Wafer edge profile control using connected edge ring hardware

Abstract

The embodiments described herein generally relate to substrate processing equipment. In one embodiment, a process kit for a substrate processing chamber is disclosed herein. The process kit includes a ring having a first ring component and a second ring component, a sliding ring, and an actuation mechanism. The first ring component is interfaced with the second ring component such that the second ring component is movable relative to the first ring component and a gap is formed between the first and second ring components. The sliding ring is positioned below the ring and in contact with the bottom surface of the second ring component. The top surface of the sliding ring is in contact with the second ring component. The actuation mechanism is interfaced with the bottom surface of the sliding ring. The actuation mechanism is configured to actuate the sliding ring so that the gap between the first and second ring components varies.

Description

Technical Field

[0001]

[0002] The embodiments described herein generally relate to a substrate processing apparatus, and more specifically to an improved apparatus for controlling a plasma edge profile for processing a substrate.

Background Art

[0002]

[0004] As semiconductor technology nodes progress by shrinking the device's feature sizes, the requirements for the uniformity of the edge critical dimensions of the substrate become more stringent, affecting the yield of the die. Commercially available plasma reactors include a plurality of adjustable knobs for controlling the process uniformity across the substrate, such as temperature, gas flow, direct current (DC) power, etc. Typically, in an etching process, a silicon substrate is etched while being electrostatically clamped to an electrostatic chuck.

[0003]

[0005] During processing, the substrate placed on the substrate support may undergo a process of depositing material on the substrate and removing or etching a portion of the material from the substrate, often performing the processes continuously or alternately. Typically, it is beneficial to have a uniform deposition rate and etching rate across the entire surface of the substrate. However, process non-uniformities are often seen across the entire surface of the substrate and can be prominent at the outer periphery or edge of the substrate. The above non-uniformity at the outer periphery may be due to the influence of the electric field termination and is sometimes called the edge effect. During deposition or etching, a process kit including at least a deposition ring may be provided to favorably affect the uniformity at the peripheral portion or edge of the substrate.

[0004]

[0006] Conventional process kits have relied on radio frequency (RF) coupling to control the plasma edge profile during processing. However, newer processing capabilities are being extended by using DC generators to control the plasma profile. It has been found that DC circuits, like RF circuits, are not coupled to the edges of the substrate support. Therefore, new processing devices have poor edge response for controlling the plasma profile and tuning for substrate processing.

[0005]

[0007] Therefore, improved equipment for substrate processing is constantly needed. [Overview of the Initiative]

[0006]

[0008] The embodiments described herein generally relate to substrate processing apparatus, process kits, and methods for using them. In one embodiment, a process kit for a substrate processing chamber disclosed herein is provided. The process kit includes an edge ring, a sliding ring, an operating mechanism, and a power coupling mechanism. The edge ring is configured to surround a substrate within a semiconductor processing chamber. The substrate processing system according to claim 1 comprises: the sliding ring positioned below the edge ring, having an upper surface configured to contact the bottom surface of the edge ring. The operating mechanism interfacees with the bottom surface of the sliding ring and is configured to move the sliding ring so that the edge ring can move. The power coupling mechanism is configured to be electromechanically coupled to the sliding ring and to be electromechanically coupled to a cathode that supplies DC power.

[0007]

[0009] In another embodiment, a processing chamber is disclosed herein. The processing chamber includes a substrate support member and a process kit. The substrate support member is configured to support a substrate. The substrate support member has a cathode connected to a DC power supply. The process kit is supported by the substrate support member. The process kit includes an edge ring, a sliding ring, an operating mechanism, and a power coupling mechanism. The edge ring is configured to surround a substrate within a semiconductor processing chamber. The substrate processing system according to claim 1, further comprising: the sliding ring positioned below the edge ring, having an upper surface configured to contact the bottom surface of the edge ring. The operating mechanism interfacees with the bottom surface of the sliding ring and is configured to move the sliding ring so that the edge ring can move. The power coupling mechanism is electromechanically coupled to the sliding ring and is configured to electromechanically couple to a cathode that supplies DC power.

[0008]

[0010] In another embodiment, a method for processing a substrate is disclosed herein. The substrate is positioned on a substrate support member placed in a substrate processing chamber. Plasma is generated on the substrate. The height of the edge ring components is adjusted by acting on sliding rings interfaced with the components to change the direction of ions at the edges of the substrate. DC power is supplied to the edge ring through sliding rings electromechanically coupled to the cathode of the substrate support member.

[0009]

[0011] To better understand the features of this disclosure described above, a more detailed description of this disclosure, which is briefly summarized above, can be obtained by referring to the embodiments. Some embodiments are shown in the accompanying drawings. However, it should be noted that the accompanying drawings show only typical embodiments of this disclosure and therefore should not be considered limiting in scope, as this disclosure may allow for other equally valid embodiments. [Brief explanation of the drawing]

[0010] [Figure 1A]This is a cross-sectional view of a processing chamber according to one embodiment. [Figure 1B] This is an enlarged partial cross-sectional view of a part of the support member shown in Figure 1A, according to one embodiment. [Figure 1C] The voltage waveform established on the substrate by the voltage waveform applied to the electrodes of the processing chamber according to a specific embodiment of this disclosure is shown. [Figure 2] This is an enlarged partial cross-sectional view of a support member shown in Figure 1A, illustrating a power coupling mechanism according to one embodiment. [Figure 3A] This is a simplified cross-sectional view of a portion of the processing chamber shown in Figure 1A, according to one embodiment, illustrating the advantages of the present disclosure. [Figure 4A-4C] One embodiment of a power coupling mechanism is shown. [Figure 5A] Another embodiment of the power coupling mechanism is shown. [Figure 5B] Another embodiment of the power coupling mechanism is shown. [Modes for carrying out the invention]

[0011]

[0019] For clarity, the same reference numerals have been used to indicate identical elements common to the figures, where applicable. Furthermore, elements of one embodiment may be advantageously adapted for use in other embodiments described herein.

