Plasma treatment equipment

Abstract

The present invention provides a plasma processing device. It is capable of suppressing the plasma from becoming unstable. A stage for placing a substrate is provided inside a processing chamber, and plasma processing is performed on the substrate in the processing chamber. A high-frequency power supply supplies high-frequency power for bias to the stage. A plurality of partitions surround the outer periphery of the upper surface of the stage and are arranged separately from each other. The recess is located between at least one set of adjacent partitions, and has an inner wall portion including a bottom wall and a plurality of side walls, constituting a counter electrode opposite to the stage.

Description

Technical Field

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

[0002] Patent Document 1 discloses a plasma processing apparatus that includes a partition member provided around a mounting table on which a substrate is mounted so as to partition a processing space for performing plasma processing from an exhaust space connected to an exhaust system.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2015-216260 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] The present disclosure provides a technology for suppressing plasma from becoming unstable.

[0008] Solutions for solving problems

[0009] A plasma processing device of a technical solution of the present disclosure comprises: a processing chamber, a high-frequency power supply, a plurality of partitions and a recess. A stage for placing a substrate is provided inside the processing chamber, and plasma processing is performed on the substrate in the processing chamber. The high-frequency power supply supplies high-frequency power for biasing to the stage. A plurality of partitions surround the outer periphery of the upper surface of the stage and are arranged separately from each other. The recess is located between at least one set of adjacent partitions, has an inner wall portion including a bottom wall and a plurality of side walls, and constitutes a counter electrode opposite to the stage.

[0010] Effects of the Invention

[0011] According to the present disclosure, it is possible to suppress plasma from becoming unstable. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a vertical cross-sectional view showing an example of a schematic structure of a plasma processing apparatus according to an embodiment.

[0013] Figure 2A It is a perspective view showing an example of the structure inside the processing chamber according to the embodiment.

[0014] Figure 2B It is a horizontal cross-sectional view showing an example of the structure inside the processing chamber according to the embodiment.

[0015] Figure 3 It is a diagram showing the flow of exhaust gas in the processing chamber according to the embodiment.

[0016] Figure 4 This is a diagram showing an example of the arrangement of fins according to another embodiment. DETAILED DESCRIPTION

[0017] Hereinafter, an embodiment of the plasma processing apparatus disclosed in the present application will be described in detail with reference to the accompanying drawings. However, the disclosed plasma processing apparatus is not limited to the embodiment.

[0018] In the manufacturing process of a flat panel display (FPD), there is a process of performing plasma processing such as plasma etching and film forming processing on a substrate such as a glass substrate. For the plasma processing, various plasma processing apparatuses such as a plasma etching apparatus and a plasma CVD film forming apparatus are used.

[0019] In the case of a plasma processing device, when a substrate is processed using plasma, a high-frequency power for bias is supplied to a lower electrode as a mounting table to attract ions. On the other hand, in the case of a plasma processing device, a high-pressure, high-energy plasma is sought to improve the processing capability of the plasma, but there is a tendency for the plasma to become unstable. Here, it is desired to suppress the instability of the plasma.

[0020] [Structure of plasma processing apparatus]

[0021] First, the structure of the plasma processing apparatus 10 according to the embodiment will be described. Figure 1 The plasma processing apparatus 10 of the present embodiment is an inductively coupled plasma processing apparatus that generates inductively coupled plasma and performs inductively coupled plasma processing such as etching and ashing on a rectangular substrate such as a glass substrate for FPD.

[0022] The plasma processing device 10 has a square cylindrical airtight main container 1 made of a conductive material, such as aluminum with an anodized inner wall. The main container 1 is assembled in a disassembled manner and grounded by a grounding wire 1a. The main container 1 is divided into an antenna chamber 3 and a processing chamber 4 at the top and bottom by a dielectric wall 2. The dielectric wall 2 constitutes the top wall of the processing chamber 4. The dielectric wall 2 is made of ceramics such as Al2O3, quartz, etc.

