Exhaust network, plasma processing apparatus, and plasma processing method

Abstract

The invention provides an exhaust network, a plasma processing apparatus, and a plasma processing method. The present invention suppresses pressure loss and abnormal discharge in the vicinity of an exhaust port. The exhaust net is provided with a plurality of circumferential partition walls and a plurality of radial partition walls. Each of the circumferential partition walls is provided with a plurality of plate-shaped parts in the circumferential direction, each plate-shaped part is provided with a first surface and a second surface which face each other and is formed by an electric conductor, and the extension direction of the first surface and the second surface of each plate-shaped part is configured to be along the direction of the central axis of the concentric circle. Each of the radial partition walls has a plurality of linear portions disposed in a radial direction from the central axis so as to intersect the circumferential partition wall, and the extending direction of the third surface and the fourth surface of each linear portion is disposed in a direction along the central axis of a concentric circle. In addition, the shape of a slit surrounded by two adjacent plate-shaped parts and two adjacent linear parts is in an arc shape with the central axis as the center. In addition, the ratio of the length of the plate-shaped part to the width of the slit is more than 2 and less than 3.

Description

Technical Field

[0001] Various aspects and embodiments of the present disclosure relate to exhaust screens, plasma processing apparatuses, and plasma processing methods. Background Art

[0002] Patent Document 1 below discloses that "the mesh member 30 is arranged near an exhaust port 159 formed in the bottom wall 104b of the processing chamber 104. The mesh member 30 is formed into a plate-like shape using a metal primarily composed of aluminum or stainless steel. The mesh member 30 is supported by an exhaust pipe 161. The exhaust pipe 161 is made of metal and is grounded via the bottom wall 104b. Therefore, the mesh member 30 is grounded via the exhaust pipe 161 and the bottom wall 104b." Patent Document 1 below also discloses that "a plurality of through-holes 31 are formed in the mesh member 30, extending through the mesh member 30 in the thickness direction. In this embodiment, the opening of each through-hole 31 is circular. This suppresses the concentration of the electric field at the opening of the through-hole 31."

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2020-188194 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] The present disclosure provides an exhaust net, a plasma processing apparatus, and a plasma processing method capable of suppressing pressure loss and abnormal discharge near an exhaust port.

[0008] Solutions for solving problems

[0009] The exhaust net in one embodiment of the present disclosure is an exhaust net provided at an exhaust port of a processing container for treating a substrate using plasma generated inside, or an exhaust pipe connected to the exhaust port. The exhaust net comprises: a plurality of circumferential partition walls arranged in a concentric shape; and a plurality of radial partition walls arranged in a radial shape. The circumferential partition walls are respectively formed to have a plurality of plate-like portions arranged in a circumferential direction, the plate-like portions having a first face and a second face relative to each other and being formed of an electrical conductor. The circumferential partition walls are respectively arranged in such a manner that the extension direction of the first face and the second face of each plate-like portion becomes a direction along the central axis of the concentric circle. The radial partition walls are respectively formed to have a plurality of straight portions arranged in a radial direction or radial direction from the central axis in such a manner as to intersect with the circumferential partition walls. The radial partition walls are respectively arranged in such a manner that the extension direction of the third face and the fourth face of each straight portion becomes a direction along the central axis of the concentric circle. Furthermore, the cylindrical slit, which is surrounded by two adjacent plate-like portions in a radial direction or radial direction from the central axis of the plurality of circumferential partition walls and two adjacent linear portions in the circumferential direction of the plurality of radial partition walls, has an arc shape centered on the central axis when viewed along the central axis. Furthermore, the ratio of the length of the plate-like portion along the central axis to the width of the slit when viewed along the central axis is greater than 2 and less than 3.

[0010] Effects of the Invention

[0011] According to various aspects and embodiments of the present disclosure, it is possible to suppress pressure loss and abnormal discharge near the exhaust port. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0013] Figure 2 Yes Figure 1 FIG. 1 is a diagram showing an example of an A-A section.

[0014] Figure 3 It is an enlarged cross-sectional view showing an example of the exhaust mechanism in this embodiment.

[0015] Figure 4 It is a plan view showing an example of the exhaust net in this embodiment.

[0016] Figure 5 It is an enlarged plan view showing an example of the shape of the slits of the exhaust net in this embodiment.

[0017] Figure 6 It is an enlarged cross-sectional view showing an example of the shape of the slits of the exhaust net in this embodiment.

[0018] Figure 7It is a top view showing an example of an exhaust net in a reference example.

[0019] Figure 8 This is a diagram showing an example of the relationship between the thickness of the exhaust net and the pressure in the processing space.

[0020] Figure 9 This is a diagram showing an example of the relationship between the thickness of the exhaust net and the total electric field under the exhaust net.

[0021] Figure 10 This is a diagram showing an example of the relationship between the thickness of the exhaust net and the number of particles passing through.

[0022] Figure 11 This is a flowchart showing an example of a plasma processing method.

[0023] Figure 12 It is a plan view showing another example of the exhaust net.

[0024] Figure 13 It is a plan view showing another example of the exhaust net.

[0025] Figure 14 It is an enlarged cross-sectional view showing another example of the slits of the exhaust net.

[0026] Description of Reference Numerals

[0027] V, gate valve; G, substrate; 1. plasma processing apparatus; 10. main body; 101. processing vessel; 102. dielectric wall; 103. antenna chamber; 103a. side wall; 104. processing chamber; 104a. side wall; 104b. bottom wall; 105. support frame; 106a. processing space; 106b. exhaust space; 111. spray housing; 112. gas diffusion chamber; 112a. gas ejection hole; 113. antenna; 113a. antenna wire; 114. matching element; 115. high-frequency power supply; 116. power supply member; 117. spacer; 118. terminal; 119. power supply line; 120. gas supply mechanism; 121. gas supply pipe; 126 , spacer; 130, mounting table; 131, substrate; 132, protective component; 133, piping; 151, power supply line; 152, matching device; 153, high-frequency power supply; 155, opening; 157, opening; 158, partition member; 159, exhaust port; 160, exhaust mechanism; 161, exhaust pipe; 162, APC valve; 163, vacuum pump; 164, foreign matter mixing prevention net; 20, control device; 30, exhaust net; 31, curved plate-shaped portion; 32, partition wall; 32a, first surface; 32b, second surface; 33, partition wall; 33a, third surface; 33b, fourth surface; 34, slit; 35, area; 36, through hole; 37, straight portion. DETAILED DESCRIPTION

[0028] The following describes in detail embodiments of an exhaust network, a plasma processing apparatus, and a plasma processing method based on the accompanying drawings. The disclosed exhaust network, plasma processing apparatus, and plasma processing method are not limited to the following embodiments. Furthermore, the following embodiments can be combined as appropriate within the scope of the present disclosure without conflicting structures or processing contents.

