Plasma processing apparatus and plasma processing method

Abstract

To provide a plasma processing device and a plasma processing method that can suppress the occurrence of distribution in the processing rate with a simple configuration.SOLUTION: A plasma processing device according to an embodiment plasma-processes a processed material, and includes a chamber that has multiple exhaust ports and can maintain an atmosphere that is depressurized from atmospheric pressure, a pump capable of exhausting the inside of the chamber through the exhaust port, a plurality of exhaust control units capable of controlling the conductance of exhaust gas by the pump, and a controller capable of controlling a conductance value for each of the plurality of exhaust control units. The plurality of exhaust control units are respectively connected to the plurality of exhaust ports. The controller replaces the conductance control value set in one of the exhaust control units with a conductance control value having a different value set in the other exhaust control units on the basis of predetermined order.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Dry processes using plasma are used in a wide range of technical fields, such as the manufacturing of semiconductor devices, surface hardening of metal parts, surface activation of plastic parts, chemical-free sterilization, etc. For example, in the manufacturing of semiconductor devices, flat panel displays, photomasks, etc., various plasma processes are performed, such as etching, ashing, removal of damage caused by etching using ions, and film formation.

[0003] A plasma processing apparatus for performing such plasma processing includes, for example, a chamber having an airtight structure, a mounting section provided inside the chamber on which the object to be processed is placed, an exhaust section that reduces the pressure inside the chamber to a predetermined level, a plasma generation section that generates plasma inside the chamber, and a gas supply section that supplies a process gas to the region inside the chamber where plasma is generated.

[0004] In this case, the mounting section is provided at the center of the bottom of the chamber. One exhaust section is connected to the periphery of the mounting section at the bottom of the chamber. Therefore, the exhaust port (the connection port of the exhaust section) is provided at a position offset from the center of the workpiece. If the exhaust port is provided at a position offset from the center of the workpiece, regions at different distances from the exhaust port will be created on the surface of the workpiece. In this case, the pressure in the region far from the exhaust port will be higher than the pressure in the region close to the exhaust port. If the pressure is lower, radicals generated by the plasma will be more easily attracted, which will tend to increase the processing rate (e.g., etching rate). Therefore, there is a risk of a distribution in the processing rate on the surface of the workpiece.

[0005] Therefore, a technique has been proposed in which multiple exhaust ports and multiple pressure sensors are provided, and the amount of exhaust from each of the multiple exhaust ports is adjusted based on the measurement results of the multiple pressure sensors (see, for example, Patent Document 1). However, this makes the configuration of the plasma processing apparatus complicated, and the control program for controlling the elements provided in the plasma processing apparatus also becomes complicated. Therefore, there has been a demand for the development of a technology that can suppress the occurrence of distribution in processing rates with a simple configuration. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-24483 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a plasma processing apparatus and a plasma processing method that can suppress the occurrence of distribution in processing rates with a simple configuration. [Means for solving the problem]

[0008] The plasma processing apparatus according to the embodiment generates plasma in a plasma generating region. The material to be treated is plasma treated with the composition. The plasma processing apparatus includes: a chamber having a plurality of exhaust ports and capable of maintaining an atmosphere reduced in pressure below atmospheric pressure; a gas supply unit that supplies a process gas to the region where the plasma is generated; a mounting portion provided inside the chamber and capable of mounting the object to be processed; a pump capable of evacuating the interior of the chamber through the exhaust port; a plurality of exhaust control units capable of controlling the conductance of exhaust by the pump; a controller capable of controlling the value of the conductance for each of the plurality of exhaust control units; Equipped with The hole through which the process gas supplied from the gas supply unit is supplied into the chamber is provided in the side wall of the chamber on one side with respect to the central axis of the chamber. , the plurality of exhaust control units are individually connected to the plurality of exhaust ports, the plurality of exhaust ports are provided so as to surround the placement portion, The controller is set to one of the exhaust control units based on a predetermined order. The control value of the conductance set in the other exhaust control unit is different from the control value of the other exhaust control unit. Replace with the conductance control value. [Effects of the Invention]

[0009] According to the embodiments of the present invention, a plasma processing apparatus and a plasma processing method are provided that are capable of suppressing the occurrence of distribution in processing rates with a simple configuration. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional view illustrating a plasma processing apparatus according to an embodiment of the present invention; [Figure 2] 2 is a cross-sectional view of the plasma processing apparatus taken along line AA in FIG. 1. [Figure 3] 10(a) to 10(d) are schematic diagrams illustrating the switching of the control values ​​of the conductance. [Figure 4] FIG. 10 is a schematic cross-sectional view illustrating a plasma processing apparatus according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments will be illustrated with reference to the drawings. In the drawings, like components are designated by like reference numerals and detailed descriptions thereof will be omitted where appropriate.