[0023] A support frame 5 protruding inward is provided between the side wall 3a of the antenna chamber 3 and the side wall 4a of the processing chamber 4 in the main body container 1. On the support frame 5, the dielectric wall 2 is placed.

[0024] An injection housing 11 for supplying a processing gas is embedded in the lower part of the dielectric wall 2. The injection housing 11 is cross-shaped and is a structure for supporting the dielectric wall 2 from below, such as a beam structure. The injection housing 11 supporting the dielectric wall 2 is suspended from the top wall of the main container 1 by a plurality of suspension rods (not shown). The support frame 5 and the injection housing 11 may also be covered by a dielectric member.

[0025] The injection shell 11 is made of a conductive material, preferably a metal, such as aluminum whose inner or outer surface is anodized to avoid generating contaminants. A gas flow path 12 extending horizontally is formed in the injection shell 11. The gas flow path 12 is connected to a plurality of gas ejection holes 12a extending downward. On the other hand, a gas supply pipe 20a is provided in the center of the upper surface of the dielectric wall 2 in a manner connected to the gas flow path 12. The gas supply pipe 20a passes through the top wall of the main container 1 to the outside and is connected to a processing gas supply system 20 including a processing gas supply source and a valve system. During plasma processing, the processing gas supplied from the processing gas supply system 20 is supplied to the gas flow path 12 of the injection shell 11 via the gas supply pipe 20a, and is ejected into the processing chamber 4 from the gas ejection holes 12a formed on the lower surface of the injection shell 11.

[0026] A high frequency (RF) antenna 13 is disposed in the antenna chamber 3. The high frequency antenna 13 is formed by arranging an antenna 13a made of a metal with good conductivity such as copper or aluminum in any conventional shape such as a loop or spiral. The high frequency antenna 13 may be a multi-antenna having a plurality of antenna units.

[0027] A power supply member 16 extending upward from the antenna chamber 3 is connected to the terminal 22 of the antenna 13a. A high-frequency power source 15 is connected to the upper end of the power supply member 16 via a power supply line 19. In addition, a matching device 14 is provided on the power supply line 19. In addition, the high-frequency antenna 13 is separated from the dielectric wall 2 by a spacer 17 composed of an insulating member. During plasma processing, a high-frequency power having a frequency of, for example, 13.56 MHz is supplied from the high-frequency power source 15 to the high-frequency antenna 13. As a result, an induced electric field is formed in the processing chamber 4, and the processing gas supplied from the injection housing 11 is plasmatized under the action of the induced electric field, thereby generating an inductively coupled plasma.

[0028] A mounting table 23 having a mounting surface 23d for mounting a rectangular substrate G is provided on the bottom wall 4b in the processing chamber 4 in a manner opposite to the high-frequency antenna 13 via the dielectric wall 2. The mounting table 23 is fixed via an insulator member 24. The insulator member 24 is formed in a frame shape. The mounting table 23 has a main body 23a, which is made of a conductive material, such as aluminum with an anodized surface. The main body 23a is formed in a rectangular shape that is the same as the substrate G or slightly larger than the substrate G. An insulator frame 23b is provided on the mounting table 23 in a manner that surrounds the entire side surface and the outer periphery of the lower surface of the main body 23a, and a side electrode 23c made of a conductive material is also provided in a manner that surrounds the entire side surface of the insulator frame 23b. The side electrode 23c is insulated from the main body 23a by the insulator frame 23b. The side electrode 23c is connected to the ground potential by a grounding member not shown. However, the side electrode 23c may be electrically connected to a spacer 50 described later, and the side electrode 23c may be grounded via the spacer 50. The substrate G placed on the mounting table 23 is held by an electrostatic chuck (not shown).

[0029] Lifting pins (not shown) for carrying in and out the substrate G penetrate the mounting table 23 via the bottom wall 4b of the main body container 1 and the insulator member 24. The lifting pins are formed to be driven up and down by a lifting mechanism (not shown) provided outside the main body container 1 to carry out the substrate G. However, the mounting table 23 may be a structure that can be lifted and lowered by the lifting mechanism.

