Plasma Processing Equipment

Abstract

To provide a plasma processing apparatus with a lift pin mechanism that can properly raise and lower a ring assembly used for plasma processing.SOLUTION: A plasma processing apparatus has a plasma processing chamber and a substrate support section 11 disposed in the plasma processing chamber. A substrate support section has a conductive base 112, an electrostatic chuck 113 having a substrate support surface, an edge ring 122 disposed to surround a substrate on the substrate support surface, a cover ring 121 disposed below the edge ring and having a plurality of through holes, a plurality of lift pins 131, at least one spacer 133 fixed to at least one of the lift pins and disposed on the lower portion 131b to surround the upper portion 131a and to support the covering ring, and at least one actuator 132 to move the plurality of lift pins in a longitudinal direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] Patent Document 1 discloses a mounting table equipped with lifter pins for supporting from below a first ring and a second ring mounted on a ring mounting surface and raising and lowering them. A through hole through which the lifter pin is inserted is formed in the second ring. The lifter pin described in Patent Document 1 is configured by connecting in the axial direction a first holding part having a smaller diameter than the through hole and supporting the first ring by inserting through the through hole, and a second holding part having a larger diameter than the through hole and supporting the second ring by a protruding part protruding from the outer periphery of the first holding part.

[0003] Patent Document 2 discloses a lift pin mechanism used when replacing a top ring and a middle ring in a substrate processing system. The lift pin mechanism described in Patent Document 2 has an upper member configured to be inserted through a through hole formed in a lower electrode and engage with the lower surface of the top ring, and a lower member configured to engage with the lower surface of the through hole. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-130603 A [Patent Document 2] International Publication No. 2020 / 231611 Summary of the Invention [Problem to be solved by the invention]

[0005] The technology disclosed herein provides a plasma processing apparatus equipped with a lift pin mechanism that can appropriately raise and lower a ring assembly used in plasma processing. [Means for solving the problem]

[0006] One aspect of the present disclosure includes a plasma processing chamber, a plasma generating unit configured to generate plasma from a processing gas in the plasma processing chamber, and a substrate support disposed in the plasma processing chamber, the substrate support including a base, an electrostatic chuck disposed above the base and having a substrate support surface, a first annular member disposed to surround a substrate on the substrate support surface, a second annular member disposed below the first annular member and having a plurality of through holes, and a plurality of lift pins disposed corresponding to the plurality of through holes, each lift pin having an upper portion having a first width and a lower portion having a first width and a lower portion having a second ... a plurality of lift pins having a lower portion having a second width greater than a first width, the upper portion configured to support the first annular member through corresponding through holes in the second annular member; at least one spacer fixed to at least one of the plurality of lift pins, the spacer being disposed on the lower portion to surround the upper portion, the spacer being configured to support the second annular member; and at least one actuator configured to vertically move the plurality of lift pins. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a plasma processing apparatus having a lift pin mechanism that can appropriately raise and lower a ring assembly used in plasma processing. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic diagram illustrating a configuration example of a plasma processing system according to an embodiment. [Diagram 2] 1 is a vertical cross-sectional view showing a configuration example of a plasma processing apparatus according to an embodiment; [Diagram 3] 5 is a schematic diagram showing a configuration example of a substrate support part according to the embodiment. FIG. [Figure 4A] 11 is an explanatory diagram showing a state in which the edge ring is lifted up; FIG. [Figure 4B]FIG. 11 is an explanatory diagram showing the state when the cover ring is lifted up. [Figure 5A] FIG. 11 is a vertical cross-sectional view showing an example of fixing the spacer. [Figure 5B] FIG. 11 is a vertical cross-sectional view showing an example of fixing the spacer. [Figure 5C] FIG. 11 is a vertical cross-sectional view showing an example of fixing the spacer. [Figure 5D] FIG. 11 is a vertical cross-sectional view showing an example of fixing the spacer. [Figure 6] FIG. 11 is a vertical cross-sectional view showing another example of the configuration of the spacer. [Figure 7A] FIG. 11 is a vertical cross-sectional view showing another example of the configuration of the spacer. [Figure 7B] FIG. 11 is a vertical cross-sectional view showing another example of the configuration of the spacer. [Figure 8A] FIG. 11 is a vertical cross-sectional view showing another example of the configuration of the spacer. [Figure 8B] 11 is an explanatory view showing a state in which the third annular member is lifted up. FIG. [Figure 9] FIG. 11 is a vertical cross-sectional view showing another example of the configuration of the spacer. [Figure 10A] FIG. 11 is a vertical cross-sectional view showing another example of the configuration of the lift pin. [Figure 10B] FIG. 13 is an explanatory diagram of a state in which the movable portion of the lift pin is left behind at the top. [Figure 11] FIG. 11 is a vertical cross-sectional view showing another example of the configuration of the spacer. [Figure 12A] FIG. 11 is an explanatory diagram showing a sequence of steps for determining the thickness of a spacer. [Figure 12B] FIG. 11 is an explanatory diagram showing a sequence of steps for determining the thickness of a spacer. [Figure 13] FIG. 11 is a flow chart showing a sequence of steps for determining the thickness of a spacer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In a semiconductor device manufacturing process, a processing gas supplied into a chamber is excited to generate plasma, and various plasma processes such as etching, film formation, and diffusion are performed on a semiconductor substrate (hereinafter simply referred to as a "substrate") supported by a substrate support. In the plasma processes, a plurality of annular members such as an edge ring and a cover ring (hereinafter the plurality of annular members are collectively referred to as a "ring assembly") are arranged to surround the substrate supported by the substrate support.

[0010] When the ring assembly is loaded and unloaded from the substrate support, lift pins having one or more steps in the axial direction are used to raise and lower each of the multiple annular members to a specified height at which they are transferred to and from the transport arm. However, when the same lift pins are used to raise and lower multiple annular members in this manner, if the position of the lift pin is adjusted to the lift position of one annular member, the amount of such adjustment or stacking tolerance may cause other annular members to be unable to be appropriately raised and lowered to the specified height, or the transport efficiency of the ring assembly may be reduced.

