Plasma processing equipment

Abstract

To provide a plasma processing apparatus that can prevent a seal member from being damaged by a plasma product.SOLUTION: A plasma processing apparatus 1 includes: a chamber 2 capable of maintaining a decompressed atmosphere; a plasma generation part inside the chamber; a gas supply part capable of supplying a process gas to a region where a plasma is generated; a placing module 3 having a cantilever structure and capable of supporting a placing part, on which a processing object is placed, on a lower side of the region where a plasma is generated; a pump 61 capable of evacuating an internal gas from the chamber via a hole provided in a bottom plate of the chamber; a valve element 62a formed into a plate shape and capable of opening and closing the hole provided in the bottom plate of the chamber; a drive part capable of changing a position of the valve element in a direction of a central axis of the chamber; a seal member 100 formed into an annular shape and provided in a surface on a side of a bottom plate of the valve element or the bottom plate; and a shield part 9 installed between the placing module and the valve element, including at least one hole penetrating in a thickness direction, having electric conductivity and grounded to the earth.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a plasma processing apparatus. [Background technology]

[0002] There is a demand for improved plasma processing performance, such as processing rate, in plasma processing equipment used for dry etching, CVD, PVD, etc. In addition, in recent years, the miniaturization of processed parts has led to a demand for more precise process control.

[0003] If by-products generated during plasma processing remain inside the chamber, the plasma processing performance may fluctuate, making precise process control impossible. In this case, precise process control can be achieved by cleaning or replacing the elements inside the chamber to which the by-products have adhered. However, if the number of maintenance operations increases or the time required for maintenance increases, the operating rate of the plasma processing apparatus will decrease.

[0004] Therefore, a plasma processing apparatus has been proposed in which a mounting portion for placing an object to be processed is supported inside the chamber and a turbomolecular pump is arranged directly below the mounting portion (see, for example, Patent Document 1). Such a plasma processing apparatus has a high effective pumping speed and can perform axisymmetric pumping without bias. Therefore, by-products generated during plasma processing can be easily discharged to the outside of the chamber.

[0005] However, it is impossible to completely prevent by-products from adhering to the elements inside the chamber. Therefore, when cleaning or replacing elements inside the chamber to which by-products have adhered, the internal pressure of the chamber is increased, which is called atmospheric venting. If a turbomolecular pump with a high pumping speed is stopped during atmospheric venting, it takes a considerable amount of time for the pumping speed to stabilize when the turbomolecular pump is restarted. For this reason, a valve is provided to airtightly close the gap between the chamber and the turbomolecular pump. If such a valve is provided, the turbomolecular pump can remain in operation during atmospheric venting.

[0006] However, depending on the process conditions (e.g., process pressure, type of process gas, etc.), the generated plasma may reach the vicinity of the valve. The valve is also provided with a seal member (e.g., an O-ring) for airtight closure. Therefore, if the generated plasma reaches the vicinity of the valve, the seal member may be damaged by plasma products such as ions and electrons. Damage to the seal member may result in the generation of particles, which may contaminate the processed object. Therefore, there has been a demand for the development of a plasma processing apparatus that can prevent the sealing member from being damaged by plasma products. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-211269 Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a plasma processing apparatus that can prevent a seal member from being damaged by plasma products. [Means for solving the problem]

[0009] The plasma processing apparatus according to the embodiment includes a chamber capable of maintaining an atmosphere reduced in pressure below atmospheric pressure, a plasma generating unit capable of generating plasma inside the chamber, a gas supply unit capable of supplying a process gas to an area inside the chamber where the plasma is generated, a cantilevered mounting module capable of supporting a mounting unit on which a workpiece to be processed is placed below the area where the plasma is generated, a pump capable of evacuating the inside of the chamber through a hole provided in a bottom plate of the chamber, a plate-shaped valve body capable of opening and closing the hole provided in the bottom plate of the chamber, a drive unit capable of changing the position of the valve body in the direction of the central axis of the chamber, a ring-shaped sealing member provided on the surface of the valve body facing the bottom plate or on the bottom plate, and a shielding unit provided between the mounting module and the valve body, having at least one hole penetrating in the thickness direction, being conductive and grounded. [Effects of the Invention]

