Plasma processing device and mounting platform

Abstract

The present invention provides a mounting table and a plasma processing device. A plurality of adhesive layers of different heights can be protected by a sealing member. The mounting table has a first mounting portion, a second mounting portion, a first adhesive layer, a second adhesive layer and a sealing member. The first mounting portion is used to mount a substrate. The second mounting portion is lower than the first mounting portion and is used to mount an edge ring surrounding the periphery of the substrate. The first adhesive layer bonds the base table and the first mounting portion. The second adhesive layer bonds the base table and the second mounting portion. The sealing member contacts the first mounting portion at a position higher than the first adhesive layer, contacts the second mounting portion at a position higher than the second adhesive layer, and blocks the space between the first mounting portion and the second mounting portion by deformation.

Description

Technical Field

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

[0002] The plasma processing apparatus includes, for example, a mounting table having a mounting portion for mounting a substrate to be processed and a base supporting the mounting portion at the bottom of the mounting portion. For such a mounting table, for example, the mounting portion is made of ceramic, the base is made of metal such as aluminum, and the mounting portion is bonded to the base using an adhesive. For the plasma processing apparatus, for example, a protective seal is provided to protect the adhesive that may be damaged by plasma.

[0003] Patent Document 1: Japanese Patent Application No. 2015-515760 Summary of the invention

[0004] Problem that the invention aims to solve

[0005] The present disclosure provides a mounting table and a plasma processing apparatus capable of protecting a plurality of adhesive layers having different heights with a single sealing member.

[0006] Solutions for solving problems

[0007] A mounting table of a technical solution disclosed in the present invention comprises a first mounting portion, a second mounting portion, a first adhesive layer, a second adhesive layer and a sealing member. The first mounting portion is used to mount a substrate. The second mounting portion is lower than the first mounting portion and is used to mount an edge ring surrounding the periphery of the substrate. The first adhesive layer bonds the base and the first mounting portion. The second adhesive layer bonds the base and the second mounting portion. The sealing member contacts the first mounting portion at a position higher than the first adhesive layer, contacts the second mounting portion at a position higher than the second adhesive layer, and blocks the space between the first mounting portion and the second mounting portion by deformation.

[0008] Effects of the Invention

[0009] According to the present disclosure, a plurality of adhesive layers having different heights can be protected by one sealing member. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 FIG. 1 is a diagram showing an example of a plasma processing apparatus according to an embodiment of the present disclosure.

[0011] Figure 2 This is a partial enlarged view of the edge ring and its vicinity in this embodiment.

[0012] Figure 3 It is a partially enlarged view of the protection target portion of this embodiment.

[0013] Figure 4It is a cross-sectional view showing an example of the sealing member according to the present embodiment.

[0014] Figure 5 This is a diagram showing an example of a state in which the sealing member of the present embodiment is attached to a protection target portion.

[0015] Figure 6 It is a cross-sectional view showing an example of a sealing member according to a modified example.

[0016] Figure 7 This is a diagram showing an example of a state in which a sealing member according to a modified example is attached to a protection target portion. DETAILED DESCRIPTION

[0017] Hereinafter, embodiments of the disclosed mounting table and plasma processing apparatus will be described in detail based on the drawings. In addition, the disclosed technology is not limited to the following embodiments.

[0018] In addition to the processing object, an edge ring surrounding the periphery of the substrate is placed on the placement portion of the placement table. Since the edge ring has a thickness compared to the substrate, the portion of the placement portion where the edge ring is placed is one level lower than the portion where the substrate is placed. Such a structure can be realized by, for example, providing a structure that allows the portion where the substrate is placed and the portion where the edge ring is placed to be separable for the base and the placement portion of the placement table. However, since there are steps and gaps in the divided portion between the base and the placement portion, there are cases where the layer of adhesive between the placement portion and the base (hereinafter also referred to as the adhesive layer) is exposed in different heights in the portion where the substrate is placed and the portion where the edge ring is placed. In this case, for the adhesive layer of the portion where the substrate is placed on the upper side in the height direction, a protective member needs to be arranged in the direction of tightening the cylinder from the outside to the inside, and an O-ring or the like can be used for protection. In addition, for the adhesive layer of the portion where the edge ring is placed on the lower side in the height direction, a protective member needs to be arranged in the direction of expanding the cylinder from the inside to the outside, and it is difficult to protect it with an O-ring. Therefore, it is expected that a plurality of adhesive layers having different heights are protected by a single sealing member.