[0029] Furthermore, with the recent miniaturization of FPD (Flat Panel Display) processes, higher power processing conditions with low pressure and high flow rates are required. However, during high-power processes, abnormal discharges may occur near the exhaust mesh. Furthermore, when the exhaust mesh is made thicker to suppress abnormal discharges, the pressure loss across the mesh increases, making low-pressure, high-flow processing difficult.

[0030] Therefore, the present disclosure provides a technology capable of suppressing pressure loss and abnormal discharge near an exhaust port.

[0031] [Structure of Plasma Processing Apparatus 1]

[0032] Figure 1 It is a longitudinal sectional view showing an example of the plasma processing apparatus 1 in this embodiment. Figure 2 Yes Figure 1 FIG. 1 is a diagram showing an example of an A-A section. Figure 2 The BB cross section of the plasma processing apparatus 1 shown in FIG. 1 corresponds to Figure 1 The plasma processing apparatus 1 in this embodiment generates inductively coupled plasma (ICP) and uses the generated plasma to perform plasma processing such as etching and film formation on a rectangular substrate G. In this embodiment, the substrate G is, for example, a glass substrate for FPD.

[0033] The plasma processing apparatus 1 includes a main body 10 and a control unit 20. The main body 10 comprises an airtight processing chamber 101, for example, in the shape of a square cylinder, formed from a conductive material such as aluminum, the inner wall of which is anodized. The processing chamber 101 is grounded. The processing chamber 101 is divided into an upper and lower compartments by a dielectric wall 102. The upper surface of the dielectric wall 102 serves as an antenna chamber 103 for housing an antenna, while the lower surface of the dielectric wall 102 serves as a processing chamber 104, where plasma is generated. The dielectric wall 102 is made of ceramics such as Al2O3 or quartz, and forms the ceiling of the processing chamber 104.

[0034] A support frame 105 projecting inward is provided between a side wall 103a of the antenna chamber 103 and a side wall 104a of the processing chamber 104 in the processing container 101. The dielectric wall 102 is supported by the support frame 105.

[0035] A shower housing 111 for supplying process gas into the process chamber 104 is disposed below the dielectric wall 102. The shower housing 111 is configured in a beam shape, for example, and is suspended from the top of the antenna room 103 by a plurality of hangers (not shown).

[0036] The shower housing 111 is made of a conductive material such as aluminum with an anodized surface. A horizontally extending gas diffusion chamber 112 is formed inside the shower housing 111. A plurality of downwardly extending gas ejection holes 112a are connected to the gas diffusion chamber 112.

[0037] A gas supply pipe 121 is provided substantially at the center of the upper surface of the dielectric wall 102 so as to communicate with the gas diffusion chamber 112 of the shower housing 111. The gas supply pipe 121 extends from the top of the antenna chamber 103 to the outside of the processing container 101 and is connected to the gas supply mechanism 120.

[0038] The gas supply mechanism 120 includes a gas supply source, a flow controller such as an MFC (Mass Flow Controller), and a valve. The flow controller controls the flow rate of the process gas supplied from the gas supply source with the valve open, and supplies the process gas at the controlled flow rate to the gas supply pipe 121. Examples of the process gas include O2 gas or a mixture of O2 and CF4 gas.

[0039] The processing gas supplied from the gas supply mechanism 120 is supplied to the gas diffusion chamber 112 in the shower housing 111 via the gas supply pipe 121 and diffuses in the gas diffusion chamber 112. The processing gas diffused in the gas diffusion chamber 112 is then ejected from the gas ejection holes 112a on the lower surface of the shower housing 111 into the space within the processing chamber 104.

[0040] Antenna 113 is installed in antenna chamber 103. Antenna 113 includes an antenna wire 113a made of a highly conductive metal such as copper. Antenna wire 113a is formed into any shape, such as a loop or spiral. Antenna 113 is separated from dielectric wall 102 by a spacer 117 made of an insulating member.

[0041] Terminal 118 of antenna wire 113a is connected to one end of a power supply member 116 extending upward from antenna chamber 103. The other end of power supply member 116 is connected to one end of a power supply line 119, and the other end of power supply line 119 is connected to a high-frequency power supply 115 via a matching device 114. High-frequency power supply 115 supplies high-frequency power, for example, at a frequency of 13.56 MHz, to antenna 113 via matching device 114, power supply line 119, power supply member 116, and terminal 118. This creates an induced electric field within processing chamber 104, located below antenna 113. Due to the induced electric field formed within processing chamber 104, the processing gas supplied from shower housing 111 is converted into plasma, generating inductively coupled plasma within processing chamber 104. High-frequency power supply 115 and antenna 113 are an example of a plasma generation mechanism.

[0042] A mounting table 130 for mounting the substrate G is provided on the bottom wall 104b of the processing chamber 104 via a spacer 126 formed into a rectangular shape using an insulating member. The mounting table 130 includes a base material 131 provided on the spacer 126 and a protective member 132 formed of an insulating member and protecting the side walls of the base material 131. The base material 131 is formed into a rectangular shape corresponding to the shape of the substrate G, and the entire mounting table 130 is formed into a square plate or square column shape. The spacer 126 and the protective member 132 are made of ceramics such as alumina or an insulating material such as Teflon (a registered trademark of DuPont Co., PTFE). In addition, an electrostatic chuck (not shown) for holding the substrate G on the mounting surface on which the substrate G is mounted is formed on the upper surface of the base material 131. During the plasma treatment, the substrate G is held on the mounting table 130.