[0030] The main body 23a of the mounting table 23 is connected to a high-frequency power supply 27 for bias by a power supply line 25 via a matching device 26. The high-frequency power supply 27 supplies high-frequency power for bias to the main body 23a during the plasma processing to form a high-frequency bias. The main body 23a of the mounting table 23 functions as a lower electrode. The frequency of the high-frequency power for bias is, for example, 6 MHz. The ions in the plasma generated in the processing chamber 4 are effectively attracted to the substrate G under the action of the high-frequency bias.

[0031] In addition, a temperature control mechanism including a heating unit such as a ceramic heater, a refrigerant flow path, and a temperature sensor (none of which are shown) for controlling the temperature of the substrate G is provided in the mounting table 23 .

[0032] In addition, in the case of the mounting table 23, there are tiny bumps on the mounting surface 23d, so when the substrate G is mounted, a tiny gap (not shown) is formed between the back side of the substrate G and the mounting surface 23d, and the gap functions as a cooling space. Among them, it is also possible that the mounting surface 23d is composed of countless tiny convex parts. The cooling space is connected to a He gas flow path 28 for supplying He gas as a heat transfer gas at a predetermined pressure. In this way, the heat transfer gas is supplied to the back side of the substrate G, so that the temperature controllability of the substrate G can be better under vacuum.

[0033] An opening 4c is formed at the center of the bottom of the bottom wall 4b of the processing chamber 4. The power supply line 25, the He gas flow path 28, and the pipes and wires of the temperature control mechanism are led out of the main body container 1 through the opening 4c.

[0034] One of the four side walls 4 a of the processing chamber 4 is provided with a carry-in / carry-out port 29 a for carrying the substrate G in and out, and a gate valve 29 for opening and closing the carry-in / carry-out port 29 a .

[0035] An exhaust port 30 is provided on the bottom wall 4b of the processing chamber 4 and on the side of the mounting table 23. The exhaust port 30 is provided on the bottom wall 4b so as to be located at a position lower than the mounting surface 23d of the mounting table 23. An exhaust unit 40 is provided at the exhaust port 30. The exhaust unit 40 includes an exhaust pipe 31 connected to the exhaust port 30, an automatic pressure control valve (APC) 32 for controlling the pressure in the processing chamber 4 by adjusting the opening of the exhaust pipe 31, and a vacuum pump 33 for exhausting the processing chamber 4 through the exhaust pipe 31. The processing chamber 4 is exhausted by the vacuum pump 33, and during the plasma processing, the opening of the automatic pressure control valve (APC) 32 is adjusted to set and maintain a predetermined vacuum atmosphere in the processing chamber 4.

[0036] Figure 2A It is a perspective view showing an example of the structure inside the processing chamber according to the embodiment. Figure 2B It is a horizontal cross-sectional view showing an example of the structure inside the processing chamber according to the embodiment. Figure 2A A perspective view showing the structure of the vicinity of the mounting table 23 in the processing chamber 4 is shown. Figure 2B A cross-sectional view of the vicinity of the stage 23 in the processing chamber 4 as viewed from above is shown. The stage 23 is arranged in the center of the processing chamber 4. The mounting surface 23d of the stage 23 is formed in a rectangular shape for mounting a rectangular substrate G. A plurality of exhaust ports 30 are formed around the stage 23 in the processing chamber 4. In the case of the present embodiment, exhaust ports 30 are respectively provided at a total of 8 locations near both ends of each side of the rectangular stage 23. The number and position of the exhaust ports 30 are appropriately set according to the size of the device.

[0037] Between the inner wall of the processing chamber 4 (the inner part of the side wall 4a) and the mounting table 23, a plate-shaped partition 50 is provided at the portion corresponding to the exhaust port 30 on each side of the mounting table 23. In the case of the present embodiment, eight partitions 50 are provided on the side of each side of the mounting table 23 so as to cover the exhaust ports 30 respectively. The partitions 50 surround the outer periphery of the upper surface of the mounting table 23 and are provided separately from each other. The portion between the exhaust ports 30 on each side is not covered by the partition 50, and a recess 51 is formed which is lower than the partition 50 and the mounting table 23.

