JP2023127761A - Plasma processing apparatus - Google Patents

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

Embodiments of the present invention relate to a plasma processing apparatus.

In plasma processing apparatuses used for dry etching, CVD, PVD, etc., it is required to improve plasma processing performance such as processing rate. Furthermore, in recent years, with the miniaturization of processing parts, precision in process control is required.

Here, if byproducts generated during plasma processing remain inside the chamber, plasma processing performance may fluctuate, making precise process control impossible. In this case, by cleaning the element inside the chamber to which the by-product has adhered or replacing the element to which the by-product has adhered, it becomes possible to perform precise process control. However, if the frequency of maintenance increases or the time required for maintenance increases, the operating rate of the plasma processing apparatus will decrease.

Therefore, a plasma processing apparatus has been proposed in which a mounting part on which a processing object is placed is supported inside a chamber, and a turbo molecular pump is disposed directly below the mounting part (see, for example, Patent Document 1). With such a plasma processing apparatus, the effective pumping speed is high, and uniform and axially symmetrical pumping can be performed. Therefore, byproducts generated during plasma processing can be easily discharged to the outside of the chamber.

However, the interior elements of the chamber cannot be completely free of by-products. Therefore, when cleaning an element inside the chamber to which byproducts have adhered or replacing an element to which byproducts have adhered, a so-called atmospheric vent is performed to increase the internal pressure of the chamber. If a turbo-molecular pump with a high pumping speed is stopped during atmospheric venting, it will take a considerable amount of time for the pumping speed to stabilize when the turbo-molecular pump is restarted. Therefore, a valve is provided to airtightly close the space between the chamber and the turbomolecular pump. If such a valve is provided, the turbomolecular pump can remain in operation during atmospheric venting.

However, depending on the process conditions (eg, process pressure, type of process gas, etc.), the generated plasma may reach the vicinity of the valve. The valve is also provided with a sealing member (for example, an O-ring) for airtight closure. Therefore, if the generated plasma reaches the vicinity of the valve, the sealing member may be damaged by plasma products such as ions and electrons. If the sealing member is damaged, particles may be generated and the processed material may be contaminated by the particles.
Therefore, it has been desired to develop a plasma processing apparatus that can suppress damage to the seal member due to plasma products.

Japanese Patent Application Publication No. 2013-211269

The problem to be solved by the present invention is to provide a plasma processing apparatus that can prevent a seal member from being damaged by plasma products.

A plasma processing apparatus according to an embodiment includes a chamber capable of maintaining an atmosphere lower than atmospheric pressure, a plasma generation section capable of generating plasma inside the chamber, and a plasma generating section inside the chamber generating the plasma. a gas supply section capable of supplying a process gas to the region; a mounting module having a cantilever structure and capable of supporting a mounting section on which a processing object is mounted below the region where the plasma is generated; a pump capable of evacuating the inside of the chamber through a hole provided in the bottom plate of the chamber; a valve body that is plate-shaped and capable of opening and closing the hole provided in the bottom plate of the chamber; and a center of the chamber. a drive unit capable of changing the position of the valve body in the axial direction; a sealing member having an annular shape and provided on a surface of the valve body on the bottom plate side or on the bottom plate; the mounting module; A shielding portion is provided between the valve body and the valve body, has at least one hole passing through the valve body in the thickness direction, is conductive, and is grounded.

According to embodiments of the present invention, a plasma processing apparatus is provided that can suppress damage to a seal member caused by plasma products.

FIG. 1 is a schematic cross-sectional view for illustrating a plasma processing apparatus according to the present embodiment. It is a schematic perspective view for illustrating a mounting module. It is a schematic cross-sectional view of a mounting module. (a) and (b) are schematic plan views for illustrating a case where a plurality of holes are provided in the shielding part.

Hereinafter, embodiments will be illustrated with reference to the drawings. Note that in each drawing, similar components are denoted by the same reference numerals, and detailed explanations are omitted as appropriate.
Moreover, in this specification, "planar dimension" is a dimension in a direction perpendicular to the central axis of the chamber.

FIG. 1 is a schematic cross-sectional view illustrating a plasma processing apparatus 1 according to the present embodiment. FIG. 2 is a schematic perspective view for illustrating the mounting module 3. As shown in FIG.
FIG. 3 is a schematic cross-sectional view of the mounting module 3.