[0010] According to an embodiment of the present invention, a plasma processing apparatus is provided that can suppress damage to a sealing member caused by plasma products. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic cross-sectional view illustrating a plasma processing apparatus according to an embodiment of the present invention; [Figure 2] FIG. 2 is a schematic perspective view illustrating a mounting module. [Figure 3] FIG. 2 is a schematic cross-sectional view of a mounting module. [Figure 4] 10(a) and 10(b) are schematic plan views illustrating a case where a plurality of holes are provided in the shielding portion. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments will be illustrated with reference to the drawings. In each drawing, like components are designated by like reference numerals and detailed descriptions thereof will be omitted where appropriate. In this specification, the "planar dimension" refers to the dimension in a direction perpendicular to the central axis of the chamber.

[0013] 1 is a schematic cross-sectional view illustrating a plasma processing apparatus 1 according to this embodiment. FIG. 2 is a schematic perspective view illustrating a mounting module 3. FIG. 3 is a schematic cross-sectional view of the mount module 3. As shown in FIG.

[0014] As shown in FIG. 1, the plasma processing apparatus 1 includes, for example, a chamber 2, a mounting module 3, a power supply unit 4, a power supply unit 5, a pressure reducing unit 6, a gas supply unit 7, a controller 8, and a shielding unit 9.

[0015] The chamber 2 has an airtight structure capable of maintaining an atmosphere at a pressure lower than atmospheric pressure. The chamber 2 includes, for example, a main body 21, a top plate 22, and a window 23. The main body 21 has a substantially cylindrical shape and is integrally provided with a bottom plate 21a at one end. The other end of the main body 21 is open. The main body 21 is formed from a metal such as an aluminum alloy. The main body 21 is also grounded. An area 21b where plasma P is generated is provided inside the main body 21. The main body 21 is provided with a loading / unloading port 21c for loading / unloading the workpiece 100. The loading / unloading port 21c is airtightly closed by a gate valve 21c1.

[0016] The processing object 100 may be, for example, a photomask, a mask blank, a wafer, a glass substrate, etc. However, the processing object 100 is not limited to the examples given above.

[0017] The top plate 22 is plate-shaped and is provided to close the opening of the main body 21. The top plate 22 faces the bottom plate 21a. A hole 22a is provided in the central region of the top plate 22, penetrating the thickness direction. The central axis of the hole 22a overlaps with the central axis 2a of the chamber 2. The hole 22a is provided to allow electromagnetic waves emitted from an electrode 51, which will be described later, to pass through. The top plate 22 is formed from a metal, for example, an aluminum alloy.

[0018] The window 23 has a plate shape and is provided on the top plate 22. The window 23 is provided so as to cover the hole 22a. The window 23 is made of a material that allows an electromagnetic field to pass through and is resistant to etching during an etching process. The window 23 can be made of a dielectric material such as quartz.

[0019] A hole 2b is provided on the side surface of the chamber 2. The hole 2b has a size and shape that allows the placement unit 31 attached to the mounting unit 32a (described later) to pass through (see FIG. 2). Therefore, the placement module 3 provided with the placement unit 31 can be removed from the chamber 2 or attached to the chamber 2 via the hole 2b. When the placement module 3 is attached to the chamber 2, the central axis of the placement unit 31 provided on the placement module 3 overlaps with the central axis 2a of the chamber 2. Note that a slider can be provided on the outer wall of the chamber 2 to facilitate the attachment and detachment of the placement module 3.

