Exhaust network, plasma processing apparatus, and plasma processing method

Abstract

To suppress a pressure loss and an abnormal discharge in a vicinity of an exhaust port.SOLUTION: An exhaust network comprises: a plurality of circumferential partition walls and a plurality of radial partition walls. In each of the circumferential partition walls, a plurality of plate-shaped parts formed of an electrical conductor having first and second surfaces opposed to each other are arranged in a circumferential direction, and extending directions of the first and second surfaces of each plate-shaped part are arranged in a direction along the central axis of the concentric circle. A plurality of the radial partition walls are arranged in a radial direction from a central axis so that a straight part intersects the circumferential partition walls, and the extending directions of a third surface and a fourth surface of each of the straight part is arranged in a direction along the central axis of the concentric circle. Further, the shape of a slit surrounded by two adjacent plate-shaped parts of the plurality of circumferential partition walls and two adjacent straight parts of the plurality of radial partition walls is an arc shape centered on the central axis when viewed from the direction along the central axis. Also, a ratio of the length of the plate-shaped part 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.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] Patent Document 1 listed below discloses that "the mesh member 30 is disposed near an exhaust port 159 formed in the bottom wall 104b of the processing chamber 104. The mesh member 30 is formed in a plate shape from a metal whose main component is 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 listed below also discloses that "the mesh member 30 has a plurality of through holes 31 formed therethrough in the thickness direction of the mesh member 30. In this embodiment, the opening of each through hole 31 has a circular shape. This makes it possible to suppress concentration of an electric field at the opening of the through hole 31." [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-188194 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides an exhaust network, a plasma processing apparatus, and a plasma processing method that can suppress pressure loss and abnormal discharge near an exhaust port. [Means for solving the problem]

[0005] An exhaust network according to one aspect of the present disclosure is an exhaust network installed at an exhaust port of a processing vessel that processes a substrate using plasma generated therein or at an exhaust pipe connected to the exhaust port. The exhaust network includes a plurality of circumferential partition walls arranged concentrically and a plurality of radial partition walls arranged radially. Each of the circumferential partition walls is formed by a plurality of plate-shaped portions arranged in the circumferential direction, each plate-shaped portion having opposing first and second surfaces and made of an electrical conductor. The circumferential partition walls are arranged such that the extension directions of the first and second surfaces of each plate-shaped portion are aligned along the central axis of the concentric circle. Each of the radial partition walls is formed by a plurality of radially or diametrically arranged partition walls from the central axis such that the linear portions intersect with the circumferential partition walls. The radial partition walls are arranged such that the extension directions of the third and fourth surfaces of each linear portion are aligned along the central axis of the concentric circle. The cylindrical slit, which is surrounded by two adjacent plate-like portions in the radial direction or the center axis of the circumferential partition walls and two adjacent linear portions in the circumferential direction of the radial partition walls, has an arc shape centered on the central axis when viewed along the central axis. The ratio of the length of the plate-like portions in the direction along the central axis to the width of the slit when viewed along the central axis is 2 or more and 3 or less. [Effects of the Invention]

[0006] According to various aspects and embodiments of the present disclosure, pressure loss and abnormal discharge near the exhaust port can be suppressed. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of a plasma processing apparatus according to this embodiment. [Figure 2] FIG. 2 is a diagram showing an example of a cross section taken along line AA in FIG. [Figure 3] FIG. 3 is an enlarged cross-sectional view showing an example of an exhaust mechanism in this embodiment. [Figure 4] FIG. 4 is a plan view showing an example of an exhaust network in this embodiment. [Figure 5]FIG. 5 is an enlarged plan view showing an example of the shape of the slits in the exhaust mesh in this embodiment. [Figure 6] FIG. 6 is an enlarged cross-sectional view showing an example of the shape of the slits of the exhaust mesh in this embodiment. [Figure 7] FIG. 7 is a plan view showing an example of an exhaust network in a reference example. [Figure 8] FIG. 8 is a diagram showing an example of the relationship between the thickness of the exhaust network and the pressure in the processing space. [Figure 9] FIG. 9 is a diagram showing an example of the relationship between the thickness of the exhaust net and the total electric field below the exhaust net. [Figure 10] FIG. 10 is a diagram showing an example of the relationship between the thickness of the exhaust network and the number of particles passing through. [Figure 11] FIG. 11 is a flowchart showing an example of a plasma processing method. [Figure 12] FIG. 12 is a plan view showing another example of an exhaust network. [Figure 13] FIG. 13 is a plan view showing another example of an exhaust network. [Figure 14] FIG. 14 is an enlarged cross-sectional view showing another example of the slits in the exhaust mesh. DETAILED DESCRIPTION OF THE INVENTION

[0008] The following describes in detail embodiments of an exhaust network, a plasma processing apparatus, and a plasma processing method with reference to the drawings. Note that the following embodiments do not limit the disclosed exhaust network, plasma processing apparatus, and plasma processing method. Furthermore, the following embodiments can be appropriately combined within the scope of not causing any contradiction between the configurations and processing contents of the present disclosure.

[0009] Recently, with the miniaturization of FPD (Flat Panel Display) processes, there is a demand for process conditions with lower pressure and higher flow rate, and higher power. However, in high-power processes, abnormal discharges can occur near the exhaust network. Furthermore, if the exhaust network is made thicker to suppress abnormal discharges, the pressure loss in the network increases, making it difficult to process at low pressure and high flow rate.

[0010] Therefore, the present disclosure provides a technique that can suppress pressure loss and abnormal discharge near the exhaust port.