As shown in FIG. 1, the plasma processing apparatus 1 includes, for example, a chamber 2, a mounting module 3, a power supply section 4, a power supply section 5, a pressure reduction section 6, a gas supply section 7, a controller 8, and a shielding section 9. It is being

The chamber 2 has an airtight structure capable of maintaining an atmosphere 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 portion 21 has a substantially cylindrical shape, and a bottom plate 21a is integrally provided at one end. The other end of the main body portion 21 is open. The main body portion 21 is made of metal such as an aluminum alloy, for example. Further, the main body portion 21 is grounded. Inside the main body portion 21, a region 21b where plasma P is generated is provided. The main body portion 21 is provided with a loading/unloading port 21c for loading and unloading the processed material 100. The loading/unloading port 21c is hermetically closed by a gate valve 21c1.

The processing object 100 can be, for example, a photomask, a mask blank, a wafer, a glass substrate, or the like. However, the processed material 100 is not limited to the illustrated example.

The top plate 22 has a plate shape and is provided so as to close the opening of the main body part 21. The top plate 22 faces the bottom plate 21a. A hole 22a passing through the thickness direction is provided in the central region of the top plate 22. The central axis of the hole 22a overlaps with the central axis 2a of the chamber 2. The hole 22a is provided to transmit electromagnetic waves emitted from the electrode 51, which will be described later. The top plate 22 is made of metal such as aluminum alloy, for example.

The window 23 has a plate shape and is provided on the top plate 22. The window 23 is provided so as to close the hole 22a. The window 23 is made of a material that can transmit an electromagnetic field and is difficult to be etched during an etching process. Window 23 can be formed from a dielectric material such as quartz, for example.

A hole 2b is provided in the side surface of the chamber 2. The hole 2b has a size and shape that allows a mounting section 31 attached to an attachment section 32a, which will be described later, to pass therethrough (see FIG. 2). Therefore, the mounting module 3 provided with the mounting section 31 can be removed from the chamber 2 or the mounting module 3 provided with the mounting section 31 can be attached to the chamber 2 via the hole 2b. Further, when the mounting module 3 is attached to the chamber 2, the central axis of the mounting section 31 provided on the mounting module 3 is arranged to overlap with the central axis 2a of the chamber 2. Note that a slider may be provided on the outer wall of the chamber 2 in order to facilitate attachment and detachment of the mounting module 3.

As shown in FIGS. 1 to 3, the mounting module 3 includes a mounting section 31, a support section 32, and a cover 33.
The mounting module 3 has a cantilevered structure and supports a mounting section 31 on which the processing object 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 surface of the chamber 2 . A mounting section 31 is provided on the distal end side of the mounting module 3. If the mounting module 3 has a cantilever structure, a space is created below the mounting section 31 provided in the internal space of the chamber 2 . Therefore, the pressure reducing part 6 can be arranged directly below the placing part 31 and coaxially with the placing part 31. In this way, the effective pumping speed is high and it becomes easy to perform uniform and axially symmetrical pumping. Therefore, byproducts generated during plasma processing can be easily discharged to the outside of the chamber 2. As a result, it becomes possible to perform precise process control. Further, since it is possible to prevent by-products from adhering to the inner wall of the chamber 2, the mounting module 3, etc., it is possible to reduce the number of maintenance operations and the time required for maintenance operations. Therefore, the operating rate of the plasma processing apparatus 1 can be improved.

Moreover, if the mounting module 3 has a cantilever structure, the mounting module 3 can be attached to the chamber 2 or removed from the chamber 2 from the direction perpendicular to the central axis 2a of the chamber 2. can do. Therefore, maintenance of the plasma processing apparatus 1 becomes easier than when the mounting part is fixed to the bottom plate 21a of the chamber 2.

The processing object 100 is placed on the placing section 31 .
The mounting section 31 includes, for example, an electrode 31a, an insulating ring 31b, and a pedestal 31c. The electrode 31a is formed from a conductive material such as metal. The upper surface of the electrode 31a can be used as a mounting surface on which the processing object 100 is placed. The electrode 31a is screwed to the base 31c, for example.