[0038] like Figure 1 As shown, the processing chamber 4 is divided by a partition 50 into a processing space 41 for performing plasma processing on the substrate G and an exhaust space 42 connected to the exhaust port 30. The processing space 41 is an area above the partition 50 in the processing chamber 4, and is an area where an inductively coupled plasma for performing plasma processing on the substrate G is formed. The exhaust space 42 is an area below the partition 50 in the processing chamber 4, and is an area for guiding the processing gas from the processing space 41 to discharge the processing gas.

[0039] The partitions 50 are made of a conductive material such as metal and are formed into a rectangular plate having no opening. Each partition 50 is arranged on each side of the mounting table 23 in such a manner that the upper surface is located at a position lower than the mounting surface 23d of the mounting table 23. Each partition 50 is connected to the ground potential by a grounding wire 50a. In particular, the partition 50 may be electrically connected to the side wall 4a and grounded via the main container 1.

[0040] like Figure 2A As shown, the partitions 50 adjacent to each other at the corners are separated and arranged in such a manner that an opening 60 for guiding the gas supplied to the processing space 41 to the exhaust space 42 is formed therebetween. In the case of this embodiment, the openings 60 exist at the four corners of the processing chamber 4. The recessed portion 51 side of the exhaust space 42 covered by the partition 50 is sealed by a sealing plate 80. The four corner sides of the exhaust space 42 are not sealed, so that the exhaust gas can flow toward the exhaust port 30. The exhaust gas does not flow from the recessed portion 51 side to the exhaust port 30, but flows from the opening 60 side to the exhaust port 30. Figure 3 The diagram shows the flow of exhaust gas in the processing chamber according to the embodiment. The processing gas introduced into the processing space 41 flows from the opening 60 to the exhaust space 42 , and is then exhausted from the exhaust port 30 to the exhaust unit 40 via the exhaust pipe 31 .

[0041] The recess 51 has an inner wall portion including a bottom wall 52 and a plurality of side walls 53a to 53d. The bottom wall 52 is formed by the bottom surface (bottom wall 4b) of the processing chamber 4. The side wall 53a is formed by the side electrode 23c. The side walls 53b and 53d are formed by the sealing plate 80. The side wall 53c is formed by the side wall 4a of the processing chamber 4. The bottom wall 4b, the side wall 4a, the side electrode 23c and the sealing plate 80 of the processing chamber 4 are all connected to the ground potential. Therefore, the inner wall portion of the recess 51 is at the ground potential. In addition, the bottom wall 52 may also be formed by a component different from the bottom surface of the processing chamber 4, in which case it may be in contact with the bottom surface or may be arranged in a suspended manner.

[0042] A plurality of fins 61 are disposed in the exhaust space 42. Figure 2A and Figure 2BIn the part covered by the partition 50, a plurality of fins 61 are arranged in parallel. The fins 61 are made of a conductive material such as metal and are formed into a rectangular plate-like member. Each fin 61 is connected to the bottom surface (bottom wall 4b) of the processing chamber 4 except the upper part of the exhaust port 30, and is arranged in a manner that the plate surface of the plate-like member is parallel to the side of the mounting table 23. That is, each fin 61 is arranged in the exhaust space 42 in a manner to form a flow direction for the exhaust gas to flow toward the exhaust port 30. The interval between each fin 61 is preferably 10mm to 200mm. Each fin 61 is connected to the ground potential using a grounding member not shown. In addition, it is also possible to electrically connect at least a portion of each fin 61 to the partition 50 and ground it with the partition 50. The gas in the processing space 41 of the processing chamber 4 flows from each opening 60 to the exhaust space 42, passes between the fins 61b, and is discharged from each exhaust port 30.