[0019] [Structure of Plasma Processing Device 1]

[0020] Figure 1 FIG. 1 is a diagram showing an example of a plasma processing apparatus according to an embodiment of the present disclosure. Figure 1 The illustrated plasma processing apparatus 1 is, for example, an RIE (Reactive Ion Etching) type plasma processing apparatus.

[0021] like Figure 1As shown, the plasma processing apparatus 1 has a cylindrical processing container 10 made of metal, such as aluminum or stainless steel. The interior of the processing container 10 becomes a processing chamber for performing plasma processing such as plasma etching and plasma CVD. The processing container 10 defines a processing space for processing a substrate W (such as a semiconductor wafer) as an example of a processed object. The processing container 10 is grounded.

[0022] A disk-shaped mounting table 11 is disposed inside the processing container 10. The mounting table 11 is used to mount the substrate W and the edge ring 33. The mounting table 11 has an electrostatic chuck 25. The mounting table 11 is supported by a cylindrical support portion 13 extending vertically upward from the bottom of the processing container 10 via a cylindrical holding member 12 formed of aluminum oxide (Al2O3).

[0023] The electrostatic chuck 25 includes a mounting portion 27 for mounting a substrate W and an edge ring 33, and a base 28 formed of aluminum. The mounting portion 27 includes a first mounting portion 27a formed of a dielectric such as ceramic and for mounting the substrate W, and a second mounting portion 27b for mounting the edge ring 33 surrounding the periphery of the substrate W. An adsorption electrode 26 as a conductive film is embedded in the first mounting portion 27a. A DC power supply 29 is connected to the adsorption electrode 26 via a switch 30. The electrostatic chuck 25 generates an electrostatic force such as a Coulomb force by using a DC voltage applied from the DC power supply 29 to the adsorption electrode 26, and uses the electrostatic force to adsorb and hold the substrate W. The edge ring 33 is formed of Si or SiC. In addition, an adsorption electrode may also be provided on the second mounting portion 27b to electrostatically adsorb the edge ring 33. The outer periphery of the electrostatic chuck 25 and the outer periphery of the edge ring 33 are covered by an insulator ring 35.

[0024] The first high-frequency power source 21 is connected to the stage 11 via a matching device 21a. The first high-frequency power source 21 applies a high-frequency power of a first frequency (e.g., a frequency of 13 MHz) for plasma generation and RIE to the stage 11. In addition, the second high-frequency power source 22 is connected to the stage 11 via a matching device 22a. The second high-frequency power source 22 applies a high-frequency power of a second frequency (e.g., a frequency of 3 MHz) for bias application lower than the first frequency to the stage 11. Thus, the stage 11 also functions as a lower electrode.

[0025] The variable DC power supply 31 is connected to the power supply line 21b via a switch 32. A DC blocking capacitor 23 is provided between the connection point between the variable DC power supply 31 and the power supply line 21b and the first high-frequency power supply 21. The DC blocking capacitor 23 blocks the DC voltage from the variable DC power supply 31 and prevents the DC voltage from flowing to the first high-frequency power supply 21. The DC voltage applied from the variable DC power supply 31 is used to apply voltage to the edge ring 33.