[0020] As shown in FIGS. 1 to 3, the mounting module 3 has a mounting portion 31, a support portion 32, and a cover 33. The mounting module 3 has a cantilever structure, and supports a mounting part 31 on which the object to be treated 100 is mounted below the region 21b where the plasma P is generated. The mounting module 3 protrudes into the chamber 2 from the side of the chamber 2. A mounting unit 31 is provided at the tip of the mounting module 3. If the mounting module 3 has a cantilever structure, a space is created below the mounting unit 31 provided in the internal space of the chamber 2. Therefore, the pressure reducing unit 6 can be disposed concentrically with the mounting unit 31 directly below the mounting unit 31. This facilitates high effective pumping speed and unbiased, axially symmetrical pumping. This facilitates the discharge of by-products generated during plasma processing to the outside of the chamber 2. As a result, precise process control is possible. Furthermore, by-products can be prevented from adhering to the inner walls of the chamber 2, the mounting module 3, and the like, thereby reducing the frequency and time required for maintenance. This improves the operating rate of the plasma processing apparatus 1.

[0021] Furthermore, if the mounting module 3 has a cantilever structure, the mounting module 3 can be attached to or detached from the chamber 2 in a direction perpendicular to the central axis 2a of the chamber 2. This makes maintenance of the plasma processing apparatus 1 easier than when the mounting unit is fixed to the bottom plate 21a of the chamber 2.

[0022] The object to be treated 100 is placed on the placement section 31 . The mounting part 31 has, for example, an electrode 31a, an insulating ring 31b, and a pedestal 31c. The electrode 31a is made of a conductive material such as metal. The upper surface of the electrode 31a can be used as a mounting surface for placing the object to be treated 100 thereon. The electrode 31a is fixed to the pedestal 31c, for example, with screws.

[0023] Furthermore, the electrode 31a may have built-in pickup pins 31a1, a temperature control unit, and the like. A plurality of pickup pins 31a1 may be provided. The plurality of pickup pins 31a1 are rod-shaped and can protrude from the upper surface of the electrode 31a. The plurality of pickup pins 31a1 are used when transferring the object to be treated 100. Therefore, the plurality of pickup pins 31a1 can be protruded from the upper surface of the electrode 31a and retracted into the electrode 31a by a drive unit (not shown).

[0024] The temperature control unit is, for example, a refrigerant circulation line (flow path), a heater, etc. The temperature control unit controls the temperature of the electrode 31a, and therefore the temperature of the object 100 to be treated placed on the electrode 31a, based on, for example, the output of a temperature sensor (not shown).

[0025] The insulating ring 31b is ring-shaped and covers the side surface of the electrode 31a, and is made of a dielectric material such as quartz. The pedestal 31c is provided between the electrode 31a and the mounting portion 32a of the support portion 32. The pedestal 31c provides insulation between the electrode 31a and the support portion 32. The pedestal 31c is made of a dielectric material such as quartz. The pedestal 31c is fastened to the mounting portion 32a of the support portion 32 with a screw, for example.

[0026] The support portion 32 supports the mounting portion 31 in the internal space of the chamber 2. The support portion 32 is disposed so as to extend between the side surface of the chamber 2 and the lower portion of the mounting portion 31. The support portion 32 has, for example, a mounting portion 32a, a beam 32b, and a flange 32c. The mounting portion 32a, the beam 32b, and the flange 32c are made of, for example, an aluminum alloy.

[0027] The mounting portion 32a is located below the mounting portion 31 in the internal space of the chamber 2. The mounting portion 32a is cylindrical. A hole 32a1 is provided on the surface of the mounting portion 32a facing the mounting portion 31 (see FIG. 3). A hole 32a2 is provided on the surface of the mounting portion 32a opposite the mounting portion 31. The wiring member 42c, refrigerant piping, etc. are connected to the electrode 31a through the hole 32a1. The hole 32a2 is used for connecting the wiring member 42c, refrigerant piping, etc., and for performing maintenance on the electrode 31a. The mounting portion 31 (base 31c) is provided on the surface of the mounting portion 32a facing the mounting portion 31. Therefore, the planar shape of the mounting portion 32a can be the same as the planar shape of the mounting portion 31. The planar dimensions of the mounting portion 32a can be approximately the same as or slightly larger than the planar dimensions of the mounting portion 31.

