JP7664776B2 - Plasma Processing Equipment - Google Patents

Description

This disclosure relates to a plasma processing apparatus.

Patent document 1 discloses a confinement ring provided in a substrate processing system. The confinement ring is provided to confine plasma within a plasma region. The confinement ring includes an annular lower wall, an outer wall, and an upper wall.

US Patent Application Publication No. 2020/0075295

The technology disclosed herein provides a highly flexible conductive baffle plate for plasma processing equipment.

A plasma processing apparatus according to one aspect of the present disclosure includes a conductive chamber connected to a ground potential, a plasma generating unit configured to generate plasma in the conductive chamber, a substrate support disposed in the conductive chamber, at least one baffle support disposed to surround the substrate support and including at least one conductive portion connected to the conductive chamber, a plurality of conductive baffle plates disposed on the at least one baffle support to surround the substrate support and arranged along the circumferential direction of the substrate support, each conductive baffle plate being connected to a ground potential via the conductive portion and the conductive chamber, and a plurality of clamp members, each clamp member configured to fix two adjacent conductive baffle plates of the plurality of conductive baffle plates to the at least one baffle support.

The present disclosure provides a highly flexible conductive baffle plate for plasma processing equipment.

FIG. 1 is an explanatory diagram illustrating a schematic configuration of a plasma processing system. 1 is a cross-sectional view showing an outline of a configuration of a plasma processing apparatus; 1 is a cross-sectional view showing an outline of an internal configuration of a plasma processing apparatus; FIG. 2 is a perspective view (partially exploded view) showing the outline of the configuration of a liner assembly. FIG. 2 is a plan view showing the outline of the configuration of a liner assembly as viewed from above. FIG. 2 is a plan view showing the outline of the configuration of a liner assembly as viewed from below. FIG. 2 is a side view showing an outline of the configuration of a liner assembly. 4 is a cross-sectional view showing an outline of a clamping structure of the liner assembly. FIG. FIG. 2 is a plan view showing an outline of the gap structure of the liner assembly. FIG. 13 is a plan view showing an outline of a gap structure of a liner assembly according to another embodiment. 4 is a cross-sectional view showing an outline of a positioning structure of a liner assembly. FIG. FIG. 2 is a perspective view (exploded view) showing the outline of the configuration of a shutter assembly. FIG. 2 is a plan view showing the outline of the configuration of a shutter assembly. FIG. 2 is a side view showing the outline of the configuration of a shutter assembly. 1 is a cross-sectional view showing an outline of a clamp structure of a shutter assembly. FIG. 2 is a plan view showing an outline of the gap structure of the shutter assembly. FIG. 2 is a perspective view (partially exploded) showing the outline of the configuration of a baffle assembly. FIG. 2 is a plan view showing an outline of the configuration of a baffle assembly. FIG. 2 is a plan view showing the outline of the configuration of a conductive baffle plate. 4 is a cross-sectional view showing an outline of a positioning structure of the baffle assembly. FIG. 1 is a cross-sectional view showing an outline of a clamping structure of a baffle assembly. 1 is a cross-sectional view showing an outline of a clamping structure of a baffle assembly. FIG. 13 is a plan view showing the outline of the configuration of a conductive baffle plate according to another embodiment.

In the manufacturing process of semiconductor devices, plasma processing such as etching and film formation is performed on a semiconductor substrate (hereinafter referred to as "substrate") in a plasma processing apparatus. In plasma processing, plasma is generated by exciting a processing gas, and the substrate is processed by the plasma.

The plasma processing apparatus has a plasma processing space formed inside the chamber. The plasma processing apparatus is also provided with a baffle plate for discharging gas inside the plasma processing space. The lower wall of the confinement ring in the above-mentioned Patent Document 1 corresponds to this baffle plate.

Conventionally, as described in Patent Document 1, the baffle plate (the lower wall of the confinement ring) is provided as a single unit. In such a case, for example, if a part of the baffle plate wears out, it affects the plasma generated in the plasma processing space, causing fluctuations in the plasma processing, and therefore the entire baffle plate needs to be replaced.

In addition, the baffle plate is made of a material such as silicon, but because silicon is a brittle material, it is difficult to produce a one-piece baffle plate with a simple shape. In other words, if the one-piece baffle plate has a complex shape, problems such as cracking may occur. Therefore, there is room for improvement in the structure of conventional baffle plates.

The technology disclosed herein has been made in consideration of the above circumstances, and provides a conductive baffle plate with a high degree of freedom in plasma processing equipment. The plasma processing equipment and baffle plate assembly according to this embodiment will be described below with reference to the drawings. Note that in this specification and the drawings, elements having substantially the same functional configuration are given the same reference numerals to avoid redundant description.