[0011] In order to appropriately raise and lower each annular member, it is necessary to individually adjust the height (position) of the step portion of the lift pin in accordance with each of the multiple annular members. However, there are difficulties in individually adjusting the height of the step portion in this manner, and this point is neither described nor suggested in Patent Document 1 nor Patent Document 2.

[0012] The technology disclosed herein has been made in consideration of the above circumstances, and provides a plasma processing apparatus equipped with a lift pin mechanism capable of appropriately raising and lowering a ring assembly used in plasma processing. Hereinafter, a plasma processing system equipped with a plasma processing apparatus according to the present embodiment will be described with reference to the drawings. Note that in this specification and the drawings, elements having substantially the same functional configurations are denoted by the same reference numerals, and duplicated explanations will be omitted.

[0013] <Plasma processing system> In one embodiment, the plasma processing system includes a plasma processing apparatus 1 and a control unit 2, as shown in FIG. 1. The plasma processing apparatus 1 includes a plasma processing chamber 10, a substrate support unit 11, and a plasma generation unit 12. The plasma processing chamber 10 has a plasma processing space. The plasma processing chamber 10 also has at least one gas supply port for supplying at least one processing gas to the plasma processing space, and at least one gas exhaust port for exhausting gas from the plasma processing space. The gas supply port is connected to a gas supply unit 20, which will be described later, and the gas exhaust port is connected to an exhaust system 40, which will be described later. The substrate support unit 11 is disposed in the plasma processing space, and has a substrate support surface for supporting a substrate.

[0014] The plasma generating unit 12 is configured to generate plasma from at least one processing gas supplied into the plasma processing space. The plasma formed in the plasma processing space is a capacitively coupled plasma (CCP). The plasma may be an alternating current (AC) plasma generator or a direct current (DC) plasma generator. Various types of plasma generating units may be used, including an AC plasma generating unit. In one embodiment, the AC signal (AC power) used in the AC plasma generating unit has a frequency in the range of 100 kHz to 10 GHz. Therefore, the AC signal is an RF (Radio Frequency) The RF signals include RF (Radio Frequency) signals and microwave signals. In one embodiment, the RF signals have a frequency in the range of 200 kHz to 150 MHz.

[0015] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various steps described in the present disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform various steps described herein. In one embodiment, a part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 may include, for example, a computer 2a. The computer 2a may include, for example, a processing unit (CPU: Central Processing Unit) 2a1, a storage unit 2a2, and a communication interface 2a3. The processing unit 2a1 may be configured to perform various control operations based on a program stored in the storage unit 2a2. The storage unit 2a2 may include a random access memory (RAM), a read only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a local area network (LAN).

[0016] <Plasma processing equipment> Next, a configuration example of a capacitively coupled plasma processing apparatus 1 will be described as an example of the above-mentioned plasma processing apparatus 1. FIG.

[0017] The plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply 20, a power supply 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support 11 and a gas inlet. The substrate support 11 is disposed in the plasma processing chamber 10. The gas inlet is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas inlet includes a shower head 13. The shower head 13 is disposed above the substrate support 11. In one embodiment, the shower head 13 constitutes at least a part of the ceiling of the plasma processing chamber 10. Inside the plasma processing chamber 10, a plasma processing space 10s is formed, which is defined by the shower head 13, a sidewall 10a of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 has at least one gas inlet for supplying at least one processing gas to the plasma processing space 10s and at least one gas outlet for exhausting gas from the plasma processing space 10s. The sidewall 10a is grounded. The showerhead 13 and the substrate support 11 are electrically isolated from the plasma processing chamber 10 .

[0018] The substrate support 11 includes a main body 110, a ring assembly 120, and a lifter 130 (see FIG. 3). The upper surface of the main body 110 has a central region 110a (substrate support surface) for supporting a substrate (wafer) W, and an annular region 110b (ring support surface) for supporting the ring assembly 120. The annular region 110b surrounds the central region 110a in a plan view. The substrate W is disposed on the central region 110a, and the ring assembly 120 is disposed on the annular region 110b so as to surround the substrate W on the central region 110a. The lifter 130 moves the ring assembly 120 in the vertical direction as described later, and transfers the ring assembly 120 to and from a transfer arm (not shown) provided outside the plasma processing apparatus 1.

[0019] 3, in one embodiment, the main body 110 includes a metal plate 111, a conductive base 112, and an electrostatic chuck 113. The metal plate 111, the conductive base 112, and the electrostatic chuck 113 are stacked in this order from the floor side of the plasma processing chamber 10. The electrostatic chuck 113 has the above-mentioned substrate support surface.

[0020] The metal plate 111 is fixed to the floor surface of the plasma processing chamber 10 and functions as a support for the conductive base 112 and the electrostatic chuck 113. The metal plate 111 has a plurality of through holes 111a (three in this embodiment) penetrating in the thickness direction. Lift pins 131, which will be described later, are inserted into the through holes 111a as shown in FIG.

[0021] The conductive base 112 serving as a base is made of a non-magnetic conductive material such as an Al alloy. The conductive material of the conductive base 112 functions as a lower electrode. An electrostatic chuck 113 (described later) is disposed on the radially inner side of the upper surface of the conductive base 112, and the radially outer side of the electrostatic chuck 113 on the upper surface constitutes the above-mentioned annular region 110b (ring support surface). In other words, the ring assembly 120 is disposed on the conductive base 112 so as to surround the electrostatic chuck 113.

[0022] Furthermore, a plurality of through holes 112a (three in this embodiment) are formed penetrating the conductive base 112 in the thickness direction. The through holes 112a are formed at positions corresponding to the through holes 111a formed in the metal plate 111, and lift pins 131 (described later) are inserted through the through holes 112a as shown in Fig. 3. The through holes 112a have the same diameter as the through holes 111a, for example.