[0012]

[0020] Embodiments of the present disclosure generally include methods and apparatus for improving the uniformity of etching rates across a substrate surface by controlling the shape of the plasma sheath formed across the substrate, such as a semiconductor wafer, during plasma processing. Embodiments of the present disclosure include adjusting one or more plasma processing variables and / or adjusting the configuration of process kit hardware that is in close proximity to and / or supports the substrate during processing. Thus, the uniformity of the plasma sheath across the wafer surface can be controlled, thereby improving the yield of the wafer processing.

[0013]

[0021] More specifically, the disclosure herein includes a processing chamber configuration including a cathode assembly comprising a cathode plate having screw connections to an anodized aluminum block connected to a sliding ring configured to allow biasing of the edge ring during processing, which can be used to adjust the shape of a plasma sheath formed across the entire substrate. The block is connected to the sliding ring by metal strap / spring contacts using an actuation assembly 151, which allows the sliding ring 150 to have a desired range of motion during processing. In addition, the conductive upper surface of the sliding ring may include a plurality of pins. In one embodiment, three silicon carbide (SiC) pins are configured to extend above the sliding ring and make direct physical and electrical contact with the edge ring positioned above it. Alternatively, the upper surface of the sliding ring may have a surface comprising a thin layer of bare metal or anodized material that provides desirable contact with the edge ring, improving DC conductivity between the surface of the sliding ring and the surface of the edge ring. Thus, the new cathode configuration enables improved source power supply to the movable edge ring through the cathode assembly.

[0014] Example of a processing system

[0022] Figure 1A is a cross-sectional view of a processing chamber 100 having a sliding ring 150 according to one embodiment. As shown, the processing chamber 100 is an etching chamber suitable for etching a substrate (e.g., substrate 101). Examples of processing chambers that may be adapted to benefit from this disclosure are the Sym3® processing chamber and the Mesa® processing chamber, both commercially available from Applied Materials, Inc. in Santa Clara, California. It is anticipated that other processing chambers, including deposition chambers and processing chambers from other manufacturers, may be adapted to benefit from this disclosure.

[0015]

[0023] The processing chamber 100 can be used for various plasma processes. In one embodiment, the processing chamber 100 can be used to perform dry etching using one or more etching agents. In one example, a plasma is formed within the processing chamber from a processing gas (e.g., CxFy where x and y can be different allowed combinations, O2, NF3, or a combination thereof).

[0016]

[0024] The processing chamber 100 has a chamber body 113 and a system controller 126. The chamber body 113 includes a lid assembly 176, one or more sidewalls 122, and a chamber base 124, which collectively, together with the chamber lid 123 of the lid assembly 176, define a processing space 129. A substrate support assembly 180 is disposed within the processing space 129.

[0017]

[0025] The lid assembly 176 includes a chamber lid 123 and one or more plasma source assemblies such as two inductively coupled plasma (ICP) assemblies 196, 197. Each ICP assembly 196, 197 includes coils 181, 182 configured to inductively couple a radio frequency (RF) waveform generated by an RF generator 118 to a plasma 103 formed within the processing space 129 of the processing chamber 100 during plasma processing. In this configuration, the chamber lid 123 includes a dielectric material configured to enable the electric fields generated by the coils 181, 182 to assist in generating and maintaining the plasma 103 within the processing space 129 during the supply of an asymmetric voltage waveform by the RF generator 118.

[0018]

[0026] One or more sidewalls 122 and a chamber base 124 are generally sized and shaped to form a structural support for elements of the processing chamber 100 and are configured to withstand pressure and the energy applied thereto while a plasma 103 is generated within a vacuum environment maintained within the processing space 129 of the processing chamber 100 during processing. In one embodiment, the one or more sidewalls 122 and the chamber base 124 are formed from a metal such as aluminum, an aluminum alloy, or a stainless steel alloy.

[0019]

[0027] The gas inlet 128 is disposed through the chamber lid 123. The gas inlet 128 is used to supply one or more processing gases from a processing gas source 119 with which it is in fluid communication to the processing space 129. The substrate 101 enters and exits the processing space 129 through an opening (not shown) in one or more of the sidewalls 122. The opening in the one or more sidewalls 122 is sealed with a slit valve (not shown) during plasma processing of the substrate 101.

[0020]

[0028] The vacuum system 120 is connected to the vacuum port 121. The vacuum system 120 may include a vacuum pump and a throttle valve (not shown). The throttle valve regulates the flow of gas through the processing chamber 100. The vacuum pump is connected to a vacuum port 121 disposed within the internal space 108 to exhaust gas from the processing chamber 100 through the vacuum port.

[0021]

[0029] A substrate support assembly 180 disposed within the processing space 129 is configured to support the substrate 101 for processing. The substrate support assembly 180 may be connected to a lift mechanism (not shown) through a shaft 138 that extends through the chamber base 124 of the chamber body 113. The lift mechanism may be flexibly sealed to the chamber body 113 by a bellows that prevents vacuum leakage around the shaft 138. The lift mechanism allows the substrate support assembly 180 to be vertically moved within the chamber body 113 between a lower transfer portion and several elevated processing positions.

[0022]

[0030] One or more lift pins (not shown) may be positioned through the substrate support assembly 180. Three or more lift pins are configured to extend through the substrate support assembly 180 so that the substrate 101 is lifted away from the substrate support surface 105A of the substrate support assembly 180. The three or more lift pins can be actuated by a lift ring (not shown) connected to a lift ring actuator (not shown) configured to raise and lower the three or more lift pins relative to the substrate support surface 105A.