<Plasma Processing System>
First, a plasma processing system according to an embodiment will be described with reference to Fig. 1. Fig. 1 is an explanatory diagram showing a schematic configuration of the plasma processing system.

In one embodiment, the plasma processing system includes a plasma processing device 1 and a control unit 2. The plasma processing device 1 includes a conductive chamber 10, a substrate support unit 11, and a plasma generation unit 12. The conductive chamber 10 has a plasma processing space. The conductive 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 described later, and the gas exhaust port is connected to an exhaust system 40 described later. The substrate support unit 11 is disposed in the plasma processing space and has a substrate support surface for supporting a substrate.

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 may be capacitively coupled plasma (CCP), inductively coupled plasma (ICP), electron-cyclotron-resonance plasma (ECR plasma), helicon wave plasma (HWP), or surface wave plasma (SWP). Also, various types of plasma generating units may be used, including alternating current (AC) plasma generating units and direct current (DC) plasma generating units. 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. Thus, AC signals include radio frequency (RF) signals and microwave signals. In one embodiment, the RF signal has a frequency in the range of 200 kHz to 150 MHz.

The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform the various steps described in this disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform the 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 memory 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 memory unit 2a2. The memory unit 2a2 may include a RAM (Random Access Memory), a ROM (Read Only Memory), a HDD (Hard Disk Drive), an SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing device 1 via a communication line such as a LAN (Local Area Network).

<Plasma Processing Apparatus>
2, a configuration example of a capacitively coupled plasma processing apparatus as an example of the plasma processing apparatus 1 will be described. Fig. 2 is a cross-sectional view showing an outline of the configuration of the plasma processing apparatus 1. In the plasma processing apparatus 1 of this embodiment, plasma processing is performed on a substrate (wafer) W, but the substrate W to be subjected to plasma processing is not limited to a wafer.

The capacitively coupled plasma processing apparatus 1 includes a conductive chamber 10, a gas supply unit 20, a power supply 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support unit 11 and a gas introduction unit. The gas introduction unit is configured to introduce at least one processing gas into the conductive chamber 10. The gas introduction unit includes a shower head 13. The substrate support unit 11 is disposed in the conductive chamber 10. The shower head 13 is disposed above the substrate support unit 11. In one embodiment, the shower head 13 constitutes at least a part of the ceiling of the conductive chamber 10. Also. The shower head 13 is supported on the side wall 10a of the conductive chamber 10 via an insulating shielding member 14. The conductive chamber 10 has a plasma processing space 10s defined by the shower head 13, the insulating shielding member 14, the side wall 10a of the conductive chamber 10, and the substrate support unit 11. The conductive chamber is connected to a ground potential. The showerhead 13 and the substrate support 11 are electrically insulated from the housing of the conductive chamber 10.

The plasma processing apparatus 1 further includes a liner assembly 15 and a baffle assembly 16. The liner assembly 15 is provided in an annular shape along the sidewall 10a of the conductive chamber 10. The liner assembly 15 is provided to confine plasma inside the plasma processing space 10s. The baffle assembly 16 is provided in an annular shape between the substrate support 11 and the liner assembly 15. The baffle assembly 16 is provided to exhaust gas inside the plasma processing space 10s.

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

In one embodiment, the main body 111 includes a base 113 and an electrostatic chuck 114. The base 113 includes a conductive member. The conductive member of the base 113 functions as a lower electrode. The electrostatic chuck 114 is disposed on the base 113. The upper surface of the electrostatic chuck 114 has a substrate support surface 111a. Note that, in one embodiment, the upper surface of the electrostatic chuck 114 may have a ring support surface 111b.

In one embodiment, the ring assembly 112 includes a focus ring 115 and a cover ring 116. The focus ring 115 is annularly disposed to surround the substrate W supported by the electrostatic chuck 114. The cover ring 116 is annularly disposed to surround the focus ring 115.

Although not shown, the substrate support 11 may also include a temperature adjustment module configured to adjust at least one of the electrostatic chuck 114, the ring assembly 112, and the substrate W to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow path, or a combination thereof. A heat transfer fluid such as brine or gas flows through the flow path. The substrate support 11 may also include a heat transfer gas supply unit configured to supply a heat transfer gas between the back surface of the substrate W and the substrate support surface 111a.

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

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 to the showerhead 13 via a respective flow controller 22. 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 at least one flow modulation device that modulates or pulses the flow rate of the at least one process gas.