[0043] A matching box 152 and a high-frequency power supply 153 are connected to the substrate 131 via a power supply line 151. The high-frequency power supply 153 supplies high-frequency bias power to the substrate 131 via the matching box 152 and the power supply line 151. By supplying high-frequency bias power to the substrate 131 via the power supply line 151 and the matching box 152, ions are attracted toward the substrate G disposed above the substrate 131. The frequency of the high-frequency power supplied to the substrate 131 by the high-frequency power supply 153 is, for example, 3.2 MHz.

[0044] A pipe 133 is provided on the base material 131 for supplying a heat transfer gas such as He gas between the substrate G and an electrostatic chuck (not shown). Since the electrostatic chuck is used to hold the substrate G, a predetermined pressure can be applied between the substrate G and the electrostatic chuck by the heat transfer gas. By controlling the pressure of the heat transfer gas supplied between the substrate G and the base material 131 via the pipe 133, the amount of heat transferred between the base material 131 and the substrate G is adjusted. In addition, a temperature regulating mechanism and a temperature sensor (both not shown) for controlling the temperature of the substrate G are provided in the base material 131 of the stage 130. Moreover, a plurality of lifting pins (not shown) for transferring the substrate G are provided on the stage 130 in a manner that allows them to protrude and retract relative to the upper surface of the base material 131.

[0045] An opening 155 for carrying in and out the substrate G is formed in the side wall 104 a of the processing chamber 104 . The opening 155 can be opened and closed by a gate valve V. By opening the gate valve V, the substrate G can be carried in and out through the opening 155 .

[0046] For example, Figure 2 As shown, four partition members 158 are provided between the side wall 104a of the processing chamber 104 and the mounting table 130 for dividing the interior of the processing chamber 104 into a processing space 106a and an exhaust space 106b. The partition members 158 are rectangular plate-shaped members without an opening. The partition members 158 are formed of a conductive material such as metal. A partition member 158 is provided between one side of the mounting table 130 and the side wall 104a of the processing chamber 104. Each partition member 158 is grounded via the side wall 104a of the processing chamber 104.

[0047] For example, Figure 2 As shown, openings 157 for allowing gas to flow from the processing space 106a to the exhaust space 106b are formed between adjacent partition members 158. Figure 2 In the example shown in FIG. 1 , the openings 157 are located at four corners of the mounting table 130 , which is substantially rectangular in plan view.

[0048] A plurality of exhaust ports 159 are formed on the bottom wall 104b of the processing chamber 104. An exhaust mechanism 160 is provided at each exhaust port 159. The exhaust mechanism 160 includes an exhaust pipe 161 connected to the exhaust port 159; an APC (Auto Pressure Controller) valve 162, which controls the pressure within the processing chamber 104 by adjusting its opening; and a vacuum pump 163 for exhausting the processing chamber 104. By exhausting the gas within the processing chamber 104 using the vacuum pump 163 and adjusting the opening of the APC valve 162, the pressure within the processing chamber 104 is maintained at a predetermined pressure.

[0049] The control device 20 includes a memory, a processor, and an input / output interface. The processor in the control device 20 reads and executes a program stored in the memory of the control device 20 to control each component of the main body 10 via the input / output interface of the control device 20.

[0050] [Detailed Structure of Exhaust Mechanism 160]

[0051] Figure 3 FIG3 is an enlarged cross-sectional view showing an example of an exhaust mechanism 160 in this embodiment. Exhaust mechanism 160 includes an exhaust pipe 161, an APC valve 162, a vacuum pump 163, a foreign matter prevention net 164, and an exhaust net 30. The foreign matter prevention net 164 is made of a metal primarily composed of, for example, stainless steel, and prevents foreign matter from entering the vacuum pump 163.

[0052] The exhaust net 30 has a plurality of slits 34 and is arranged near the exhaust port 159 formed on the bottom wall 104b of the processing chamber 104. More specifically, the exhaust net 30 is arranged at the exhaust port 159 or the exhaust pipe 161 connected to the exhaust port 159. The exhaust net 30 is formed into a plate shape using an electrical conductor such as a metal with aluminum or stainless steel as a main component. The exhaust net 30 is supported by the exhaust pipe 161. Alternatively, the exhaust net 30 can also be supported at the exhaust port 159 by the inner wall of the exhaust port 159. The exhaust pipe 161 is made of metal and is grounded via the bottom wall 104b. Therefore, the exhaust net 30 is grounded via the exhaust pipe 161 and the bottom wall 104b. In this embodiment, the exhaust pipe 161 is formed into a roughly cylindrical shape. The central axis of the exhaust pipe 161 is defined as the axis X.

[0053] Figure 4The figure is a top view of an example of an exhaust net 30 in this embodiment. The exhaust net 30 includes multiple partition walls 32 and multiple partition walls 33. The multiple partition walls 32 are arranged concentrically, and the multiple partition walls 33 are arranged radially from the center of the concentric circles of the partition walls 32. Each partition wall 32 is formed by multiple curved plate-like portions 31 arranged circumferentially. Furthermore, each partition wall 33 is formed by multiple straight portions 37 arranged radially or radially from the center of the concentric circles. The curved plate-like portions 31 are examples of plate-like portions, the straight portions 37 are examples of straight portions, the partition wall 32 is an example of a circumferential partition wall, and the partition wall 33 is an example of a radial partition wall. Furthermore, although the multiple partition walls 33 are arranged radially, for convenience of explanation, the individual partition walls 33 forming the radial pattern will be referred to as "radial partition walls." The multiple partition walls 32 arranged concentrically are each formed by multiple curved plate-like portions 31 arranged circumferentially. The curved plate-shaped portion 31 constituting the partition wall 32 has a first surface 32a and a second surface 32b facing each other. In this embodiment, the partition wall 32 is arranged concentrically around the axis X, and the curved plate-shaped portion 31 is arranged in the circumferential direction.

[0054] The plurality of curved plate-like portions 31 constituting the partition wall 32 are arranged so that the first surface 32a and the second surface 32b extend in directions along the axis X. In this embodiment, the plurality of curved plate-like portions 31 constituting the partition wall 32 are arranged so that the first surface 32a and the second surface 32b are parallel to the axis X.