[0023]

[0031] The substrate support assembly 180 includes a substrate support 202 (e.g., an ESC substrate support) and one or more lower electrodes, which are connected to a plasma source such as a capacitively coupled plasma (CCP) assembly. Typically, the substrate support 202 is formed from a dielectric material, such as a bulk sintered ceramic material such as a corrosion-resistant metal oxide or metal nitride material, e.g., aluminum oxide (Al2O3), aluminum nitride (AlN), titanium oxide (TiO), titanium nitride (TiN), yttrium oxide (Y2O3), mixtures thereof, or combinations thereof. In embodiments herein, the substrate support 202 further includes a bias electrode 104 embedded within its dielectric material.

[0024]

[0032] The substrate support assembly 180 may additionally include a cooling plate 204, a base 206, and a grounding plate 112. The cooling plate 204 is electrically isolated from the chamber base 124 by the base 206, and the grounding plate 112 is interposed between the base 206 and the chamber base 124. The substrate support 202 is thermally coupled to the cooling plate 204 and is positioned on the cooling plate 204. In some embodiments, the cooling plate 204 is configured to regulate the temperature of the substrate support 202 and the substrate 101 positioned on the substrate support 202 during substrate processing. In some embodiments, the cooling plate 204 is positioned on the base 206. The cooling plate 204 may include a plurality of cooling channels (not shown) for circulating a coolant. The cooling plate 204 may be coupled to or engaged with the substrate support 202 by adhesive or any suitable mechanism.

[0025]

[0033] The substrate support assembly 180 includes a process kit 200 supported on the substrate support assembly 180. The process kit 200 includes an edge ring 210, a support ring 214 (shown in Figures 1B and 2), an outer ring 274 (shown in Figure 1B), and a sliding ring 150. The support ring 214 and the edge ring 210 are interfaced with each other so that the edge ring 210 is movable relative to the support ring 214. The sliding ring 150 is positioned to move the edge ring 210 vertically up and down relative to the support ring 214. An actuator assembly 151 is connected to the sliding ring 150 and positioned below the sliding ring 150. The actuator assembly 151 consists of pins, such as three pins connected to a linear actuator, so that the pins contact the underside of the sliding ring 150 and move the sliding ring up and down. In one embodiment, the actuator assembly 151 consists of three actuators that act together to raise and lower the sliding ring 150. The vertical motion of the sliding ring 150 is imparted to the edge ring 210 through contact between the sliding ring 150 and the edge ring 210, causing the edge ring to move up and down.

[0026]

[0034] Referring further to Figure 1B, Figure 1B is an enlarged partial cross-sectional view of the support member of Figure 1A showing a power coupling mechanism 500 according to one embodiment. The processing chamber 100 may include a bias assembly 299 which may include one or more plasma source assemblies, each adapted to supply asymmetric voltage waveforms to one or more electrodes and / or one or more coils disposed within the processing chamber 100. One or more lower electrodes may include a bias electrode 104 and / or edge electrode 115 disposed within the process kit 200 and coupled to one or more plasma source assemblies, such as a waveform generation assembly. A first waveform generation assembly 208 may be coupled to the bias electrode 104 by a transmission line 157. In some embodiments, the first waveform generation assembly 208 is also electrically coupled to the edge electrode 115 via a conductive tube 167, and the edge electrode 115 may include a sliding ring 150, as will be further described below. The waveform generation assembly 208 is configured to supply the PV waveform generated by a PV waveform generator, such as the PV waveform generator 208A, to the plasma 103 formed in the processing space 129 of the processing chamber 100 during plasma processing. In one embodiment, the first PV waveform generator 208A of the first waveform generation assembly 208 is configured to bias both the bias electrode 104 and the edge electrode 115.

[0027]

[0035] The PV waveform generator 208A is configured to supply multiple asymmetric pulsed voltage waveforms to one or more electrodes in the plasma processing chamber to control and maintain the plasma formed in the processing area and / or to control the formation of a sheath on the surface of the substrate during processing. The plasma processing method and apparatus described herein are configured to improve the control of various properties of the generated plasma and to control the ion energy distribution (IED) of plasma-generated ions interacting with one or more areas on the surface of the substrate during plasma processing. The ability to synchronize and control waveform characteristics such as frequency, waveform shape, and applied voltage on-time in the voltage waveform pulses provided to each pulsed voltage waveform applied to the electrodes makes it possible to improve the control of the generated plasma. As a result, the accuracy of the plasma processing can be increased. This will be described in more detail herein.

[0028]

[0036] Figure 1C shows two distinct voltage waveforms established on a substrate 101 placed on the substrate support surface 105A of the substrate support assembly 180 of the processing chamber 100 by supplying a PV waveform to the bias electrode 104 of the processing chamber 100. The first waveform (e.g., waveform 225) is an example of an uncompensated PV waveform established on the substrate 101 during plasma processing. The second waveform (e.g., waveform 227) is an example of a compensated PV waveform established on the substrate 101 by applying a negative slope waveform to the bias electrode 104 of the processing chamber 100 during the "ion current phase" portion of the PV waveform cycle using a current source (not shown). The compensated PV waveform can alternatively be established by applying a negative voltage ramp during the ion current phase of the PV waveform generated by the PV waveform generator 208A.

[0029]

[0037] Waveforms 225 and 227 include two main stages, namely the ion current stage and the sheath collapse stage. Both parts of waveforms 225 and 227 (e.g., the ion current stage and the sheath collapse stage) can be established alternately and / or separately on the substrate 101 during plasma processing. At the start of the ion current stage, the supply of the negative portion (e.g., the ion current portion) of the PV waveform supplied to the bias electrode 104 by the PV waveform generator 208A causes a voltage drop on the substrate 101, resulting in a high-voltage sheath on the substrate 101. The high-voltage sheath allows plasma-generated positive ions to be accelerated toward the biased substrate 101 during the ion current stage, and thus, in the case of an RIE process, controls the amount and characteristics of the etching process that occurs on the surface of the substrate 101 during plasma processing. In some embodiments, it is desirable that the ion current stage includes a region of the PV waveform that achieves a voltage on the substrate 101 that is stable or minimally fluctuating throughout the stage, as shown in Figure 1C by waveform 227. As indicated by the positive slope of waveform 225, significant fluctuations in the voltage established on the substrate 101 during the ion current phase undesirably cause fluctuations in the ion energy distribution (IED), resulting in the formation of undesirable characteristics of the etched features on the substrate 101 during the RIE process.