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

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 conductive member of the substrate support 11 and/or the conductive member of the shower head 13 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 multiple source RF signals having different frequencies. The generated one or more source RF signals are supplied to the conductive member of the substrate support 11 and/or the conductive member of the shower head 13. The second RF generating unit 31b is coupled to the conductive member of the substrate support 11 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 generator 31b may be configured to generate multiple bias RF signals having different frequencies. The generated bias RF signal or signals are provided to the conductive members of the substrate support 11. Also, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

The power supply 30 may also include a DC power supply 32 coupled to the conductive chamber 10. The DC power supply 32 includes a first DC generator 32a and a second DC generator 32b. In one embodiment, the first DC generator 32a is connected to a conductive member of the substrate support 11 and configured to generate a first DC signal. The generated first DC signal is applied to the conductive member of the substrate support 11. In one embodiment, the first DC signal may be applied to another electrode, such as an electrode in an electrostatic chuck. In one embodiment, the second DC generator 32b is connected to a conductive member of the showerhead 13 and configured to generate a second DC signal. The generated second DC signal is applied to the conductive member of the showerhead 13. In various embodiments, the first and second DC signals may be pulsed. The first and second DC generating units 32a and 32b may be provided in addition to the RF power source 31, or the first DC generating unit 32a may be provided in place of the second RF generating unit 31b.

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

<Arrangement of liner assembly and baffle assembly>
Next, a description will be given of the arrangement of the above-mentioned liner assembly 15 and baffle assembly 16. Fig. 3 is a cross-sectional view showing an outline of the internal configuration of the plasma processing apparatus.

The liner assembly 15 is provided in an annular shape along the side wall (inner wall) 10a of the conductive chamber 10. The liner assembly 15 is connected to a conductive upper wall 17 provided on the lower surface of the insulating shielding member 14. The conductive upper wall 17 is formed of a conductive material, such as Si or SiC.

The baffle assembly 16 is provided in an annular shape between the liner assembly 15 and the Si ring 18 provided along the outer periphery of the substrate support 11. The baffle assembly 16 is provided to exhaust gas from inside the plasma processing space 10s.

In this embodiment, a gap is formed between the conductive liner 201 of the liner assembly 15 (described later) and the conductive baffle plate 300 of the baffle assembly 16 (described later). The outer diameter of the conductive liner 201 and the outer diameter of the conductive baffle plate 300 may be the same, and a gap may be formed between the lower surface of the conductive liner 201 and the upper surface of the conductive baffle plate 300. Alternatively, the inner diameter of the conductive liner 201 may be larger than the outer diameter of the conductive baffle plate 300, and a gap may be formed between the inner surface of the conductive liner 201 and the outer surface of the conductive baffle plate 300. In other embodiments, the conductive liner 201 and the conductive baffle plate 300 may be in contact with each other.

<Liner assembly>
Next, the configuration of the above-mentioned liner assembly 15 will be described. Fig. 4 is a perspective view (partially exploded view) showing the outline of the configuration of the liner assembly 15. Fig. 5 is a plan view seen from above showing the outline of the configuration of the liner assembly 15. Fig. 6 is a plan view seen from below showing the outline of the configuration of the liner assembly 15. Fig. 7 is a side view showing the outline of the configuration of the liner assembly 15.

The liner assembly 15 has a conductive ring 200, a plurality of conductive liners 201, and a plurality of clamp members 202. The conductive ring 200 is made of a conductive material, for example, Al. The conductive ring 200 is made of a conductive material, for example, Si or SiC. The clamp members 202 are not particularly limited, but are made of, for example, Al.

The conductive ring 200 has an annular shape in a plan view. As shown in FIG. 8, a step portion 200a is formed on the radially inner upper surface of the conductive ring 200, and a step portion 200b is formed on the radially outer lower surface. A conductive upper wall 17 is provided on the step portion 200a. A clamp member 202 is provided on the step portion 200b.

As shown in FIG. 3, the conductive ring 200 is attached to the conductive chamber 10. The conductive ring 200 is positioned so as not to be exposed to the plasma processing space 10s. In other words, the conductive ring 200 is attached to the conductive chamber 10 while being separated from the plasma processing space 10s. This makes it possible to prevent the conductive ring 200 from being damaged even if the conductive ring 200 is made of Al. The conductive ring 200 is connected to a ground potential via the conductive chamber 10.

The conductive liners 201 are attached to the conductive ring 200 and extend downward from the conductive ring 200. The conductive liners 201 are connected to a ground potential via the conductive ring 200 and the conductive chamber 10.

Each conductive liner 201 has a plate shape formed by dividing a cylinder. The multiple conductive liners 201 have an overall annular shape in a planar view, and are arranged side by side in the circumferential direction of the conductive ring 200. In this embodiment, the number of conductive liners 201 (number of divisions) is five, and each conductive liner 201 is divided almost equally. In other words, the dimensions of the conductive liners 201 in a planar view are almost the same. The number of conductive liners 201 is arbitrary. The number of conductive liners 201 is, for example, 2 to 10, and more preferably 4 to 6.