[0012] Fig. 1 is a schematic cross-sectional view illustrating a plasma processing apparatus 1 according to this embodiment. Fig. 2 is a cross-sectional view of the plasma processing apparatus 1 taken along line AA in Fig. 1. As shown in FIG. 1, the plasma processing apparatus 1 may include, for example, a chamber 2, a mounting unit 3, a gas supply unit 4, a power supply unit 5, a power supply unit 6, an exhaust unit 7, and a controller 8.

[0013] The chamber 2 has an airtight structure capable of maintaining an atmosphere at a reduced pressure below atmospheric pressure. The chamber 2 is cylindrical. The outline of the chamber 2 in plan view can be a shape that is point-symmetric with respect to the central axis 2a of the chamber 2. The outline of the chamber 2 in plan view can be, for example, a regular hexagon, a regular octagon, or a circle. For example, the shape of the chamber 2 can be a cylinder or a regular polygonal cylinder. In this case, the outline of the chamber 2 in plan view is preferably a circle. That is, the chamber 2 is preferably cylindrical. A cylindrical chamber 2 can make the distance between the center of the workpiece 100 placed on the placement unit 3 and the inner wall of the chamber 2 approximately the same in all directions around the central axis 2a. This makes it easy to make the distribution of the exhaust volume and the distribution of the amount of plasma products inside the chamber 2 approximately symmetric with respect to the central axis 2a. The chamber 2 can be made of a metal such as an aluminum alloy or stainless steel, and can be grounded, for example.

[0014] The bottom 21 of the chamber 2 is, for example, plate-shaped. The bottom 21 is provided with a plurality of exhaust ports 21a. The exhaust ports 21a are provided, for example, so as to surround the mounting portion 3. The exhaust ports 21a penetrate the bottom 21 in the thickness direction, for example. As shown in FIG. 2, the exhaust ports 21a can be provided at positions that are rotationally symmetric with respect to the central axis 2a of the chamber 2 as the axis of symmetry (axis of rotation) in a plan view. The exhaust ports 21a illustrated in FIG. 2 are eight-fold symmetric. The number of exhaust ports 21a is not limited to the illustrated number. However, considering the symmetry of exhaust with respect to the workpiece 100 placed on the mounting portion 3 and the miniaturization and cost reduction of the plasma processing apparatus 1, the number of exhaust ports 21a is preferably two or more and eight or less. Furthermore, the opening dimensions of the exhaust ports 21a can be, for example, approximately the same.

[0015] A window 22 is provided at the upper end of the chamber 2. The window 22 is plate-shaped and is attached to the upper end of the chamber 2 in an airtight manner. The window 22 can be made of a material that allows an electromagnetic field to pass through and is resistant to etching during an etching process. The window 22 can be made of a dielectric material such as quartz.

[0016] A loading / unloading port 23 for loading / unloading the workpiece 100 can be provided on the side wall of the chamber 2. The loading / unloading port 23 can be opened and closed by a gate valve 24. The gate valve 24 can be provided with a sealing member such as an O-ring. When the gate valve 24 having the sealing member is pressed against the vicinity of the loading / unloading port 23 by an opening / closing mechanism (not shown), the loading / unloading port 23 is airtightly closed.

[0017] The object to be processed 100 is placed on the placement unit 3. The placement unit 3 is provided, for example, inside the chamber 2 and on the bottom 21 of the chamber 2. The central axis of the placement unit 3 can overlap, for example, with the central axis 2a of the chamber 2.

[0018] The mounting portion 3 includes, for example, an electrode 31 , a base 32 , and an insulating ring 33 . The electrode 31 can be provided, for example, inside the base 32. The electrode 31 faces the window 22. The object to be treated 100 is placed above the electrode 31. The electrode 31 is made of, for example, a conductive material such as a metal.