[0023] The upper surface of the electrostatic chuck 113 constitutes the above-mentioned central region 110a (substrate support surface). An adsorption electrode (not shown) for adsorbing and holding the substrate W on the central region 110a is provided inside the electrostatic chuck 113. The electrostatic chuck 113 is configured by sandwiching the adsorption electrode between a pair of dielectric films made of a nonmagnetic dielectric material such as ceramics.

[0024] Further, a notch 113a is formed at the outer circumferential end of the upper surface of the electrostatic chuck 113. At least a part of the edge ring 122 is supported by the notch 113a as shown in FIG.

[0025] The ring assembly 120 includes a plurality of annular members. As shown in FIG. 3 as an example, the ring assembly 120 includes a cover ring 121 and an edge ring 122 as the plurality of annular members. The cover ring 121 and the edge ring 122 are stacked in this order and supported on the annular region 110b (ring support surface). The ring assembly 120 is lifted up from the annular region 110b (ring support surface) by the operation of a lifter 130 described later, which allows the ring assembly 120 to be transferred to and from a transfer arm (not shown) arranged outside the plasma processing apparatus 1.

[0026] The cover ring 121 as the second annular member is made of an insulator such as quartz. A step is formed on the upper part of the cover ring 121, and the upper surface of the outer periphery is formed higher than the upper surface of the inner periphery. The upper surface of the inner periphery of the cover ring 121 constitutes a support surface for the edge ring 122. In addition, a plurality of through holes 121a, for example three in this embodiment, are formed in the inner periphery of the cover ring 121, penetrating in the thickness direction. The through holes 121a are formed at positions corresponding to the through holes 112a formed in the conductive base 112, and a first pin portion 131a of a lift pin 131 described later is inserted through the through holes 121a as shown in FIG. 3. The through holes 121a have a diameter smaller than that of the through holes 112a.

[0027] The edge ring 122 as the first annular member may also be called a focus ring, and improves in-plane uniformity of plasma processing on the substrate W. The edge ring 122 may be made of silicon, silicon carbide, quartz, or the like. In one embodiment, the first annular member 122 is disposed to surround the substrate on the substrate support surface, and the second annular member 121 is disposed below the first annular member 122. In one embodiment, the first annular member 122 is supported by the second annular member 121.

[0028] As shown in Fig. 3, in one embodiment, the lifter 130 includes a lift pin 131, an actuator 132, and a spacer 133 (shim). A plurality of lift pins 131, for example, three in this embodiment, are provided corresponding to the through holes 121a formed in the cover ring 121. The lift pin 131 also includes a plurality of pin portions having different diameters. As shown in Fig. 3 as an example, the lift pin 131 includes a first pin portion 131a and a second pin portion 131b as the plurality of pin portions. The first pin portion 131a and the second pin portion 131b are integrally configured.

[0029] The first pin portion 131a as the upper portion has a diameter (first width W1 in FIG. 3) smaller than at least the through hole 121a formed in the cover ring 121. The first pin portion 131a is axially connected to the upper surface of the second pin portion 131b described below, and moves vertically (axially) together with the second pin portion 131b by the operation of the actuator 132. The first pin portion 131a is configured to be able to protrude and retract from the upper surface of the inner periphery of the cover ring 121 via the through hole 121a, and thereby supports the lower surface of the edge ring 122 supported on the upper surface of the cover ring 121 and moves (lifts up) in the vertical direction, as shown in FIG. 4A.

[0030] The second pin portion 131b as the lower portion has a larger diameter (second width W2 in FIG. 3) than at least the through hole 121a formed in the cover ring 121. That is, the second pin portion 131b has a step portion S on the upper surface that protrudes radially outward from the outer periphery of the first pin portion 131a. The second pin portion 131b is configured to be able to support the lower surface of the through hole 121a (the lower surface of the cover ring 121) by the step portion S, and thereby supports the lower surface of the cover ring 121 and moves (lifts up) it in the vertical direction as shown in FIG. 4B. In one embodiment, the multiple lift pins 131 are arranged corresponding to the multiple through holes 121a of the second annular member 121. Each lift pin 131 has an upper portion 131a having a first width W1 and a lower portion 131b having a second width W2 larger than the first width W1. The upper portion 131a is configured to support the first annular member 122 through a corresponding through hole 121a of the second annular member 121. Thus, the upper portion 131a has a top portion for supporting the lower surface of the first annular member 122. In one embodiment, the plurality of lift pins 131 includes a first lift pin, a second lift pin, and a third lift pin. The plurality of through holes 121a includes a first through hole, a second through hole, and a third through hole. The upper portion of the first lift pin is configured to support the first annular member 122 through a first through hole of the second annular member 121. The upper portion of the second lift pin is configured to support the first annular member 122 through a second through hole of the second annular member 121. The upper portion of the third lift pin is configured to support the first annular member 122 through a third through hole of the second annular member 121.

[0031] The actuator 132 moves the lift pins 131 along the vertical direction (axial direction) to raise and lower the ring assembly 120 (cover ring 121 and edge ring 122) on the conductive base 112. This moves the ring assembly 120 to a specified height (hereinafter simply referred to as "specified height") at which the ring assembly 120 is transferred to and from the aforementioned transfer arm (not shown). Examples of the actuator include an electric actuator, an air cylinder, a motor, etc.

[0032] The number of actuators 132 arranged in the lifter 130 is not particularly limited. That is, for example, the multiple lift pins 131 may be moved vertically together by one actuator 132. Also, for example, multiple actuators 132 may be arranged corresponding to the respective lift pins 131, and each lift pin 131 may be moved vertically independently. Therefore, at least one actuator 132 is configured to move the multiple lift pins 131 vertically. In one embodiment, the single actuator 132 is configured to move the multiple lift pins 131 vertically. In one embodiment, the at least one actuator 132 has multiple actuators corresponding to the multiple lift pins 131, respectively, and each actuator is configured to move the corresponding lift pin 131 vertically. That is, the at least one actuator 132 may have a first actuator, a second actuator, and a third actuator. The first actuator is configured to move the first lift pin vertically. The second actuator is configured to move the second lift pin vertically. The third actuator is configured to move the third lift pin vertically.