Of the five conductive liners 201, the four conductive liners 201A have the same height length, but the conductive liner 201B has a height length smaller than that of the conductive liner 201A. The conductive liner 201B is disposed opposite the substrate W loading/unloading opening formed in the side wall 10a of the conductive chamber 10, and a shutter assembly 210, which will be described later, is disposed below the conductive liner 201B.

As shown in FIG. 3, the conductive liners 201 are arranged in a ring shape along the sidewall 10a of the conductive chamber 10 inside the conductive chamber 10. The conductive liners 201 are also arranged at a distance from the sidewall 10a. The first surface (inner surface) 201a of the conductive liner 201 is exposed to the plasma processing space 10s. Therefore, the first surface 201a is exposed to the plasma generated in the plasma processing space 10s. The second surface (outer surface) 201b of the conductive liner 201 opposite the first surface 201a faces the sidewall (inner wall) 10a.

A gap 203 is formed between two adjacent conductive liners 201 among the multiple conductive liners 201. In this embodiment, five gaps 203 are formed for five conductive liners 201. This gap 203 can prevent the two adjacent conductive liners 201 from interfering with each other even if they thermally expand.

Here, if the gap 203 is formed in the radial direction, i.e., radially, there is a risk that the outside of the conductive liner 201 will be exposed to plasma. In this regard, in this embodiment, as shown in FIG. 9, the gap 203 is formed at an angle to the radial direction. In such a case, the outside of the conductive liner 201 is not exposed to the plasma processing space 10s, and exposure to plasma can be suppressed. This can also suppress the plasma from reaching the conductive chamber 10.

The configuration of the gap 203 is not limited to this embodiment. For example, as shown in FIG. 10, the gap 203 may have a labyrinth-like structure (labyrinth structure) with multiple folded portions. The labyrinth structure may be designed arbitrarily, but for example, unevenness may be formed on the side surface of the conductive liner 201. In such a case, exposure of the outer space of the conductive liner 201 to plasma can be further suppressed.

The multiple clamp members 202 secure the conductive ring 200 and the multiple conductive liners 201. Specifically, each clamp member 202 secures two adjacent conductive liners 201 to the conductive ring 200 with a gap 203 formed therebetween. The clamp members 202 are provided across the gap 203 on the second surface of the conductive liner 201. The number of clamp members 202 matches the number of conductive liners 201 (gaps 203), and is five in this embodiment.

As shown in FIG. 8, the clamp member 202 has a generally L-shape in cross section. The upper portion 202a of the clamp member 202 is disposed on the step portion 200b of the conductive ring 200. The lower portion 202b of the clamp member 202 is inserted into a recess formed on the second surface 201b of the conductive liner 201. The clamp member 202 is not exposed to the plasma processing space 10s and is not exposed to plasma.

A screw is attached to the upper portion 202a of the clamp member 202, for example, by inserting it from the top surface of the conductive ring 200. This screw fixes the clamp member 202 to the conductive ring 200.

A recess is formed on the upper surface (surface facing the conductive ring 200) of the upper portion 202a of the clamp member 202, and a conductive elastic member is provided in the recess. A recess is formed on the upper surface (surface facing the conductive liner 201) of the lower portion 202b of the clamp member 202, and a conductive elastic member is provided in the recess. The reactive force of these conductive elastic members presses the conductive liner 201 into contact with the conductive ring 200.

A recess is formed on the inner surface of the upper portion 202a of the clamp member 202, and a resin plug 207 is provided in the recess. The resin plug 207 protrudes inward from the inner surface of the upper portion 202a and contacts the conductive liner 201. Here, since the clamp member 202 is made of Al and the conductive liner 201 is made of Si, there is a risk of cracks or the like occurring when the clamp member 202 and the conductive liner 201 come into contact with each other. Therefore, by providing the resin plug 207, a minute gap is formed between the clamp member 202 and the conductive liner 201, and direct contact is avoided. The number of resin plugs 207 is arbitrary, but in this embodiment, two resin plugs 207 are provided for one clamp member 202 as shown in FIG. 9. In one embodiment, each of the multiple resin plugs 207 has a first end and a second end. The first end of the resin plug 207 is disposed in a recess formed in the clamp member 202, and the second end of the resin plug 207 protrudes inward from the clamp member 202.