[0028] One end of beam 32b is connected to the side surface of mounting portion 32a. The other end of beam 32b is connected to flange 32c via hole 2b penetrating the side surface of chamber 2. Beam 32b extends through the internal space of chamber 2 from the side surface of chamber 2 toward central axis 2a of chamber 2. Beam 32b has, for example, a rectangular cylindrical shape. The internal space of beam 32b is connected to the external space of chamber 2 (atmospheric space) via hole 32c1 provided in flange 32c.

[0029] The flange 32c is attached to the outer wall of the chamber 2. For example, the flange 32c is screwed to the outer wall of the chamber 2. The flange 32c is plate-shaped and has a hole 32c1 that penetrates through in the thickness direction.

[0030] The cover 33 is provided on the surface of the mounting portion 32a opposite to the mounting portion 31 side. The cover 33 is, for example, screwed to the mounting portion 32a. When the cover 33 is attached to the mounting portion 32a, the hole 32a2 is airtightly closed. The cover 33 is made of, for example, an aluminum alloy.

[0031] As shown in FIG. 1, the power supply unit 4 includes, for example, a power supply 41 and a matching unit . The power supply unit 4 is a so-called bias control high frequency power supply. That is, the power supply unit 4 controls the energy of ions attracted to the object 100 placed on the placement unit 31.

[0032] The power supply 41 outputs high frequency power having a frequency suitable for attracting ions (for example, a frequency of 27 MHz to 1 MHz). The matching unit 42 includes, for example, a matching circuit 42a and a fan 42b. The matching circuit 42a is provided to match the impedance on the power supply 41 side with the impedance on the plasma P side. The matching circuit 42a is electrically connected to the power supply 41 and the electrode 31a via a wiring member (bus bar) 42c. The fan 42b sends air into the inside of the support part 32. The fan 42b is provided to cool the wiring member 42c and the matching circuit 42a provided inside the support part 32.

[0033] In this case, the alignment part 42 can be provided on the flange 32c of the support part 32. If the alignment part 42 is provided on the flange 32c, the stage module 3 and the alignment part 42 can be moved together when removing the stage module 3 from the chamber 2 or attaching the stage module 3 to the chamber 2. This improves maintainability.

[0034] The power supply unit 5 includes an electrode 51 , a power supply 52 , and a matching circuit 53 . The power supply unit 5 can be a high-frequency power supply for generating the plasma P. That is, the power supply unit 5 generates the plasma P by causing a high-frequency discharge inside the chamber 2. In this embodiment, the power supply unit 5 serves as a plasma generating unit that generates plasma P inside the chamber 2.

[0035] The electrode 51 is provided on the window 23 outside the chamber 2. The electrode 51 has, for example, a plurality of conductor portions that generate an electromagnetic field and a plurality of capacitance portions (capacitors). The power supply 52 outputs high frequency power having a frequency of approximately 100 KHz to 100 MHz. For example, the power supply 52 outputs high frequency power having a frequency (e.g., a frequency of 13.56 MHz) suitable for generating plasma P. The power supply 52 may also be capable of changing the frequency of the high frequency power it outputs.

[0036] The matching circuit 53 is provided to match the impedance on the power supply 52 side with the impedance on the plasma P side. The matching circuit 53 is electrically connected to the power supply 52 and the electrode 51 via wiring 54.

[0037] 1 is a dual-frequency plasma processing apparatus having an inductively coupled electrode at the top and a capacitively coupled electrode at the bottom. However, the plasma generation method is not limited to the example shown. The plasma processing apparatus 1 may be, for example, a plasma processing apparatus using inductively coupled plasma (ICP) or a plasma processing apparatus using capacitively coupled plasma (CCP).

