Symmetric plasma process chamber

Abstract

To provide a plasma processing apparatus, for which a need exists, the plasma processing apparatus improving electrical, gas flow, and thermal symmetry for plasma uniformity control.SOLUTION: There is provided a plasma chamber design that allows extremely symmetrical electrical, thermal, and gas flow conductance through a chamber. By providing such symmetry, plasma formed within the chamber naturally improves uniformity across the whole surface of a substrate disposed in the processing region of the chamber. Further, addition to other chamber, such as providing the ability to manipulate a gap between an upper electrode 112 and a lower electrode 161 as well as between a gas flow inlet and a substrate being processed, allows better control of plasma processing and uniformity as compared to conventional systems.SELECTED DRAWING: Figure 1

Description

2. Background of the Invention

[0001] FIELD OF THEINVENTION The present invention generally relates to a substrate manufacturing method and a plasma generating method for generating a plasma by applying high frequency power between electrodes. More specifically, the present invention relates to an electrical, gas flow, and US20100233633A1 - Plasma processing chamber providing thermal symmetry for improved plasma uniformity control - Google Patents Regarding.

[0002] Description of Related Art Electronic devices such as flat panel displays and integrated circuits are typically manufactured by depositing layers onto a substrate. They are produced by a series of processing steps that deposits a thin film of silicon on a substrate and then etches the deposited material into the desired pattern. The process is generally performed using physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma CVD, etc. D (PECVD), and other plasma processes. Specifically, plasma processes include vacuum chambers. A process gas mixture is supplied to the chamber and electrical or electromagnetic power (RF power) is applied to the process. The chemical gases must be excited into a plasma state. The plasma creates a mixture of gases that can be mixed to produce the desired deposition or It is decomposed into ion species that perform the etching process.

[0003] One problem encountered in plasma processing is non-uniform processing between the center and edge regions of the substrate. The difficulty involved in establishing a uniform plasma density over the substrate surface during processing is One of the reasons for the difficulty in establishing a uniform plasma density is the physical process charac- teristics. Natural electrical, gas flow, and thermal skews due to asymmetries in the blade design. This bias naturally leads to non-uniform plasma density depending on the direction. as well as other process variables or "knobs" for controlling center-to-edge plasma uniformity. " makes it difficult to use.

[0004] Thus, electrical, gas flow, and thermal control for improved plasma uniformity control. A need exists for a plasma processing apparatus with improved symmetry. Summary of the Invention

[0005] In one embodiment of the present invention, a plasma processing system is provided that includes a lid assembly and a chamber body that enclose a processing region. A substrate support assembly is disposed within the chamber body. An exhaust assembly is provided that defines an exhaust region within a chamber body. The chamber body includes a processing region. a plurality of substrate support members arranged symmetrically about a central axis of the substrate support assembly, the plurality of substrate support members being fluidly connected to the exhaust region; The substrate support assembly includes a passageway for supporting the substrate from the processing region and the exhaust region. The lower electrode and the support are disposed in the central region. A plurality of access tubes are disposed in the central region. a chamber body disposed through the chamber body to provide access to the substrate support assembly; They are arranged symmetrically around the axis.

[0006] In another embodiment, the plasma processing apparatus includes a lid assembly and a chamber that enclose a processing region. The chamber includes a body. The substrate support assembly is disposed within the chamber body. The lid assembly is a central manifold configured to distribute a process gas into the process region; The upper electrode includes one or more outer manifolds configured to distribute the The lid assembly also includes a plurality of gas chambers symmetrically arranged around a central axis of the substrate support assembly. It includes a ring manifold coupled via tubing to one or more outer manifolds.