11, a positioning pin 208 is provided between the conductive ring 200 and the conductive liner 201. The positioning pin 208 is inserted into a recess formed on the upper surface of the conductive liner 201 and a recess formed on the lower surface of the conductive ring 200. A plurality of positioning pins 208 are provided in the circumferential direction. Thus, each of the plurality of positioning pins 208 has a first end and a second end. The first end of the positioning pin 208 is disposed in a recess formed on the upper surface of the conductive liner 201, and the second end of the positioning pin 208 is disposed in a recess formed on the lower surface of the conductive ring 200. The plurality of positioning pins 208 adjust the center position of the conductive ring 200 and the center positions of the plurality of conductive liners 201, i.e., the conductive ring 200 and the plurality of conductive liners 201 are centered.

The positioning pin 208 is made of, for example, resin. In this case, the thermal expansion of the positioning pin 208 can be suppressed, and interference with the conductive liner 201 can be suppressed.

According to the above liner assembly 15, the conductive liner is divided to have multiple conductive liners 201. Therefore, even if maintenance of one conductive liner 201 becomes necessary, only that one conductive liner 201 needs to be replaced. In other words, only the conductive liner 201 that affects the process variation needs to be replaced. Therefore, there is no need to replace the entire liner as with conventional integrated liners, and workability can be improved.

Even if the conductive liner 201 is made of brittle material (tough material) such as Si or SiC, it is possible to simulate complex shapes by combining multiple conductive liners 201. Furthermore, the layout consisting of multiple conductive liners 201 can be changed, making it possible to respond to various process conditions anticipated depending on the process situation.

In addition, because conventional one-piece liners are large in volume, the size of the Si ingot from which the liner is cut is also large. In contrast, in this embodiment, the liner is divided into multiple conductive liners 201, so the volume of each conductive liner 201 is smaller, and the size of the Si ingot from which the conductive liners 201 are cut is also smaller. This minimizes waste of the Si ingot and reduces material costs.

In addition, there is a difference between the thermal expansion coefficient of the conductive ring 200 made of Al and the thermal expansion coefficient of the conductive liner 201 made of Si or SiC. Specifically, the thermal expansion coefficient of the conductive ring 200 is greater than that of the conductive liner 201. For this reason, when a conventional integrated liner is used, thermal stress occurs when the ring and the liner are brought into contact or fixed. In contrast, in this embodiment, the conductive liner 201 is divided into a plurality of conductive liners 201, and a gap 203 is formed between two adjacent conductive liners 201, so that each conductive liner 201 follows the conductive ring 200, thereby reducing thermal stress. As a result, cracking of the conductive liner 201 due to thermal stress can be suppressed, and the conductive liner 201 can function as a path to the ground potential.

Since the conductive liners 201 are made of Si or SiC, the resistance value of each conductive liner 201 can be changed, and the temperature of the conductive liner 201 can be changed. In such a case, it is also possible to partially change the temperature of multiple conductive liners 201, and the amount of deposits that adhere to the conductive liners 201 can be adjusted.

<Shutter Assembly>
3, a shutter assembly 210 is provided below one conductive liner 201B among the five conductive liners 201. The conductive liner 201B and the shutter assembly 210 are provided to face an entrance for loading and unloading the substrate W formed on the side wall 10a of the conductive chamber 10.

Figure 12 is a perspective view (exploded view) showing the outline of the configuration of the shutter assembly 210. Figure 13 is a plan view showing the outline of the configuration of the shutter assembly 210. Figure 14 is a side view showing the outline of the configuration of the shutter assembly 210.

The shutter assembly 210 has a conductive shutter 211, a valve body 212, and a clamp member 213. The conductive shutter 211 is made of a conductive material, such as Si or SiC. The valve body 212 and the clamp member 213 are each made of a conductive material, such as Al.

The shutter assembly 210 is configured to be freely raised and lowered by a lifting mechanism (not shown). When the substrate W is loaded or unloaded from the conductive chamber 10, the shutter assembly 210 is lowered and the shutter assembly 210 is opened. On the other hand, for example, when the substrate W is subjected to plasma processing, the shutter assembly 210 is raised and the shutter assembly 210 is closed.

The conductive shutter 211 has at least approximately the same shape as the conductive liner 201B in a plan view, and is provided extending downward from the conductive liner 201B. When the shutter assembly 210 is closed, the conductive shutter 211 comes into contact with the conductive liner 201B. In this case, the valve body 212 on the outer side of the conductive shutter 211 is not exposed to the plasma processing space 10s, and exposure to plasma can be suppressed.

The valve body 212 is provided on the outside of the conductive shutter 211. A step portion 212a is formed on the lower portion of the valve body 212, and the conductive shutter 211 is supported by the step portion 212a.