[0038] The pressure reducing unit 6 includes, for example, a pump 61 and a valve 62 . The pressure reducing section 6 is located below the mounting section 31 and reduces the pressure inside the chamber 2 to a predetermined pressure. The pump 61 evacuates the interior of the chamber 2 through a hole 21a1 provided in the bottom plate 21a of the chamber 2. The pump 61 may be, for example, a turbo molecular pump (TMP). The pump 61 is provided outside the chamber 2. The pump 61 is connected to the hole 21a1 provided in the bottom plate 21a of the chamber 2.

[0039] In this case, the central axis of the hole 21a1 overlaps with the central axis 2a of the chamber 2. Therefore, the central axis of the mounting unit 31 provided in the mounting module 3 and the central axis of the hole 21a1 provided in the bottom plate 21a of the chamber 2 overlap with the central axis 2a of the chamber 2. If the central axis of the mounting unit 31 and the central axis of the hole 21a1 inside the chamber 2 overlap with the central axis 2a of the chamber 2, the effective pumping speed is high and axially symmetrical pumping can be performed without bias.

[0040] Here, when cleaning elements inside the chamber 2 to which by-products have adhered or when replacing elements to which by-products have adhered, the internal pressure of the chamber 2 is increased, which is called atmospheric venting. Typically, the pump 61 is stopped during atmospheric venting. Here, a pump 61 with a high pumping speed may be used to increase the effective pumping speed. An example of a pump 61 with a high pumping speed is a large TMP. In this case, it takes a considerable amount of time to stop the pump 61. Furthermore, after stopping the pump 61, it is necessary to restart the pump 61 after cleaning or replacing the elements. However, when a pump 61 with a high pumping speed is used to increase the effective pumping speed, it may take a considerable amount of time for the pumping speed of the restarted pump 61 to stabilize.

[0041] Therefore, in order to keep the pump 61 in operation during atmospheric venting, the plasma processing apparatus 1 is provided with a valve 62. The valve 62 includes a valve body 62a, a drive portion 62b, and a seal member 62c. The valve 62 may be, for example, a so-called poppet valve. The valve element 62a is plate-shaped and is provided inside the chamber 2. The valve element 62a faces the hole 21a1. The planar dimensions of the valve element 62a are larger than the planar dimensions of the hole 21a1. Therefore, the valve element 62a can open and close the hole 21a1 provided in the bottom plate 21a of the chamber 2. As shown in FIG. 1, the planar dimensions of the valve element 62a can be the same as or larger than the planar dimensions of the mounting portion 31. In this way, the planar dimensions of the hole 21a1 can be increased, which makes it easier to achieve a high effective pumping speed and to perform axially symmetrical pumping without bias.

[0042] The driver 62b changes the position of the valve element 62a in the direction of the central axis 2a of the chamber 2. That is, the driver 62b raises or lowers the valve element 62a. The driver 62b includes, for example, a shaft 62a1 connected to the valve element 62a and a control motor (for example, a servo motor) that moves the shaft 62a1.

[0043] The sealing member 62c is annular and made of an elastic material such as rubber. The sealing member 62c may be, for example, an O-ring. When viewed from the direction along the central axis 2a, the annular sealing member 62c surrounds the hole 21a1 and is located inside the valve body 62a. Note that while FIG. 1 illustrates an example in which the sealing member 62c is provided on the surface of the valve body 62a facing the bottom plate 21a, the sealing member 62c may also be provided on the bottom plate 21a.

[0044] When the valve body 62a is raised by the drive unit 62b, a hole 21a1 provided in the bottom plate 21a of the chamber 2 is opened. Therefore, the internal space of the chamber 2 and the pump 61 communicate with each other via the hole 21a1.