[0019] The pedestal 32 can be provided on the bottom 21 of the chamber 2. The pedestal 32, for example, provides insulation between the electrode 31 and the chamber 2. The pedestal 32 is formed from a dielectric material such as quartz. The insulating ring 33 is ring-shaped and covers the side surface of the base 32. The insulating ring 33 is made of a dielectric material such as quartz.

[0020] The gas supply unit 4 supplies the process gas G to a region inside the chamber 2 where plasma is generated. A pressure control unit 41 may be provided between the gas supply unit 4 and the chamber 2. The pressure control unit 41 controls, for example, at least one of the flow rate and pressure of the process gas G to be supplied. The pressure control unit 41 may be, for example, an MFC (Mass Flow Controller).

[0021] The process gas G can be selected appropriately depending on the type of process, the material of the surface of the workpiece 100, and the like. For example, in the case of an etching process, the process gas G can be a gas containing fluorine atoms, such as CF4 or CF3, so as to generate highly reactive radicals. For example, the process gas G can be a gas containing fluorine atoms, such as CF4, alone. The process gas G can also be a mixed gas of a gas containing fluorine atoms, such as CF4, and a gas such as oxygen gas or nitrogen gas. The process gas G can also be a mixed gas of a gas containing fluorine atoms, such as CF4, and a rare gas, such as argon gas or helium gas. However, the process gas G is not limited to the examples given above.

[0022] The power supply unit 5 generates a plasma P by generating a high frequency discharge inside the chamber 2 . The power supply unit 5 includes, for example, an antenna 51, a power supply 52, and a matching box 53. The antenna 51 is provided outside the chamber 2 and above the window 22. The antenna 51 has, for example, a plurality of conductor parts that generate an electromagnetic field and a plurality of capacitance parts (capacitors).

[0023] The power supply 52 applies high frequency power having a frequency of about 100 KHz to 100 MHz to the antenna 51. In this case, the power supply 52 applies high frequency power having a relatively high frequency (for example, a frequency of 13.56 MHz) suitable for generating plasma P to the antenna 51.

[0024] The matching box 53 is provided between the antenna 51 and the power supply 52. ​​The matching box 53 may include a matching circuit for matching the impedance on the power supply 52 side with the impedance on the plasma P side.

[0025] The power supply unit 6 can be a so-called high frequency power supply for bias control. The power supply unit 6 is provided to control the energy of ions attracted to the object 100 placed on the placement unit 3.

[0026] The power supply unit 6 includes, for example, a power supply 61 and a matching box 62 . The power supply 61 applies to the electrode 31 a radio frequency power having a relatively low frequency (for example, a frequency of 13.56 MHz or less) suitable for attracting ions. The matching box 62 is provided between the electrode 31 and the power supply 61. The matching box 62 may include a matching circuit for matching the impedance on the power supply 61 side with the impedance on the plasma P side.

[0027] The exhaust unit 7 exhausts air to a predetermined pressure inside the chamber 2. As will be described later, the exhaust unit 7 also suppresses the occurrence of pressure distribution, and therefore distribution in the processing rate, on the surface of the processing object.

[0028] The exhaust unit 7 includes, for example, a pump 71 and a plurality of exhaust control units 72 . The pump 71 is, for example, a turbo molecular pump (TMP), etc. One pump 71 may be provided for the plurality of exhaust control units 72, or one pump 71 may be provided for each of the plurality of exhaust control units 72. That is, the pump 71 only needs to be able to evacuate the interior of the chamber 2 via the exhaust port 21a.

[0029] However, in consideration of simplifying the configuration, reducing the size, and reducing the cost of the plasma processing apparatus 1, it is preferable to provide one pump 71 for multiple exhaust control units 72, as illustrated in Fig. 1. In this case, the multiple exhaust control units 72 and the single pump 71 can be connected via, for example, a piping member 73.

[0030] The exhaust control units 72 are, for example, valves that can control the conductance of exhaust by the pump 71. The exhaust control units 72 are, for example, butterfly valves. Each of the exhaust control units 72 can be provided with a control motor 72b such as a servo motor. In this way, the control motor 72b can be controlled by an electric signal to change the angle of the valve element 72a of the butterfly valve, and therefore the exhaust conductance.

[0031] Each of the exhaust control units 72 is connected to an exhaust port 21 a provided in the chamber 2 .