As shown in FIG. 15, the clamp member 213 is provided on the upper surface side of the conductive shutter 211 and the valve body 212, and fixes the conductive shutter 211 and the valve body 212. The clamp member 213 and the valve body 212 are fixed on the outside of the conductive shutter 211 by, for example, a number of screws.

A recess is formed on the lower surface of the clamp member 213 (the surface facing the conductive shutter 211), and a conductive elastic member is provided in the recess. The conductive shutter 211 is pressed into contact with the clamp member 213 by the reaction force of the conductive elastic member.

Positioning pins are provided between the conductive shutter 211 and the valve body 212. The positioning pins are inserted into recesses formed on the lower surface of the conductive shutter 211 and recesses formed on the upper surface of the valve body 212. A plurality of positioning pins are provided in the circumferential direction. The relative positions of the conductive shutter 211 and the valve body 212 (and the clamp member 213) are adjusted by these multiple positioning pins.

The positioning pin is made of, for example, resin. In this case, thermal expansion of the positioning pin can be suppressed, and interference with the conductive shutter 211 can be suppressed.

As shown in FIG. 16, a recess is formed on the inner surface of the valve body 212, and a resin plug 217 is provided in the recess. The resin plug 217 protrudes inward from the inner surface of the valve body 212 and contacts the conductive shutter 211. By providing this resin plug 217, a small gap is formed between the conductive shutter 211 and the valve body 212, preventing direct contact. The number of resin plugs 217 is arbitrary, but in this embodiment, two resin plugs 217 are provided.

<Baffle Assembly>
Next, a description will be given of the configuration of the above-mentioned baffle assembly 16. Fig. 17 is a perspective view (partially exploded view) showing the outline of the configuration of the baffle assembly 16. Fig. 18 is a plan view showing the outline of the configuration of the baffle assembly 16.

The baffle assembly 16 has a plurality of conductive baffle plates 300 and a plurality of clamp members 301. The baffle assembly 16 is supported by a plurality of baffle supports 302. The conductive baffle plates 300 are made of a conductive material, for example, Si or SiC. The clamp members 301 are made of, but are not limited to, Al. The baffle supports 302 are made of a conductive material, for example, Al.

The multiple conductive baffle plates 300 are arranged on the multiple baffle supports 302 and are provided between the Si ring 18 and the multiple conductive liners 201 (conductive shutters 211). The multiple conductive baffle plates 300 are connected to ground potential via the baffle supports 302 and the conductive chamber 10.

As shown in FIG. 19, each conductive baffle plate 300 has an arc-shaped plate shape formed by dividing a ring plate. A plurality of openings (slits) 303 are formed in the conductive baffle plate 300. Gas in the plasma processing space 10s is rectified and discharged through these multiple openings 303. The dimensions of the openings 303 can be set arbitrarily.

The multiple conductive baffle plates 300 have an overall annular shape in a plan view, and are arranged in a circumferential direction along the outer periphery of the substrate support part 11. That is, the multiple conductive baffle plates 300 are arranged on at least one baffle support part 302 so as to surround the substrate support part 11, and are arranged along the circumferential direction of the substrate support part 11. In this embodiment, the number of conductive baffle plates 300 (number of divisions) is five, and each conductive baffle plate 300 is divided almost equally. That is, the dimensions of the conductive baffle plates 300 in a plan view are almost the same. The number of conductive baffle plates 300 is arbitrary. The number of conductive baffle plates 300 is, for example, 2 to 10, and more preferably 4 to 6.

A gap 304 is formed between two adjacent conductive baffle plates 300. In this embodiment, five gaps 304 are formed for the five conductive baffle plates 300. These gaps 304 can prevent the two adjacent conductive baffle plates 300 from interfering with each other even if they thermally expand.

The multiple baffle support parts 302 are provided along the outer periphery of the substrate support part 11. That is, at least one baffle support part 302 is arranged to surround the substrate support part 11. Each baffle support part 302 has a substantially rectangular shape and is attached to the substrate support part 11 and the conductive chamber 10. The baffle support part 302 is connected to the ground potential via the conductive chamber 10. Note that the number of baffle support parts 302 is arbitrary, but the multiple baffle support parts 302 are arranged at substantially equal intervals in the circumferential direction.

In this embodiment, the baffle support 302 is made of Al, and constitutes the conductive portion in this disclosure. In other embodiments, the baffle support 302 may have a composite structure of a conductive portion and an insulating portion. In such a case, the clamp member 301 fixes two adjacent conductive baffle plates 300 to the conductive portion of the baffle support 302. Thus, at least one baffle support 302 includes at least one conductive portion connected to the conductive chamber 10.