[0043] Back to Figure 1 . An exhaust mesh portion 70 is provided at each exhaust port 30. The exhaust mesh portion 70 has an opening corresponding to the size of the exhaust port 30 and can be installed at the exhaust port 30. An exhaust net is provided at the opening of the exhaust mesh portion 70. The exhaust net is formed by a member having a plurality of slits, a mesh member, or a member having a plurality of punched holes, so that gas can pass through. Among them, the exhaust mesh portion 70 can also be a plurality of exhaust nets that are overlapped.

[0044] The plasma processing apparatus 10 of the embodiment includes a control unit 100 composed of a microprocessor (computer), a user interface 101, and a storage unit 102. The control unit 100 sends commands to various components of the plasma processing apparatus 10, such as valves, high-frequency power supplies, vacuum pumps, etc., to control them. In addition, the user interface 101 includes: a keyboard for an operator to perform input operations such as command input for managing the plasma processing apparatus 10, a display for visually displaying the working status of the plasma processing apparatus 10, etc. The user interface 101 is connected to the control unit 100. The storage unit 102 stores: a control program for realizing various processes performed in the plasma processing apparatus 10 under the control of the control unit 100, and a program for causing each component of the plasma processing apparatus 10 to perform a process according to a process condition, that is, a process recipe. The storage unit 102 is connected to the control unit 100. The process recipe is stored in a storage medium in the storage unit 102. The storage medium may be a hard disk or semiconductor memory built into the computer, or a portable device such as a CDROM, a DVD, or a flash memory. In addition, the recipe may be appropriately transmitted from other equipment via, for example, a dedicated line. Thus, as required, an arbitrary processing recipe is read from the storage unit 102 according to instructions from the user interface 101 and the control unit 100 executes the processing recipe, thereby performing a desired process in the plasma processing apparatus 10 under the control of the control unit 100.

[0045] Next, a description will be given of a processing operation when a plasma processing such as plasma etching or plasma ashing is performed on the substrate G using the plasma processing apparatus 10 configured as described above.

[0046] First, the gate valve 29 of the plasma processing apparatus 10 is opened. The substrate G is introduced into the processing chamber 4 from the introduction and delivery port 29a by a conveying mechanism (not shown) and is placed on the placement surface 23d of the placement table 23. The plasma processing apparatus 10 fixes the substrate G on the placement table 23 by an electrostatic chuck (not shown). Next, the plasma processing apparatus 10 supplies the processing gas from the processing gas supply system 20 to the processing chamber 4 through the gas ejection hole 12a of the injection housing 11. In addition, the plasma processing apparatus 10 controls the pressure by an automatic pressure control valve (APC) 32, and evacuates the processing chamber 4 from the exhaust port 30 by a vacuum pump 33 through an exhaust pipe 31, thereby maintaining the pressure atmosphere in the processing chamber at, for example, 0.66Pa to 26.6Pa.

[0047] At this time, the plasma processing apparatus 10 supplies He gas as heat transfer gas to the cooling space on the back side of the substrate G through the He gas flow path 28 to avoid a temperature increase or temperature change of the substrate G.

[0048] Next, the plasma processing device 10 supplies high-frequency power, for example, of 13.56 MHz, from the high-frequency power supply 15 to the high-frequency antenna 13, thereby forming a uniform induced electric field in the processing chamber 4 with the aid of the dielectric wall 2. Under the action of the induced electric field formed in this way, the processing gas in the processing chamber 4 is plasmatized to generate a high-density inductively coupled plasma. The plasma is used to perform plasma processing on the substrate G, for example, plasma etching or plasma ashing is performed on a predetermined film of the substrate G. At the same time, the plasma processing device 10 supplies high-frequency power, for example, of 6 MHz, from the high-frequency power supply 27 to the mounting table 23, thereby forming a high-frequency bias voltage, and effectively attracting ions in the plasma generated in the processing chamber 4 to the substrate G.