[0045] When the valve body 62a is lowered by the drive unit 62b, the seal member 62c is sandwiched between the valve body 62a and the bottom plate 21a of the chamber 2. With the seal member 62c sandwiched between the valve body 62a and the bottom plate 21a of the chamber 2, the hole 21a1 provided in the bottom plate 21a of the chamber 2 is closed airtightly. This blocks communication between the internal space of the chamber 2 and the pump 61. As a result, the pump 61 can remain in operation during atmospheric venting.

[0046] Furthermore, changing the position of the valve element 62a in the direction of the central axis 2a of the chamber 2 changes the distance between the valve element 62a and the bottom plate 21a of the chamber 2. The space between the valve element 62a and the bottom plate 21a of the chamber 2 serves as an exhaust flow path. Therefore, changing the dimensions of this portion changes the conductance, making it possible to control the exhaust volume, exhaust speed, and the like. For example, the controller 8 can control the position of the valve element 62a based on the output of a vacuum gauge (not shown) that detects the internal pressure of the chamber 2. In other words, if the valve 62 is provided, it is also possible to control the exhaust volume, exhaust speed, and the like.

[0047] The gas supply unit 7 supplies the process gas G to a region 21b inside the chamber 2 where the plasma P is generated. The gas supply unit 7 includes, for example, a gas storage unit 71, a gas control unit 72, and an on-off valve 73. The gas storage unit 71, the gas control unit 72, and the on-off valve 73 are provided outside the chamber 2.

[0048] The gas storage unit 71 stores the process gas G and supplies the stored process gas G to the inside of the chamber 2. The gas storage unit 71 may be, for example, a high-pressure cylinder that stores the process gas G. The gas storage unit 71 and the gas control unit 72 are connected via piping.

[0049] The gas control unit 72 controls the flow rate, pressure, etc. of the process gas G when it is supplied from the gas storage unit 71 to the inside of the chamber 2. The gas control unit 72 may be, for example, an MFC (Mass Flow Controller). The gas control unit 72 and the on-off valve 73 are connected via piping.

[0050] The on-off valve 73 is connected to a gas supply port 22b provided in the chamber 2 via a pipe. The on-off valve 73 controls the supply and stop of the process gas G. The on-off valve 73 may be, for example, a two-port solenoid valve. The function of the on-off valve 73 may also be imparted to the gas control unit 72.

[0051] The process gas G may be a gas that generates desired plasma products (radicals, ions, electrons, etc.) when excited and activated by the plasma P. For example, if the plasma processing is an etching process, the process gas G may be a gas that generates plasma products that can etch the exposed surface of the workpiece 100. In this case, the process gas G may be, for example, a chlorine-containing gas or a fluorine-containing gas. The process gas G may be, for example, a mixed gas of chlorine gas and oxygen gas, CHF3, a mixed gas of CHF3 and CF4, a mixed gas of SF6 and helium gas, etc. However, the type of process gas G is not limited to the examples given above and may be changed as appropriate depending on the type of plasma processing and the material of the portion of the workpiece 100 to be processed.

[0052] The controller 8 includes a calculation unit such as a CPU (Central Processing Unit) and a storage unit such as a memory. The controller 8 may be, for example, a computer. The controller 8 controls the operation of each element provided in the plasma processing apparatus 1 based on a control program stored in the storage unit.

[0053] For example, the controller 8 controls the pressure reducing unit 6 based on the output of a vacuum gauge (not shown) that detects the internal pressure of the chamber 2, so that the internal pressure of the chamber 2 becomes a predetermined value. The controller 8 also controls the gas supply unit 7 to supply the process gas G to the region 21b where the plasma P is generated. The controller 8 also controls the power supply unit 5 to introduce electromagnetic waves into the region 21b. This generates the plasma P in the region 21b, and the process gas G is excited and activated by the plasma P, generating reaction products such as ions, electrons, and radicals.