[0026] An annular coolant chamber 34 extending in the circumferential direction is provided inside the base 28. A coolant at a predetermined temperature, such as cooling water, is circulated and supplied to the coolant chamber 34 from a cooling unit via pipes 36 and 37 to cool the electrostatic chuck 25 and the substrate W.

[0027] In addition, a heat-conducting gas supply unit 38 is connected to the electrostatic chuck 25 via a gas supply line 39. The heat-conducting gas supply unit 38 supplies a heat-conducting gas to a space between the upper surface of the electrostatic chuck 25 and the back surface of the substrate W via the gas supply line 39. As the heat-conducting gas, a gas having thermal conductivity, such as He gas, is preferably used.

[0028] An exhaust path 14 is formed between the side wall of the processing container 10 and the cylindrical support portion 13. An annular partition 15 is provided at the entrance of the exhaust path 14, and an exhaust port 16 is provided at the bottom of the exhaust path 14. An exhaust device 18 is connected to the exhaust port 16 via an exhaust pipe 17. The exhaust device 18 has a vacuum pump to reduce the pressure of the processing space in the processing container 10 to a predetermined vacuum degree. In addition, the exhaust pipe 17 has an automatic pressure control valve (Automatic Pressure Control valve) (hereinafter referred to as "APC") as a variable butterfly valve, and the APC automatically controls the pressure in the processing container 10. In addition, a gate valve 20 for opening and closing the delivery port 19 of the substrate W is installed on the side wall of the processing container 10.

[0029] A gas shower head 24 is disposed on the top of the processing container 10. The gas shower head 24 includes an electrode plate 40 and an electrode support 41 that supports the electrode plate 40 in a manner that allows the electrode plate 40 to be detachable. The electrode plate 40 has a plurality of vent holes 40a. A buffer chamber 42 is provided inside the electrode support 41, and a processing gas supply unit 43 is connected to a gas inlet 41a of the buffer chamber 42 via a gas supply pipe 44. In addition, a magnet 45 extending in an annular or concentric shape is disposed around the processing container 10.

[0030] Each component of the plasma processing apparatus 1 is connected to the control unit 46. The control unit 46 controls each component of the plasma processing apparatus 1. Examples of the components include the exhaust device 18, the matching devices 21a and 22a, the first high-frequency power supply 21, the second high-frequency power supply 22, the switches 30 and 32, the DC power supplies 29 and 31, the heat transfer gas supply unit 38, and the processing gas supply unit 43.

[0031] The control unit 46 includes a CPU 46 a and a memory 46 b , and reads and executes a control program and a processing recipe for the plasma processing apparatus 1 stored in the memory 46 b , thereby causing the plasma processing apparatus 1 to perform a predetermined process such as etching.

[0032] For the plasma processing apparatus 1, for example, during etching processing, first, the gate valve 20 is opened, and the substrate W is introduced into the processing container 10 and placed on the electrostatic chuck 25. A DC voltage is applied from the DC power supply 29 to the adsorption electrode 26 so that the substrate W is adsorbed on the electrostatic chuck 25, and a DC voltage is applied from the variable DC power supply 31 to the base 28. Thus, a voltage is applied to the edge ring 33. In addition, a heat transfer gas is supplied between the electrostatic chuck 25 and the substrate W. Then, a processing gas is introduced from the processing gas supply unit 43 into the processing container 10, and the pressure in the processing container 10 is reduced by using the exhaust device 18 or the like. In addition, the first high-frequency power supply 21 and the second high-frequency power supply 22 are supplied to the mounting table 11 with the first high-frequency power supply and the second high-frequency power supply.

[0033] In the processing container 10 of the plasma processing apparatus 1, a horizontal magnetic field directed in one direction is formed by the magnet 45, and a vertical RF electric field is formed by high-frequency power applied to the mounting table 11. Thus, the processing gas ejected from the gas shower head 24 is converted into plasma, and a predetermined plasma processing is performed on the substrate W using radicals and ions in the plasma.