[0007] In yet another embodiment, the plasma processing apparatus includes a lid assembly and a chamber surrounding a processing region. The substrate support assembly is disposed within the chamber body. The upper liner is The upper liner is disposed within the chamber body surrounding the processing region. The plate support assembly has a cylindrical wall with a plurality of slots symmetrically arranged about a central axis. The backing liner is bonded to the cylindrical wall covering at least one of the plurality of slots. The mesh liner is disposed annularly around the substrate support assembly and is secured to the upper liner. The substrate is electrically coupled to the input connector. [Brief description of the drawings]

[0008] In order to provide a detailed understanding of the above-described features of the present invention, the present invention has been briefly summarized above. The invention will now be more particularly described with reference to embodiments, some of which are illustrated in the accompanying drawings, in which: However, the attached drawings show only typical embodiments of the present invention. and therefore should not be construed as limiting the scope thereof, and the present invention is not limited to other equivalent It should be noted that this may include useful embodiments. [Figure 1] 1 is a schematic cross-sectional view of a plasma processing apparatus according to an embodiment of the present invention. [Diagram 2] 2 is a schematic top view of an upper electrode of the processing apparatus of FIG. 1. [Figure 3A] 2 is a schematic perspective view of an upper liner assembly disposed within an upper portion of a chamber body that surrounds a processing region of the processing apparatus of FIG. 1. [Figure 3B] FIG. 2 is a partial cross-sectional view of a portion of the chamber body and upper liner assembly. [Figure 4] 4 is a schematic diagram of the processing apparatus taken along line 4-4 shown in FIG. 1. [Diagram 5] FIG. 2 is a schematic diagram of the layout of access tubes extending through the processing apparatus of FIG. 1. Detailed Description

[0009] As previously mentioned, the problem with conventional plasma systems is that asymmetries within the chamber result in uneven distribution of plasma. In the embodiment of the present invention, it is difficult to provide a uniform plasma density. Highly symmetric electrical, thermal, and gas flow conductances are possible through the This problem is mitigated by providing a chamber design that provides such symmetry. By providing such a plasma, the plasma formed in the chamber is disposed within the processing region of the chamber. This naturally improves uniformity across the surface of the substrate placed on it. For example, the gap between the upper and lower electrodes or between the gas inlet and the substrate to be processed can be manipulated. The new system provides better control and uniformity of the plasma process than conventional systems. It provides a large process window that allows for uniformity.

[0010] FIG. 1 is a schematic cross-sectional view of a plasma processing apparatus 100 according to an embodiment of the present invention. The Zuma processing apparatus 100 is suitable for use in plasma etch chambers, plasma enhanced chemical vapor deposition chambers, and physical A deposition chamber, a plasma processing chamber, an ion implantation chamber, or other suitable vacuum processing chamber. As shown in FIG. 1, a plasma processing apparatus 100 generally includes a chamber. The chamber lid assembly 110, the chamber body assembly 140, and the exhaust assembly 190 are included. These generally surround the processing region 102 and the exhaust region 104. The gas is introduced into the processing region 102 and ignited into a plasma using RF power. 105 is disposed on a substrate support assembly 160, and a plasma process (e.g., , etching, chemical vapor deposition, physical vapor deposition, ion implantation, plasma annealing, plasma processing , mitigation, or other plasma processes) generated in the processing region 102. The spent process gases and by-products are exhausted from the plasma process through the exhaust region 104. A vacuum is maintained within the processing region 102 by an exhaust assembly 190 which removes material.

[0011] The lid assembly 110 is generally separated and supported by a chamber body assembly 140. The chamber includes an upper electrode 112 (or anode) that is supported by the upper electrode 112 and a chamber lid 114 that surrounds the upper electrode 112. 2 is a schematic top view of the upper electrode 112. The upper electrode 112 includes a conductive gas inlet tube. The conductive gas inlet tube 126 is coupled to the RF power source 103 via the The central axis (CA) of the main assembly 140 is coaxial with the central axis (CA) of the main assembly 140, which allows the RF power and the processing gas The upper electrode 112 is attached to a heat transfer plate 118. The shower head plate 116 includes a heat transfer plate 118 and a gas inlet tube. All tubes 126 are constructed from RF conductive materials (such as aluminum and stainless steel). .