[0055] The plurality of straight portions 37 constituting the partition wall 33 are arranged radially or diametrically from the central axis (axis X) of the concentric circle in which the plurality of partition walls 32 are arranged so as to intersect the partition wall 32. The plurality of straight portions 37 constituting the partition wall 33 have a third surface 33a and a fourth surface 33b facing each other.

[0056] The plurality of straight portions 37 constituting the partition wall 33 are arranged so that the third surface 33a and the fourth surface 33b extend in directions along the axis X. In the present embodiment, the plurality of straight portions 37 constituting the partition wall 33 are arranged so that the third surface 33a and the fourth surface 33b extend in directions parallel to the axis X.

[0057] In addition, the cylindrical slit 34 is formed by the two curved plate-like portions 31 adjacent to each other in the radial direction or radial direction of the adjacent two partition walls 32 and the two linear portions 37 adjacent to each other in the circumferential direction of the adjacent two partition walls 33. When viewed from the direction along the central axis of the concentric circle of the partition wall 32, for example, Figure 4As shown, the shape of the slit 34 is an arc centered on the central axis. Furthermore, the straight portions 37 of the partition wall 33 forming the ends of the slit 34 do not necessarily need to be flat. If the ends of the slit 34 are formed with curved surfaces, the straight portions 37 will also be curved surfaces. The partition wall 33 can be formed by arranging multiple straight portions 37 so that their center lines are aligned.

[0058] In addition, the exhaust net 30 can also be formed as a whole by cutting a single plate-like member to form the partition wall 32 and the partition wall 33, but the partition wall 32 and the partition wall 33 can also be made separately as a plurality of separate members and combined to form. In this case, the plurality of partition walls 32 are respectively composed of a curved plate-like member formed by combining a plurality of curved plate-like portions 31 in the circumferential direction. In addition, the plurality of partition walls 33 are respectively composed of a straight plate-like member formed by combining a plurality of straight portions 37 in a radial direction or a radial direction. The straight plate-like member is arranged in a manner that intersects with the curved plate-like member constituting the partition wall 32 so that the long side direction is along the radial direction or the radial direction from the central axis (axis X) of the concentric circle in which the plurality of partition walls 32 are arranged. The plurality of straight plate-like members are arranged radially.

[0059] In addition, in this embodiment, at least a portion of the outer periphery of the exhaust net 30 when viewed from the direction along the central axis of the concentric circle of the partition wall 32 is in an arc shape. Figure 4 In the example, a portion of the outer periphery of the exhaust mesh 30 when viewed from a direction along the central axis of the concentric circles of the partition walls 32 is in an arc shape included in a circle centered on the central axis of the concentric circles of the partition walls 32 .

[0060] Figure 5 It is an enlarged plan view showing an example of the shape of the slits 34 of the exhaust net 30 in this embodiment. Figure 6 It is an enlarged cross-sectional view showing an example of the shape of the slits 34 of the exhaust net 30 in this embodiment. Figure 5 The slit 34 is shown as an example when viewed from the direction along the axis X. Figure 5 As shown in FIG. 1 , the narrower width of the slit 34 (the width in the radial direction or radial direction from the central axis) is defined as the width W1 of the slit 34. Figure 5 As shown in FIG. 3 , the width of the curved plate-shaped portion 31 is defined as the width W2 of the curved plate-shaped portion 31. Figure 6As shown, the thickness of the exhaust net 30 along the central axis (axis X) of the concentric circle of the partition wall 32 is defined as the thickness L of the exhaust net 30. The thickness L of the exhaust net 30 is the length of the curved plate-shaped portion 31 along the central axis and is an example of the length of the plate-shaped portion along the central axis. In this embodiment, the curved plate-shaped portion 31 constituting the partition wall 32 and the straight portion 37 constituting the partition wall 33 have the same width. In this embodiment, the width W1 is, for example, not less than 5 mm and not more than 8 mm.

[0061] In addition, for example Figure 4 As shown, in the region 35a near the central axis (axis X) of the concentric circles of the partition walls 32, the intervals between the straight portions 37 of the circumferentially adjacent partition walls 33 are narrow, and therefore the opening area of ​​the slits 34 is small. Therefore, near the central axis of the concentric circles of the partition walls 32, the conductivity of the exhaust net 30 is low. On the other hand, in the region 35b near the outer periphery of the exhaust net 30, the intervals between the straight portions 37 of the circumferentially adjacent partition walls 33 are large, and therefore the opening area of ​​the slits 34 is large, and the conductivity of the exhaust net 30 is high. Figure 4 In the exhaust net 30 shown in the example, the intervals between the straight portions 37 of the partition walls 33 increase as the distance from the central axis of the concentric circles of the partition walls 32 increases, and the opening area of ​​the slits 34 increases. Therefore, in the exhaust net 30 of this embodiment, the conductivity increases as the distance from the central axis of the concentric circles of the partition walls 32 increases.

[0062] Here, for example Figure 7 As shown, an exhaust net 30' having evenly spaced through holes 36 of the same size is used as a reference example. The gas flowing within exhaust pipe 161 tends to concentrate near the center of exhaust pipe 161 due to viscous resistance near the inner wall of exhaust pipe 161. Therefore, when using such an exhaust net 30', the flow of gas containing charged particles generated by plasma concentrates near the center of exhaust net 30', potentially causing a localized increase in pressure. This localized increase in pressure can easily lead to abnormal discharge in that area.

[0063] In contrast, in this embodiment, for example, Figure 4 As shown, the conductivity of the exhaust mesh 30 increases as the distance from the central axis of the concentric circle of the partition wall 32 increases. As a result, the airflow flowing through the exhaust pipe 161 is also dispersed to the surrounding area when passing through the exhaust mesh 30, which can suppress the pressure from being locally increased near the center and the occurrence of abnormal discharge.

[0064] [Relationship between the Thickness of the Exhaust Net 30 and the Pressure in the Processing Space 106a]

[0065] Figure 81 is a diagram showing an example of the relationship between the thickness of the exhaust net 30 and the pressure in the processing space 106a. Figure 8 The simulation results illustrated in FIG. 2 show the pressure in the processing space 106 a when the pressure in the exhaust pipe 161 is fixed at 15 mT (approximately 2.0 Pa).