[0033] The spacer 133 is fixed on a step portion S formed on the upper surface of the second pin portion 131b so as to surround the first pin portion 131a. The spacer 133 has a thickness H that is approximately equal to a distance D between the lower surface of the cover ring 121 and the step portion S when the edge ring 122 is lifted up to a specified height (first height H1) by the first pin portion 131a as shown in Fig. 4A. The spacer 133 is thus disposed on the upper surface (on the step portion S) of the second pin portion 131b, and supports the lower surface of the through hole 121a (the lower surface of the cover ring 121) in place of the upper surface of the second pin portion 131b, thereby moving (lifting up) the cover ring 121 in the vertical direction.

[0034] The spacer 133 does not need to be fixed to all of the lift pins 131 of the lifter 130, but may be provided on at least one of the lift pins 131. Specifically, the gap (separation distance D) formed between the lower surface of the cover ring 121 and the step portion S during lift-up of the edge ring 122 may differ for each of the lift pins 131 due to stacking tolerances and machine differences. For this reason, the spacer 133 may be provided only on the lift pins 131 in which a gap (separation distance D) is formed between the lower surface of the cover ring 121 and the step portion S. Therefore, at least one spacer 133 is fixed to at least one of the lift pins 131. The spacer 133 is provided on or above the lower portion 131b of the corresponding lift pin 131 so as to surround the upper portion 131a of the corresponding lift pin 131. The spacer 133 is configured to support the second annular member 121. Therefore, the spacer 133 has an annular support surface for supporting the second annular member 121. In one embodiment, the spacer 133 may have a third width W3 (see FIG. 4A). In one embodiment, the third width W3 is substantially the same as the second width W2. The third width W3 can be designed arbitrarily within a range capable of supporting the second annular member 121. In one embodiment, at least one spacer 133 has a first spacer fixed to a first lift pin. In one embodiment, at least one spacer 133 has a first spacer, a second spacer, and a third spacer. The first spacer is fixed to the first lift pin. The second spacer is fixed to the second lift pin. The third spacer is fixed to the third lift pin. In one embodiment, the first spacer, the second spacer, and the third spacer are configured with the same material, thickness, and / or shape. In one embodiment, the first spacer, the second spacer and the third spacer are made of different materials, thicknesses and / or shapes.

[0035] Furthermore, the material constituting the spacer 133 is not particularly limited, and can be made of at least one material selected from conductive materials such as Si or SiC, or insulating materials such as PCTFE, PTFE, quartz (Qz), SA, or Y2O3. However, there is a risk that the spacer 133 may be exposed to the plasma atmosphere when lifting up the ring assembly 120. For this reason, it is desirable that the spacer 133 be made of a material that is at least radical resistant.

[0036] Furthermore, the method of fixing the spacer 133 to the lift pin 131 is not particularly limited. Specifically, for example, the spacer 133 may be fixed to the first pin portion 131a by fitting as shown in FIG. 5A. At this time, the lower portion of the first pin portion 131a and the spacer 133 may be tapered as shown in FIG. 5B. For example, as shown in FIG. 5C, a threaded portion 133a may be formed on the outer peripheral surface of the lower portion of the first pin portion 131a and on the inner peripheral surface of the spacer 133, and the spacer 133 may be screwed to the first pin portion 131a and fixed. In one embodiment, the spacer 133 has a threaded inner peripheral surface, the upper portion 131a of the lift pin 131 has a threaded outer peripheral surface, and the threaded inner peripheral surface and the threaded outer peripheral surface are screwed to each other. By fixing the spacer 133 by forming a threaded portion in this manner, it is possible to appropriately suppress the spacer 133 from falling off the first pin portion 131a. 5D, an annular elastic member 133b (e.g., FFKM rubber) may be disposed on the radially inner side of the spacer 133 as a member for preventing the spacer 133 from falling off, and the spacer 133 may be fixed to the first pin portion 131a by the elastic member 133b. By fixing the spacer 133 by the elastic member 133b in this manner, the spacer 133 can be prevented from falling off the first pin portion 131a, and abnormal discharge between the lift pin 131 and the cover ring 121 can be prevented.

[0037] Although not shown, the substrate support 11 may include a temperature adjustment module configured to adjust at least one of the ring assembly 120, the electrostatic chuck 113, and the substrate W to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow path, or a combination thereof. A heat transfer fluid such as brine or gas flows through the flow path. The substrate support 11 may also include a heat transfer gas supply unit configured to supply a heat transfer gas (backside gas) between the back surface of the substrate W and the upper surface of the electrostatic chuck 113.

[0038] Returning to the explanation of Figure 2. The shower head 13 is configured to introduce at least one processing gas from the gas supply unit 20 into the plasma processing space 10s. The shower head 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and multiple gas inlets 13c. The processing gas supplied from the gas supply unit 20 to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the multiple gas inlets 13c. The shower head 13 also includes a conductive member. The conductive member of the shower head 13 functions as an upper electrode. In addition to the shower head 13, the gas introduction unit may include one or more side gas injectors (SGI) attached to one or more openings formed in the side wall 10a.

[0039] The gas supply 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply 20 is configured to supply at least one process gas from a respective gas source 21 through a respective flow controller 22 to the showerhead 13. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply 20 may include one or more flow modulation devices to modulate or pulse a flow rate of the at least one process gas.

[0040] The power source 30 includes an RF power source 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power source 31 is configured to supply at least one RF signal (RF power), such as a source RF signal and a bias RF signal, to a conductive member (lower electrode) of the substrate support 11 and / or a conductive member (upper electrode) of the showerhead 13. This causes a plasma to be formed from at least one processing gas supplied to the plasma processing space 10s. Thus, the RF power source 31 can function as at least a part of the plasma generating unit 12. In addition, a bias potential is generated on the substrate W by supplying a bias RF signal to the lower electrode, and ion components in the formed plasma can be attracted to the substrate W.