[0030]

[0038] Returning to Figures 1A and 1B, in one configuration, the bias electrode 104 is also used as a chucking pole used to fix (i.e., chuck) the substrate 101 to the substrate support surface 105A of the substrate support 202 and to further bias the substrate 101 to the plasma 103 using one or more of the voltage waveform bias schemes described herein. Typically, the bias electrode 104 is formed from one or more conductive components (e.g., one or more metal meshes, foils, plates, or a combination thereof).

[0031]

[0039] The bias assembly 299 may also include a clamp network 209 for high-voltage bias applied to the bias electrode 104 and / or edge electrode 115. In some embodiments, the bias electrode 104 is electrically coupled to the clamp network 209, and the edge electrode 115 is electrically coupled to a separate clamp network (not shown). The clamp network uses a high-voltage DC power supply to provide a chucking voltage to the bias electrode 104 and / or edge electrode 115, such as a static DC voltage between approximately -5000V and approximately +5000V.

[0032]

[0040] In some embodiments, the edge electrode 115 is positioned below the edge of the substrate and at a distance from the center of the bias electrode 104. Generally, for a processing chamber 100 configured to process a circular substrate, the edge electrode 115 is annular in shape, made of a conductive material, and configured to surround at least a portion of the bias electrode 104. In some embodiments, the edge electrode 115 is configured to surround at least a portion of the bias electrode 104 when viewed perpendicular to the substrate support surface 105A. In one embodiment, the sliding ring 150 is positioned below the edge ring 210. In another embodiment, the sliding ring 150 includes a plurality of connected structures (e.g., pins, arc segments, etc.) configured to contact and support the edge ring 210.

[0033]

[0041] During operation, conventionally, the PV waveform generator 208A is configured to supply a PV waveform to a chucking mesh (e.g., bias electrode 104) on the substrate support 202. Unfortunately, the supply of the PV waveform to the bias electrode 104 is typically weakly DC-coupled to the edge electrode 115. Therefore, in some embodiments, the processing chamber 100 includes a bias assembly 299 configured to provide an improved supply of the PV waveform to at least one electrode located within the process kit 200, such as the bias electrode 104 and the sliding ring 150. In some configurations, the bias assembly 299 is provided to overcome the weak DC coupling to the electrodes present in the plasma processing system.

[0034]

[0042] In some embodiments of the bias assembly 299, the PV waveform generator 208A is electrically connected to the cooling plate 204 via a conductive tube 167 electrically connected to the output of the PV waveform generator 208A in an effort to supply a PV waveform to the edge electrode 115. Generally, the PV waveform generator 208A is a voltage waveform generating power supply used to control sheath formation on the surface of the substrate during plasma processing.

[0035]

[0043] During processing, the PV waveform generator 208A of the bias assembly 299 simultaneously transmits a voltage waveform, such as a pulsed voltage waveform, to both the bias electrode 104 and the cooling plate 204 in the substrate support 202. The cooling plate 204 has electromechanical coupling through a power coupling mechanism 500 ( schematically shown, for example, in Figure 1B) configured to provide a voltage waveform to an edge electrode 115, which may include a sliding ring 150. The power coupling mechanism 500 may include conductive cables, wires, straps, or other flexible elements configured to transmit the generated voltage waveform provided from the PV waveform generator 208A to components in the edge electrode 115. In one embodiment, the power coupling mechanism 500 includes a first end 150B coupled to a conductive tube 167 through a portion of the cooling plate 204, a second end 150C coupled to a portion of the edge electrode 115 (e.g., a sliding ring 150), and a central section located within a channel (not shown) formed in the cooling plate 204 and / or base 206. In another embodiment, the power coupling mechanism 500 includes a first end 150B coupled to the conductive tube 167 through a portion of the base 206, a second end 150C coupled to a portion of the edge electrode 115 (e.g., a sliding ring 150), and an intermediate portion located in a channel (not shown) formed within the cooling plate 204 and / or the base 206. The channel and intermediate portion of the power coupling mechanism 500 are configured to allow movement (e.g., bending, translation, etc.) of the power coupling mechanism 500 when the sliding ring 150 moves relative to the substrate support surface 105A using the actuation assembly 151 (Figure 1A). In yet another embodiment, the power coupling mechanism 500 includes a first end 150B directly coupled to the conductive tube 167, a second end 150C coupled to a portion of the edge electrode 115 (e.g., a sliding ring 150), and an intermediate portion located in a channel (not shown) formed within the cooling plate 204 and / or the base 206. The channels and intermediate sections of the power coupling mechanism 500 are configured to allow movement of the power coupling mechanism 500 (e.g., bending, translation) when the sliding ring 150 moves relative to the substrate support surface 105A using the actuation assembly 151 (Figure 1A).

[0036]

[0044] As schematically shown in Figure 1B, the clamp network 209 is connected to the bias electrode 104 via the transmission line 157 and can be connected to the edge electrode 115 via the power coupling mechanism 500, part of the cooling plate 204, or part of the base 206, and the conductive tube 167.

[0037]

[0045] As shown in Figure 1A, the system controller 126, also referred to herein as the processing chamber controller, operates to control the operation of the processing system 100. For example, the system controller 126 may control the operation of the bias assembly 299. The system controller 126 includes a central processing unit (CPU) 133, memory 134, and support circuitry 135. The system controller 126 is used to control the process sequence (including the substrate biasing method described herein) used to process the substrate 101. The CPU 133 is a general-purpose computer processor configured for use in an industrial environment to control the processing chamber and its associated subprocessors. The memory 134 described herein, generally non-volatile memory, may include random access memory, read-only memory, floppy or hard disk drives, or other suitable forms of local or remote digital storage. The support circuitry 135 is conventionally connected to the CPU 133 and includes a cache, clock circuitry, input / output subsystems, power supplies, etc., and combinations thereof. Software instructions (programs) and data may be coded and stored in the memory 134 to instruct the processor in the CPU 133. A software program (or computer instruction) readable by the CPU 133 in the system controller 126 determines which tasks can be performed by the components in the processing chamber 100. Typically, the software program readable by the CPU 133 in the system controller 126 includes code, which, when executed by the processor (CPU 133), performs tasks according to the plasma processing method described herein. The program may include instructions used to control various hardware and electrical components in the processing chamber 100 to perform various processing tasks and various processing sequences used to implement the method described herein.