Moreover, a pickup pin 31a1, a temperature control section, etc. can be built into the electrode 31a. A plurality of pickup pins 31a1 can 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 processing object 100. Therefore, the plurality of pickup pins 31a1 can be protruded from the upper surface of the electrode 31a and retracted into the inside of the electrode 31a by a drive unit (not shown).

The temperature control unit is, for example, a refrigerant circulation line (flow path), a heater, or the like. The temperature control unit controls the temperature of the electrode 31a and, in turn, the temperature of the processing object 100 placed on the electrode 31a, based on, for example, an output from a temperature sensor (not shown).

The insulating ring 31b has a ring shape and covers the side surface of the electrode 31a. The insulating ring 31b is made of a dielectric material such as quartz, for example.
The pedestal 31c is provided between the electrode 31a and the attachment part 32a of the support part 32. The pedestal 31c provides insulation between the electrode 31a and the support section 32. The pedestal 31c is made of a dielectric material such as quartz, for example. The pedestal 31c is screwed to the attachment portion 32a of the support portion 32, for example.

The support section 32 supports the mounting section 31 in the internal space of the chamber 2 . The support part 32 is arranged so as to extend between the side surface of the chamber 2 and the lower part of the mounting part 31.
The support portion 32 includes, for example, a mounting portion 32a, a beam 32b, and a flange 32c. The attachment portion 32a, the beam 32b, and the flange 32c are made of, for example, an aluminum alloy.

The attachment part 32a is located in the internal space of the chamber 2 and below the mounting part 31. The attachment portion 32a has a cylindrical shape. A hole 32a1 is provided in the surface of the mounting portion 32a on the mounting portion 31 side (see FIG. 3). A hole 32a2 is provided on the surface of the mounting portion 32a opposite to the mounting portion 31 side. The wiring member 42c, refrigerant piping, etc. are connected to the electrode 31a through the hole 32a1. The hole 32a2 is used when connecting the wiring member 42c, refrigerant piping, etc., and when performing maintenance of the electrode 31a. The mounting section 31 (pedestal 31c) is provided on the surface of the mounting section 32a on the mounting section 31 side. 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 made comparable to or slightly larger than the planar dimensions of the mounting portion 31.

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

Flange 32c is attached to the outer wall of chamber 2. The flange 32c is screwed to the outer wall of the chamber 2, for example. The flange 32c has a plate shape and has a hole 32c1 passing through the thickness direction.

The cover 33 is provided on the surface of the mounting portion 32a on the opposite side 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 attachment portion 32a, the hole 32a2 is hermetically closed. The cover 33 is made of, for example, an aluminum alloy.

As shown in FIG. 1, the power supply section 4 includes, for example, a power supply 41 and a matching section 42.
The power supply unit 4 is a high frequency power supply for so-called bias control. That is, the power supply section 4 controls the energy of ions drawn into the processing object 100 placed on the mounting section 31.

The power source 41 outputs high frequency power having a frequency suitable for drawing in ions (for example, a frequency of 27 MHz to 1 MHz).
The matching section 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 source 41 side and the impedance on the plasma P side. The matching circuit 42a is electrically connected to the power source 41 and the electrode 31a via a wiring member (bus bar) 42c.
The fan 42b sends air into the support section 32. The fan 42b is provided to cool the wiring member 42c and the matching circuit 42a provided inside the support portion 32.

In this case, the matching part 42 can be provided on the flange 32c of the support part 32. If the matching part 42 is provided on the flange 32c, the mounting module 3 and the matching part 42 can be moved together when the mounting module 3 is removed from the chamber 2 or when the mounting module 3 is attached to the chamber 2. can be done. Therefore, it is possible to improve maintainability.

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 plasma P. That is, the power supply section 5 generates a high frequency discharge inside the chamber 2 to generate plasma P.
In this embodiment, the power supply section 5 serves as a plasma generation section that generates plasma P inside the chamber 2 .