[0041] In one embodiment, the RF power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating unit 31a is coupled to the lower electrode and / or the upper electrode via at least one impedance matching circuit, and is configured to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 13 MHz to 150 MHz. In one embodiment, the first RF generating unit 31a may be configured to generate a plurality of source RF signals having different frequencies. The generated one or more source RF signals are supplied to the lower electrode and / or the upper electrode. The second RF generating unit 31b is coupled to the lower electrode via at least one impedance matching circuit, and is configured to generate a bias RF signal (bias RF power). In one embodiment, the bias RF signal has a lower frequency than the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 400 kHz to 13.56 MHz. In one embodiment, the second RF generating unit 31b may be configured to generate a plurality of bias RF signals having different frequencies. The generated bias RF signal or signals are provided to the lower electrode, and in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0042] The power supply 30 may also include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generator 32a and a second DC generator 32b. In one embodiment, the first DC generator 32a is connected to the lower electrode and configured to generate a first DC signal. The generated first bias DC signal is applied to the lower electrode. In one embodiment, the first DC signal may be applied to another electrode, such as a chucking electrode in the electrostatic chuck 113. In one embodiment, the second DC generator 32b is connected to the upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to the upper electrode. In various embodiments, at least one of the first and second DC signals may be pulsed. It is noted that the first and second DC generators 32a, 32b may be provided in addition to the RF power supply 31, or the first DC generator 32a may be provided instead of the second RF generator 31b.

[0043] The exhaust system 40 may be connected to, for example, a gas exhaust port 10e provided at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure regulating valve regulates the internal pressure of the plasma processing space 10s. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0044] Although various exemplary embodiments have been described above, the present invention is not limited to the above-described exemplary embodiments, and various additions, omissions, substitutions, and modifications may be made. In addition, elements in different embodiments can be combined to form other embodiments.

[0045] In the plasma processing apparatus 1 configured as above, the thickness H of the spacer 133 provided on the lifter 130 is set to a thickness H that is approximately equal to the separation distance D between the lower surface of the cover ring 121 and the step portion S when the edge ring 122 is lifted up to a specified height (first height H1) by the first pin portion 131a. In other words, the spacer 133 is configured to have a thickness H that can correct the above-mentioned separation distance D that occurs due to the adjustment amount of the height position of the lift pin 131 set to appropriately transport the edge ring 122 and the stacking tolerance of the components of the lifter 130. As a result, in the substrate support portion 11 according to this embodiment, after the edge ring 122 is transported by the first pin portion 131a, the lifting up of the cover ring 121 can be started efficiently without vertical movement of the lift pin 131 to correct the separation distance D.

[0046] In addition, by arranging the spacer 133 in this manner and minimizing the separation distance D (gap) between the underside of the cover ring 121 and the step portion S, the risk of discharge during transportation of the ring assembly 120 due to residual charges, etc. can be reduced.

[0047] Here, the inventors have found that when the spacer 133 is arranged on the lifter 130 in this way, it is possible to add other functions in addition to the above-mentioned function of correcting the separation distance D (piling tolerance) by optimizing the shape, material, etc. of the spacer 133. Therefore, the configuration of the spacer 133 according to another embodiment will be described below with reference to the drawings.

[0048] <Spacer according to the second embodiment> First, in the above embodiment, the spacer 133 is made of one member, but the spacer may be made of multiple members. Specifically, as shown in FIG. 6, the spacer 200 may have multiple members 201 (two members 201a and 201b in the illustrated example) stacked in the thickness direction (axial direction of the lift pin 131). In this case, the members 201a and 201b may be made of the same material or different materials. In this case, the material of each of the multiple members 201 is not particularly limited, but it is desirable that the member 201 (member 201a in the illustrated example) placed at the top (on the cover ring 121 side) is made of a material having at least radical resistance. In one embodiment, the spacer 200 is made of a laminate having multiple layers 201a and 201b, and each of the multiple layers 201a and 201b has an insulating material or a conductive material.

[0049] As described above, the size of the gap (separation distance D) formed between the lower surface of the cover ring 121 and the step portion S may differ for each of the multiple lift pins 131 provided on the lifter 130 due to stacking tolerances, etc. In such a case, the number of members 201 arranged on the step portion S may be adjusted according to the size of the gap (separation distance D) formed. In other words, the number of members 201 constituting the spacer 200 may differ for each lift pin 131.

[0050] According to this embodiment, by forming the spacer 200 from a plurality of members 201 in this manner, it is possible to appropriately correct the stacking tolerance in accordance with the gap (separation distance D) formed between the lower surface of the cover ring 121 and the step portion S. In addition, at this time, by manufacturing the members 201 having a small thickness as standard products and adjusting the number of layers thereof in accordance with the size of the gap (separation distance D), it is possible to significantly reduce costs compared to the case of sequentially manufacturing spacers having different thicknesses in accordance with the size of the gap (separation distance D).

[0051] Furthermore, it is considered that the spacer disposed inside the plasma processing apparatus 1 will be worn out due to, for example, the effects of plasma processing, aging, etc. According to this embodiment, by forming the spacer 200 from a plurality of members 201 in this way, even if the spacer 200 is worn out in this way, it is necessary to replace only the worn member 201, not the entire spacer 200. From this viewpoint as well, the cost of the plasma processing apparatus 1 can be reduced.

[0052] <Spacer according to the third embodiment> Next, in the above embodiment, the spacer is configured by an annular member having a simple rectangular shape in cross section, but the cross-sectional shape of the spacer is not limited to this. Specifically, as shown in FIG. 7A or FIG. 7B, the upper surface (tip shape) may be tapered or rounded so that the thickness of the spacer 210 decreases from the radial inside to the radial outside. Therefore, the spacer 210 has an annular support surface for supporting the second annular member 121. The annular support surface is inclined downward from the inner circumference (inner side) to the outer circumference (outer side). The annular support surface, i.e., the upper part of the spacer 210, has a tapered or rounded shape.