[0066] In addition, Figure 8 The simulation results shown in the example are based on the Figure 7 The exhaust net 30' is shown in FIG. Figure 8 The gap shown in the example is the diameter of the opening of the through hole 36 in the reference example, and is the width W1 of the slit 34 in the embodiment. Figure 8 The beam width exemplified in the embodiment is the width W2 of the curved plate-shaped portion 31. Figure 8 The thickness shown is Figure 6 The thickness L is shown in FIG.

[0067] Reference Figure 8 In the exhaust network 30' of the reference example, the pressure in the processing space 106a is 24.0 mT, which is 9.0 mT lower than the pressure in the exhaust pipe 161. That is, a pressure loss of 9.0 mT (hereinafter referred to as pressure loss) occurs in the exhaust network 30'.

[0068] On the other hand, in the exhaust net 30 of this embodiment, when the thickness L is 15 mm or less, the pressure in the processing space 106a is lower than that of the reference example. That is, from the perspective of suppressing the pressure loss of the exhaust net 30 to be lower than that of the reference example, it is preferable that the thickness L of the exhaust net 30 is 15 mm or less. Figure 8 In the simulation, since the width W1 of the slit 34 is 5 mm, the ratio of the thickness L of the exhaust net 30 to the width W1 of the slit 34 is preferably 3 or less.

[0069] [Relationship between the Thickness of the Exhaust Net 30 and the Total Electric Field Under the Exhaust Net 30]

[0070] Figure 9 This is a diagram showing an example of the relationship between the thickness of the exhaust net 30 and the total electric field under the exhaust net 30. The "total electric field" refers to the cumulative value of the electric field in a certain area calculated by simulation, for example, Figure 9 In , the electric field in the area below the exhaust net 30 is accumulated by volume. Figure 9 In the simulation results shown in FIG, there is a tendency that the greater the thickness L of the exhaust net 30 is, the smaller the total electric field under the exhaust net 30 is.

[0071] In the experiment, the total electric field under the exhaust mesh 30 was calculated based on the measured value of the electric field when no abnormal discharge occurred, and was 4.6 mV·m 2 The total electric field under the exhaust network 30 calculated based on the actual measured value of the electric field when abnormal discharge occurs is 12.1 mV·m 2 Therefore, the total electric field under the exhaust net 30 is 4.6 mV·m 2 The following are combinations of the width W1 of the slit 34 and the thickness L of the exhaust net 30.

[0072] Reference Figure 9 If the ratio of the thickness L of the exhaust net 30 to the width W1 of the slit 34 is 2 or more, the total electric field under the exhaust net 30 becomes 4.6 mV·m 2 Therefore, from the viewpoint of preventing abnormal discharge in the exhaust mesh 30 , the ratio of the thickness L of the exhaust mesh 30 to the width W1 of the slit 34 is preferably 2 or more.

[0073] according to Figure 8 and Figure 9 Based on the simulation results, in order to satisfy both the viewpoints of suppressing the pressure loss to be lower than that of the reference example and the viewpoint of preventing abnormal discharge, the ratio of the thickness L of the exhaust mesh 30 to the width W1 of the slit 34 is preferably 2 to 3. In other words, the ratio of the length of the plate-like portion along the central axis to the width W1 of the slit 34 is preferably 2 to 3.

[0074] [Relationship between the Thickness of the Exhaust Net 30 and the Number of Particles Passing Through]

[0075] Figure 10 : is a diagram showing an example of the relationship between the thickness of the exhaust net 30 and the number of particles passing through. Figure 10 In this example, the number of particles backwashed from vacuum pump 163 that passed through exhaust net 30 or exhaust net 30' and entered processing space 106a was simulated. Specifically, the simulation examined how many of the 270 particles emitted in random directions from exhaust pipe 161 toward exhaust net 30 or exhaust net 30' passed through exhaust net 30 or exhaust net 30'. Particles that collided with exhaust net 30 (exhaust net 30') were counted as particles that subsequently did not pass through exhaust net 30 (exhaust net 30').

[0076] Reference Figure 10 In the exhaust net 30' of the reference example, 45 of the 270 particles collided with the exhaust net 30' and 225 passed through the exhaust net 30'. On the other hand, in the exhaust net 30 of the present embodiment, the number of recoil particles passing through was less than that of the reference example when the thickness of the exhaust net 30 was within the range of 5 to 15 mm. Figure 10In the exhaust net 30 of the present embodiment in the example of FIG, the width W1 of the slit 34 is 5 mm.

[0077] according to Figure 10 According to the simulation results, when the ratio of the thickness L of the exhaust net 30 to the width W1 of the slit 34 is in the range of 2 to 3, the number of recoil particles passing therethrough can be reduced compared to the reference example.

[0078] [Plasma treatment method]

[0079] Figure 11 This is a flowchart showing an example of a plasma processing method. Figure 11 Each process illustrated in FIG is realized by the control device 20 controlling each part of the main body 10 .

[0080] First, the substrate G is introduced into the processing chamber 104 (step S10). In step S10, the gate valve V is opened, and the substrate G is introduced into the processing chamber 104 through the opening 155 and placed on the mounting table 130. Then, the gate valve V is closed.

[0081] Next, a processing gas is supplied to the processing space 106a (step S11). Step S11 is an example of step a). In step S11, the processing gas is supplied from the gas supply mechanism 120 via the gas supply pipe 121 to the gas diffusion chamber 112 in the spray housing 111, and diffuses within the gas diffusion chamber 112. The processing gas diffused within the gas diffusion chamber 112 is then ejected from the gas ejection holes 112a on the lower surface of the spray housing 111 into the processing space 106a. The processing gas supplied to the processing space 106a is exhausted through the exhaust net 30 of the exhaust mechanism 160.

[0082] Next, the pressure within the processing space 106a is adjusted using the exhaust mechanism 160 (step S12). Step S12 is an example of step b). In step S12, the pressure within the processing space 106a is adjusted to a predetermined pressure by exhausting the processing gas within the processing space 106a via the exhaust network 30 using the vacuum pump 163 and adjusting the opening of the APC valve 162.

[0083] Next, plasma is generated within processing space 106a (step S13). In step S13, high-frequency power, for example, at a frequency of 13.56 MHz, is supplied from high-frequency power supply 115 to antenna 113 via matching unit 114, power supply line 119, power supply member 116, and terminal 118. The inductive electric field formed within processing space 106a below antenna 113 then converts the processing gas supplied from shower housing 111 into plasma, generating inductively coupled plasma within processing space 106a.