[0011] [Configuration of plasma processing apparatus 1] FIG. 1 is a longitudinal sectional view showing an example of a plasma processing apparatus 1 according to this embodiment. FIG. 2 is a plan view showing an example of the AA cross section of FIG. 1. The BB cross section of the plasma processing apparatus 1 shown in FIG. 2 corresponds to FIG. 1. The plasma processing apparatus 1 according to this embodiment generates inductively coupled plasma (ICP) and performs plasma processing such as etching and film formation on a rectangular substrate G using the generated plasma. In this embodiment, the substrate G is, for example, a glass substrate for an FPD.

[0012] The plasma processing apparatus 1 includes a main body 10 and a control device 20. The main body 10 includes an airtight processing chamber 101 having a rectangular cylindrical shape and an inner wall surface formed of a conductive material such as anodized aluminum. The processing chamber 101 is grounded. The processing chamber 101 is divided into upper and lower sections by a dielectric wall 102. The upper surface of the dielectric wall 102 constitutes an antenna chamber 103 in which an antenna is housed, and the lower surface of the dielectric wall 102 constitutes a processing chamber 104 in which plasma is generated. The dielectric wall 102 is made of ceramics such as Al2O3 or quartz, and forms the ceiling wall of the processing chamber 104.

[0013] A support shelf 105 protruding 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 vessel 101. The dielectric wall 102 is supported by the support shelf 105.

[0014] A shower housing 111 for supplying processing gas into the processing chamber 104 is disposed below the dielectric wall 102. The shower housing 111 is configured, for example, in the shape of a beam, and is suspended from the ceiling of the antenna room 103 by a plurality of suspenders (not shown).

[0015] 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 gas discharge holes 112a extending downward communicate with the gas diffusion chamber 112.

[0016] A gas supply pipe 121 is provided at approximately 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 passes through from the ceiling of the antenna chamber 103 to the outside of the processing vessel 101 and is connected to a gas supply mechanism 120.

[0017] The gas supply mechanism 120 includes a gas supply source, a flow rate controller such as an MFC (Mass Flow Controller), and a valve. With the valve open, the flow rate controller controls the flow rate of the process gas supplied from the gas supply source, and supplies the process gas with the controlled flow rate to the gas supply pipe 121. The process gas is, for example, O2 gas or a mixed gas of O2 gas and CF4 gas.

[0018] 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 within the gas diffusion chamber 112. The processing gas that has diffused within the gas diffusion chamber 112 is then discharged into the space within the processing chamber 104 from the gas discharge holes 112a on the bottom surface of the shower housing 111.

[0019] An antenna 113 is disposed within the antenna chamber 103. The antenna 113 has an antenna wire 113a made of a highly conductive metal such as copper. The antenna wire 113a is formed in any shape, such as a ring or a spiral. The antenna 113 is separated from the dielectric wall 102 by a spacer 117 made of an insulating material.

[0020] One end of a power supply member 116 extending above the antenna chamber 103 is connected to a terminal 118 of the antenna wire 113a. One end of a power supply line 119 is connected to the other end of the power supply member 116, and the other end of the power supply line 119 is connected to a high-frequency power supply 115 via a matching box 114. The high-frequency power supply 115 supplies high-frequency power of, for example, 13.56 MHz to the antenna 113 via the matching box 114, the power supply line 119, the power supply member 116, and the terminal 118. This generates an inductive electric field in the processing chamber 104 below the antenna 113. The inductive electric field formed in the processing chamber 104 converts the processing gas supplied from the shower housing 111 into plasma, generating inductively coupled plasma in the processing chamber 104. The high-frequency power supply 115 and the antenna 113 are an example of a plasma generation mechanism.

[0021] A mounting table 130 on which a substrate G is placed is disposed on the bottom wall 104b of the processing chamber 104 via a rectangular spacer 126 made of an insulating material. The mounting table 130 includes a base 131 provided on the spacer 126 and a protective member 132 made of an insulating material and covering the sidewall of the base 131. The base 131 has a rectangular shape corresponding to the shape of the substrate G, and the entire mounting table 130 is formed in the shape of a square plate or a square pillar. The spacer 126 and the protective member 132 are made of an insulating material such as ceramics such as alumina or Teflon (PTFE, a registered trademark of DuPont). An electrostatic chuck (not shown) for holding the substrate G is formed on the mounting surface of the base 131 on which the substrate G is placed, and the substrate G is held on the mounting table 130 during plasma processing.

[0022] A matching box 152 and a high-frequency power supply 153 are connected to the substrate 131 via a power feed line 151. The high-frequency power supply 153 supplies high-frequency bias power to the substrate 131 via the power feed line 151 and the matching box 152. When the high-frequency bias power is supplied to the substrate 131 via the power feed line 151 and the matching box 152, ions are attracted to the substrate G arranged 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.

[0023] The base 131 is provided with a pipe 133 for supplying a heat transfer gas, such as He gas, between the substrate G and an electrostatic chuck (not shown). Because the substrate G is held by the electrostatic chuck, a predetermined pressure can be applied between the substrate G and the electrostatic chuck by the heat transfer gas. The amount of heat transferred between the base 131 and the substrate G is adjusted by controlling the pressure of the heat transfer gas supplied between the substrate G and the base 131 via the pipe 133. A temperature adjustment mechanism and a temperature sensor (neither of which are shown) for controlling the temperature of the substrate G are provided within the base 131 of the mounting table 130. Furthermore, the mounting table 130 is provided with a plurality of lift pins (not shown) that can be raised and lowered relative to the upper surface of the base 131 for transferring the substrate G.

[0024] An opening 155 for loading and unloading a substrate G is formed in the sidewall 104a of the processing chamber 104, and the opening 155 can be opened and closed by a gate valve V. When the gate valve V is opened, the substrate G can be loaded and unloaded through the opening 155.