[0038]

[0046] Figure 2 is another partial cross-sectional view of a part of a substrate support assembly 180 according to one embodiment, showing a power coupling mechanism 500 of a process kit 200 placed on the substrate support assembly 180. As described above, the substrate support assembly 180 includes a substrate support 202 (electrostatic chuck), a cooling plate 204 (or cathode), and a base 206. The cooling plate 204 is placed on the base 206. The cooling plate 204 may include a plurality of cooling channels (not shown) for circulating a coolant. The cooling plate 204 may be engaged with the substrate support 202 by adhesive or any suitable mechanism. The substrate support 202 may include one or more heaters (not shown). One or more heaters may be individually controllable. One or more heaters enable the substrate support 202 to heat the substrate 101 from the bottom surface of the substrate 101 to a desired temperature.

[0039]

[0047] As described above, the process kit 200 is supported on a substrate support assembly 180 and includes an edge ring 210, a support ring 214, an outer ring 274, and a sliding ring 150. The support ring 214 and the edge ring 210 are interfaced with each other. The support ring 214 includes a top surface 218, a bottom surface 220, an inner edge 222, and an outer edge 224. The top surface 218 is substantially parallel to the bottom surface 220. The inner edge 222 is substantially parallel to the outer edge 224 and substantially perpendicular to the bottom surface 220. In some embodiments, the support ring 214 further includes a stepped surface 226. In the illustrated embodiment, the stepped surface 226 is formed on the outer edge 224 such that the stepped surface 226 is substantially parallel to the bottom surface 220. The stepped surface 226 defines a recess for receiving the edge ring 210. Generally, the height of the support ring 214 is limited by the height of the substrate support 202. For example, the inner edge 222 of the support ring 214 does not extend above the height of the substrate support 202. In this way, the support ring 214 protects the sides of the substrate support 202. In some embodiments, when the substrate 101 is positioned on the substrate support surface 105A of the substrate support 202, it partially extends over the support ring 214.

[0040]

[0048] The edge ring 210 has a ring body 216 including a top surface 228, a bottom surface 230, an inner edge 232, and an outer edge 234. The top surface 228 is substantially parallel to the bottom surface 230. The inner edge 232 is substantially parallel to the outer edge 234 and substantially perpendicular to the bottom surface 230. In one embodiment, the edge ring 210 interfaces with a support ring 214 via the bottom surface 230. For example, the bottom surface 230 of the edge ring 210 interfaces with a stepped surface 226 in the support ring 214. In another embodiment, the edge ring 210 may further include a stepped surface (not shown) formed on the inner edge 232, thereby interface with a stepped surface 226 of the support ring 214. When interfaced with the support ring 214, the inner edge 232 of the edge ring 210 is spaced apart from the substrate 101. For example, the inner edge 232 of the edge ring 210 can be spaced between approximately 0.02 mm and approximately 0.1 mm from the substrate 101.

[0041]

[0049] In one embodiment, when interfaced, the edge ring 210 and the support ring 214 form a continuous bottom surface 238. In another embodiment, when interfaced, the support ring 214 and the edge ring 210 do not form a continuous bottom surface 238. Rather, in some embodiments, the top surface 218 of the support ring 214 may be higher than the top surface 228 of the edge ring 210. In other embodiments, the bottom surface 230 of the edge ring 210 may be located below the bottom surface 220 of the support ring 214. Thus, in some embodiments, the support ring 214 and the edge ring 210 do not form a continuous top or bottom surface.

[0042]

[0050] The sliding ring 150 has an upper surface 254 and a lower surface 256. The sliding ring 150 may be formed from a conductive material, such as a metal that may include aluminum, stainless steel, copper, nickel, or other desired conductive material. The sliding ring 150 is positioned below the edge ring 210. For example, the sliding ring 150 is positioned below the edge ring 210. The sliding ring 150 contacts the lower surface 238 of the edge ring 210. Optionally, the sliding ring 150 has conductive pins 291. The conductive pins 291 may extend through the upper surface 218. In one embodiment, the sliding ring 150 has three conductive pins 291 formed from silicon carbide (SiC). The conductive pins 291 increase the source power conductance from the sliding ring 150 to the edge ring 210. Alternatively, the upper part of the sliding ring 150 may have anodized bare metal or a thin layer to make flat contact with the edge ring 210 in order to improve conductivity between the sliding ring 150 and the edge ring 210.

[0043]

[0051] In one embodiment, the sliding ring 150 extends to the length of the substrate support 202 and the cooling plate 204 so that its height is substantially equal to the combined height of the substrate support 202 and the cooling plate 204. The sliding ring 150 may have a slot 259, which is better shown in Figure 5A, which will be discussed later. Following Figure 2, the slot 259 is electromechanically coupled to a power coupling mechanism 500, which was first shown in Figure 3A but is also shown in other figures. In one embodiment, the power coupling mechanism 500 is sized to move within the slot 239 of the sliding ring 150. In some embodiments, as shown in Figures 3A and 3B, the power coupling mechanism 500 makes the sliding ring 150 biasable by supplying power from a power source (e.g., a PV waveform supplied from a PV waveform generator 208A and / or a DC bias supplied from a DC power source in the clamp network 209) from the cooling plate 204 to the edge ring 210. Alternatively, the power coupling mechanism 500 can bias the sliding ring 150 from the base 206 to the edge ring 210, as shown in Figure 2. It should be understood that the power coupling mechanism 500 can electrically couple the sliding ring 150 to a cathode, for example, the cooling plate 204, or alternatively, the base 206, or the conductive tube 167.