[0012] The showerhead plate 116 includes a central manifold 120 and one or more outer manifolds 1 One or more outer manifolds 122 surround the central manifold 120. The central manifold 120 receives gas from the gas source 106 via a gas inlet tube 126. The process gas is received and distributed through the gas passages 121 to the process region 10. The outer manifold 122 receives the process gas and distributes it to the central portion of the gas supply 1. 06 to allow for the same or different gas mixture as received in the central manifold 120 The outer manifold 122 then supplies gas to the processing region 1 through a plurality of gas passages 123. The manifolds 120, 122 distribute the process gas received in the manifolds 120, 122 to the outer portions of the manifolds 120, 122. 122. The manifolds 120, 122 function as a single gas supply, providing uniform pressure to each gas coupled to each manifold 120, 122. The dual-mode showerhead plate 116 has a sufficient volume to accommodate the passage 121. The Nifold configuration allows for improved control of the delivery of gases into the processing region 102. For example, The processing gas supplied to the center of the processing region 102, i.e., the center of the substrate 105 placed therein, The process gas is supplied to the outside of the process region 102, i.e., the outside of the substrate 105. The flow rate and / or pressure can be different from that of the conventional single manifold. In contrast to the version, the multi-manifold showerhead plate 116 is center-to-edge This allows for greater control over the results of processing.

[0013] 1 and 2, process gas from the gas source 106 enters through an inlet tube 126 A ring manifold 128 is arranged concentrically around the From the ring manifold 128, multiple gas tubes 12 9 to the outer manifold 122. In one embodiment, the ring manifold The hold 128 is a ring manifold that allows gas to flow evenly from the ring manifold 128 into the gas tube 129. The ring manifold 128 and the gas chamber 126 include recursive gas passages to ensure proper flow. The tube 129 is made from a conductive material (such as aluminum or stainless steel). As such, the ring manifold 128 and gas tubes 129 can potentially This leads to a bias in the electric field provided by the upper electrode 112 which has an effect on the uniformity of the plasma. This can affect the symmetry of the RF currents that are generated.

[0014] To prevent such bias in the electric field, the gas tubes 129 are symmetrically positioned about a central axis (CA) that extends vertically through the processing apparatus 100. As such, the gas tubes 129 extend at equal angles (A) from a centrally located ring manifold 128, which distributes process gas through the cooling plate 118 and into the outer manifold 122. For example, the embodiment shown in FIG. 2 shows three gas tubes 129 spaced at 120 degree angles. In other examples (not shown), more or fewer gas tubes 129 may be used, provided they are symmetrically positioned about the central axis (CA), i.e., at equal angles to each other. By employing a ring-shaped manifold and symmetrically positioned gas tubes 129 about the central axis (CA), the electrical symmetry of the upper electrode 112 is significantly improved over conventional systems, resulting in a more uniform and consistent plasma formation in the processing region 102. Additionally, the symmetrical arrangement of gas tubes 129 provides gas in a uniform circular array within outer manifold 122, thereby providing an azimuthally uniform pressure distribution within outer manifold 122, which in turn provides an azimuthally uniform gas flow through gas passages 123 into processing region 102, thereby enhancing processing uniformity.

[0015] Heat transfer fluid is supplied from a fluid source 109 to the heat transfer plate 118 through a fluid inlet tube 130. The fluid circulates through one or more fluid channels 119 disposed within the heat transfer plate 118. , and returned to the fluid source 109 via fluid outlet tube 131. Suitable heat transfer fluids include: Water, water-based mixtures of ethylene glycol, perfluoropolyethers (e.g., gal The heat transfer fluids may include, for example, DEN(R) fluids, oil-based heat transfer fluids, or similar fluids.

[0016] The fluid inlet tube 130 and the fluid outlet tube 131 are each made of a non-conductive material (such as a suitable plastic material). Thus, the tubes themselves do not affect the electrical symmetry of the upper electrode 112. However, the fitting 132 is made of a conductive material (such as aluminum or stainless steel), which may affect the electrical symmetry of the upper electrode 112 causing a bias effect. Thus, a conductive plug 133 made of the same material and having the same size and shape as the fitting 132 is symmetrically arranged about the central axis (CA) as shown in FIG. 2, whereby the plug 133 and the fitting 132 together define a circular array centered about the central axis (CA) of the chamber body assembly 140. The addition of the conductive plug 133 improves the electrical symmetry of the upper electrode 112, resulting in a more uniform and consistent plasma formation in the processing region 102 than is available in conventional systems.