[0025] As shown in FIG. 2, for example, four partition members 158 are provided between the sidewall 104a of the processing chamber 104 and the mounting table 130 to separate the processing chamber 104 into a processing space 106a and an exhaust space 106b. The partition members 158 are rectangular plate-shaped members without openings. The partition members 158 are formed of a conductive material such as metal. One partition member 158 is provided between one of the side surfaces of the mounting table 130 and the sidewall 104a of the processing chamber 104. Each partition member 158 is grounded via the sidewall 104a of the processing chamber 104.

[0026] 2, openings 157 through which gas flows from the processing space 106a to the exhaust space 106b are formed between adjacent partition members 158. In the example of Fig. 2, the openings 157 are located at the four corners of the mounting table 130, which has a substantially rectangular shape in a plan view.

[0027] A plurality of exhaust ports 159 are formed in the bottom wall 104b of the processing chamber 104. An exhaust mechanism 160 is provided for 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 that controls the pressure inside the processing chamber 104 by adjusting its opening, and a vacuum pump 163 for exhausting the inside of the processing chamber 104. Gas inside the processing chamber 104 is exhausted by the vacuum pump 163, and the pressure inside the processing chamber 104 is maintained at a predetermined pressure by adjusting the opening of the APC valve 162.

[0028] The control device 20 has 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 in the control device 20, thereby controlling each part of the main body 10 via the input / output interface of the control device 20.

[0029] [Details of Exhaust Mechanism 160] 3 is an enlarged cross-sectional view showing an example of an exhaust mechanism 160 in this embodiment. The 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 network 30. The foreign matter prevention net 164 is made of a metal whose main component is, for example, stainless steel, and prevents foreign matter from entering the vacuum pump 163.

[0030] The exhaust network 30 has a plurality of slits 34 and is installed near an exhaust port 159 formed in the bottom wall 104b of the processing chamber 104. More specifically, the exhaust network 30 is installed in the exhaust port 159 or in an exhaust pipe 161 connected to the exhaust port 159. The exhaust network 30 is formed in a plate shape using an electrical conductor such as a metal primarily composed of aluminum or stainless steel. The exhaust network 30 is supported by the exhaust pipe 161. Alternatively, the exhaust network 30 may 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 network 30 is grounded via the exhaust pipe 161 and the bottom wall 104b. In this embodiment, the exhaust pipe 161 is formed in a substantially cylindrical shape. The central axis of the exhaust pipe 161 is defined as axis X.

[0031] FIG. 4 is a plan view showing an example of an exhaust network 30 according to this embodiment. The exhaust network 30 has a plurality of partition walls 32 and a plurality of partition walls 33. The plurality of partition walls 32 are arranged concentrically, and the plurality of partition walls 33 are arranged radially from the center of the concentric circle of the partition walls 32. Each partition wall 32 is formed of a plurality of curved plate-like portions 31 arranged in the circumferential direction. Each partition wall 33 is formed of a plurality of straight portions 37 arranged radially or in the radial direction from the center of the concentric circle. The curved plate-like portions 31 are an example of a plate-like portion, the straight portions 37 are an example of a straight portion, the partition walls 32 are an example of a circumferential partition wall, and the partition walls 33 are an example of a radial partition wall. Note that, although the arrangement of the plurality of partition walls 33 forms a radial pattern, for convenience of explanation, the individual partition walls 33 forming the radial pattern will be referred to as a "radial partition wall." The plurality of concentrically arranged partition walls 32 are each composed of a plurality of curved plate-like portions 31 arranged in the circumferential direction. The curved plate-like portions 31 constituting the partition walls 32 have opposing first and second surfaces 32a and 32b. In this embodiment, the partition walls 32 are arranged concentrically about the axis X, and the curved plate-like portions 31 are arranged in the circumferential direction.

[0032] The curved plate portions 31 constituting the partition wall 32 are arranged such that the extension directions of the first surfaces 32a and the second surfaces 32b are aligned along the axis X. In this embodiment, the curved plate portions 31 constituting the partition wall 32 are arranged such that the first surfaces 32a and the second surfaces 32b are parallel to the axis X.

[0033] The plurality of linear portions 37 constituting the partition wall 33 are arranged in a radial direction or a center axis (axis X) of the concentric circle on which the plurality of partition walls 32 are arranged, so as to intersect with the partition walls 32. The plurality of linear portions 37 constituting the partition wall 33 have a third surface 33a and a fourth surface 33b facing each other.

[0034] The plurality of linear portions 37 constituting the partition wall 33 are arranged such that the extension directions of the third surface 33a and the fourth surface 33b are parallel to the axis X. In this embodiment, the plurality of linear portions 37 constituting the partition wall 33 are arranged such that the extension directions of the third surface 33a and the fourth surface 33b are parallel to the axis X.

[0035] Furthermore, two curved plate-like portions 31 adjacent to each other in the radial direction or the diametrical direction in two adjacent partition walls 32 and two straight portions 37 adjacent to each other in the circumferential direction in two adjacent partition walls 33 form a cylindrical slit 34. When viewed from a direction along the central axis of the concentric circles of the partition walls 32, the shape of the slit 34 is an arc shape centered on the central axis, as shown in FIG. 4, for example. Note that the straight portions 37 of the partition walls 33 that form the ends of the slit 34 do not necessarily have to be flat, and when both ends of the slit 34 are formed as curved surfaces, the straight portions 37 also become curved surfaces. It is sufficient that the center lines of the plurality of straight portions 37 are arranged on the same line to form the partition wall 33.