[0084] Next, it is determined whether a predetermined time has passed (step S14). The predetermined time refers to the time required to perform a predetermined treatment on the substrate G using the plasma generated in step S13. If the predetermined time has not passed (step S14: No), the process shown in step S14 is performed again. Instead of determining whether a predetermined time has passed, a determination based on endpoint detection using a spectrophotometer may be used. In addition, when applying a predetermined treatment to the substrate G, by adjusting the opening of the APC valve 162 while exhausting the treatment gas while supplying the treatment gas, it is possible to maintain a certain pressure or change it to a preset pressure while applying the treatment to the substrate G.

[0085] If the predetermined time has elapsed (step S14: Yes), plasma generation within processing space 106a is stopped (step S15). In step S15, plasma generation is stopped by stopping the supply of high-frequency power from high-frequency power supply 115. The supply of processing gas is also stopped at this time. Steps S13 to S15 are an example of step c).

[0086] Next, the processing gas in the processing space 106 a is exhausted (step S16 ). In step S16 , the processing gas in the processing space 106 a is exhausted through the exhaust network 30 by the vacuum pump 163 .

[0087] Next, the substrate G is carried out from the processing space 106a (step S17). In step S17, the gate valve V is opened, and the substrate G is carried out from the processing space 106a through the opening 155. Then, the plasma processing method shown in this flowchart ends.

[0088] The above is a description of the embodiment. As described above, the exhaust net (exhaust net 30) in this embodiment is provided at the exhaust port (exhaust port 159) of the processing container (processing container 101) for treating the substrate (substrate G) using the plasma generated inside, or at the exhaust pipe (exhaust pipe 161) connected to the exhaust port. The exhaust net comprises: a plurality of circumferential partition walls (partition walls 32) arranged concentrically; and a plurality of radial partition walls (partition walls 33) arranged radially. The circumferential partition walls are respectively formed to have a plurality of plate-like portions (curved plate-like portions 31) arranged in the circumferential direction, and the plate-like portions (curved plate-like portions 31) have a first surface (first surface 32a) and a second surface (second surface 32b) relative to each other and are formed of an electrical conductor. In addition, the circumferential partition walls are arranged in such a manner that the extension direction of the first surface and the second surface of each plate-like portion becomes a direction along the central axis of the concentric circle. The radial partition walls are formed so that a plurality of them are arranged in a radial direction or radial direction from the central axis in such a manner that a straight portion (straight portion 37) intersects with a circumferential partition wall. In addition, the radial partition walls are arranged so that the third surface (third surface 33a) and the fourth surface (fourth surface 33b) of each straight portion are in a direction along the central axis of the concentric circle. In addition, a cylindrical slit (slit 34) is formed, which is surrounded by two plate-like portions adjacent in a radial direction or radial direction from the central axis among the plurality of circumferential partition walls and two straight portions adjacent in a circumferential direction among the plurality of radial partition walls. The shape of the cylindrical slit is an arc centered on the central axis when viewed from the direction along the central axis. In addition, the ratio of the length (L) of the plate-like portion in the direction along the central axis to the width (W1) of the slit when viewed from the direction along the central axis is greater than 2 and less than 3. Thus, pressure loss and abnormal discharge near the exhaust port can be suppressed.

[0089] Furthermore, in the above-described embodiment, each plate-like portion is arranged so that the first surface and the second surface are parallel to the central axis of the circumferential partition wall.

[0090] In the above embodiment, at least part of the outer periphery of the exhaust net is arc-shaped when viewed along the central axis of the circumferential partition wall. This allows the exhaust net 30 to be easily arranged at the opening of the exhaust port 159 .

[0091] In the above embodiment, at least a portion of the outer periphery of the exhaust net, when viewed along the central axis of the circumferential partition wall, is arc-shaped and contained within a circle centered on the central axis of the circumferential partition wall. This facilitates placement of the exhaust net 30 within the opening of the exhaust port 159.

[0092] In the above embodiment, the width of the slit when viewed from the direction along the central axis of the circumferential partition wall is 5 mm or more and 8 mm or less. This can increase the conductivity of the exhaust mesh.

[0093] In the above embodiment, the slit conductivity increases as it moves away from the central axis of the circumferential partition wall. This can suppress a local pressure increase near the center of the exhaust mesh 30 and prevent abnormal discharge.

[0094] In addition, the plasma processing apparatus (plasma processing apparatus 1) in the above-mentioned embodiment includes a processing container (processing container 101), a mounting table (mounting table 130), a gas supply mechanism (gas supply mechanism 120), an exhaust mechanism (exhaust mechanism 160) and a plasma generating mechanism (high-frequency power supply 115, antenna 113). The processing container accommodates the substrate (substrate G). The mounting table is provided in the processing container and mounts the substrate. The gas supply mechanism supplies processing gas into the processing container. The exhaust mechanism has an exhaust net (exhaust net 30) configured at an exhaust port (exhaust port 159) or an exhaust pipe (exhaust pipe 161) connected to the exhaust port, and discharges the gas in the processing container through the exhaust net. The plasma generating mechanism generates plasma in the processing container by plasma-forming the processing gas supplied to the processing container. The exhaust net has a plurality of circumferential partition walls (partition walls 32) and a plurality of radial partition walls (partition walls 33). The circumferential partition walls are each formed by circumferentially arranging a plurality of plate-like portions (curved plate-like portions 31), each of which has a first surface (first surface 32a) and a second surface (second surface 32b) facing each other and formed of an electrical conductor. Furthermore, the circumferential partition walls are arranged so that the first and second surfaces of each plate-like portion extend in a direction along the central axis of the concentric circles. The radial partition walls are each formed by arranging a plurality of straight portions (straight portions 37) in a radial direction or radial direction from the central axis, with the straight portions intersecting the circumferential partition walls. Furthermore, the radial partition walls are arranged so that the third surface (third surface 33a) and the fourth surface (fourth surface 33b) of each straight portion extend in a direction along the central axis of the concentric circles. Furthermore, a cylindrical slit (slit 34) is formed, which is surrounded by two plate-like portions adjacent in a radial direction or radial direction from the central axis of the plurality of circumferential partition walls and two straight portions adjacent in the circumferential direction of the plurality of radial partition walls. The cylindrical slit is shaped like an arc centered on the central axis when viewed along the central axis. Furthermore, the ratio of the length (L) of the plate-like portion along the central axis to the width (W1) of the slit when viewed along the central axis is greater than 2 and less than 3. This reduces pressure loss and abnormal discharge near the exhaust port.