[0034] [Structure of the Peripheral Part of the Mounting Table 11]

[0035] Next, use Figure 2 and Figure 3 The structure of the peripheral portion of the mounting table 11 will be described. Figure 2 FIG. 1 is a partial enlarged view of the edge ring of this embodiment. Figure 2 As shown, the second mounting portion 27b on which the edge ring 33 is mounted is a structure that is one level lower than the first mounting portion 27a on which the substrate W is mounted. The base 28 is a structure that can be divided into a base 28a to which the first mounting portion 27a is bonded by a first adhesive layer 50, a base 28b to which the second mounting portion 27b is bonded by a second adhesive layer 51, and a base 28c to which the base 28b and the edge ring 33 are electrically connected. The bases 28b and 28c are electrically connected, and the bases 28c and the edge ring 33 are electrically connected, respectively, by means of conductive members 47 and 48. The conductive members 47 and 48 are also called conductive tapes or spirals, and are conductive elastic members. The outer peripheral sides of the bases 28b and 28c and the outer peripheral side of the edge ring 33 are covered by an insulator ring 35.

[0036] The first adhesive layer 50 is exposed on the side of the first carrier portion 27a and the base 28a. In addition, since there is a gap between the base 28a and the base 28b, the second adhesive layer 51 is exposed on the side of the second carrier portion 27b and the base 28b. In other words, the first adhesive layer 50 and the second adhesive layer 51 are exposed in a state of different heights. The first adhesive layer 50 and the second adhesive layer 51 are, for example, epoxy-based or silicone-based adhesives, and contain fillers such as silicon. In order to protect such first adhesive layer 50 and second adhesive layer 51, in the present embodiment, a sealing member is arranged in the area 60 as the protection object portion.

[0037] Figure 3 is a partial enlarged view of the protection object part of this embodiment. Figure 3 As shown in FIG. 6 , during plasma treatment, ions and radicals penetrate into region 60 as shown in path 61. It is understood that in this case, as long as the sealing member is in contact with the surface 62 of the first carrier 27a and the surface 63 of the second carrier 27b, the first adhesive layer 50 and the second adhesive layer 51 can be protected. Figure 3 In the figure, the gaps between the first mounting portion 27 a and the edge ring 33 and other portions are drawn larger for the purpose of explaining the path 61 .

[0038] In the region 60, due to the tolerance of the components, the intervals between the first mounting portion 27a, the second mounting portion 27b, and the bases 28a and 28b are different for each mounting table 11. In addition, the intervals between them may change due to shaking and thermal expansion during installation. Therefore, the sealing member arranged in the region 60 is required to always contact the inner peripheral side surface 62 and the outer peripheral side surface 63 even if the interval changes.

[0039] [Structure of the Sealing Member 70]

[0040] Figure 4 It is a cross-sectional view showing an example of the sealing member according to the present embodiment. Figure 4 The sealing member 70 shown is a sealing member installed in the area 60 as the protection object part, and the lower part 71 is elastically deformed as shown in the state 71a. The sealing member 70 can use a FFKM (perfluoroelastomer) material with free radical resistance, for example. In addition, the sealing member 70 is, for example, a ring-shaped member with elasticity and a diameter slightly smaller than the diameter of the outer periphery of the base 28a. In addition, as long as it can be sealed, the diameter of the sealing member 70 can also be the same as the diameter of the outer periphery of the base 28a, and can also be slightly larger than the diameter of the outer periphery of the base 28a.

[0041] The surface 72 of the lower part 71 abuts against the surface 63 of the second carrier 27b. A convex portion 73 abutting against the surface 62 of the first carrier 27a is formed on the upper part of the sealing member 70. In addition, when the fulcrum 74 abuts against the base 28a and the sealing member 70 is elastically deformed, the fulcrum 74 becomes a fulcrum when the surface 72 and the convex portion 73 are used as the points of action. Moreover, the longitudinal dimension of the sealing member 70 at the cross section is larger than the lateral dimension. The sealing member 70 is easily installed on the protection object part by making the longitudinal dimension larger than the lateral dimension.