[0053] According to this embodiment, by subjecting the upper surface of the spacer 210 to tapering or rounding, the lower surface of the through hole 121a formed in the cover ring 121 is brought into contact with the tapered portion (rounded portion), thereby positioning the cover ring 121 on the annular region 110b (ring support surface), and the productivity of the plasma processing apparatus 1 can be improved. Furthermore, since the cover ring 121 can be positioned by the spacer 210 in this manner, there is no need to provide a positioning function to the lift pin 131. That is, the lift pin 131 can be configured with a simple shape, and this reduces the cost of manufacturing the plasma processing apparatus 1.

[0054] When the tapered portion (rounded portion) is formed in the spacer 210 in this manner, the lower surface of the cover ring 121 (the lower portion of the through hole 121a) may be formed in a shape that fits with the tapered portion (rounded portion). In this case, the positioning effect of the cover ring 121 can be further improved.

[0055] In addition, when the spacer is made up of multiple members as in the second embodiment described above, it is sufficient to form an inclined surface (tapered or rounded) only in the member arranged at the top (on the cover ring 121 side).

[0056] <Spacer according to the fourth embodiment> In the third embodiment described above, the cross-sectional shape of the spacer is configured so that the thickness of spacer 210 decreases from the radial inside to the radial outside. However, as in spacer 220 shown in FIG. 8A, a step portion S2 may be formed on the upper surface of the spacer so that the upper surface of the inner periphery is higher than the upper surface of the outer periphery.

[0057] In the plasma processing apparatus 1 according to the embodiment, as shown in Fig. 3, the edge ring 122 and the cover ring 121 are configured to be able to be lifted up independently by forming a step portion S in the lift pin 131. In this case, for example, when the ring assembly 120 includes a third annular member in addition to the cover ring 121 and the edge ring 122, it is necessary to form a new step portion in the lift pin 131 and lift up the third annular member by the new step portion. In other words, it is necessary to change the design of the lift pin 131, and the change in design and replacement of the member require time and cost.

[0058] In this respect, according to the present embodiment, by forming the step portion S2 on the upper surface of the spacer 220 in this manner, the step portion S2 can be used to lift up the third annular member 123 as shown in FIG. 8B. That is, even if it becomes necessary to provide a new annular member in the ring assembly 120, the third annular member 123 can be lifted up only by installing the spacer 220 without changing the design of the lift pin 131. This allows for a significant reduction in time and cost compared to the case where the design of the lift pin 131 is changed. In one embodiment, the substrate support 11 further includes a third annular member 123 disposed between the first annular member 122 and the second annular member 121. The third annular member 123 has a plurality of other through holes 123a formed corresponding to the plurality of through holes 121a of the second annular member 121. The upper portion 131a of the lift pin 131 is configured to support the first annular member 122 via the corresponding through holes 121a of the second annular member 121 and the corresponding other through holes 123a of the third annular member 123. The spacer 220 has a lower spacer portion 220a having a third width W3 and an upper spacer portion 220b having a fourth width W4 smaller than the third width W3 (see FIG. 8A). The upper spacer portion 220b is configured to support the third annular member 123 through a corresponding through hole 121a of the second annular member 121. Thus, the upper spacer portion 220b has an annular support surface for supporting the third annular member 123. The lower spacer portion 220a is configured to support the second annular member 121. Thus, the lower spacer portion 220a has an annular support surface for supporting the second annular member 121.

[0059] <Spacer according to the fifth embodiment> In the above embodiments, the spacer is made of at least one material selected from, for example, PCTFE, PTFE, Qz, SA, etc., but as shown in FIG. 9, an elastic member 231 (e.g., FFKM rubber, etc.) may be provided between the spacer 230 and the first pin portion 131a as an anti-disengagement member (see also FIG. 5D).

[0060] According to this embodiment, by disposing the elastic member 231 between the spacer 230 and the first pin portion 131a in this manner, the elastic force of the elastic member 231 fixes the spacer 230 to the first pin portion 131a, and thus it is possible to appropriately prevent the spacer 230 from falling off. Furthermore, for example, when the spacer 230 has insulating properties, the installation of the elastic member 231 improves the withstand voltage, and this makes it possible to prevent abnormal discharge between the first pin portion 131a and the covering ring 121. Furthermore, for example, when the spacer 230 has conductivity, the installation of the spacer 230 imparts conductivity to the first pin portion 131a, thereby preventing charging of the first pin portion 131a and suppressing abnormal discharge.

[0061] <Spacer according to the sixth embodiment> As shown in FIG. 3, the substrate support 11 may be formed by stacking a plurality of members (metal plate 111, conductive base 112, and electrostatic chuck 113 in the illustrated example). In this case, the positions of the through holes (through holes 111a, 112a in the illustrated example) formed in each member may be misaligned due to differences in temperature and thermal expansion coefficients of each member. In this case, if the first pin portion 131a and the second pin portion 131b of the lift pin 131 are integrally formed as described above, the ring assembly 120 may not be lifted up properly due to the misalignment of the through holes, or the lift pin 131 may be damaged. For this reason, the lift pin 131 provided in the lifter 130 may have a split pin structure in which a fixed portion 240 connected to the actuator 132 and a movable portion 241 that moves in the horizontal direction following the misalignment of the through holes are independently formed as shown in FIG. 10A.

[0062] However, when lift pin 131 has a split pin structure in this way, there is a concern that after ring assembly 120 is lifted up, only fixed portion 240 will descend, and movable portion 241 will be left behind above as shown in FIG. 10B.