[0095] In the above-described embodiment, the central axis of the circumferential partition wall coincides with the central axis of the exhaust pipe, thereby making it possible to easily arrange the exhaust mesh 30 at the opening of the exhaust port 159 .

[0096] In addition, the above embodiment is a plasma treatment method in a plasma treatment device (plasma treatment device 1). The plasma treatment device includes a treatment container (treatment container 101), a mounting table (mounting table 130), a gas supply mechanism (gas supply mechanism 120), an exhaust mechanism (exhaust mechanism 160), a plasma generating mechanism (high-frequency power supply 115, antenna 113) and a control device (control device 20). The treatment container stores a substrate (substrate G). The mounting table is provided in the treatment container and carries the substrate. The gas supply mechanism supplies treatment gas into the treatment container. The exhaust mechanism has an exhaust net (exhaust net 30) configured at an exhaust port (exhaust port 159) or an exhaust pipe (exhaust pipe 161) connected to the exhaust port, and discharges the gas in the treatment container through the exhaust net. The plasma generating mechanism generates plasma in the treatment container by plasma-forming the treatment gas supplied to the treatment container. The exhaust net has a plurality of circumferential partition walls (partition walls 32) and a plurality of radial partition walls (partition walls 33). The circumferential partition walls are each formed by circumferentially arranging a plurality of plate-like portions (curved plate-like portions 31), each of which has a first surface (first surface 32a) and a second surface (second surface 32b) facing each other and formed of an electrical conductor. Furthermore, the circumferential partition walls are arranged so that the first and second surfaces of each plate-like portion extend in a direction along the central axis of the concentric circles. The radial partition walls are each formed by arranging a plurality of straight portions (straight portions 37) in a radial direction or radial direction from the central axis, with the straight portions intersecting the circumferential partition walls. Furthermore, the radial partition walls are arranged so that the third surface (third surface 33a) and the fourth surface (fourth surface 33b) of each straight portion extend in a direction along the central axis of the concentric circles. Furthermore, a cylindrical slit (slit 34) is formed, which is surrounded by two plate-like portions adjacent in a radial direction or radial direction from the central axis of the plurality of circumferential partition walls and two straight portions adjacent in the circumferential direction of the plurality of radial partition walls. The shape of the cylindrical slit is an arc centered on the central axis when viewed from the direction along the central axis. In addition, the ratio of the length (L) of the plate-like portion in the direction along the central axis to the width (W1) of the slit when viewed from the direction along the central axis is greater than 2 and less than 3. The control device performs steps a), b), and c). In step a), the gas supply mechanism is controlled to supply a processing gas into the processing container. In step b), the exhaust mechanism is controlled to discharge the gas in the processing container through the exhaust net. In step c), the plasma generating mechanism is controlled to plasmatize the processing gas supplied to the processing container, and the substrate on the mounting table is processed using plasma. In this way, pressure loss and abnormal discharge near the exhaust port can be suppressed.

[0097] [other]

[0098] In addition, the technology disclosed in the present application is not limited to the above-described embodiment, and various modifications can be made within the scope of the gist of the technology.

[0099] For example, in the above-mentioned embodiment, for example Figure 4 As shown, a portion of the outer periphery of the exhaust mesh 30 viewed from the direction along the central axis (axis X) of the concentric circles of the partition wall 32 has an arc shape included in a circle centered on the central axis of the concentric circles of the partition wall 32. However, the disclosed technology is not limited thereto.

[0100] As another example, for the exhaust net 30, for example Figure 12 As shown, the outer periphery of the exhaust mesh 30 when viewed from the direction along the central axis (axis X) of the concentric circles of the partition walls 32 may have a circular shape centered on the central axis of the concentric circles of the partition walls 32 .

[0101] Or, as another example, for the exhaust net 30, for example Figure 13 As shown, the outer periphery of the exhaust mesh 30 when viewed from the direction along the central axis (axis X) of the concentric circle of the partition wall 32 may also be rectangular.

[0102] In addition, in the above-mentioned embodiment, for example Figure 6 As shown, the plurality of curved plate-like portions 31 constituting the partition wall 32 are arranged in such a manner that the first surface 32a and the second surface 32b are parallel to the central axis (axis X) of the concentric circle of the partition wall 32. However, the disclosed technology is not limited thereto. As another example, for example Figure 14 As shown, the first surfaces 32 a and the second surfaces 32 b of the plurality of curved plate-shaped portions 31 constituting the partition wall 32 may be arranged along the axis X, but not parallel to the axis X. The same applies to the partition wall 33 .

[0103] In addition, in the above embodiment, the center axis of the concentric circle (axis X) defines the center axis of the exhaust pipe 161 as axis X, but any axis in the exhaust pipe 161 that is parallel to the center axis of the exhaust pipe 161 can also be set as the center axis of the concentric circle (axis X).

[0104] In the above embodiment, an inductively coupled plasma processing apparatus including a dielectric window is described as an example of the plasma processing apparatus 1 . However, the disclosed technology can also be applied to an inductively coupled plasma processing apparatus including a metal window instead of a dielectric window.

[0105] In the above embodiment, inductively coupled plasma is cited as an example of a plasma source, but the disclosed technology can also be applied to other plasma processing apparatuses. Examples of plasma sources other than inductively coupled plasma include capacitively coupled plasma (CCP), microwave-excited surface wave plasma (SWP), electron cyclotron resonance plasma (ECP), and helicon excited plasma (HWP).

[0106] Furthermore, the embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. In practice, the embodiments described above can be implemented in a variety of forms. Furthermore, the embodiments described above may be omitted, replaced, or modified in various forms without departing from the appended claims and their spirit.