[0049] After the processing gas is plasmatized in the processing space 41 in the processing chamber 4 and provided for plasma processing, the remaining part that has not been plasmatized is sucked by the vacuum pump 33 together with the reaction products, etc., and is discharged from the opening 60 to the exhaust space 42 from the exhaust port 30 through the exhaust pipe 31.

[0050] Here, in the case of the plasma processing apparatus 10, the larger the substrate G is, the more high-energy high-frequency power needs to be supplied to the mounting table 23. However, in the case of the plasma processing apparatus 10, if high-energy high-frequency power is supplied to the mounting table 23, arcs will be generated, and the mounting table 23 will become unstable electrically. For example, in the case of the plasma processing apparatus 10, if the size of the substrate G is larger than the size of the 8th generation (2160mm×2460mm), it is necessary to supply higher-energy high-frequency power to the mounting table 23. However, in the case of the plasma processing apparatus 10, even if the mounting table 23 is enlarged as the substrate G is enlarged, the size of the entire device cannot be increased in proportion to the size of the substrate G. For example, the manufactured plasma processing apparatus 10 is transported to the customer's factory by truck, but there is a limit to the size that the truck can transport. In the case where the size of the plasma processing apparatus 10 is larger than the size that can be transported by the truck, the plasma processing apparatus 10 needs to be constructed so that it can be divided into transportable sizes, and the structure becomes complicated, especially in the case of horizontal division. Therefore, it is preferable that the plasma processing apparatus 10 has a size that can be transported by a truck at least in the horizontal direction, so as to reduce the workload of dividing the plasma processing apparatus 10 for transportation and the workload of assembling the plasma processing apparatus 10 at the customer's factory. In addition, in the case of the plasma processing apparatus 10, if the height of the space between the injection housing 11 and the mounting table 23 is wide, the density of the generated plasma will decrease, and the processing efficiency will decrease. Therefore, in the case of the plasma processing apparatus 10, even if the mounting table 23 is enlarged as the substrate G is enlarged, the height of the processing chamber 4 should be maintained. Therefore, in the case of the plasma processing apparatus 10, the size of the substrate G that can be processed is increased by enlarging the mounting table 23, and the ratio of the area of ​​the inner wall (the inner part of the side wall 4a) of the processing chamber 4 that functions as the counter electrode to the area of ​​the mounting table 23 for mounting the substrate G is reduced. As a result, in the case of the plasma processing apparatus 10, the larger the size of the substrate G that can be processed is, the greater the return current density to the counter electrode is, and the arc is more likely to be generated, which becomes electrically unstable.

[0051] Here, in the case of the plasma processing apparatus 10 of the embodiment, a plurality of partitions 50 are provided separately from each other in a manner to surround the outer periphery of the upper surface of the mounting table 23, and a recess 51 is formed between the partitions 50. In addition, in the case of the plasma processing apparatus 10, the inner wall portion of the recess 51 is at a ground potential. The inner wall portion of the recess 51 functions as a counter electrode facing the mounting table 23 that forms a high-frequency bias. Thus, in the case of the plasma processing apparatus 10, the area of ​​the counter electrode is enlarged corresponding to the inner wall portion (bottom wall 52, side walls 53a to 53d) of the recess 51, so that even when the mounting table 23 is enlarged as the substrate G is enlarged, electrical stability can be ensured and unstable discharge can be suppressed.

[0052] In addition, in the case of the plasma processing apparatus 10, the side electrode 23c is provided not only on the inner wall of the recess 51 but also on the entire surface of the side surface of the outer periphery of the mounting table 23, and the side electrode 23c is also at the ground potential. The side electrode 23c functions as a counter electrode facing the mounting table 23 that forms a high-frequency bias. Therefore, in the case of the plasma processing apparatus 10, the area of ​​the counter electrode is enlarged corresponding to the side electrode 23c, so that even if the mounting table 23 is enlarged as the substrate G is enlarged, electrical stability can be ensured and unstable discharge can be suppressed.