[0036] Furthermore, the exhaust network 30 may be formed by forming the partition walls 32 and 33 as a single unit by a method such as machining from a single plate-like member, or by forming the partition walls 32 and 33 as multiple individual members and combining them. In this case, each of the multiple partition walls 32 is made of a curved plate-like member with multiple curved plate-like portions 31 connected in the circumferential direction. Also, each of the multiple partition walls 33 is made of a straight plate-like member with multiple straight portions 37 connected in the radial or radial direction. The straight plate-like members are arranged so that their longitudinal directions extend radially or radially from the central axis (axis X) of the concentric circle on which the multiple partition walls 32 are arranged, so as to intersect with the curved plate-like members that make up the partition wall 32. The multiple straight plate-like members are arranged radially.

[0037] In this embodiment, at least a portion of the outer periphery of the exhaust network 30 is arc-shaped when viewed from a direction along the central axis of the concentric circles of the partition walls 32. In the example of Fig. 4, a portion of the outer periphery of the exhaust network 30 when viewed from a direction along the central axis of the concentric circles of the partition walls 32 is arc-shaped and is included in a circle whose center is the central axis of the concentric circles of the partition walls 32.

[0038] FIG. 5 is an enlarged plan view showing an example of the shape of the slits 34 of the exhaust network 30 in this embodiment. FIG. 6 is an enlarged cross-sectional view showing an example of the shape of the slits 34 of the exhaust network 30 in this embodiment. FIG. 5 illustrates an example of the slits 34 when viewed from a direction along the axis X. For example, as shown in FIG. 5, the narrower width of the slits 34 (the width in the radial or circumferential direction from the central axis) is defined as the width W1 of the slits 34. Also, as shown in FIG. 5, the width of the curved plate-shaped portion 31 is defined as the width W2 of the curved plate-shaped portion 31. Also, as shown in FIG. 6, the thickness of the exhaust network 30 in the direction along the central axis (axis X) of the concentric circles of the partition wall 32 is defined as the thickness L of the exhaust network 30. The thickness L of the exhaust network 30 is the length of the curved plate-shaped portion 31 in the direction along the central axis and is an example of the length of the plate-shaped portion in the direction 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.

[0039] 4, for example, in a 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 partition walls 33 adjacent in the circumferential direction are narrow, and therefore the opening area of ​​the slits 34 is small. Therefore, the conductance of the exhaust network 30 is small near the central axis of the concentric circles of the partition walls 32. On the other hand, in a region 35b near the outer periphery of the exhaust network 30, the intervals between the straight portions 37 of the partition walls 33 adjacent in the circumferential direction are wide, and therefore the opening area of ​​the slits 34 is large, and therefore the conductance of the exhaust network 30 is high. In the exhaust network 30 illustrated in FIG. 4, the intervals between the straight portions 37 of the partition walls 33 become wider with increasing distance from the central axis of the concentric circles of the partition walls 32, and therefore the opening area of ​​the slits 34 increases. Therefore, in the exhaust network 30 of this embodiment, the conductance increases with increasing distance from the central axis of the concentric circles of the partition walls 32.

[0040] Consider, as a reference example, an exhaust network 30' in which through-holes 36 of the same size are formed at equal intervals, as shown in FIG. 7. Gas flowing inside the exhaust pipe 161 tends to concentrate near the center of the exhaust pipe 161 rather than near the inner wall due to viscous resistance near the inner wall of the exhaust pipe 161. Therefore, when such an exhaust network 30' is used, the flow of gas containing charged particles due to plasma may concentrate near the center of the exhaust network 30', causing localized pressure increases. When pressure increases locally, abnormal discharge is more likely to occur in that location.

[0041] 4, the conductance of the exhaust network 30 increases with increasing distance from the central axis of the concentric circles of the partition wall 32. As a result, the gas flow through the exhaust pipe 161 is dispersed to the peripheral area as it passes through the exhaust network 30, which makes it possible to prevent localized pressure buildup near the center and suppress the occurrence of abnormal discharge.

[0042] [Relationship between the thickness of the exhaust network 30 and the pressure in the processing space 106a] 8 is a diagram showing an example of the relationship between the thickness of the exhaust network 30 and the pressure in the processing space 106a. The simulation results shown in FIG. 8 show the pressure in the processing space 106a when the pressure in the exhaust pipe 161 is fixed at 15 mT (approximately 2.0 Pa).

[0043] In addition, the simulation results illustrated in FIG. 8 use the exhaust mesh 30' illustrated in FIG. 7 as a reference example. The gap illustrated in FIG. 8 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. The beam width illustrated in FIG. 8 is the width W2 of the curved plate-shaped portion 31 in the embodiment. The thickness illustrated in FIG. 8 is the thickness L illustrated in FIG. 6.

[0044] 8, in the exhaust network 30′ of the reference example, the pressure in the processing space 106a is 24.0 mT, and the difference with the pressure in the exhaust pipe 161 is 9.0 mT. That is, a pressure loss of 9.0 mT (hereinafter referred to as pressure loss) occurs in the exhaust network 30′.

[0045] On the other hand, in the exhaust network 30 of this embodiment, when the thickness L is 15 mm or less, the pressure in the processing space 106a is lower than that in the reference example. That is, from the viewpoint of keeping the pressure loss caused by the exhaust network 30 lower than that in the reference example, it is preferable that the thickness L of the exhaust network 30 is 15 mm or less. In the simulation of FIG. 8, the width W1 of the slits 34 is 5 mm, and therefore it is preferable that the ratio of the thickness L of the exhaust network 30 to the width W1 of the slits 34 is 3 or less.