[0017] Referring back to FIG. 1, the chamber body assembly 140 comprises a conductive material that is resistant to the processing environment. The chamber includes a chamber body 142 made from a conductive material, such as aluminum or stainless steel. The substrate support assembly 160 is centrally disposed within the chamber body 142 and is oriented along a central axis (CA). 1 and 2. The processing region 102 is symmetrically arranged about its periphery to support a substrate 105 therein.

[0018] FIG. 3A illustrates an upper liner disposed within the upper portion of the chamber body 142 that surrounds the processing region 102. 1 is a schematic isometric view of an upper liner assembly 144. The upper liner assembly 144 is Process compatible materials (e.g., aluminum, stainless steel, and / or yttria (e.g., For example, it can be made of aluminum coated with yttria. The external liner assembly 144 protects the chamber body 142 from plasma in the processing region 102 . Top is shielded and removable to allow for regular cleaning and maintenance In one embodiment, the upper liner assembly 144 provides temperature symmetry and In order to improve the symmetry of the plasma supplied to the processing region 102, for example, an AC heater may be used. The temperature is controlled by a temperature adjusting device (not shown).

[0019] 1 and 3A, the chamber body 142 includes an upper liner assembly 144. The inner liner assembly 144 includes a shelf 143 that supports an outer flange 145 of the upper liner assembly 144. The side flanges 146 support the upper electrode 112. The insulator 113 supports the upper liner assembly. 144 and the upper electrode 112, thereby forming a chamber body assembly 1 40 and the upper electrode 112.

[0020] The upper liner assembly 144 includes inner and outer flanges (146, 145), a bottom wall 1 48, and an outer wall 147 attached to an inner wall 149. The outer wall 147 and the inner wall 149 The outer wall 147 is a substantially vertical cylindrical wall. The chamber body 142 is disposed to shield the plasma in the processing region 102. 160 from the substrate support assembly 160. The bottom wall 148 has a portion in which an exhaust passage 189 is formed, which will be described subsequently in this specification. Except for the area, it is bonded to the inner and outer walls (149, 147).

[0021] Referring back to FIG. 1, the processing region 102 includes a substrate support assembly 160 to / from the substrate support assembly 160. A slit valve 142 disposed within the chamber body 142 allows for insertion and removal of the plate 105. The upper liner assembly 144 is accessed through a slit valve. The chamber body has a slot 150 disposed therethrough that coincides with the tunnel 141. The assembly 140 is adapted to seal the slit valve tunnel 141 and the slot 150. The slit valve door 153 is vertically extended to allow passage of the substrate 105. An actuator positioned and configured to retract the slit valve door 153 vertically. The slit valve door assembly 151 includes a slit valve door 152. For this reason, the slit valve door assembly 151 and its components are hatched in FIG. The slit valve door 153 provides increased electrical symmetry within the liner. To this end, the material of the upper liner assembly 144 (e.g., yttria coated aluminum) In one embodiment, the slit valve may be made of a material that substantially matches the thickness of the slit valve. The pad 153 is an upper liner to provide improved thermal symmetry within the processing region 102. To match the temperature of the assembly 144, for example by an AC heater (not shown), Temperature controlled.

[0022] 3A, additional slots 154 substantially corresponding in size and shape to the slots 150 are disposed through the upper liner assembly 144. The slots 154 are disposed symmetrically through the upper liner assembly 144 about the central axis (CA). For example, as shown in FIG. 3A, two slots 154 are disposed at an angle of 120 degrees from the slots 150, such that the slots 150 and 154 form a circular array about the central axis (CA). The slots 154 are disposed symmetrically around the upper liner assembly 144 to compensate for changes in current density and / or distribution present in the upper liner assembly 144 due to the presence of the slots 150. The slots 150 and 154 may also be disposed along each gas tube 129 to provide improved electrical symmetry within the chamber.