[0044]

[0052] The sliding ring 150 surrounds the cooling plate 204, thereby forming a laterally spaced gap 258. In one embodiment, the laterally spaced gap 258 is greater than 0 inches and less than or equal to 0.03 inches. The sliding ring 150 interfaces with a lift pin 260. For example, the lift pin 260 may be operably connected to the sliding ring 150. The lift pin 260 is driven by an actuation assembly 151, which may include a pneumatic actuator or an electric motor-driven actuator assembly. In some embodiments, the lift pin 260 may be driven by a lift pin actuation mechanism (not shown) independent of the actuation assembly 151. The actuation assembly 151 enables the sliding ring 150 to be moved and positioned vertically within the processing chamber 100. As a result of the vertical movement of the sliding ring 150, the actuation assembly 151 raises the edge ring 210 to one or more vertical positions controllable by the system controller 126. The edge ring 210 may be lifted above the support ring 214, thereby forming a gap between the stepped surface of the support ring 214 and the stepped surface of the edge ring 210.

[0045]

[0053] In another embodiment, the sliding ring 150 may be moved manually, thus eliminating the need for the lift pin 260. The sliding ring 150 may include a cavity (not shown) and an access orifice formed therein. The cavity is formed downward to the bottom of the sliding ring 150. The cavity is configured to house a lead screw (not shown). The lead screw can be rotated to raise and lower the sliding ring 150 relative to the substrate support surface 105A of the substrate support 202.

[0046]

[0054] The process kit 200 may further include a quartz ring 272. In one embodiment, the quartz ring 272 is formed from an upper quartz tube 271 and a lower quartz tube 273. The upper quartz tube 271 includes a top surface 276, an inner edge 280, and an outer edge 282. The lower quartz tube 273 includes a bottom surface 278, a top surface 279, an inner edge 281, and an outer edge 283. The top surface 276 of the upper quartz tube 271 is substantially parallel to the bottom surface 278 of the lower quartz tube 273. The inner edge 280 of the upper quartz tube 271 is positioned adjacent to the sliding ring 150 and the edge ring 210. In one embodiment, the top surface 279 of the lower quartz tube 273 is adjacent to the sliding ring 150. In another example, the inner edge 281 of the lower quartz tube 273 is adjacent to the sliding ring 150.

[0047]

[0055] Figure 3A is a simplified cross-sectional view of a portion of the processing chamber in Figure 1, showing a power coupling configuration used to bias the edge ring 210 during processing according to one embodiment. Bias power (e.g., PV waveform and / or bias supplied from the clamp network 209) can be supplied to the edge ring 210 from the cooling plate 204 or cathode through the sliding ring 150. The amount of power coupled as the sliding ring 150 is improved by the power coupling mechanism 500. The power coupling mechanism 500 prevents power fluctuations as the sliding ring 150 moves up and down by providing electromechanical coupling that provides direct contact between the power-supplied components, since DC power does not effectively perform capacitive coupling.

[0048]

[0056] Voltage V applied to edge ring 210 DC By keeping the controlled voltage V constant or controlling it within the PV waveform pulse phase (e.g., the ion current phase), it becomes possible to control the plasma sheath formed on the substrate 101 and edge ring 210. DCThis can be used to control the profile of the plasma sheath 404 at the edge 406 of the substrate 101 in order to compensate for the uniformity of the critical dimensions at the edge 406 of the substrate 101. The plasma sheath 404 is a thin region of a strong electric field formed by space charges that bind the body of the plasma to its material boundary. Mathematically, the thickness d of the sheath is expressed by the Child-Langmuir equation. TIFF2026513554000002.tif17170

[0049]

[0057] In the above equation, i is the ion current density, ε is the permittivity of vacuum, e is the fundamental charge, Vp is the plasma potential, and V DC V is a DC voltage. In the case of an etching reactor, a plasma sheath 404 is formed between the plasma, the substrate 101 to be etched, the chamber body 113, and all other parts of the processing chamber 100 that are in contact with the plasma. Ions generated in the plasma are accelerated within the plasma sheath and move perpendicular to the boundary of the formed plasma sheath. V is the voltage applied to the edge ring 210. DC Controlling the V affects the thickness d of the sheath 404. The sheath thickness d of the sheath 404 can be measured relative to the edge ring 210. For example, the thickness d is shown in Figures 3A and 3B. In the illustrated embodiment, the actuation assembly 151 moves the sliding ring 150 upward to raise the edge ring 210. Controlling the bias applied to the edge ring 210 affects the V DC Since the sheath thickness formed on the upper surface of the edge ring 210 remains constant, the sheath thickness remains constant. Therefore, when the sliding ring 150 is actuated, the sheath 404 rises perpendicular to the position of the substrate. Thus, moving the sliding ring 150 affects the shape of the sheath 404 at the edge 406 of the substrate 101, controlling the direction of ions accelerated through the sheath toward the surface of the substrate.

[0050]

[0058] Figure 3B shows a portion of the processing chamber 100 in Figure 3A, with the edge ring 210 in the raised position. As illustrated and as described in Figure 3A, raising the sliding ring 150 causes the edge ring 210 to rise, resulting in a change in the shape of the plasma sheath 404 at the edge of the substrate. A constant potential V DC In a configuration where a bias is applied, the sheath thickness d and shape of the plasma sheath 404 remain constant throughout the plasma process. In a configuration where the bias applied to the sliding ring 150 and edge ring 210 is pulsed, the sheath thickness d controlled during the ion current phase of each pulse is controlled so that the thickness and shape of the plasma sheath 404 remain constant throughout the primary etching portion of the PV waveform.