[0063] Therefore, in the spacer 250 according to the sixth embodiment, when the lift pin 131 has a split pin structure, the movable part 241 is prevented from remaining on the upper side. Specifically, as shown in Fig. 11, the spacer 250 is made of a high specific gravity member 251 (e.g., titanium, tungsten, etc.), and further, in order to protect the high specific gravity member 251 from radicals and the like, a coating layer 252 (e.g., PCTFE, PTFE, etc.) is formed so as to cover the surface.

[0064] In the above description, the fixed part 240 is assumed to be a part of the lift pin 131 having a split pin structure as shown in FIG. 10A and FIG. 10B. However, the fixed part 240 can also be assumed to be the substrate support part 11 fixed to the actuator 132. In this case, the movable part 241 and the spacer 250 shown in FIG. 10 constitute the lift pin 131 according to the technology of the present disclosure, and the fixed part 240 constitutes a part of the substrate support part 11. In other words, the movable part 241 as the lift pin 131 is supported from below by the fixed member 240 and is connected to the actuator 132 via the fixed member 240. In one embodiment, the substrate support part 11 further includes a fixed member 240 fixed to at least one actuator 132, and the lift pin 131 is supported by the fixed member 240. The spacer 250 has a high specific gravity member 251 and a coating layer 252 formed to cover the surface of the high specific gravity member 251.

[0065] As a result, the weight of the movable part 241 is increased by the spacer 250, and even if the movable part 241 remains at the upper position after the ring assembly 120 is lifted up, the movable part 241 can be lowered to the standby position by its own weight.

[0066] Although various embodiments have been described above, the effects imparted to the spacer are not limited to the exemplary embodiments described above. In addition, it is also possible to form other embodiments by combining the elements of the first to sixth embodiments described above. For example, as described above, the spacer may be composed of a plurality of members (second embodiment), and further, a tapered portion (rounded portion) may be formed in the member arranged at the top (the cover ring 121 side) (third embodiment). Also, for example, a step portion S2 may be formed in the spacer (fourth embodiment), and further, an elastic member may be arranged on the radial inside of the spacer (fifth embodiment).

[0067] <Spacer design method> Next, a method for designing the spacer configured as above, more specifically, a method for determining the spacer thickness H, will be described with reference to the drawings. The method for determining the spacer thickness H described below is performed at the start-up of the plasma processing apparatus 1 or immediately after replacing the ring assembly 120, that is, at the time of initial setting of the lifter 130 relative to the ring assembly 120.

[0068] 12A(a), the lifter 130 is moved to a standby position (a position where the tip of the first pin portion 131a does not protrude from the upper surface of the inner periphery of the cover ring 121) in a state where the edge ring 122 is not supported on the upper surface of the cover ring 121 (step P1 in FIG. 13). Next, with the lifter 130 placed in the standby position, the distance (depth) D1 (see FIG. 12A(a)) between the tip of the lift pin 131 and the upper surface of the inner periphery of the cover ring 121 is measured (step P2 in FIG. 13).

[0069] The method of measuring the distance (depth) D1 in step P2 is not particularly limited, and may be, for example, measured manually using a dial gauge or the like, or may be measured automatically using a laser displacement meter or the like.

[0070] Next, the distance (depth) D1 measured in step P2 is corrected by the actuator 132 to make the height position of the tip of the lift pin 131 approximately coincident with the height position of the upper surface of the inner periphery of the cover ring 121 as shown in Fig. 12A(b) (step P3 in Fig. 13). Note that the height position of the lifter 130 after the position of the tip of the lift pin 131 has been corrected is output to the control unit 2 as the contact position (first contact position) of the edge ring 122 and the first pin portion 131a.

[0071] Next, with the position of the lifter 130 maintained at the first contact position, the cover ring 121 is removed from the annular region 110b (ring support surface) of the conductive base 112 as shown in FIG. 12A(c) (Step P4 in FIG. 13).

[0072] 12A(d), the lifter 130 is moved from the contact position between the edge ring 122 and the first pin portions 131a to a transfer position for the edge ring 122 (a position where the edge ring 122 supported at the tip of the first pin portion 131a reaches a specified height) (step P5 in FIG. 13). Next, with the lifter 130 placed at the transfer position for the edge ring 122, the distance (depth) D2 (see FIG. 12A(d)) between the step portion S (upper surface of the second pin portion 131b) of the lift pin 131 and the upper surface of the conductive base 112 (support surface of the cover ring 121) is measured (step P6 in FIG. 13).

[0073] The method of measuring the distance (depth) D2 in step P6 is not particularly limited, and may be, for example, manually measured using a dial gauge or the like, or may be automatically measured using a laser displacement meter or the like.

[0074] Subsequently, the thickness H of the spacer 133 is determined so that the distance (depth) D2 measured in step P6 is minimized (step P7 in FIG. 13). Next, as shown in FIG. 12B(a), the spacer 133 having the thickness H determined in step P7 is placed on the step portion S (upper surface of the second pin portion 131b) of the lift pin 131 (step P8 in FIG. 13).

[0075] The spacer installed on the step portion S of the lift pin 131 is not limited to the above-mentioned spacer 133 (first embodiment), and the spacers 200, 210, 220, 230, and 250 according to the second to sixth embodiments can be appropriately selected.

[0076] Next, with the spacer 133 placed on the step portion S, the distance (depth) D3 (see FIG. 12B(a)) between the upper surface of the spacer 133 and the upper surface of the conductive base 112 (the support surface of the cover ring 121) is measured (step P9 in FIG. 13).

[0077] The method of measuring the distance (depth) D3 in step P9 is not particularly limited, and may be, for example, measured manually using a dial gauge or the like, or may be measured automatically using a laser displacement meter or the like.

[0078] Next, the distance (depth) D3 measured in step P9 is corrected by the actuator 132 to make the height position of the upper surface of the spacer 133 approximately coincident with the height position of the upper surface of the conductive base 112 (the support surface of the covering 121) as shown in Fig. 12B(b) (step P10 in Fig. 13). Note that the height position of the lifter 130 after the position of the upper surface of the spacer 133 has been corrected is output to the control unit 2 as the contact position (second contact position) between the covering 121 and the spacer 133.