[0032] The controller 8 includes, for example, a calculation unit such as a CPU (Central Processing Unit) and a storage unit such as a memory. The calculation unit controls the operation of each element provided in the plasma processing apparatus 1 based on a control program stored in the storage unit. For example, the controller 8 can be a computer.

[0033] For example, the controller 8 controls the operation of each element provided in the plasma processing apparatus 1 to perform plasma processing such as etching on the processing object 100. For example, the controller 8 controls the pump 71 and a plurality of exhaust control units 72 to exhaust the inside of the chamber 2 to a predetermined pressure. In this case, the controller 8 can control the value of exhaust conductance for each of the plurality of exhaust control units 72.

[0034] For example, as described above, in a plan view, the multiple exhaust ports 21a are provided at positions that are rotationally symmetrical with respect to the central axis 2a of the chamber 2 as the axis of symmetry (axis of rotation). Therefore, it is considered that the distribution of exhaust volume inside the chamber 2 is approximately symmetrical with respect to the central axis 2a of the chamber 2. However, when the type of plasma processing or processing conditions change, the distribution of exhaust volume inside the chamber 2 may change.

[0035] In this case, multiple pressure sensors can be provided inside chamber 2, and the exhaust conductance can be controlled for each of multiple exhaust control units 72 based on signals from the multiple pressure sensors. In this way, even if the type of plasma processing or processing conditions change, it is possible to prevent distribution in the exhaust amount inside chamber 2. If distribution in the exhaust amount can be prevented, it is possible to prevent distribution in the amount of plasma products on the processing surface of workpiece 100, and ultimately distribution in the processing rate. However, this requires a pressure sensor for each of the exhaust ports 21a, and the control program becomes complicated.

[0036] Therefore, in the plasma processing apparatus 1 according to this embodiment, the controller 8 replaces the conductance control value set in one exhaust control unit 72 with a different conductance control value set in another exhaust control unit 72 based on a predetermined order. For example, among the exhaust control units 72 arranged in a circumferential direction in a plan view, adjacent exhaust control units 72 have different conductance control values ​​(angle or opening of the valve body 72a). The controller 8 swaps the conductance control values ​​set for each of the exhaust control units 72, for example, clockwise or counterclockwise.

[0037] 3(a) to 3(d) are schematic diagrams illustrating the replacement of the control values ​​of the conductance. 3(a) to 3(d) show cases where the conductance control value is sequentially shifted clockwise. For example, the controller 8 sets the conductance control value at a certain point in time to the example shown in FIG. 3(a). For example, conductance C1 is when the opening of valve element 72a is 60%. For example, conductance C2 is when the opening of valve element 72a is 80%. For example, conductance C3 is when the opening of valve element 72a is 100%. For example, conductance C4 is when the opening of valve element 72a is 40%. For example, conductance C5 is when the opening of valve element 72a is 20%. As the opening of valve element 72a increases, the flow path resistance decreases, and therefore the conductance increases, and the exhaust volume increases.

[0038] Next, after a predetermined time has elapsed, the controller 8 sequentially changes the conductance control value, for example, clockwise, as shown in FIG. 3(b). Next, after a predetermined time has elapsed, the controller 8 sequentially changes the conductance control value, for example, clockwise, as shown in FIG. 3(c). Next, after a predetermined time has elapsed, the controller 8 sequentially changes the conductance control value, for example, clockwise, as shown in FIG. 3(d). In this way, the region with a high exhaust rate and the region with a low exhaust rate move clockwise inside chamber 2. Therefore, by continuously switching the control value of conductance in this way, the pressure in the region with a high exhaust rate and the pressure in the region with a low exhaust rate are averaged, thereby making it possible to suppress the occurrence of a distribution in the exhaust rate inside chamber 2. If the occurrence of a distribution in the exhaust rate can be suppressed, it is possible to suppress the occurrence of a distribution in the amount of plasma products on the processing surface of workpiece 100, and ultimately a distribution in the processing rate. Furthermore, there is no need to provide a pressure sensor for each of the plurality of exhaust ports 21a, and the control program can be simplified.

[0039] Although the example shows a case where the conductance control values ​​are switched clockwise, the conductance control values ​​may be switched counterclockwise. Also, although the example shows a case where the conductance control values ​​are switched sequentially, the switch may be performed at predetermined intervals, such as every other value. That is, the conductance control values ​​can be switched in a predetermined order.