[0023] FIG. 3B is a partial cross-section of the chamber body 142 and a portion of the upper liner assembly 144. FIG. 1 is a perspective view of a slot 154 of the upper liner assembly 144. A backing liner 155 may be provided. The backing liner 155 is a slit valve. It is constructed with the same size, shape and materials as the Budor 153. Also, the backing light The liner 155 is in conductive contact with the upper liner assembly 144. 44. Thus, the backing liner 155 is in electrical and thermal contact with the A more uniform plasma density within the processing region 102 than is available in the previous system. To allow for electrical as well as thermal symmetry around the upper liner assembly 144 This provides even more functionality.

[0024] FIG. 4 is a schematic diagram of a semiconductor device according to the present invention taken along line 4-4 shown in FIG. 1, with substrate 105 removed for clarity. 1 and 4, a substrate support assembly 100 is shown. The cavity 160 is centrally disposed within the central region 156 of the chamber body assembly 140. The substrate support assembly 160 has a common axis (CA). The substrate support assembly 160 generally includes a lower electrode 161 (or cover 162). A hollow base 162 having a central axis (CA) passing through its center, and a central region 156 and is supported by a central support member 157 supported by the chamber body 142. The central axis (CA) also passes through the center of the central support member 157. A wiring network (not shown) and cables routed through the hollow pedestal 162 as described below. The upper electrode 112 and the lower electrode 113 are connected to an RF power source 103 via a power line (not shown). When the electric field is applied to the lower electrode 161 and the lower electrode 162, the electric field formed between them is The process gas is ignited to generate a plasma.

[0025] The central support member 157 is attached to the chamber body by fasteners and O-rings (not shown) or the like. 142, and the lower electrode 161 is sealed against the central The central region 156 is sealed against the support member 157. and can be maintained at atmospheric pressure while the processing region 102 is maintained under vacuum. .

[0026] The actuation assembly 163 is disposed within the central region 156 and is connected to the chamber body 142 and / or The actuator assembly 163 is attached to the central support member 157. The actuation assembly 163 is shown without hatching to minimize confusion. An actuator 164 (e.g., a motor), a lead screw 165, and a base 162 The actuator 164 includes a lead screw 166 attached to it. The lead screw 165 then rotates the nut 166, which then moves the nut 166 up and down. The lower electrode 161 is supported by the base 162, so that the base 162 moves up and down. The actuation assembly 163 includes the chamber body 142, the central support member 157, and the upper electrode 112. The lower electrode 161 in the processing region 102 is provided with a vertical movement relative to the lower electrode 161. Such vertical movement of 61 provides a variable gap between the bottom electrode 161 and the top electrode 112. This provides a control to increase the electric field formed between them, as well as In addition, it provides greater control over the density of the plasma formed in the processing region 102. Since the substrate 105 is supported by the lower electrode 161, the substrate 105 and the shower head The gap between the substrate 105 and the gate plate 116 can also be changed to adjust the processing gas distribution over the entire surface of the substrate 105. This provides greater control over the fabric.

[0027] Also, the lower electrode 161 supports the inner wall 149 of the upper liner assembly 144. A plasma screen 159 overlying the plasma shields the substrate support assembly from the plasma in the processing region 102. The plasma screen 15 is provided to protect the assembly 160 and the bellows 158. 9 is coupled to the pedestal 162 and moves vertically with the pedestal 162, The overlap between the nozzle 159 and the inner wall 149 of the upper liner assembly 144 is The screen 159 and upper liner assembly 144 are released, leaving the area below the pedestal 162 The exposure allows the pedestal 162 to utilize its full operating range without allowing it to be exposed to process gases. is enough to make it possible.