[0054] The generated ions and electrons collide with the exposed surface of the treatment object 100, thereby physically treating the treatment object 100. At this time, the controller 8 controls the power supply unit 4 to control the energy of the ions drawn into the treatment object 100. Furthermore, the generated radicals come into contact with the exposed surface of the treatment object 100, thereby chemically treating the treatment object 100. It should be noted that known techniques can be applied to the control program for controlling the operation of each element and the process conditions, and therefore detailed explanations will be omitted.

[0055] Here, depending on the process conditions such as the process pressure and the type of process gas G, plasma P may also be generated outside region 21b. For example, plasma P may be generated in the range from region 21b to the vicinity of valve body 62a of valve 62. Even if plasma P is generated in such a wide range, the generated reaction products are still supplied to the exposed surface of the workpiece 100. Therefore, the desired plasma processing can be performed on the workpiece 100.

[0056] However, when plasma P is generated near valve element 62a, reaction products such as ions, electrons, and radicals are generated near valve element 62a. As described above, seal member 62c is provided on the surface of valve element 62a facing the bottom plate 21a or on bottom plate 21a. Therefore, when reaction products are generated near valve element 62a, the generated reaction products are more likely to reach seal member 62c.

[0057] In this case, if radicals generated near the valve body 62a come into contact with the seal member 62c, there is a risk that the seal member 62c may be damaged by a chemical reaction.

[0058] Furthermore, when ions are incident on the seal member 62c, the seal member 62c is damaged by physical impact. When the seal member 62c is damaged, particles are generated, and there is a risk that the object 100 to be processed will be contaminated by the particles.

[0059] Therefore, the plasma processing apparatus 1 is provided with a shielding unit 9. As shown in Fig. 1, the shielding unit 9 is provided inside the chamber 2, between the mount module 3 and the valve 62 (valve body 62a).

[0060] The shielding portion 9 is made of a conductive material such as an aluminum alloy or stainless steel. The shielding portion 9 is grounded. As described above, since the chamber 2 is grounded, the shielding portion 9 can be grounded by contacting the shielding portion 9 with the inner wall of the chamber 2 or the like. For example, the peripheral edge of the shielding portion 9 can be connected to the inner wall of the main body 21 of the chamber 2 or to the bottom plate 21a of the chamber 2. If the shielding portion 9 is provided, which is conductive and grounded, the shielding portion 9 can remove ions and radicals that are incident on the sealing member 62c.

[0061] The shielding portion 9 has a plate shape and can be provided, for example, parallel to the bottom plate 21a of the chamber 2. The plate-shaped shielding portion 9 can be provided with at least one hole 9a penetrating through in the thickness direction.

[0062] 1, when one hole 9a is provided, the central axis of the hole 9a can be made to overlap with the central axis 2a of the chamber 2. In this way, it is possible to perform axially symmetrical exhaust without bias. Furthermore, when one hole 9a is provided, it is preferable that the sealing member 62c is positioned outside the hole 9a when viewed from the direction along the central axis 2a of the chamber 2. In this way, it is possible to prevent ions and electrons from reaching the sealing member 62c through the hole 9a.

[0063] Here, it is also possible to provide a shielding unit 9 in the space between the mount module 3 and the inner wall of the main body 21 of the chamber 2. However, since this space is narrow, providing a shielding unit 9 in this space would make the conductance too small, making it difficult to increase the effective pumping speed. On the other hand, since the space between the mount module 3 and the valve 62 is large, even if the shielding part 9 is provided in this space, it is possible to prevent the conductance from decreasing, which makes it easy to increase the effective pumping speed.

[0064] Furthermore, the shielding portion 9 may be provided with not only one hole 9a but also a plurality of holes. When multiple holes are provided, it is preferable that the sealing member 62c be positioned outside the area where the multiple holes are provided when viewed from the direction along the central axis 2a of the chamber 2. In this way, it is possible to prevent ions and electrons from reaching the sealing member 62c through the multiple holes.