[0040] FIG. 4 is a schematic cross-sectional view illustrating a plasma processing apparatus 101 according to another embodiment. The plasma processing apparatus 101 is a microwave-excited plasma processing apparatus generally called a "Chemical Dry Etching (CDE) apparatus" or a "remote plasma apparatus." The plasma processing apparatus 101 generates plasma products from a process gas G using plasma P, and processes an object to be processed 100 mainly using radicals contained in the plasma products.

[0041] As shown in FIG. 4, the plasma processing apparatus 101 may include, for example, a chamber 102, a mounting unit 103, a gas supply unit 104, a plasma generation unit 105, a microwave generation unit 106, an exhaust unit 7, and a controller 108.

[0042] The chamber 102 has an airtight structure capable of maintaining an atmosphere at a reduced pressure below atmospheric pressure. The chamber 102 is cylindrical. As with the chamber 2 described above, the outline of the chamber 102 in plan view can be a shape that is point-symmetric with respect to the central axis 102a of the chamber 102. The outline of the chamber 102 in plan view can be, for example, a regular hexagon, a regular octagon, or a circle. In this case, as with the chamber 2 described above, the outline of the chamber 102 in plan view is preferably a circle. That is, the chamber 102 is preferably cylindrical. The chamber 102 can be made of a metal such as an aluminum alloy or stainless steel.

[0043] A current rectifying plate 102b can be provided inside the chamber 102. The current rectifying plate 102b can be provided on the inner wall of the chamber 102 so as to be approximately parallel to the mounting surface of the mounting portion 103. A radical-containing gas is introduced into the space between the current rectifying plate 102b and the ceiling of the chamber 102 via a transport pipe 105c. The provision of the current rectifying plate 102b makes it easy to make the amount of radicals on the treatment surface of the workpiece 100 approximately uniform.

[0044] A plurality of exhaust ports 102c1 are provided in the bottom 102c of the chamber 102. The plurality of exhaust ports 102c1 can be provided so as to surround the mounting portion 103. The plurality of exhaust ports 102c1 penetrate the bottom 102c in the thickness direction. Similar to the plurality of exhaust ports 21a described above, the plurality of exhaust ports 102c1 can be provided at positions that are rotationally symmetric with respect to the central axis 102a of the chamber 102 as the axis of symmetry (axis of rotation) in a plan view. Similar to the plurality of exhaust ports 21a described above, the number of exhaust ports 102c1 is preferably two or more and eight or less. Furthermore, the opening dimensions of the plurality of exhaust ports 102c1 can be, for example, approximately the same.

[0045] A loading / unloading port 102d for loading / unloading the workpiece 100 can be provided on a side wall of the chamber 102. The loading / unloading port 102d can be opened and closed by a gate valve 102e. The gate valve 102e can be provided with a sealing member such as an O-ring. When the gate valve 102e having the sealing member is pressed against the vicinity of the loading / unloading port 102d by an opening / closing mechanism (not shown), the loading / unloading port 102d is airtightly closed.

[0046] The mounting section 103 is provided inside the chamber 102. The processing object 100 is placed on the upper surface of the mounting section 103. In this case, the processing object 100 may be placed directly on the upper surface of the mounting section 103, or may be placed on the mounting section 103 via a support member (not shown). The mounting section 103 may be provided with a holding device such as an electrostatic chuck.

[0047] The gas supply unit 104 is connected to the end of the discharge tube 105a opposite to the chamber 102 side. The gas supply unit 104 supplies the process gas G into the discharge tube 105a. A pressure control unit 41 can be provided between the gas supply unit 104 and the discharge tube 105a. The pressure control unit 41 controls the pressure of the process gas G supplied into the discharge tube 105a.

[0048] The plasma generating section 105 includes, for example, a discharge tube 105a, an introduction waveguide 105b, and a transport tube 105c. Discharge tube 105a has an area therein for generating plasma P, and is provided at a position separated from chamber 102. Discharge tube 105a has a tubular shape and can be made of a material that has high transmittance to microwaves M and is resistant to etching. For example, discharge tube 105a can be made of a dielectric material such as alumina or quartz.