[0042] Figure 5 1 is a diagram showing an example of a state in which the sealing member of the present embodiment is installed on the protection object portion. Figure 5 As shown, when the sealing member 70 is installed in the area 60, the lower part 71 is elastically deformed into the state 71a, and the surface 72 is in contact with the surface 63. In addition, the sealing member 70 is elastically deformed in a manner that the convex portion 73 is in contact with the surface 62, and the fulcrum 74 is in contact with the base 28a and becomes a fulcrum. At this time, for the sealing member 70, even if the intervals between the parts of the mounting platform 11 change, under the action of the restoring force of the elastically deformed part to return to the original state, the convex portion 73 continues to contact the surface 62 on the inner peripheral side, and the surface 72 continues to contact the surface 63 on the outer peripheral side. That is, the convex portion 73 of the sealing member 70 follows the offset of the first mounting portion 27a side and is sealed by the tightening force. In addition, the surface 72 of the sealing member 70 follows the offset of the second mounting portion 27b side and is sealed by the restoring force of the elastic deformation. Thus, with respect to the mounting table 11 , a plurality of adhesive layers having different heights, that is, the first adhesive layer 50 and the second adhesive layer 51 can be protected by a single sealing member 70 .

[0043] [Modifications]

[0044] Next, sealing members of other shapes in the region 60 will be described. Figure 6 It is a cross-sectional view showing an example of a sealing member according to a modified example. Figure 6 The sealing member 80 shown is a sealing member installed in the area 60 as the protection object part in the same manner as the sealing member 70, and the lower part 81 can be elastically deformed as in the state 81a. The sealing member 80 can use, for example, FFKM material with free radical resistance in the same manner as the sealing member 70. In addition, the sealing member 80 is, for example, an annular shape with elasticity and a diameter slightly smaller than the diameter of the periphery of the base 28a. In addition, as long as it can be sealed, the diameter of the sealing member 80 can also be the same as the diameter of the periphery of the base 28a, and can also be slightly larger than the diameter of the periphery of the base 28a.

[0045] The surface 82 of the lower part 81 abuts against the surface 63 of the second carrier 27b. A convex portion 83 abutting against the surface 62 of the first carrier 27a is formed on the upper part of the sealing member 80. In addition, when the fulcrum 84 abuts against the base 28a and the sealing member 80 is elastically deformed, the fulcrum 84 becomes a fulcrum when the surface 82 and the convex portion 83 are used as the points of action. Moreover, the longitudinal dimension of the sealing member 80 at the cross section is larger than the lateral dimension. The sealing member 80 is easily installed on the protection object part by making the longitudinal dimension larger than the lateral dimension.

[0046] Figure 7 1 is a diagram showing an example of a state in which a sealing member of a modified example is installed on a protection target portion. Figure 7 As shown, when the sealing member 80 is installed in the region 60, the lower portion 81 is elastically deformed in a state 81a, and the surface 82 is in contact with the surface 63. In addition, the sealing member 80 is elastically deformed in a state that the convex portion 83 is in contact with the surface 62, and the fulcrum 84 is in contact with the base 28a and becomes a fulcrum. At this time, for the sealing member 80, even if the interval between the parts of the mounting platform 11 changes, under the action of the restoring force of the elastically deformed part to return to the original state, the convex portion 83 continues to contact the surface 62 on the inner peripheral side, and the surface 82 continues to contact the surface 63 on the outer peripheral side. That is, the convex portion 83 of the sealing member 80 follows the offset of the first mounting portion 27a side and is sealed by the tightening force. In addition, the surface 82 of the sealing member 80 follows the offset of the second mounting portion 27b side and is sealed by the restoring force of the elastic deformation. Thus, the mounting table 11 can be protected by a single sealing member 80 for a plurality of adhesive layers having different heights, namely, the first adhesive layer 50 and the second adhesive layer 51. In addition, since the sealing members 70 and 80 are not pressed into grooves like O-rings, they can be easily attached and detached.