Electrode 51 is provided outside chamber 2 and above window 23 . The electrode 51 has, for example, a plurality of conductor parts and a plurality of capacitor parts (capacitors) that generate an electromagnetic field.
The power source 52 outputs high frequency power having a frequency of about 100 KHz to 100 MHz. For example, the power supply 52 outputs high frequency power having a frequency suitable for generating plasma P (for example, a frequency of 13.56 MHz). Further, the power source 52 may be capable of changing the frequency of the high frequency power it outputs.

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

Note that the plasma processing apparatus 1 illustrated in FIG. 1 is a two-frequency plasma processing apparatus that has an inductively coupled electrode on the upper part and a capacitively coupled electrode on the lower part. However, the plasma generation method is not limited to the exemplified method. The plasma processing apparatus 1 may be, for example, a plasma processing apparatus using inductively coupled plasma (ICP), a plasma processing apparatus using capacitively coupled plasma (CCP), or the like.

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

In this case, the central axis of the hole 21a1 overlaps with the central axis 2a of the chamber 2. Therefore, the center axis of the mounting section 31 provided in the mounting module 3 and the center axis of the hole 21a1 provided in the bottom plate 21a of the chamber 2 overlap with the center axis 2a of the chamber 2. If the central axis of the mounting part 31 and the central axis of the hole 21a1 overlap with the central axis 2a of the chamber 2 inside the chamber 2, the effective exhaust speed will be high and the exhaust will be uniform and axially symmetrical. It can be performed.

Here, when cleaning the element to which byproducts have adhered inside the chamber 2 or replacing the element to which byproducts have adhered, a so-called atmospheric vent is performed to increase the internal pressure of the chamber 2. . Normally, the pump 61 is stopped when venting the atmosphere. Here, in order to increase the effective pumping speed, a pump 61 with a fast pumping speed may be used. The pump 61 with a high pumping speed is, for example, a large TMP. In this case, it takes a considerable amount of time to stop the pump 61. Further, when the pump 61 is stopped, it is necessary to restart the pump 61 after cleaning or replacing elements. However, if a pump 61 with a high pumping speed is used to increase the effective pumping speed, it may take a considerable amount of time until the pumping speed of the restarted pump 61 becomes stable.

Therefore, the plasma processing apparatus 1 is provided with a valve 62 in order to keep the pump 61 in an operating state during atmospheric venting.
The valve 62 includes a valve body 62a, a driving portion 62b, and a seal member 62c. The valve 62 can be, for example, a so-called poppet valve.
The valve body 62a has a plate shape and is provided inside the chamber 2. The valve body 62a faces the hole 21a1. The planar dimension of the valve body 62a is larger than the planar dimension of the hole 21a1. Therefore, the valve body 62a can open and close the hole 21a1 provided in the bottom plate 21a of the chamber 2. Further, as shown in FIG. 1, the planar dimension of the valve body 62a can be the same as or larger than the planar dimension of the placing section 31. In this way, the planar dimension of the hole 21a1 can be increased, so that the effective pumping speed is high and it is easy to perform uniform and axially symmetrical pumping.

The drive unit 62b changes the position of the valve body 62a in the direction of the central axis 2a of the chamber 2. That is, the drive unit 62b raises the valve body 62a or lowers the valve body 62a. The drive unit 62b includes, for example, a shaft 62a1 connected to the valve body 62a, and a control motor (such as a servo motor) that moves the shaft 62a1.

The seal member 62c has an annular shape and is made of an elastic material such as rubber. The seal member 62c can be, for example, an O-ring. The sealing member 62c, which has an annular shape when viewed from the direction along the central axis 2a, surrounds the hole 21a1 and is located inside the valve body 62a. Although FIG. 1 illustrates a case where the seal member 62c is provided on the surface of the valve body 62a on the bottom plate 21a side, the seal member 62c may be provided on the bottom plate 21a.

When the valve body 62a is raised by the driving part 62b, the 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.

When the valve body 62a is lowered by the drive unit 62b, the sealing member 62c is sandwiched between the valve body 62a and the bottom plate 21a of the chamber 2. By sandwiching the seal member 62c 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 airtight. Therefore, communication between the internal space of the chamber 2 and the pump 61 is cut off. As a result, the pump 61 can remain in operation during atmospheric venting.