Claims

1. An exhaust net provided at an exhaust port of a processing container for processing a substrate using plasma generated therein or an exhaust pipe connected to the exhaust port, wherein: The exhaust net has: a plurality of circumferential partition walls arranged concentrically; and A plurality of radial partition walls are arranged radially from the central axis of the concentric circles in a radial direction or radial direction. The circumferential partition wall is provided with a plurality of plate-like portions in the circumferential direction, each of the plate-like portions having a first surface and a second surface facing each other and being formed of an electrical conductor, wherein the first surface and the second surface of each of the plate-like portions extend in a direction along the central axis of the concentric circles. The radial partition walls are each provided with a plurality of straight portions in a radial direction or radial direction from the central axis so as to intersect with the circumferential partition walls, the straight portions having a third surface and a fourth surface facing each other and being formed of an electrical conductor, and the radial partition walls are arranged so that the third surface and the fourth surface of each of the straight portions extend in a direction along the central axis of the concentric circles. The shape of the cylindrical slit surrounded by two of the plate-like portions adjacent in the radial direction or radial direction from the central axis of the plurality of circumferential partition walls and two of the linear portions adjacent in the circumferential direction of the plurality of radial partition walls is an arc shaped with the central axis as the center when viewed from the direction along the central axis. A ratio of a length of the plate-shaped portion in a direction along the central axis to a width of the slit when viewed from a direction along the central axis is 2 or more and 3 or less.

2. The exhaust net according to claim 1, wherein Each of the plate-like portions is arranged such that the first surface and the second surface are parallel to the central axis, and each of the linear portions is arranged such that the third surface and the fourth surface are parallel to the central axis.

3. The exhaust net according to claim 1 or 2, wherein: At least a portion of the outer periphery of the exhaust net when viewed from a direction along the central axis has an arc shape.

4. The exhaust net according to claim 3, wherein: At least a portion of the outer periphery of the exhaust net when viewed from a direction along the central axis has an arc shape included in a circle centered on the central axis.

5. The exhaust net according to claim 1 or 2, wherein: The outer periphery of the exhaust mesh has a rectangular shape when viewed from a direction along the central axis.

6. The exhaust net according to claim 1, wherein The width of the slit when viewed in a direction along the central axis is 5 mm or more and 8 mm or less.

7. The exhaust net according to claim 1, wherein The further away from the central axis, the greater the conductivity of the slit.

8. A plasma processing apparatus, wherein: The plasma processing device comprises: a processing container for receiving a substrate; a mounting table disposed in the processing container and mounting the substrate; a gas supply mechanism for supplying a processing gas into the processing container; an exhaust mechanism having an exhaust net disposed at the exhaust port or an exhaust pipe connected to the exhaust port, and exhausting the gas in the processing container through the exhaust net; as well as a plasma generating mechanism for generating plasma in the processing container by converting the processing gas supplied into plasma. The exhaust network has: a plurality of circumferential partition walls arranged concentrically; and A plurality of radial partition walls are arranged radially from the central axis of the concentric circles in a radial direction or radial direction. The circumferential partition wall is provided with a plurality of plate-like portions in the circumferential direction, each of the plate-like portions having a first surface and a second surface facing each other and being formed of an electrical conductor, wherein the first surface and the second surface of each of the plate-like portions extend in a direction along the central axis of the concentric circles. The radial partition walls are each provided with a plurality of straight portions in a radial direction or radial direction from the central axis so as to intersect with the circumferential partition walls, the straight portions having a third surface and a fourth surface facing each other and being formed of an electrical conductor, and the radial partition walls are arranged so that the third surface and the fourth surface of each of the straight portions extend in a direction along the central axis of the concentric circles. The shape of the cylindrical slit surrounded by two of the plate-like portions adjacent in the radial direction or radial direction from the central axis of the plurality of circumferential partition walls and two of the linear portions adjacent in the circumferential direction of the plurality of radial partition walls is an arc shaped with the central axis as the center when viewed from the direction along the central axis. A ratio of a length of the plate-shaped portion in a direction along the central axis to a width of the slit when viewed from a direction along the central axis is 2 or more and 3 or less.

9. The plasma processing apparatus according to claim 8, wherein: The central axis is consistent with the central axis of the exhaust pipe.

10. A plasma processing method, comprising: a processing container for receiving a substrate; a mounting table disposed in the processing container and mounting the substrate; a gas supply mechanism for supplying a processing gas into the processing container; an exhaust mechanism having an exhaust net disposed at the exhaust port or an exhaust pipe connected to the exhaust port, and exhausting the gas in the processing container through the exhaust net; a plasma generating mechanism for generating plasma in the processing container by converting the processing gas supplied into plasma; as well as control device, The exhaust network has: a plurality of circumferential partition walls arranged concentrically; and A plurality of radial partition walls are arranged radially from the central axis of the concentric circles in a radial direction or radial direction. The circumferential partition wall is provided with a plurality of plate-like portions in the circumferential direction, each of the plate-like portions having a first surface and a second surface facing each other and being formed of an electrical conductor, wherein the first surface and the second surface of each of the plate-like portions extend in a direction along the central axis of the concentric circles. The radial partition walls are each provided with a plurality of straight portions in a radial direction or radial direction from the central axis so as to intersect with the circumferential partition walls, the straight portions having a third surface and a fourth surface facing each other and being formed of an electrical conductor, and the radial partition walls are arranged so that the third surface and the fourth surface of each of the straight portions extend in a direction along the central axis of the concentric circles. The shape of the cylindrical slit surrounded by two of the plate-like portions adjacent in the radial direction or radial direction from the central axis of the plurality of circumferential partition walls and two of the linear portions adjacent in the circumferential direction of the plurality of radial partition walls is an arc shaped with the central axis as the center when viewed from the direction along the central axis. The ratio of the length of the plate-like portion in the direction along the central axis to the width of the slit when viewed from the direction along the central axis is 2 or more and 3 or less. In this plasma treatment method, The control device performs: Step a, supplying a processing gas into the processing container by controlling the gas supply mechanism; Step b, exhausting the gas in the processing container through the exhaust net by controlling the exhaust mechanism; as well as In step c, the plasma generating mechanism is controlled to convert the processing gas supplied into plasma, thereby processing the substrate on the mounting table using the plasma.

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