As shown in FIG. 20, a positioning pin 305 is provided between the conductive baffle plate 300 and the baffle support 302. The positioning pin 305 is inserted into a recess formed on the upper surface of the baffle support 302 and a recess formed on the lower surface of the conductive baffle plate 300. Thus, the positioning pin 305 has a first end and a second end. The first end of the positioning pin 305 is disposed in a recess formed on the upper surface of the conductive part of the baffle support 302, and the second end of the positioning pin 305 is disposed in a recess formed on the lower surface of the conductive baffle plate 300. In addition, in order to suppress cracking of the conductive baffle plate 300, the recess of the conductive baffle plate 300 may have a diameter slightly larger than that of the positioning pin 305.

The positioning pins 305 are provided in, for example, two locations. The number of positioning pins 305 is arbitrary and may be one or more. The relative positions of the multiple conductive baffle plates 300 and the baffle support portion 302 are adjusted by the positioning pins 305.

The positioning pin 305 is made of, for example, resin. In this case, the thermal expansion of the positioning pin 305 can be suppressed, and interference with the conductive baffle plate 300 can be suppressed.

The multiple clamp members 301 fix the multiple conductive baffle plates 300 and the multiple baffle support parts 302. Specifically, each clamp member 301 fixes two adjacent conductive baffle plates 300 of the multiple conductive baffle plates 300 to the baffle support part 302 with a gap 304 formed. That is, the two adjacent conductive baffle plates 300 are fixed to the baffle support part 302 while maintaining the gap 304. The number of clamp members 301 matches the number of conductive baffle plates 300 (gaps 304), and is five in this embodiment.

In this embodiment, the clamp member 301 is made of Al, and a protective member 306 is provided on the exposed surface of the clamp member 301 to prevent exposure to plasma. The protective member 306 is made of, for example, quartz. The exposed surfaces of the clamp member 301 are the top and side surfaces, and as shown in FIG. 21, the protective member 306 has a gate-like shape in cross section so as to cover these exposed surfaces. A protective member 306 is provided for each of the multiple clamp members 301, and there are five of them in total.

As shown in Figures 21 and 22, the clamp member 301 has a generally T-shape in cross section. The upper part 301a of the clamp member 301 is larger than the gap 304 and is engaged with the conductive baffle plate 300. The lower part 301b of the clamp member 301 is fitted into the gap 304. The clamp member 301 is fixed to the baffle support part 302 by, for example, screws. The number of screws is arbitrary, but is, for example, two.

A conductive elastic member is provided between the lower surface (surface facing the conductive baffle plate 300) of the upper portion 301a of the clamp member 301 and the conductive baffle plate 300. A recess is formed in the lower surface (surface facing the baffle support portion 302) of the lower portion 301b of the clamp member 301, and a conductive elastic member is provided in the recess. The reaction force of these conductive elastic members presses the conductive baffle plate 300 into contact with the baffle support portion 302.

According to the above baffle assembly 16, the conductive baffle plate is divided to have multiple conductive baffle plates 300, so that, for example, even if maintenance of one conductive baffle plate 300 becomes necessary, only that one conductive baffle plate 300 needs to be replaced. In other words, only the conductive baffle plate 300 that affects the process fluctuation needs to be replaced. Therefore, there is no need to replace the entire baffle plate as with the conventional integrated baffle plate, and workability can be improved.

Even if the conductive baffle plate 300 is made of brittle material (tough material) such as Si or SiC, it is possible to simulate complex shapes by combining multiple conductive baffle plates 300. Furthermore, the layout consisting of multiple conductive baffle plates 300 can be changed, making it possible to accommodate various process conditions anticipated depending on the process situation.

In addition, because the conventional one-piece baffle plate has a large volume, the size of the Si ingot from which the baffle plate is cut is also large. In contrast, in this embodiment, the baffle plate is divided into multiple conductive baffle plates 300, so the volume of each conductive baffle plate 300 is smaller, and the size of the Si ingot from which the conductive baffle plates 300 are cut is also smaller. This minimizes waste of the Si ingot and reduces material costs.

In addition, there is a difference between the thermal expansion coefficient of the Al baffle support portion 302 and the thermal expansion coefficient of the Si or SiC conductive baffle plate 300. Specifically, the thermal expansion coefficient of the baffle support portion 302 is greater than that of the conductive baffle plate 300. For this reason, when a conventional integrated baffle plate is used, thermal stress occurs when the baffle plate and the support portion are brought into contact or fixed. In contrast, in this embodiment, the baffle plate is divided into a plurality of conductive baffle plates 300, and a gap 304 is formed between two adjacent conductive baffle plates 300, so that each conductive baffle plate 300 follows the baffle support portion 302, thereby reducing thermal stress. As a result, cracking of the conductive baffle plate 300 due to thermal stress can be suppressed, and the conductive baffle plate 300 can function as a path to the ground potential.