[0051]

[0059] As described above, in one embodiment, the sliding ring 150 is electrically coupled to the base 206 via the power coupling mechanism 500 in order to generate and maintain a bias on the edge ring 210. Alternatively, when the cooling plate 204 is energized, the sliding ring 150 is electrically coupled to the cooling plate 204 via the power coupling mechanism 500. That is, the base 206 or the cooling plate 204 may be configured to supply a bias to the sliding ring 150. Since the sliding ring 150 is movable relative to both the base 206 and the cooling plate 204 of the substrate support assembly 180, the power coupling mechanism 500 is configured to provide a direct connection between the sliding ring 150 and the substrate support assembly 180. As shown in Figure 2, the power coupling mechanism 500 is mechanically fixed to the base 206. For example, fasteners 205 such as bolts can be used to attach the power coupling mechanism 500, which is mechanically fixed to the base 206. The power coupling mechanism 500 forms a physical electrical connection that allows the bias voltage to move between the sliding ring 150 and the cathode.

[0052]

[0060] Figures 4A to 4C show one embodiment of the power coupling mechanism 500. The power coupling mechanism 500 includes a mounting block 502 and a connecting member 530. The mounting block 502 is fixed to the cathode. The connecting member 530 is installed between the mounting block 502 and the sliding ring 150. The connecting member 530 is configured to allow movement between the mounting block 502 and the sliding ring 150.

[0053]

[0061] The mounting block 502 has a body 501. The body 501 has a fastener through hole 510, a side surface 521, and a top surface 522. The top surface 522 is oriented to face away from the slot 259 of the sliding ring 150 when the mounting block 502 is mounted on the cathode. The side surface 521 is oriented to face away from the cathode.

[0054]

[0062] The fastener through-hole 510 is configured to receive a fastener 205 for mechanically connecting the body 501 of the mounting block 502 to the cathode. The fastener 205 and the body 501 of the mounting block 502 are formed of a conductive material such as metal for conducting source power to the mounting block 502. The body 501 further has one or more mounting points 520 for mechanically connecting the mounting block 502 to the connecting member 530. The mounting points 520 are located on the side surface 521. Alternatively, the mounting points 520 are located on the top surface 522. The mounting points 520 may be holes suitable for fasteners. In one embodiment, the mounting points 520 are through-holes suitable for bolt-type fasteners. In another embodiment, the mounting points 520 are threaded holes suitable for receiving screw-type fasteners. Alternatively, the mounting points 520 may be slots crimped into the connecting member 530. In yet another embodiment, the mounting point 520 may alternatively be welded to the connecting member 530. It should be understood that the mounting point 520 can be any suitable mechanism that facilitates the electromechanical coupling between the mounting block 502 and the connecting member 530.

[0055]

[0063] The connecting member 530 has a body 533. The body 533 has a first end 531 and a second end 532. The body 533 has a first mounting position 541 at the first end 531. In one embodiment, the first mounting position 541 may be a hole configured to align with a mounting point 520 of the connecting member 530. Bolts, screws, rivets, welds, or other suitable fasteners may extend through the first mounting position 541 and the mounting point 520 to electromechanically connect the first end 531 of the connecting member 530 to the mounting block 502. The first mounting position 541 is configured to interface with and mechanically connect to the mounting point 520 of the connecting member 530.

[0056]

[0064] The main body 533 has a second mounting position 542 at its second end 532. The second mounting position 542 is configured to be electromechanically connected to the sliding ring 150. For example, the sliding ring 150 may have one or more holes aligned with the second mounting position 542. Bolts, screws, rivets, welds, or other suitable fasteners may extend through the second mounting position 542 and holes in the sliding ring 150 to electromechanically connect the second end 532 of the connecting member 530 to the mounting block 502.

[0057]

[0065] The main body 533 additionally has an intermediate section 555. The intermediate section 555 is configured to be elastically deformable while maintaining conductivity between the second end 532 of the main body 533 and the first end 531 of the main body 533. For example, the intermediate section 555 may be a ribbon of metal or other conductive material. In one embodiment, the intermediate section 555 is formed from a stainless steel spring with a PTFE coating. The intermediate section 555 is configured to allow the second end 532 of the main body 533 to move relative to the first end 531 of the main body 533. For example, Figure 5B shows the intermediate section 555 of the power coupling mechanism 500 in a compressed state 591. For example, Figure 5C shows the intermediate section 555 of the power coupling mechanism 500 in an extended state 592. The first end 531 is closer to the second end 532 in the compressed state 591 than in the extended state 592. Therefore, the first end 531 is movable relative to the second end 532. In this way, the power coupling mechanism 500 allows the sliding ring 150 to move up and down while maintaining an electrical connection to the source power.

[0058]

[0066] Figures 5A and 5B show another embodiment of the power coupling mechanism 500. The power coupling mechanism 500 includes a mounting block 602 and a connecting member 630. The mounting block 602 is fixed to the cathode. The connecting member 630 is installed between the mounting block 602 and the sliding ring 150. In one embodiment, the connecting member 630 is a strap. The connecting member 630 is configured to allow movement between the mounting block 602 and the sliding ring 150.

[0059]

[0067] The mounting block 602 has a body 601 and a bottom surface 609. The body 601 has a fastener through hole 610. The fastener through hole 610 is configured to receive a fastener 205 for mechanically connecting the body 601 of the mounting block 602 to the cathode. The fastener 205 and the body 601 of the mounting block 602 are formed of a conductive material such as metal for conducting source power to the mounting block 602. The bottom surface 609 is oriented to face away from the slot 259 of the sliding ring 150 when the mounting block 602 is mounted to the cathode.

[0060]

[0068] The main body 601 further has one or more mounting points 620 located on its bottom surface. The mounting points 620 are configured to mechanically connect the mounting block 602 and the connecting member 630. The mounting points 620 may be holes suitable for fasteners. In one embodiment, the mounting point 620 is a through hole suitable for a bolt fastener. In another embodiment, the mounting point 620 is a threaded hole suitable for receiving a screw fastener. In yet another embodiment, the mounting point 620 may be welded to the connecting member 630 instead. It should be understood that the mounting points 620 may be any suitable mechanism to facilitate the electromechanical coupling between the mounting block 602 and the connecting member 630.