[0079] Thereafter, the lifter 130 is moved to a waiting position as shown in FIG. 12B(c) (step P11 in FIG. 13), and then the cover ring 121 and the edge ring 122 are sequentially placed on the annular region 110b (ring support surface) as shown in FIG. 12B(d) (step P12 in FIG. 13), completing the series of steps for determining the spacer thickness H.

[0080] According to this embodiment, by appropriately determining the thickness H of the spacer based on the distance (depth) D2 between the step portion S of the lift pin 131 and the upper surface of the conductive base 112, the stacking tolerance of each component and unit of the lifter 130 can be appropriately alleviated.

[0081] Also, at this time, by appropriately selecting the spacers 200, 210, 220, 230, 250 according to the various embodiments described above, in addition to relaxing the stacking tolerance, the spacers (lift pins 131) can be provided with the various functions shown in the second to sixth embodiments. Therefore, at least one actuator 132 is configured to move the plurality of lift pins 131 vertically between a first raised position (see FIG. 4A), a second raised position (see FIG. 4B), and a lowered position (see FIG. 3). At the first raised position, i.e., the transport position of the first annular member 122, the first annular member 122 is disposed at a first height H1 (see FIG. 4A). At the second raised position, i.e., the transport position of the second annular member 121, the second annular member 121 is disposed at a first height H1 (see FIG. 4B). Note that the plasma processing is performed when the plurality of lift pins 131 are in the lowered position, i.e., when the plurality of lift pins 131 are stored (see FIG. 3). In the example of FIG. 8B, at least one actuator 132 is configured to move the lift pins 131 vertically between a first raised position, a second raised position, a third raised position, and a lowered position. The first raised position, the second raised position, and the lowered position are the same as those described above. The third raised position is a state between the first raised position and the second raised position. In this case, the third annular member 123 is disposed at a first height H1 at the third raised position, i.e., the transport position of the third annular member 123. The spacer 133 has a vertical dimension D determined based on the distance between the upper surface (or upper portion) of the lower portion 131b and the lower surface of the second annular member 121 at the first raised position.

[0082] The embodiments disclosed herein should be considered as illustrative and not restrictive in all respects. The above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0083] 1. Plasma processing equipment 10 Plasma Processing Chamber 11 Substrate support 12 Plasma generating section 112 Conductive base 113 Electrostatic Chuck 120 Ring Assembly 121 Covering 121a Through hole 122 Edge Ring 130 Lifter 131 Lift pin 131a 1st pin part 131b 2nd pin part 132 Actuator 133 Spacer

Claims

1. a plasma processing chamber; a plasma generating unit configured to generate a plasma from a process gas in the plasma processing chamber; a substrate support disposed within the plasma processing chamber; The substrate support includes: The base and an electrostatic chuck disposed above the base and having a substrate support surface; a first annular member disposed to surround the substrate on the substrate support surface; a second annular member disposed below the first annular member and having a plurality of through holes; a plurality of lift pins arranged corresponding to the plurality of through holes, each lift pin having an upper portion having a first width and a lower portion having a second width greater than the first width, the upper portion configured to support the first annular member through a corresponding through hole of the second annular member; at least one spacer secured to at least one of the plurality of lift pins, the spacer being disposed on the lower portion to surround the upper portion, the spacer being configured to support the second annular member; and and at least one actuator configured to vertically move the plurality of lift pins.

2. The plasma processing apparatus according to claim 1 , wherein the spacer is made of an insulating material.

3. The plasma processing apparatus according to claim 1 , wherein the spacer is made of a conductive material.

4. The plasma processing apparatus according to claim 1 , wherein the spacer is configured by a laminate having a plurality of layers, each of the plurality of layers having an insulating material or a conductive material.

5. The insulating material is Qz, SA, Y ２ O ３ 5. The plasma processing apparatus according to claim 2, further comprising: PTFE or PCTFE.

6. The plasma processing apparatus according to claim 3 or 4, wherein the conductive material comprises Si or SiC.

7. 7. The plasma processing apparatus according to claim 1, further comprising a drop-off prevention member arranged between said upper portion and said spacer and made of an FFKM rubber material.

8. 7. The plasma processing apparatus of claim 1, wherein the spacer has an inner peripheral threaded surface and the upper portion has an outer peripheral threaded surface, the inner peripheral threaded surface and the outer peripheral threaded surface being threadedly engaged with each other.

9. 9. The plasma processing apparatus according to claim 1, wherein the spacer has a support surface for supporting the second annular member, the support surface being inclined downward from the inside to the outside.

10. The plasma processing apparatus according to claim 9 , wherein the support surface has a tapered or rounded shape.

11. the substrate support further includes a third annular member disposed between the first annular member and the second annular member, the third annular member has a plurality of other through holes formed corresponding to the plurality of through holes of the second annular member, the upper portion of the lift pin is configured to support the first annular member through a corresponding through hole of the second annular member and a corresponding other through hole of the third annular member; The plasma processing apparatus of any one of claims 1 to 10, wherein the spacer has a lower spacer portion having a third width and an upper spacer portion having a fourth width smaller than the third width, the upper spacer portion configured to support the third annular member through a corresponding through hole of the second annular member, and the lower spacer portion configured to support the second annular member.

12. the substrate support further includes a fixing member fixed to the at least one actuator; the lift pin is supported by the fixed member; The spacer is A high specific gravity material; The plasma processing apparatus according to claim 1 , further comprising: a coating layer formed so as to cover a surface of the high specific gravity member.

13. the at least one actuator is configured to move the plurality of lift pins vertically between a first raised position, a second raised position, and a lowered position, wherein in the first raised position, the first annular member is disposed at a first height, and in the second raised position, the second annular member is disposed at the first height; The plasma processing apparatus of claim 1 , wherein the spacer has a vertical dimension determined based on a distance between the lower portion and the second annular member in the first raised position.

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