[0049] Lead-in waveguide 105b is connected to the outside of discharge tube 105a so as to be approximately perpendicular to discharge tube 105a. A matching termination box 105b1 is provided at the end of lead-in waveguide 105b. A stub tuner 105b2 is provided at the inlet side of lead-in waveguide 105b (the side where microwaves M are introduced).

[0050] An annular slot 105b3 is provided at the connection between lead-in waveguide 105b and discharge tube 105a. Microwaves M propagated through lead-in waveguide 105b are radiated into discharge tube 105a via slot 105b3.

[0051] One end of the transport pipe 105c is connected to the end of the discharge tube 105a opposite to the gas supply unit 104 side. The other end of the transport pipe 105c can be connected to the side wall of the chamber 102, etc. The transport pipe 105c is made of a material that is resistant to radicals contained in the plasma products. The transport pipe 105c is made of, for example, quartz, stainless steel, ceramics, fluororesin, etc.

[0052] Microwave generating unit 106 is provided at the end of lead-in waveguide 105b opposite to the discharge tube 105a side. Microwave generating unit 106 generates microwaves M of a predetermined frequency (e.g., 2.75 GHz) and radiates them toward lead-in waveguide 105b.

[0053] The controller 108 includes, for example, a calculation unit such as a CPU (Central Processing Unit) and a storage unit such as a memory. The calculation unit controls the operation of each element provided in the plasma processing apparatus 101 based on a control program stored in the storage unit. For example, the controller 108 can be a computer.

[0054] For example, the controller 108 controls the operation of each element provided in the plasma processing apparatus 101 to perform plasma processing such as etching on the object 100 to be processed.

[0055] For example, the controller 108 controls the pump 71 and the plurality of exhaust control units 72 to exhaust the inside of the chamber 102 to a predetermined pressure. At this time, the inside of the discharge tube 105a communicating with the chamber 102 is also exhausted.

[0056] Next, controller 108 controls gas supply unit 104 and pressure control unit 41 to supply process gas G at a predetermined pressure into discharge tube 105a. Controller 108 also controls microwave generation unit 106 to radiate microwaves M of a predetermined power into introduction waveguide 105b. The radiated microwaves M propagate through introduction waveguide 105b and are radiated into discharge tube 105a via slot 105b3.

[0057] The energy of the microwaves M radiated inside the discharge tube 105a generates a plasma P. The generated plasma P excites and activates the process gas G, generating plasma products including radicals, ions, and the like.

[0058] A gas containing plasma products is supplied into the chamber 102 via the transport pipe 105c. At this time, ions with short lifespans cannot reach the interior of the chamber 102, while radicals with long lifespans reach the interior of the chamber 102. The radical-containing gas supplied into the chamber 102 is rectified by the rectifying plate 102b and reaches the processing surface of the workpiece 100, where plasma processing such as etching is performed. In this case, chemical processing using radicals is mainly performed. Furthermore, since ions used for physical processing are not supplied into the chamber 102, the processing surface of the workpiece 100 is not damaged by the ions. Therefore, the plasma processing apparatus 101 is suitable for removing damage caused by, for example, an etching process using ions.

[0059] Furthermore, in the plasma processing apparatus 101 according to this embodiment, the controller 108, similar to the controller 8 described above, replaces the conductance control value set in one exhaust control unit 72 with a different conductance control value set in another exhaust control unit 72 based on a predetermined order. For example, the controller 108 replaces the conductance control values ​​set for each of the plurality of exhaust control units 72 in a clockwise or counterclockwise direction. Therefore, similar to the above, the pressure in the high-exhaust area and the pressure in the low-exhaust area are equalized, thereby preventing a distribution in the exhaust amount within the chamber 102. If the distribution in the exhaust amount can be prevented, the distribution in the amount of plasma products on the processing surface of the workpiece 100, and therefore the distribution in the processing rate, can be prevented. Furthermore, there is no need to provide a pressure sensor for each of the exhaust ports 102c1, and the control program can be simplified.