[0061]

[0069] The main body 633 has a second mounting position 642 at its second end 632. The second mounting position 642 is configured to be electromechanically connected to a sliding ring 150. For example, the sliding ring 150 may have one or more holes aligned with the second mounting position 642. Bolts, screws, rivets, welds, or other suitable fasteners may extend through the second mounting position 642 and holes in the sliding ring 150 to electromechanically connect the second end 632 of the connecting member 630 to the mounting block 602.

[0062]

[0070] The main body 633 additionally has an intermediate section 655. The intermediate section 655 is configured to be elastically deformable while maintaining conductivity between the second end 632 and the first end 631 of the main body 633. For example, the intermediate section 655 may be a thin sheet metal plate. Alternatively, the intermediate section 655 may be a wire. The intermediate section 655 is configured to allow the second end 632 of the main body 633 to move relative to the first end 631 of the main body 633. For example, as the sliding ring 150 moves, the intermediate section 655 may bend or flex. In this way, the power coupling mechanism 600 allows the sliding ring 150 to move up and down while maintaining an electrical connection to the source power.

[0063]

[0071] The connecting member 630 may be formed from an aluminum material. To ensure good conductivity throughout the entire lifespan of the connecting member 630, it is assumed that the connecting member 630 is not coated. In one embodiment, the sliding ring 150 is formed from aluminum. The sliding ring 150 may be anodized along the bottom surface 256. The sliding ring 150 may also be yttria coated with anodizing along the bottom surface 256. The connecting member 630 is electrically connected to the sliding ring 150 via screws or other suitable fasteners. For example, the connecting member 630 is electrically connected to the mounting block 602 by screws, and the mounting block 602 is connected to the base 206 by screws 205.

[0064]

[0072] Advantageously, the power coupling mechanism 500 provides hard contact between the cathode (such as the base plate) and the sliding ring, and provides sufficient DC voltage to the sliding ring.

[0065]

[0073] While the above description applies to specific embodiments, other embodiments and further embodiments may be devised without departing from the basic scope of this disclosure, the scope of which is defined by the appended claims.

Claims

1. A process kit for a substrate processing chamber, An edge ring configured to surround the substrate within the semiconductor processing chamber, A sliding ring positioned below the edge ring, having an upper surface configured to contact the bottom surface of the edge ring, An operating mechanism that interface-connects with the bottom surface of the sliding ring, the operating mechanism configured to move the sliding ring so that the edge ring can move, A power coupling mechanism configured to be electromechanically coupled to the sliding ring and to be electromechanically coupled to the cathode that supplies DC power, A process kit equipped with the following features.

2. The process kit according to claim 1, wherein the sliding ring is formed from a conductive material.

3. The aforementioned sliding ring, Pins extending from the top surface A process kit according to claim 1, comprising:

4. The aforementioned power coupling mechanism A mounting block configured to be fixed to the cathode, A connecting member extending between the mounting block and the sliding ring A process kit according to claim 1, comprising:

5. The aforementioned sliding ring, Slot configured to receive the aforementioned mounting block A process kit according to claim 4, comprising:

6. The process kit according to claim 4, wherein the connecting member is a ribbon attached to the side surface of the sliding ring.

7. The process kit according to claim 6, wherein the connecting member has a first end and a second end that is movable relative to the first end.

8. The process kit according to claim 4, wherein the connecting member is a flat plate attached to the bottom surface of the sliding ring.

9. The process kit according to claim 1, wherein the sliding ring has a thin strip of metal along its upper surface to contact the edge ring.

10. A processing chamber, A substrate support member configured to support a substrate, having a cathode configured to receive power from a DC power supply, A process kit supported by the aforementioned substrate support member, An edge ring configured to surround the substrate within a semiconductor processing chamber. A sliding ring positioned below the edge ring, having an upper surface configured to contact the bottom surface of the edge ring, An operating mechanism that interface-connects with the bottom surface of the sliding ring, the operating mechanism configured to move the sliding ring so that the edge ring can move, and A power coupling mechanism configured to be electromechanically coupled to the sliding ring and to be electromechanically coupled to the cathode that supplies DC power. Process kit including A processing chamber equipped with the following features.

11. The processing chamber according to claim 10, wherein the power coupling mechanism is a strap.

12. The processing chamber according to claim 10, wherein the sliding ring is formed from a conductive material.

13. The processing chamber according to claim 10, wherein the sliding ring component includes a pin extending from the upper surface.

14. The aforementioned power coupling mechanism A mounting block configured to be fixed to the cathode, A connecting member extending between the mounting block and the sliding ring The processing chamber according to claim 10, including the processing chamber described in claim 10.

15. The aforementioned sliding ring, Slot configured to receive the aforementioned mounting block The processing chamber according to claim 14, including the processing chamber described in claim 14.

16. The processing chamber according to claim 14, wherein the connecting member is a ribbon attached to the side surface of the sliding ring.

17. The processing chamber according to claim 16, wherein the connecting member has a first end and a second end that is movable relative to the first end.

18. The processing chamber according to claim 14, wherein the connecting member is a flat plate attached to the bottom surface of the sliding ring.

19. The processing chamber according to claim 10, wherein the sliding ring has a thin strip of metal along its upper surface to contact the edge ring.

20. A method for processing a substrate, Positioning the substrate on a substrate support member placed inside the substrate processing chamber, Forming plasma above the substrate, By operating a sliding ring interfaced with the component, the height of the component of the edge ring is adjusted to change the direction of ions at the edge of the substrate, The method of supplying DC power to the edge ring through the sliding ring, wherein the sliding ring is electromechanically coupled to the cathode in the substrate support member, and the method of supplying DC power. A method that includes this.

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