[0046] [Relationship between the thickness of the exhaust mesh 30 and the total electric field under the exhaust mesh 30] 9 is a diagram showing an example of the relationship between the thickness of the exhaust mesh 30 and the total electric field strength below the exhaust mesh 30. The "total electric field strength" is the integrated value of the electric field strength over the volume in a certain region calculated by simulation. For example, in FIG. 9, it is the value obtained by integrating the electric field strength over the volume in the region below the exhaust mesh 30. In the simulation results shown in FIG. 9, the total electric field strength below the exhaust mesh 30 tends to decrease as the thickness L of the exhaust mesh 30 increases.

[0047] In the experiment, the total electric field under the exhaust network 30 calculated based on the actual measured electric field value when no abnormal discharge occurred was 4.6 mV m 2 In addition, the total electric field under the exhaust network 30 calculated based on the actual measured value of the electric field when abnormal discharge occurred was 12.1 mV m 2 Therefore, the total electric field under the exhaust net 30 is 4.6 mV m 2 Consider the following combinations of the width W1 of the slit 34 and the thickness L of the exhaust mesh 30.

[0048] Referring to FIG. 9, if the ratio of the thickness L of the exhaust mesh 30 to the width W1 of the slit 34 is 2 or more, the total electric field under the exhaust mesh 30 is 4.6 mV m 2 Therefore, from the viewpoint of preventing abnormal discharge in the exhaust network 30, it is preferable that the ratio of the thickness L of the exhaust network 30 to the width W1 of the slits 34 be 2 or more.

[0049] 8 and 9, in order to satisfy both the viewpoints of suppressing pressure loss lower than in the reference example and the viewpoint of preventing abnormal discharge, it is preferable that the ratio of the thickness L of the exhaust network 30 to the width W1 of the slit 34 be equal to or greater than 2 and equal to or less than 3. In other words, it is preferable that the ratio of the length of the plate-shaped portion in the direction along the central axis to the width W1 of the slit 34 be equal to or greater than 2 and equal to or less than 3.

[0050] [Relationship between the thickness of the exhaust net 30 and the number of particles passing through] FIG. 10 is a diagram showing an example of the relationship between the thickness of the exhaust network 30 and the number of particles passing through. In the example of FIG. 10, the number of particles that rebound from the vacuum pump 163 and enter the processing space 106a after passing through the exhaust network 30 or the exhaust network 30' was simulated. Specifically, 270 particles were emitted in random directions from the exhaust pipe 161 side toward the exhaust network 30 or the exhaust network 30', and it was simulated how many of those particles would pass through the exhaust network 30 or the exhaust network 30'. Note that in this calculation, it was assumed that particles that collided with the exhaust network 30 (exhaust network 30') would not subsequently pass through the exhaust network 30 (exhaust network 30').

[0051] Referring to Figure 10, in the exhaust mesh 30' of the reference example, 45 of 270 particles collided with the exhaust mesh 30' and 225 passed through the exhaust mesh 30'. On the other hand, in the exhaust mesh 30 of this embodiment, the number of passing recoil particles was lower than in the reference example in all exhaust mesh 30 thickness ranges of 5 to 15 mm. In the exhaust mesh 30 of this embodiment in the example of Figure 10, the width W1 of the slits 34 is 5 mm.

[0052] According to the simulation results of FIG. 10, when the ratio of the thickness L of the exhaust network 30 to the width W1 of the slit 34 is in the range of 2 to 3, the number of passing recoil particles can be reduced compared to the reference example.

[0053] [Plasma treatment method] 11 is a flowchart showing an example of a plasma processing method. Each process illustrated in FIG. 11 is realized by the control device 20 controlling each part of the main body 10.

[0054] First, the substrate G is loaded into the processing chamber 104 (step S10). In step S10, the gate valve V is opened, and the substrate G is loaded into the processing chamber 104 through the opening 155 and placed on the mounting table 130. Then, the gate valve V is closed.

[0055] Next, a processing gas is supplied into the processing space 106a (step S11). Step S11 is an example of process a). In step S11, the processing gas is supplied from the gas supply mechanism 120 through the gas supply pipe 121 to the gas diffusion chamber 112 in the shower housing 111, and diffuses within the gas diffusion chamber 112. The processing gas that has diffused within the gas diffusion chamber 112 is then discharged into the processing space 106a from the gas discharge holes 112a on the bottom surface of the shower housing 111. The processing gas supplied into the processing space 106a is exhausted via the exhaust network 30 of the exhaust mechanism 160.

[0056] Next, the exhaust mechanism 160 adjusts the pressure in the processing space 106a (step S12). Step S12 is an example of process b). In step S12, the vacuum pump 163 exhausts the processing gas in the processing space 106a through the exhaust network 30, and the opening of the APC valve 162 is adjusted to adjust the pressure in the processing space 106a to a predetermined pressure.

[0057] Next, plasma is generated in the processing space 106a (step S13). In step S13, high-frequency power having a frequency of, for example, 13.56 MHz is supplied from the high-frequency power supply 115 to the antenna 113 via the matching box 114, the power supply line 119, the power supply member 116, and the terminal 118. Then, the processing gas supplied from the shower housing 111 is converted into plasma by an inductive electric field formed in the processing space 106a below the antenna 113, and inductively coupled plasma is generated in the processing space 106a.

[0058] Next, it is determined whether a predetermined time has elapsed (step S14). The predetermined time is the time required for the substrate G to undergo a predetermined process using the plasma generated in step S13. If the predetermined time has not elapsed (step S14: No), the process shown in step S14 is executed again. Instead of determining whether a predetermined time has elapsed, determination by end point detection using a spectrophotometer may be used. When performing a predetermined process on the substrate G, the substrate G can be processed by controlling the pressure, such as maintaining a constant pressure or changing it to a predetermined pressure, by supplying a process gas while adjusting the aperture of the APC valve 162 and exhausting the process gas.