Further, when the position of the valve body 62a in the direction of the central axis 2a of the chamber 2 is changed, the distance between the valve body 62a and the bottom plate 21a of the chamber 2 is changed. The space between the valve body 62a and the bottom plate 21a of the chamber 2 becomes an exhaust flow path. Therefore, changing the dimensions of this part changes the conductance, making it possible to control the exhaust volume, exhaust speed, etc. For example, the controller 8 can control the position of the valve body 62a based on the output of a vacuum gauge (not shown) that detects the internal pressure of the chamber 2. That is, if the valve 62 is provided, the exhaust amount, exhaust speed, etc. can also be controlled.

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

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

The gas control unit 72 controls the flow rate, pressure, etc. when supplying the process gas G from the gas storage unit 71 into the chamber 2 . The gas control unit 72 can be, for example, an MFC (Mass Flow Controller). The gas control section 72 and the on-off valve 73 are connected via piping.

The on-off valve 73 is connected to the gas supply port 22b provided in the chamber 2 via piping. The on-off valve 73 controls supply and stop of the process gas G. The on-off valve 73 can be, for example, a 2-port solenoid valve. Note that the gas control section 72 can also have the function of the on-off valve 73.

The process gas G can be a gas that, when excited and activated by the plasma P, generates desired plasma products (radicals, ions, electrons, etc.). For example, when the plasma treatment is an etching treatment, the process gas G can be a gas in which a plasma product that can etch the exposed surface of the workpiece 100 is generated. In this case, the process gas G can be, for example, a gas containing chlorine, a gas containing fluorine, or the like. The process gas G can be, for example, a mixed gas of chlorine gas and oxygen gas, CHF ₃ , a mixed gas of CHF ₃ and CF ₄ , a mixed gas of SF ₆ and helium gas, or the like. However, the type of process gas G is not limited to the exemplified one, and can be changed as appropriate depending on the type of plasma processing, the material of the portion of the processing object 100 to be processed, and the like.

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 can 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 section.

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 reaches a predetermined value. Further, the controller 8 controls the gas supply section 7 to supply the process gas G to the region 21b where the plasma P is generated. Further, the controller 8 controls the power supply section 5 to introduce electromagnetic waves into the region 21b. Then, plasma P is generated in the region 21b, the process gas G is excited and activated by the plasma P, and reaction products such as ions, electrons, and radicals are generated.

The generated ions and electrons collide with the exposed surface of the workpiece 100, thereby physically processing the workpiece 100. At this time, the controller 8 can control the power supply unit 4 to control the energy of the ions drawn into the processing object 100. In addition, the generated radicals come into contact with the exposed surface of the processing object 100, so that the processing object 100 is chemically treated.
Note that since known techniques can be applied to the control program that controls the operation of each element and the process conditions, detailed explanation will be omitted.

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

However, when plasma P is generated in the vicinity of the valve body 62a, reaction products such as ions, electrons, and radicals are generated in the vicinity of the valve body 62a. As described above, the seal member 62c is provided on the surface of the valve body 62a on the bottom plate 21a side or on the bottom plate 21a. Therefore, when reaction products are generated near the valve body 62a, the generated reaction products easily reach the seal member 62c.

In this case, if the radicals generated near the valve body 62a come into contact with the seal member 62c, there is a risk that the seal member 62c will be damaged due to a chemical reaction.

Further, when ions are incident on the seal member 62c, the seal member 62c is damaged due to physical impact. If the sealing member 62c is damaged, particles may be generated and the object to be processed 100 may be contaminated by the particles.

Therefore, the plasma processing apparatus 1 is provided with a shielding section 9. As shown in FIG. 1, the shielding part 9 is provided inside the chamber 2 and between the mounting module 3 and the valve 62 (valve body 62a).

The shielding part 9 is formed from a conductive material such as aluminum alloy or stainless steel. The shielding part 9 is grounded. As described above, since the chamber 2 is grounded, by bringing the shielding part 9 into contact with the inner wall of the chamber 2, the shielding part 9 can be grounded. For example, the peripheral end of the shielding part 9 can be connected to the inner wall of the main body part 21 of the chamber 2 or to the bottom plate 21a of the chamber 2.
If the shielding part 9 is electrically conductive and is grounded, the shielding part 9 can remove ions and radicals that enter the seal member 62c.