[0053] In addition, in the case of the plasma processing apparatus 10, the partition plate 50 is at a ground potential. The partition plate 50 functions as a counter electrode facing the mounting table 23 that forms a high-frequency bias. Therefore, in the case of the plasma processing apparatus 10, the area of ​​the counter electrode is enlarged corresponding to the partition plate 50, so that even if the mounting table 23 is enlarged as the substrate G is enlarged, electrical stability can be ensured and unstable discharge can be suppressed.

[0054] In addition, in the case of the plasma processing device 10, a plurality of fins 61 are arranged in parallel on the upstream side of the flow direction of the exhaust gas flowing toward the exhaust port 30. Thus, when the plasma-formed gas flows toward the exhaust port 30, the gas contacts the fins 61 and is deactivated. Thus, it is possible to suppress the plasma-formed gas from flowing through the exhaust port 30 and generating unstable discharge inside the exhaust portion 40. Among them, as long as the gas can pass through, it is not necessarily limited to a parallel configuration, and other configurations can also be used. In addition, when the fin 61 is at a ground potential, the fin 61 functions as a counter electrode relative to the mounting table 23, so that unstable discharge can be suppressed. In addition, a plurality of partitions 50 are separately arranged around the mounting table 23 in a manner that an opening 60 is formed between adjacent partitions 50. The fin 61 is arranged in the portion covered by the partition 50.

[0055] Among them, Figure 2A and Figure 2B In the example, the case where the fin 61 is arranged only in the portion covered by the partition 50 is described as an example, but the arrangement of the fin 61 is not limited to this. The fin 61 can be arranged on the inner surface of the processing chamber 4 and can be set at any position when it helps to expand the counter electrode. Among them, the fin 61 is preferably arranged at a position lower than the mounting surface 23d of the mounting table 23 to prevent the attached by-products such as sediment from falling on the mounting surface 23d of the mounting table 23.

[0056] Figure 4 FIG. 1 is a diagram showing an example of the arrangement of fins according to another embodiment. Figure 4 In the case of, a plurality of fins 62 are also arranged in parallel in the recess 51. The fins 62 are made of a conductive material such as metal and are formed into a rectangular plate-like member. Each fin 62 is connected to a ground potential by means of a grounding member not shown. Among them, each fin 62 can also be electrically connected to the bottom wall 4b of the processing chamber 4, so that each fin 62 is grounded. The fin 62 is not covered by the partition plate 50 and is therefore exposed to the plasma. In this case, the fin 62 directly functions as a counter electrode opposite to the mounting table 23, so that the enlargement effect of the counter electrode can be improved.

[0057] As described above, the plasma processing device 10 of the present embodiment includes: a processing chamber 4, a high-frequency power supply 27, a plurality of partitions 50, and a recess 51. A mounting table 23 for mounting a substrate G is provided inside the processing chamber 4, and a plasma treatment is performed on the substrate G in the processing chamber 4. The high-frequency power supply 27 supplies high-frequency power for bias to the mounting table 23. The plurality of partitions 50 surround the outer periphery of the upper surface of the mounting table 23 and are arranged separately from each other. The recess 51 is provided between at least one set of adjacent partitions 50, and has an inner wall portion including a bottom wall 52 and a plurality of side walls 53a to 53d, constituting an opposite electrode opposite to the mounting table 23. As a result, the plasma processing device 10 can expand the area of ​​the opposite electrode opposite to the mounting table 23, thereby being able to suppress the plasma from becoming unstable.

[0058] In addition, side electrodes 23c constituting counter electrodes facing the mounting table 23 are provided on the entire side surfaces of the outer periphery of the mounting table 23. Thus, the plasma processing apparatus 10 can increase the area of ​​the counter electrodes facing the mounting table 23, thereby preventing plasma from becoming unstable.