[0059] If the predetermined time has elapsed (step S14: Yes), the generation of plasma in the processing space 106a is stopped (step S15). In step S15, the supply of high frequency power from the high frequency power supply 115 is stopped, thereby stopping the generation of plasma. At this time, the supply of processing gas is also stopped. Steps S13 to S15 are an example of process c).

[0060] Next, the processing gas in the processing space 106a is exhausted (step S16). In step S16, the processing gas in the processing space 106a is exhausted through the exhaust network 30 by the vacuum pump 163.

[0061] Next, the substrate G is unloaded from the processing space 106a (step S17). In step S17, the gate valve V is opened, and the substrate G is unloaded from the processing space 106a through the opening 155. Then, the plasma processing method shown in this flowchart is completed.

[0062] The embodiment has been described above. As described above, the exhaust network (exhaust network 30) in this embodiment is installed in the exhaust port (exhaust port 159) of a processing vessel (processing vessel 101) that processes a substrate (substrate G) using plasma generated therein, or in the exhaust pipe (exhaust pipe 161) connected to the exhaust port. The exhaust network includes a plurality of circumferential partition walls (partition walls 32) arranged concentrically and a plurality of radial partition walls (partition walls 33) arranged radially. Each of the circumferential partition walls is formed by a plurality of plate-shaped portions (curved plate-shaped portions 31) that have opposing first and second surfaces (first and second surfaces 32a and 32b) and are formed of electrical conductors and are arranged in the circumferential direction. The circumferential partition walls are arranged such that the extension directions of the first and second surfaces of each plate-shaped portion are aligned along the central axis of the concentric circle. Each of the radial partition walls is formed by arranging a plurality of linear portions (linear portions 37) in a radial direction or a radial direction from the central axis so that the linear portions intersect with the circumferential partition walls. The radial partition walls are arranged such that the third surface (third surface 33a) and the fourth surface (fourth surface 33b) of each linear portion are oriented along the central axis of the concentric circles. A cylindrical slit (slit 34) is formed by two adjacent plate-like portions in the radial direction or the 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. The cylindrical slit has an arc shape centered on the central axis when viewed from the direction along the central axis. 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 2 or more and 3 or less. This makes it possible to suppress pressure loss and abnormal discharge near the exhaust port.

[0063] 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, thereby increasing the conductance of the exhaust network.

[0064] In the above-described embodiment, at least a part of the outer periphery of the exhaust mesh is arc-shaped when viewed from the direction along the central axis of the circumferential partition wall, which makes it easy to position the exhaust mesh 30 at the opening of the exhaust port 159.

[0065] In the above-described embodiment, at least a part of the outer periphery of the exhaust mesh when viewed from the direction along the central axis of the circumferential partition wall is an arc included in a circle centered on the central axis of the circumferential partition wall, which makes it possible to easily position the exhaust mesh 30 at the opening of the exhaust port 159.

[0066] In the above embodiment, the width of the slit when viewed from the direction along the central axis of the circumferential partition is 5 mm or more and 8 mm or less, thereby making it possible to increase the conductance of the exhaust network.

[0067] In the above-described embodiment, the conductance of the slit increases with increasing distance from the central axis of the circumferential partition wall, which makes it possible to prevent localized pressure buildup near the center of the exhaust network 30 and suppress the occurrence of abnormal discharge.

[0068] The plasma processing apparatus (plasma processing apparatus 1) in the above-described embodiment includes a processing vessel (processing vessel 101), a mounting table (mounting table 130), a gas supply mechanism (gas supply mechanism 120), an exhaust mechanism (exhaust mechanism 160), and a plasma generation mechanism (high-frequency power supply 115, antenna 113). The processing vessel accommodates a substrate (substrate G). The mounting table is provided in the processing vessel, and the substrate is placed on the mounting table. The gas supply mechanism supplies a processing gas into the processing vessel. The exhaust mechanism has an exhaust network (exhaust network 30) disposed at an exhaust port (exhaust port 159) or an exhaust pipe (exhaust pipe 161) connected to the exhaust port, and exhausts gas from the processing vessel through the exhaust network. The plasma generation mechanism generates plasma in the processing vessel by converting the processing gas supplied into the processing vessel into plasma. The exhaust network includes multiple circumferential partitions (partitions 32) and multiple radial partitions (partitions 33). Each of the circumferential partition walls is formed by arranging a plurality of plate-like portions (curved plate-like portions 31) in the circumferential direction. The plate-like portions have opposing first and second surfaces (first and second surfaces 32a and 32b) and are made of electrical conductors. The circumferential partition walls are arranged such that the extending directions of the first and second surfaces of each plate-like portion are aligned along the central axis of the concentric circle. Each of the radial partition walls is formed by arranging a plurality of linear portions (linear portions 37) in the radial or radial direction from the central axis so that they intersect with the circumferential partition walls. The radial partition walls are arranged such that the extending directions of the third surface (third surface 33a) and the fourth surface (fourth surface 33b) of each linear portion are aligned along the central axis of the concentric circle. A cylindrical slit (slit 34) is formed by being surrounded by two adjacent plate-like portions in the radial 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. The cylindrical slit has an arc shape centered on the central axis when viewed along the central axis. The ratio of the length (L) of the plate-shaped portion along the central axis to the width (W1) of the slit when viewed along the central axis is equal to or greater than 2 and equal to or less than 3. This makes it possible to suppress pressure loss and abnormal discharge near the exhaust port.

[0069] In the above embodiment, the central axis of the circumferential partition coincides with the central axis of the exhaust pipe, which makes it easy to arrange the exhaust mesh 30 at the opening of the exhaust port 159.