Moreover, the shielding part 9 exhibits a plate shape, and can be provided in parallel with the bottom plate 21a of the chamber 2, for example. The plate-shaped shielding portion 9 can be provided with at least one hole 9a passing through the thickness direction.

As shown in FIG. 1, when one hole 9a is provided, the central axis of the hole 9a can be made to overlap the central axis 2a of the chamber 2. In this way, uniform and axially symmetrical exhaust can be performed.
Further, when one hole 9a is provided, it is preferable that the sealing member 62c is located 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.

Here, it is also possible to provide a shielding part 9 in the space between the mounting module 3 and the inner wall of the main body part 21 of the chamber 2. However, since this space is narrow, if the shielding section 9 is provided in this space, the conductance will become too small. Therefore, it becomes difficult to increase the effective pumping speed.
On the other hand, since the space between the mounting module 3 and the valve 62 is wide, even if the shielding part 9 is provided in this space, it is possible to suppress the conductance from becoming small. Therefore, it becomes easy to increase the effective pumping speed.

Moreover, the shielding part 9 may be provided with not only one hole 9a but also a plurality of holes.
When a plurality of holes are provided, it is preferable that the sealing member 62c be located outside the region where the plurality of holes are provided, as 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 plurality of holes.

FIGS. 4(a) and 4(b) are schematic plan views for illustrating a case in which the shielding portion 9 is provided with a plurality of holes 9a1 to 9a3.
Note that in order to avoid complexity, in FIG. 4, the area where the hole of the shielding part 9 is provided is illustrated.

As shown in FIGS. 4(a) and 4(b), there are no particular limitations on the number, shape, and size of the holes. For example, as shown in FIG. 4(a), the number, shape, and dimensions of the holes 9a1 may be different from the number, shape, and dimensions of the holes 9a2. As shown in FIG. 4(b), a plurality of the same holes 9a3 may be provided. In this case, it is preferable to make the total area of the plurality of holes and the area of one hole as large as possible. In this way, it is possible to prevent the conductance from becoming small, so it is possible to prevent the effective pumping speed from becoming slow.

In addition, when providing a plurality of holes 9a1 to 9a3, the holes may be provided at positions that are point symmetrical about the central axis 2a of the chamber 2, for example, as shown in FIGS. 4(a) and 4(b). is preferred. Further, it is preferable that the holes provided at point-symmetrical positions have the same shape and size. In this way, it becomes easy to perform uniform and axially symmetrical exhaust.

The embodiments have been illustrated above. However, the invention is not limited to these descriptions.
Appropriate design changes made by those skilled in the art with respect to the above-described embodiments are also included within the scope of the present invention as long as they have the characteristics of the present invention.
For example, the shape, material, arrangement, etc. of the components included in the plasma processing apparatus 1 are not limited to those illustrated, and can be changed as appropriate.
Furthermore, the elements provided in each of the embodiments described above can be combined to the extent possible, and combinations of these are also included within the scope of the present invention as long as they include the features of the present invention.

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

Claims (6)

A chamber capable of maintaining an atmosphere lower than atmospheric pressure,
a plasma generating section 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 cantilevered structure and capable of supporting a mounting section on which a processing object is placed below the 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 valve body having a plate shape and 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 sealing member having an annular shape and provided on a surface of the valve body on the bottom plate side or on the bottom plate;
a shielding portion provided between the mounting module and the valve body, having at least one hole penetrating through the thickness direction, having conductivity and being grounded;
Plasma processing equipment equipped with The shielding part has a plate shape and is provided in parallel with 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. The plasma processing apparatus according to claim 1, wherein the shielding part has one hole, and a central axis of the hole of the shielding part overlaps with a central axis of the chamber. 4. The plasma processing apparatus according to claim 3, wherein the sealing member is located outside the hole of the shielding part when viewed from a direction along the central axis of the chamber. The shielding part has a plurality of the holes, and the sealing member is located outside a region of the shielding part in which the plurality of holes are provided, when viewed from a direction along the central axis of the chamber. The plasma processing apparatus according to claim 1 or 2. 6. The plasma processing apparatus according to claim 5, wherein the plurality of holes of the shielding part are provided at positions that are point symmetrical about the central axis of the chamber.

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