Since the conductive baffle plates 300 are made of Si or SiC, the resistance value of each conductive baffle plate 300 can be changed, and the temperature of the conductive baffle plate 300 can be changed. In such a case, it is also possible to change the temperature partially in multiple conductive baffle plates 300, and the amount of deposits that adhere to the conductive baffle plates 300 can be adjusted.

In addition, in order to create a temperature difference between the conductive liner 201 and the conductive baffle plate 300, it is also possible to partially change the temperature by changing the resistance value of part of the conductive liner 201 or the conductive baffle plate 300.

The size and number of the openings 303 formed in the conductive baffle plate 300 can be changed as desired, so that the exhaust conductance when discharging gas from the plasma processing space 10s can be controlled. For example, as shown in FIG. 23, the conductive baffle plate 300 is formed with a plurality of first openings 303a and a plurality of second openings 303b. By making the size of the first openings 303a and the size of the second openings 303b different, the exhaust conductance can be controlled. Also, by making the number of the first openings 303a and the number of the second openings 303b different, the exhaust conductance can be controlled.

The exhaust conductance can also be controlled by changing the thickness of the multiple conductive baffle plates 300. For example, the exhaust conductance can be controlled by making the first thickness of the first conductive baffle plate 300 and the second thickness of the second conductive baffle plate 300 different. If the thicknesses of two adjacent conductive baffle plates 300 are different, the design of the clamp member 301 is modified as appropriate.

As described above, by changing the size, number, or thickness of the openings 303 in the conductive baffle plate 300, it is possible to partially control the exhaust conductance.

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

For example, in the above embodiment, the conductive liner 201, the conductive shutter 211, and the conductive baffle plate 300 are each made of Si or SiC, but they may also be made of quartz, which is an insulating material.

REFERENCE SIGNS LIST 1 Plasma processing apparatus 10 Conductive chamber 11 Substrate support section 12 Plasma generating section 300 Conductive baffle plate 301 Clamp member 302 Baffle support section W Substrate

Claims (12)

a conductive chamber connected to a ground potential;
a plasma generating unit configured to generate a plasma in the conductive chamber;
a substrate support disposed within the conductive chamber;
at least one baffle support disposed around the substrate support and including at least one conductive portion connected to the conductive chamber;
a plurality of conductive baffle plates arranged on the at least one baffle support so as to surround the substrate support and arranged along a circumferential direction of the substrate support, each conductive baffle plate being connected to a ground potential via the conductive portion and the conductive chamber;
a plurality of clamp members, each clamp member configured to secure two adjacent conductive baffle plates of the plurality of conductive baffle plates to the at least one baffle support. The clamping member further includes a plurality of protective members configured to cover the plurality of clamping members,
The plasma processing apparatus of claim 1 , wherein the clamp member is made of a metallic material. The plasma processing apparatus according to claim 1 or 2, wherein the conductive baffle plate is made of Si or SiC. The plasma processing apparatus according to any one of claims 1 to 3, wherein the number of the plurality of conductive baffle plates is 2 to 10. The plasma processing apparatus of claim 4, wherein the number of the conductive baffle plates is 4 to 6. A gap is formed between the two adjacent conductive baffle plates,
The plasma processing apparatus of claim 1 , wherein the clamping members are configured to secure the two adjacent conductive baffle plates to the at least one baffle support while maintaining the gap. The plasma processing apparatus according to any one of claims 1 to 6, wherein the clamping member is configured to fix the two adjacent conductive baffle plates to the at least one baffle support portion so that the two adjacent conductive baffle plates are pressed against the conductive portion. Further comprising one or more locating pins;
8. The plasma processing apparatus of claim 1, wherein the positioning pin has a first end and a second end, the first end being positioned within a recess formed in an upper surface of the at least one conductive portion, and the second end being positioned within a recess formed in a lower surface of the conductive baffle plate. The plasma processing apparatus of claim 8, wherein the positioning pin is made of resin. the conductive baffle plate having a first number of first openings and a second number of second openings;
The plasma processing apparatus of claim 1 , wherein the first number is different from the second number.
the conductive baffle plate having a plurality of first openings and a plurality of second openings;
11. The plasma processing apparatus of claim 1, wherein the first opening has a size different from the second opening.
the plurality of conductive baffle plates includes a first conductive baffle plate and a second conductive baffle plate;
the first conductive baffle plate has a first thickness;
the second conductive baffle plate has a second thickness;
The plasma processing apparatus according to any one of claims 1 to 11, wherein the first thickness and the second thickness are different.

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