[0059] In addition, an exhaust space 42 connected to the exhaust port 30 for exhausting the inside of the processing chamber 4 is formed at the lower part of the partition plate 50. The plasma processing apparatus 10 includes a sealing plate 80 between the recess 51 and the exhaust space 42. The sealing plate 80, the side surface of the mounting table 23, and the inner side surface of the processing chamber 4 constitute the side wall of the recess 51. Thus, the plasma processing apparatus 10 can make the recess 51 wider and increase the area of ​​the inner wall portion.

[0060] In addition, the plasma processing device 10 further includes a plurality of plate-like members (fins 61) made of a conductive material and connected to a ground potential at a position upstream of the exhaust port 30 relative to the flow direction of the exhaust gas toward the exhaust port 30 in the exhaust space 42. Thus, the plasma processing device 10 can deactivate the plasmatized gas flowing toward the exhaust port 30 at the fins 61, thereby suppressing unstable discharge.

[0061] The above embodiments are described, but it should be noted that all aspects of the embodiments disclosed this time are illustrative and are not intended to limit the present invention. In fact, the above embodiments can be embodied in a variety of forms. In addition, the above embodiments can also be omitted, replaced, and changed in a variety of forms without departing from the claims and their purpose.

[0062] For example, in the above embodiment, a case where a high-frequency antenna is provided on the upper part of the processing chamber via a dielectric window (dielectric wall 2) is shown as an inductively coupled plasma processing apparatus 10, but it is also applicable to a case where a high-frequency antenna is provided via a metal window instead of a dielectric window. In this case, the supply of the processing gas may be provided by providing a gas injection member on the metal window instead of supplying the processing gas from a cross-shaped injection housing such as a beam structure.

[0063] Furthermore, in the above embodiment, an example in which the openings 60 are formed at the four corners of the processing chamber is shown, but the present invention is not limited to this.

[0064] In addition, the above embodiment is described with reference to an apparatus for performing plasma etching and plasma ashing, but it can also be applied to other plasma processing apparatuses 10 such as CVD film forming. In addition, the above embodiment shows an example of using a rectangular substrate for FPD as a substrate, but it can also be applied to the case of processing other rectangular substrates, and is not limited to rectangular, and can also be applied to circular substrates such as semiconductor wafers.

Claims

1. A plasma processing device, comprising: a processing chamber, in which a mounting table for mounting a substrate is provided, and in which a plasma treatment is performed on the substrate; a high frequency power supply for supplying high frequency power for biasing the mounting table; a plurality of partitions surrounding the outer periphery of the upper surface of the mounting table and arranged to be separated from each other; as well as a recessed portion, located between at least one set of adjacent partitions, having an inner wall portion including a bottom wall and a plurality of side walls, constituting a counter electrode opposite to the mounting table, An exhaust space connected to an exhaust port for exhausting the processing chamber is formed at the lower part of the partition. A sealing plate is further provided between the recess and the exhaust space, The sealing plate, the side surface of the mounting table and the inner side surface of the processing chamber constitute the side wall of the recessed portion. Wherein, the counter electrode is a ground electrode connected to a ground potential.

2. The plasma processing apparatus according to claim 1, wherein: A side electrode is provided on the entire surface of a side surface of an outer periphery of the mounting table, and the side electrode constitutes a counter electrode facing the mounting table.

3. The plasma processing apparatus according to claim 1, wherein: The plasma processing apparatus further includes a plurality of plate-like members made of a conductive material and connected to a ground potential at positions upstream of the exhaust port in the exhaust space with respect to the flow direction of the exhaust gas toward the exhaust port.

4. The plasma processing apparatus according to any one of claims 1 to 3, wherein: The bottom wall is arranged on the bottom surface of the processing chamber.

5. The plasma processing apparatus according to any one of claims 1 to 3, wherein: The mounting platform is rectangular in plan view. The processing chamber is rectangular in top view. The plurality of partitions are separately arranged so as to form openings at corners of the processing chamber. The recessed portion is formed on a side surface of a side portion of the mounting table.

6. The plasma processing apparatus according to any one of claims 1 to 3, wherein: The spacer constitutes a counter electrode facing the mounting table.

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