[0028] The substrate support assembly 160 further includes a lift pin assembly 167, which Facilitates loading and unloading of the substrate 105. The lift pin assembly 167 The lift pin plate 16 includes lift pins 168 attached to a pin plate 169. 9 is disposed within an opening 170 in the bottom electrode 161, and the lift pin 168 is disposed within the opening 17 1 and the processing region 102. The pin plate 169 passes through an opening 173 in the lower electrode 161 and into the hollow base 162. The actuator 195 (e.g., a motor) is connected to a lead screw 172 extending from the actuator 195. The actuator 195 can be mounted on the base 162. The actuator 195 is shown without hatching to minimize disturbance. Rotating the nut advances or retreats the lead screw 172. 2 is coupled to the lift pin plate 169. Thus, the actuator 195 This causes the lead screw 172 to move the lift pin plate 169 up and down. The lift pin 168 is extended or retracted. Thus, the actuator 195 is connected to the lower electrode This allows the lift pins 168 to be extended or retracted regardless of the vertical position of 161. By providing such independent actuation of the lift pins 168, the vertical direction of the substrate 105 The orientation of the electrode 161 can be changed independently of the vertical position of the lower electrode 161. This allows for greater flexibility during both loading and unloading of the substrate 105 as well as during processing of the substrate 105. This allows for precise position control, e.g., lifting the substrate during processing to allow for backside gas to be introduced You can escape from under the board.

[0029] The substrate support assembly 160 includes a vent line 11 connecting the opening 170 with the exhaust region 104. A vent line 174 runs centrally through the hollow base 162, as described below. A number of access channels are arranged in a symmetrical spoke pattern around a central axis (CA). The vent line leads out of the chamber body 142 through one of the tubes 180. 174 is any liquid that may leak into the opening 170 through the lift pin hole 171. To remove process gases, an opening 170 is provided for exhaust. The exhaust of 0 is present on the back side of the substrate 105 placed on the lower electrode 161 or the lift pins 168. It also helps remove any process gases that may be present.

[0030] The substrate support assembly 160 is provided with an inert gas supply line 178 disposed therethrough. The gas supply 177 may also include a gas port 176 coupled to a reactive gas supply 177. 7 is connected to the gas supply line 178 and the An inert gas (such as helium) is supplied to the rear surface of the substrate 105 through the gas port 176. Gas supply lines 178 are also routed through the hollow pedestal 162 and include multiple access channels. It is led out of the chamber body 142 through one of the tubes 180 .

[0031] The substrate support assembly 160 is adapted to provide temperature control to the lower electrode 161 during processing. Heat exchange fluid is supplied from a heat exchange fluid source 198 through one or more heat exchange channels (not shown) in the lower electrode 161. The system may further include one or more fluid inlet lines 179 and fluid outlet lines 181 leading from the The fluid inlet line 179 and the fluid outlet line 181 run from the lower electrode 161 to the hollow pedestal. 162 and enters the chamber through one of a number of access tubes 180. It is led out from the body 142 .

[0032] In one embodiment, the substrate support assembly 160 includes one or more electrodes disposed within the lower electrode 161. and a temperature sensor 182 for facilitating temperature control of the lower electrode 161. can be done.

[0033] In one embodiment, the lower electrode 161 is an electrostatic chuck and is therefore disposed within A voltage source (not shown) is connected to one or more electrodes (not shown) connected to the substrate 105. The upper electrode is biased, which creates a suction current to hold the substrate 105 in place during processing. A cable connection coupling one or more electrodes to a voltage source passes through hollow base 162. and is guided from the chamber body 142 through one of a number of access tubes 180. The person is led outside.

[0034] FIG. 5 illustrates the access tube 180 within the spoke 191 of the chamber body assembly 140. 1 and 5, the spokes 191 and the access The tubes 180 are spun around a central axis (CA) of the processing device 100 as shown. In the illustrated embodiment, three identical access chutes are arranged symmetrically in a grid pattern. A tube 180 is disposed through the chamber body 142 and into the central region 156, thereby A plurality of tubes and cables are provided from the outside of the chamber body 142 to the lower electrode 161. To facilitate vertical movement of the lower electrode 162, an access tube 1 An opening 183 through each of the electrodes 80 is approximately equal to the vertical range of travel of the bottom electrode 161. For example, in one configuration, the bottom electrode 162 can be moved vertically a distance of about 7.2 inches. In this case, the height of each opening 183 of the access tube 180 is also about 7.2 Keeping these distances roughly the same minimizes the length of cable required. and further prevents the cables from binding and wearing out during vertical movement of the lower electrode 161. Also, the width (W) of the spokes 191 is minimized, which helps to achieve a high aspect ratio. Ratio (height:width) is provided, which still allows for utilities (e.g. gas, wiring) The open area of ​​the exhaust channel 189 is increased while allowing sufficient room for The configuration reduces the flow resistance of the exhaust gases and, as a result, the energy consumption for pumping is low. This reduces the load on the pump, resulting in a smaller, lower cost pump.