[0065] 4(a) and 4(b) are schematic plan views illustrating the case where a plurality of holes 9a1 to 9a3 are provided in the shielding portion 9. FIG. To avoid complication, FIG. 4 shows only the area where the holes of the shielding portion 9 are provided.

[0066] As shown in Figures 4(a) and 4(b), the number, shape, and dimensions of the holes are not particularly limited. For example, as shown in Figure 4(a), the number, shape, and dimensions of holes 9a1 may be different from the number, shape, and dimensions of holes 9a2. As shown in Figure 4(b), multiple identical holes 9a3 may be provided. In this case, it is preferable to make the total area of ​​the multiple holes and the area of ​​each hole as large as possible. This can prevent the conductance from decreasing, thereby preventing the effective pumping speed from slowing down.

[0067] Furthermore, when providing multiple holes 9a1 to 9a3, it is preferable to provide the holes at positions that are point-symmetric with respect to the central axis 2a of the chamber 2, as shown in Figures 4(a) and 4(b), for example. It is also preferable that the shapes and dimensions of the holes provided at the point-symmetric positions are the same. In this way, it becomes easier to perform unbiased, axisymmetric exhaust.

[0068] Although the embodiments have been described above, the present invention is not limited to these descriptions. Any design modifications made by a person skilled in the art to the above-described embodiments are included within the scope of the present invention as long as they include the features of the present invention. For example, the shapes, materials, arrangements, etc. of the components included in the plasma processing apparatus 1 are not limited to those exemplified, and can be changed as appropriate. Furthermore, the elements of each of the above-described embodiments can be combined to the greatest extent possible, and such combinations are also included within the scope of the present invention as long as they include the features of the present invention. [Explanation of symbols]

[0069] 1 plasma processing apparatus, 2 chamber, 2a central axis, 3 mounting module, 5 power supply unit, 6 pressure reducing unit, 7 gas supply unit, 9 shielding unit, 9a hole, 9a1 to 9a3 holes, 21a bottom plate, 21a1 hole, 61 pump, 62 valve, 62a valve body, 62b drive unit, 62c seal member, 100 processing object

Claims

1. a chamber capable of maintaining an atmosphere reduced in pressure below atmospheric pressure; a plasma generating unit capable of generating plasma inside the chamber; a gas supply unit capable of supplying a process gas to a region inside the chamber where the plasma is generated; a mounting module having a cantilever structure and capable of supporting a mounting section on which an object to be processed is placed below a region where the plasma is generated; a pump capable of evacuating the inside of the chamber through a hole provided in a bottom plate of the chamber; a plate-shaped valve body that can open and close the hole provided in the bottom plate of the chamber; a drive unit capable of changing the position of the valve element in the direction of the central axis of the chamber; a sealing member having an annular shape and provided on a surface of the valve body facing the bottom plate or on the bottom plate; a shielding portion provided between the mounting module and the valve body, the shielding portion having at least one hole penetrating in a thickness direction, the shielding portion being conductive and grounded; A plasma processing apparatus comprising:

2. The shielding portion has a plate shape and is provided parallel to the bottom plate, 2. The plasma processing apparatus according to claim 1, wherein the central axis of the hole provided in the bottom plate of the chamber overlaps with the central axis of the chamber.

3. 3. The plasma processing apparatus according to claim 1, wherein the shielding portion has one hole, and the central axis of the hole in the shielding portion overlaps with the central axis of the chamber.

4. 4. The plasma processing apparatus according to claim 3, wherein the sealing member is located outside the hole in the shielding portion when viewed from a direction along the central axis of the chamber.

5. 3. The plasma processing apparatus according to claim 1, wherein the shielding portion has a plurality of the holes, and when viewed from a direction along the central axis of the chamber, the sealing member is located outside the area of ​​the shielding portion where the plurality of holes are provided.

6. 6. The plasma processing apparatus according to claim 5, wherein the plurality of holes in the shielding portion are provided at positions that are point-symmetric with respect to the central axis of the chamber.

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