[0060] In the above, an inductively coupled plasma (ICP) processing apparatus and a CDE (remote plasma) apparatus have been described as examples of plasma processing apparatuses, but the present invention can be applied to various plasma processing apparatuses equipped with a pump 71 and multiple exhaust control units 72. For example, the plasma processing apparatus may be a capacitively coupled plasma (CCP) processing apparatus (e.g., a parallel plate RIE (Reactive Ion Etching) apparatus) or another microwave-excited plasma processing apparatus (e.g., an SWP (Surface Wave Plasma) apparatus). The plasma processing apparatus according to this embodiment may be a film forming apparatus such as a sputtering apparatus or a plasma CVD apparatus. That is, the plasma processing apparatus according to this embodiment may be any apparatus that performs plasma processing on the object 100 to be processed. It should be noted that since known techniques can be applied to the basic configuration of other plasma processing apparatuses, detailed explanations will be omitted.

[0061] The plasma processing method according to the present embodiment may further include a step of evacuating the region where the plasma P is generated through a plurality of exhaust ports. Then, based on a predetermined order, the control value of exhaust conductance set for one exhaust port is replaced with a control value of exhaust conductance having a different value set for another exhaust port. In this case, the plurality of exhaust ports can be provided so as to surround the placement portion on which the object to be treated 100 is placed. Furthermore, the conductance control values ​​set for each of the plurality of exhaust ports can be switched clockwise or counterclockwise. The details of the exhaust process can be the same as those described above, and therefore will not be described in detail.

[0062] Although the embodiments have been described above as examples, the present invention is not limited to these descriptions. With respect to the above-described embodiments, those skilled in the art may add or delete components or modify the design as appropriate, and such addition or deletion or modification is also encompassed within the scope of the present invention as long as it comprises the features of the present invention. For example, the shape, size, material, arrangement, number, etc. of each element included in the plasma processing apparatus 1, 101 are not limited to those exemplified, and can be changed as appropriate. [Explanation of symbols]

[0063] 1 plasma processing apparatus, 2 chamber, 2a central axis, 3 mounting portion, 4 gas supply portion, 5 power supply portion, 7 exhaust portion, 8 controller, 21a exhaust port, 71 pump, 72 exhaust control portion, 100 processing object, 102 chamber, 102c1 exhaust port, 103 mounting portion, 104 gas supply portion, 105 plasma generation portion, 106 microwave generation portion, 108 controller

Claims

1. A plasma processing apparatus for performing plasma processing on an object to be processed by plasma products generated in a plasma generating region, comprising: a chamber having a plurality of exhaust ports and capable of maintaining an atmosphere reduced in pressure below atmospheric pressure; a gas supply unit that supplies a process gas to the region where the plasma is generated; a mounting portion provided inside the chamber and capable of mounting the object to be processed; a pump capable of evacuating the interior of the chamber through the exhaust port; a plurality of exhaust control units capable of controlling the conductance of exhaust by the pump; a controller capable of controlling the value of the conductance for each of the plurality of exhaust control units; Equipped with a hole through which the process gas supplied from the gas supply unit is supplied into the chamber is provided in a side wall of the chamber on one side with respect to a central axis of the chamber; the plurality of exhaust control units are individually connected to the plurality of exhaust ports, the plurality of exhaust ports are provided so as to surround the placement portion, The controller replaces the conductance control value set in one of the exhaust control units with a different conductance control value set in another of the exhaust control units based on a predetermined order.

2. 2. The plasma processing apparatus according to claim 1, wherein the chamber has a cylindrical shape or a regular polygonal cylindrical shape.

3. the plurality of exhaust ports are provided at the bottom of the chamber; 3. The plasma processing apparatus according to claim 1, wherein the plurality of exhaust ports are provided at positions that are rotationally symmetric with respect to a central axis of the chamber.

4. 4. The plasma processing apparatus according to claim 1, wherein the controller switches the control values ​​of the conductance set for each of the plurality of exhaust control units clockwise or counterclockwise.

5. 1. A plasma processing method for plasma processing an object to be processed by plasma products generated in a plasma generation region, comprising: a step of placing the object to be processed on a placement portion provided inside the chamber; supplying a process gas to a region where the plasma is generated through a hole provided in a sidewall of the chamber on one side of the central axis of the chamber; a step of evacuating an area where the plasma is generated through a plurality of exhaust ports provided so as to surround the mounting portion, A plasma processing method in which, based on a predetermined order, the control value of the exhaust conductance set for one of the exhaust ports is replaced with a control value of the exhaust conductance having a different value set for another of the exhaust ports.

6. 6. The plasma processing method according to claim 5, wherein the conductance control values ​​set for each of the plurality of exhaust ports are switched clockwise or counterclockwise.

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