[0035] To further facilitate cabling to the lower electrode 161, the cabling may be provided with multiple access For example, the fluid lines (179, 181), the gas supply lines (182, 184), All of the insulators 178 and vacuum tubes 174 are provided through access tube 180a. The temperature sensor cable 184 and other electrical cables (e.g., The electrical cables to the actuators 164, 195 are provided through an access tube 180b. It can also provide RF voltage supply and other electrical cables (e.g., chucking function An electrical cable to the electrodes for the catheter can be provided through the access tube 180c. In this way, the number and quantity of cables from the outside of the chamber body 142 to the lower electrode 162 can be reduced. The lower electrode 161 is provided with a suitable clearance to facilitate movement of the lower electrode 161 while providing an access To minimize the size of the access tube 180, the access tube 180 is divided between the do.

[0036] The access tube 180 may be constructed from a material such as aluminum or stainless steel. The symmetrical spoke arrangement of the access tubes 180 allows for electrical In one embodiment, the access tubing is designed to further promote thermal symmetry. The access tubes 180 are spaced 120 degrees apart, and each of the access tubes 180 is The symmetrical placement of the access tubes 180 allows for a greater degree of freedom in the processing area. This allows for a much more uniform plasma formation within the region 102, resulting in a uniform plasma across the entire surface of the substrate 105 during processing. In order to improve control of plasma density over a wide area, the plasma may be selectively induced within the chamber body 142, particularly in the processing region. It also provides electrical and thermal symmetry within region 102 .

[0037] 1 and 4, the exhaust passage 189 is symmetrically arranged about a central axis (CA). The exhaust passage 189 is disposed in the upper liner assembly 144. from the exhaust region 104 and from the chamber body 142 through the exhaust port 196 The exhaust port 196 is located within the chamber body assembly 140 and allows gases to escape to the outside. It is centered around the axis (CA) so that the gas flows uniformly through the exhaust passage 189. The exhaust liner 187 protects the chamber body 142 from the process gases during exhaust. In order to achieve this, each exhaust passage in an exhaust channel 188 provided in the chamber body 142 The exhaust liner 187 is disposed below the upper liner 189 as described above. It may be constructed of similar materials as the core assembly 144.

[0038] The exhaust channel 188 is configured to circulate the processing region 102 so that there is substantially no electrical interaction. However, the exhaust channel 1 around the central axis (CA) is The symmetrical arrangement of 88 provides improved thermal and gas flow symmetry within the processing apparatus 100. For example, the symmetrical arrangement of the exhaust channels 188 about the central axis (CA) and therefore the processing The treatment region 102 promotes symmetrical removal of gas from the treatment region 102, resulting in a symmetrical removal of the substrate 1 05. Also, the exhaust channel 188 and exhaust liner The symmetrical arrangement of the nozzles 187 promotes symmetrical heat distribution within the chamber. The symmetrical arrangement of exhaust channels 188 in the apparatus 100 provides uniform airflow within the processing region 102. Facilitates plasma formation and allows for flexible control of plasma density and gas flow within the processing region 102 .

