls the power supply to stop the application of voltage to the electrodes, controls the plasma generation unit to generate a first plasma and discharge the edge ring on the ring support surface, A substrate processing system that controls the following in this order: (b) controlling the lifter to bring it into contact with the lower surface of the edge ring, and controlling the plasma generation unit to generate a second plasma and discharge the edge ring; (c) controlling the lifter to raise the edge ring to a position higher than the height position of the edge ring in (b), and controlling the plasma generation unit to generate a third plasma and discharge the edge ring; and (d) controlling the lifter and the transport robot to transport the edge ring from the processing container to the reduced pressure transport device.

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