[0070] The above-described embodiment is a plasma processing method in a plasma processing apparatus (plasma processing apparatus 1). The plasma processing apparatus includes a processing vessel (processing vessel 101), a mounting table (mounting table 130), a gas supply mechanism (gas supply mechanism 120), an exhaust mechanism (exhaust mechanism 160), a plasma generation mechanism (high-frequency power supply 115, antenna 113), and a control device (control device 20). The processing vessel accommodates a substrate (substrate G). The mounting table is provided in the processing vessel and the substrate is placed on it. The gas supply mechanism supplies a processing gas into the processing vessel. The exhaust mechanism has an exhaust network (exhaust network 30) disposed in an exhaust port (exhaust port 159) or an exhaust pipe (exhaust pipe 161) connected to the exhaust port, and exhausts gas from the processing vessel through the exhaust network. The plasma generation mechanism generates plasma in the processing vessel by converting the processing gas supplied into the processing vessel into plasma. The exhaust network includes a plurality of circumferential partition walls (partition walls 32) and a plurality of radial partition walls (partition walls 33). Each of the circumferential partition walls is formed by arranging a plurality of plate-like portions (curved plate-like portions 31) in the circumferential direction. The plate-like portions have opposing first and second surfaces (first and second surfaces 32a and 32b) and are made of electrical conductors. The circumferential partition walls are arranged such that the extension directions of the first and second surfaces of each plate-like portion are aligned along the central axis of the concentric circles. The radial partition walls are arranged in a plurality of radial directions from the central axis so that their straight line portions (straight line portions 37) intersect with the circumferential partition walls. The radial partition walls are arranged such that the extension directions of the third surface (third surface 33a) and fourth surface (fourth surface 33b) of each straight line portion are aligned along the central axis of the concentric circles. Furthermore, a cylindrical slit (slit 34) is formed, surrounded by two plate-like portions adjacent in the radial direction or the diameter direction from the central axis in the multiple circumferential partition walls and two linear portions adjacent in the circumferential direction in the multiple 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. Furthermore, 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 2 or more and 3 or less. The control device executes steps a), b), and c). In step a), a processing gas is supplied into the processing vessel by controlling a gas supply mechanism.In step b), the exhaust mechanism is controlled to exhaust the gas inside the processing vessel through the exhaust network. In step c), the plasma generation mechanism is controlled to generate plasma from the processing gas supplied into the processing vessel, and the substrate on the mounting table is processed by the plasma. This makes it possible to suppress pressure loss and abnormal discharge near the exhaust port.

[0071] [others] The technology disclosed in this application is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist thereof.

[0072] 4, for example, a part of the outer periphery of the exhaust network 30 when viewed from a direction along the central axis (axis X) of the concentric circle of the partition wall 32 has an arc shape that is included in a circle whose center is the central axis of the concentric circle of the partition wall 32. However, the disclosed technology is not limited to this.

[0073] As another example, as shown in FIG. 12, the outer periphery of the exhaust network 30 when viewed from a direction along the central axis (axis X) of the concentric circle of the partition wall 32 may be circular, with the central axis of the concentric circle of the partition wall 32 as the center.

[0074] Alternatively, as another example, the outer periphery of the exhaust network 30 may be rectangular when viewed in a direction along the central axis (axis X) of the concentric circles of the partition walls 32, as shown in FIG.

[0075] In the above-described embodiment, as shown in Fig. 6, 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 central axis (axis X) of the concentric circles of the partition wall 32. However, the disclosed technology is not limited to this. As another example, as shown in Fig. 14, 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 along the axis X, but they do not have to be parallel to the axis X. The same applies to the partition wall 33.

[0076] In addition, in the above-described embodiment, the central axis (axis X) of the concentric circles is defined as the central axis of the exhaust pipe 161, but any axis within the exhaust pipe 161 that is parallel to the central axis of the exhaust pipe 161 may be defined as the central axis (axis X) of the concentric circles.

[0077] Furthermore, in the above-described embodiment, an inductively coupled plasma processing apparatus having a dielectric window was described as an example of the plasma processing apparatus 1, but the disclosed technology can also be applied to an inductively coupled plasma processing apparatus having a metal window instead of a dielectric window.

[0078] Although the above-described embodiment uses an inductively coupled plasma as an example of the plasma source, 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 wave-excited plasma (HWP).

[0079] It should be noted that the disclosed embodiments are illustrative in all respects and should not be considered limiting. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0080] V Gate Valve G board 1. Plasma processing equipment 10 Main Unit 101 Processing container 102 Dielectric Wall 103 Antenna Room 103a side wall 104 Processing Room 104a side wall 104b Bottom wall 105 Support shelf 106a Processing space 106b Exhaust space 111 shower enclosure 112 Gas diffusion chamber 112a Gas discharge hole 113 Antenna 113a antenna wire 114 Matching box 115 High frequency power supply 116 Power supply member 117 Spacer 118 terminals 119 Power line 120 Gas supply mechanism 121 Gas supply pipe 126 Spacer 130 Mounting table 131 Base material 132 Protective material 133 Piping 151 Power line 152 Matching box 153 High frequency power supply 155 Aperture 157 Aperture 158 Partition member 159 Exhaust port 160 Exhaust mechanism 161 Exhaust pipe 162 APC valve 163 Vacuum Pump 164 Foreign matter prevention net 20 Control device 30 Exhaust Network 31 curved plate-shaped part 32 Bulkhead 32a First Side 32b Second Side 33 Bulkhead 33a Third Face 33b Fourth Side 34 Slit 35 areas 36 Through hole 37 Straight section