[0047] In the above-mentioned embodiment, the sealing members 70 and 80 are ring-shaped members, but the present invention is not limited thereto and may be, for example, a plurality of arc-shaped members divided in the circumferential direction.

[0048] As described above, according to the present embodiment, the mounting table 11 includes the first mounting portion 27a, the second mounting portion 27b, the first adhesive layer 50, the second adhesive layer 51, and the sealing member 70. The first mounting portion 27a is used to mount the substrate W. The second mounting portion 27b is lower than the first mounting portion 27a and is used to mount the edge ring 33 surrounding the periphery of the substrate W. The first adhesive layer 50 bonds the base 28a and the first mounting portion 27a. The second adhesive layer 51 bonds the base 28b and the second mounting portion 27b. The sealing member 70 contacts the first mounting portion 27a at a position higher than the first adhesive layer 50, contacts the second mounting portion 27b at a position higher than the second adhesive layer 51, and blocks the gap between the first mounting portion 27a and the second mounting portion 27b by deformation. As a result, a plurality of adhesive layers (the first adhesive layer 50 and the second adhesive layer 51 ) having different heights can be protected by a single sealing member 70 . In addition, the sealing member 70 can be easily attached to and detached from the mounting table 11 .

[0049] Furthermore, according to the present embodiment, the lower portion 71 of the sealing member 70 that contacts the second mounting portion 27b is deformed. As a result, even if the intervals between the portions of the mounting table 11 change, close contact can be maintained.

[0050] According to the present embodiment, the upper portion (convex portion 73) of the sealing member 70 in contact with the first mounting portion 27a is convex toward the first mounting portion 27a. As a result, the sealing member 70 can be in close contact with the first mounting portion 27a as the upper portion of the first adhesive layer 50.

[0051] According to the present embodiment, the longitudinal dimension of the sealing member 70 in the cross section is larger than the lateral dimension. As a result, the sealing member 70 can be easily attached to and detached from the mounting table 11 .

[0052] The embodiments disclosed herein are illustrative in all aspects and are not restrictive. The embodiments described above may be omitted, replaced, or modified in various forms without departing from the scope of the claims and the gist thereof.

[0053] In addition, in the above-mentioned embodiment, the plasma processing apparatus 1 that uses capacitively coupled plasma as a plasma source to perform plasma processing on the substrate W is described as an example, but the disclosed technology is not limited to this. As long as it is an apparatus that processes the substrate W using plasma, the plasma source is not limited to capacitively coupled plasma, and any plasma source such as inductively coupled plasma, microwave plasma, and magnetron plasma can be used.

Claims

1. A mounting platform, wherein: The mounting platform has: a first mounting portion for mounting a substrate; a second mounting portion, which is lower than the first mounting portion and is used to mount an edge ring surrounding the periphery of the substrate; a first adhesive layer for bonding the base and the first mounting portion; a second adhesive layer for bonding the base and the second mounting portion; as well as A sealing member contacts the first mounting portion at a position above the first adhesive layer and contacts the second mounting portion at a position above the second adhesive layer, and blocks a space between the first mounting portion and the second mounting portion by deforming.

2. The mounting table according to claim 1, wherein: The lower portion of the sealing member in contact with the second placement portion is deformed.

3. The mounting table according to claim 1 or 2, wherein: An upper portion of the sealing member that contacts the first mounting portion is convex toward the first mounting portion.

4. The mounting table according to claim 1 or 2, wherein: The sealing member has a longitudinal dimension greater than a lateral dimension at a cross section.

5. A plasma processing device, wherein: This plasma processing apparatus comprises the mounting table according to any one of claims 1 to 4.

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