[0039] The exhaust assembly 190 is disposed at the bottom of the chamber body 142 adjacent the exhaust region 104. The exhaust assembly includes a throttle valve 192 coupled to a vacuum pump 194. The throttle valve 192 is used in combination with a vacuum pump 194. This may be a poppet type valve that allows the exhaust passage 189 to exit the processing region 102. and out of the chamber through a centrally located exhaust port 189. By selectively drawing the vacuum conditions within the processing region 102, the processing region 102 can be further This provides more flexible control of the plasma conditions in region 102. As shown in FIG. As seen above, poppet-type valves provide a uniform 360 degree gap 198 through which Exhaust gases are drawn through the exhaust port 189. In contrast, a conventional damper-type throttle The valve provides a non-uniform gap for the flow of exhaust gas. For example, a damper-type valve When the valve is opened, one side of the valve draws more gas than the other side of the valve. As shown, poppet-type throttle valves are conventionally used in conventional plasma processing chambers. This is less susceptible to the effect of bias in gas conductance than the damper-type throttle valve.

[0040] Referring again to FIG. 1 and FIG. 4, a conductive gradient mesh liner 400 is provided as the upper liner. The inclined mesh liner 400 is disposed at the bottom of the assembly 144. Process-compatible materials (e.g., aluminum, stainless steel, and / or yttria (e.g., The mesh line may be made of aluminum coated with yttria. The liner 400 includes a bottom wall 402 and an outer wall 404 that extends angled outwardly and upwardly from the bottom wall 402. The outer wall 404 may have a number of openings 410 formed therethrough. The openings 410 are symmetrically arranged around the central axis of the gradient mesh liner 400. This allows the exhaust gases to be drawn evenly through it, and then The plasma density and the plasma concentration in the processing region 102 are increased. In one embodiment, the gradient mesh liner 400 provides greater control over the flow of gas. The central axis of is aligned with the central axis (CA) of the chamber body assembly 140.

[0041] The bottom wall 402 of the mesh liner 400 is secured to the bottom wall 148 of the upper liner assembly 144. and / or electrically coupled to the inner wall 149. Further, the mesh liner 400 The outer wall 404 is electrically coupled to the outer wall 147 of the upper electrode liner assembly 144. When an RF plasma is present in the processing region 102, the return to ground can be The RF current for which the impedance is sought flows along the surface of the mesh liner 400 into the upper liner assembly. The mesh liner 400 can then be moved to the outer wall 147 of the bridge 144. The circularly symmetric configuration provides a symmetric RF return to ground and the upper liner assembly 4 00 below to bypass any RF symmetry.

[0042] Thus, embodiments of the present invention provide highly symmetrical electrical, thermal, and chamber By providing a chamber design that allows for conductance of gas flow through the Conventional plasmas have difficulty in providing uniform plasma density due to asymmetry within the chamber. By providing such symmetry, the formation in the chamber is solved. The generated plasma is uniform across the surface of a substrate disposed within the processing region of the chamber. This improved symmetry was accompanied by the addition of other chambers (e.g., upper It provides the ability to manipulate the gap between the electrode and the lower electrode, and between the gas inlet and the substrate to be processed. (e.g., ion beam splitting) allows for greater control and uniformity of plasma processing compared to conventional systems. do.

[0043] While the above is directed to embodiments of the present invention, other and further embodiments of the present invention are disclosed herein. The scope of the present invention is within the scope of the following claims. It is determined based on the range.

Claims

[Claim 1] A plasma processing apparatus comprising: a lid assembly and a chamber body enclosing a processing region; a substrate support assembly disposed in the chamber body, a support pedestal disposed in a central region of the chamber body sealed from the processing region; a lower electrode supported by a support; a central support member sealed to the chamber body and the lower electrode; a plasma screen supported by the lower electrode and extending along a periphery of the substrate support assembly; an upper liner having an inner wall overlapping a portion of the plasma screen; a plurality of lift pins disposed within the substrate support assembly; a substrate support assembly including an actuator disposed within the central region and configured to vertically move a plurality of lift pins coupled to a lift pin plate; a plurality of access tubes disposed symmetrically through the chamber body below the central support member and providing access to the central region, each of the access tubes being spaced vertically from the processing region; a plurality of exhaust passages disposed through the upper liner and symmetrically arranged about a central axis of the substrate support assembly; A plasma processing apparatus comprising a plurality of exhaust channels symmetrically disposed within a chamber body, each exhaust channel extending between two of the plurality of access tubes and below the plurality of exhaust passages.

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