Claims

1. An exhaust network installed at an exhaust port of a processing vessel that processes a substrate using plasma generated inside or at an exhaust pipe connected to the exhaust port, A plurality of circumferential partition walls arranged concentrically; a plurality of radial partition walls arranged radially in a radial direction or a diameter direction from the central axis of the concentric circles; Equipped with each of the circumferential partition walls has a plurality of plate-like portions, each of the plate-like portions having a first surface and a second surface facing each other and made of an electrical conductor, arranged in the circumferential direction, and the extending direction of the first surface and the second surface of each of the plate-like portions is oriented along the central axis of the concentric circle; each of the radial partition walls has a third surface and a fourth surface opposed to each other, and a plurality of straight line portions formed of an electrical conductor are arranged in a radial direction or a radial direction from the central axis so as to intersect with the circumferential partition walls, and the extending directions of the third surface and the fourth surface of each of the straight line portions are oriented along the central axis of the concentric circle; a cylindrical slit surrounded by two of the plate-like portions adjacent in a radial direction or a diameter direction from a central axis in the plurality of circumferential partition walls and two of the linear portions adjacent in the circumferential direction in the plurality of radial partition walls has an arc shape centered on the central axis when viewed from a direction along the central axis, An exhaust network, wherein the ratio of the length of the plate-shaped 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.

2. 2. The exhaust network of claim 1, wherein each of the plate-shaped portions is arranged so that the first surface and the second surface are parallel to the central axis, and each of the linear portions is arranged so that the third surface and the fourth surface are parallel to the central axis.

3. The exhaust network according to claim 1 or 2, wherein at least a portion of an outer periphery of the exhaust network when viewed in a direction along the central axis is arc-shaped.

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

5. The exhaust network according to claim 1 or 2, wherein an outer periphery of the exhaust network when viewed along the central axis is rectangular.

6. The exhaust network according to claim 1 , wherein the width of the slit when viewed along the central axis is not less than 5 mm and not more than 8 mm.

7. The exhaust network according to claim 1 , wherein the conductance of the slits increases with increasing distance from the central axis.

8. a processing vessel for accommodating a substrate; a mounting table provided in the processing chamber and on which the substrate is placed; a gas supply mechanism for supplying a processing gas into the processing chamber; an exhaust mechanism including an exhaust network disposed at an exhaust port or an exhaust pipe connected to the exhaust port, and configured to exhaust gas from the processing vessel through the exhaust network; a plasma generating mechanism that generates plasma in the processing vessel by converting the processing gas supplied into the processing vessel into plasma; Equipped with The exhaust network includes: A plurality of circumferential partition walls arranged concentrically; a plurality of radial partition walls arranged radially in a radial direction or a diameter direction from a central axis of the concentric circles, each of the circumferential partition walls has a first surface and a second surface facing each other, and a plurality of plate-like portions formed of an electrical conductor are arranged in the circumferential direction, and the extending direction of the first surface and the second surface of each of the plate-like portions is oriented along the central axis of the concentric circle; each of the radial partition walls has a third surface and a fourth surface opposed to each other, and a plurality of straight line portions formed of an electrical conductor are arranged in a radial direction or a radial direction from the central axis so as to intersect with the circumferential partition walls, and the extending directions of the third surface and the fourth surface of each of the straight line portions are oriented along the central axis of the concentric circle; a cylindrical slit surrounded by two of the plate-like portions adjacent in a radial direction or a diameter direction from a central axis in the plurality of circumferential partition walls and two of the linear portions adjacent in a circumferential direction in the plurality of radial partition walls has an arc shape centered on the central axis when viewed from a 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 the 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 coincides with the central axis of the exhaust pipe.

10. a processing vessel for accommodating a substrate; a mounting table provided in the processing chamber and on which the substrate is placed; a gas supply mechanism for supplying a processing gas into the processing chamber; an exhaust mechanism including an exhaust network disposed at an exhaust port or an exhaust pipe connected to the exhaust port, and configured to exhaust gas from the processing vessel through the exhaust network; a plasma generating mechanism that generates plasma in the processing vessel by converting the processing gas supplied into the processing vessel into plasma; Control device and Equipped with The exhaust network includes: A plurality of circumferential partition walls arranged concentrically; a plurality of radial partition walls arranged radially in a radial direction or a diameter direction from a central axis of the concentric circles, each of the circumferential partition walls has a first surface and a second surface facing each other, and a plurality of plate-like portions formed of an electrical conductor are arranged in the circumferential direction, and the extending direction of the first surface and the second surface of each of the plate-like portions is oriented along the central axis of the concentric circle; each of the radial partition walls has a third surface and a fourth surface opposed to each other, and a plurality of straight line portions formed of an electrical conductor are arranged in a radial direction or a radial direction from the central axis so as to intersect with the circumferential partition walls, and the extending directions of the third surface and the fourth surface of each of the straight line portions are oriented along the central axis of the concentric circle; a cylindrical slit surrounded by two of the plate-like portions adjacent in a radial direction or a diameter direction from a central axis in the plurality of circumferential partition walls and two of the linear portions adjacent in the circumferential direction in the plurality of radial partition walls has an arc shape centered on the central axis when viewed from a direction along the central axis, A plasma processing method for a plasma processing apparatus, wherein 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 the direction along the central axis is 2 or more and 3 or less, The control device a) controlling the gas supply mechanism to supply a processing gas into the processing vessel; b) controlling the exhaust mechanism to exhaust gas from the processing vessel through the exhaust network; c) controlling the plasma generating mechanism to generate plasma from the processing gas supplied into the processing vessel, and processing the substrate on the mounting table with the plasma; A plasma processing method.

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