Optimizing RF signal ground feedback in plasma processing systems.

Abstract

A fixed outer support flange (flange 1) is formed to surround an electrode in a plasma processing system. Flange 1 has a vertical portion and a horizontal portion extending radially outward from a lower end of the vertical portion. A connecting outer support flange (flange 2) is formed to surround flange 1. Flange 2 has a vertical portion and a horizontal portion extending radially outward from a lower end of the vertical portion. The vertical portion of flange 2 is concentrically disposed outside the vertical portion of flange 1. Flange 2 is spaced from flange 1 and is movable along the vertical portion of flange 1. Each of a plurality of conductive straps has a first end connected to flange 2 and a second end connected to flange 1.

Description

[Technical field]

[0001] 1. Field of disclosure

[0002] The present disclosure relates to semiconductor device manufacturing. [Background technology]

[0003] 2. Description of Related Technology

[0004] Plasma etching processes are often used in the fabrication of semiconductor devices on semiconductor wafers. In a plasma etching process, a semiconductor wafer containing the semiconductor device under fabrication is exposed to a plasma generated in a plasma processing region. The plasma interacts with material on the semiconductor wafer to remove material from the semiconductor wafer and / or modify material so that it can subsequently be removed from the semiconductor wafer. The plasma can be generated using specific reactive gases, such that components of the plasma can interact with material to be removed or modified from the semiconductor wafer without significant interaction with material on other wafers that is not removed / modified. The plasma is generated using radio frequency (RF) signals to excite specific reactive gases. These RF signals are transmitted through a plasma processing region that contains the reactive gases and in which the semiconductor wafer is held for exposure. The transmission path of the RF signal through the plasma processing region can affect how the plasma is generated in the plasma processing region. For example, in areas of the plasma processing region where a larger amount of RF signal power is transmitted, the reactive gases can be excited to a greater extent, resulting in spatial non-uniformity of the plasma characteristics throughout the plasma processing region. The spatial non-uniformity of the plasma characteristics may manifest itself as spatial non-uniformity of ion density, ion energy, and / or reactive species density, among other plasma characteristics. Corresponding spatial non-uniformity of the plasma characteristics may result in spatial non-uniformity of the plasma processing results on the semiconductor wafer. That is, the uniformity of the plasma processing results on the semiconductor wafer may be affected by how the RF signal is transmitted through the plasma processing region. The present disclosure is described in this context. Summary of the Invention

[0005] In an exemplary embodiment, a plasma processing system is disclosed. The plasma processing system includes an electrode having a substantially cylindrical shape defined by a top surface, a bottom surface, and an outer surface. The plasma processing system also includes a ceramic layer formed on the top surface of the electrode. The ceramic layer is configured to receive and support a semiconductor wafer. The plasma processing system also includes an RF signal generator electrically connected to the electrode via an impedance match system. The RF signal generator is configured to generate and provide an RF signal to the electrode. The plasma processing system also includes a fixed outer support flange formed to surround the outer surface of the electrode. The fixed outer support flange has a fixed spatial relationship with respect to the electrode. The fixed outer support flange has a vertical portion and a horizontal portion extending radially outward from a lower end of the vertical portion. The fixed outer support flange is electrically connected to a reference ground potential. The plasma processing system also includes an interlocking outer support flange formed to surround the fixed outer support flange. The interlocking outer support flange has a vertical portion and a horizontal portion extending radially outward from a lower end of the vertical portion. The vertical portion of the interlocking outer support flange is concentrically disposed outboard of the vertical portion of the fixed outer support flange. The interlocking outer support flange is spaced from the fixed outer support flange such that the interlocking outer support flange is vertically movable relative to the fixed outer support flange. The plasma processing system also includes a plurality of conductive straps. Each of the plurality of conductive straps has a first end connected to the horizontal portion of the interlocking outer support flange and a second end connected to the horizontal portion of the fixed outer support flange.

[0006] In an exemplary embodiment, a ground return assembly for a plasma processing system is disclosed. The ground return assembly includes a fixed outer support flange formed to surround an electrode in the plasma processing system and having a fixed spatial relationship with respect to the electrode. The fixed outer support flange has a vertical portion and a horizontal portion extending radially outward from a lower end of the vertical portion. The ground return assembly also includes an interlocking outer support flange formed to surround the fixed outer support flange. The interlocking outer support flange has a vertical portion and a horizontal portion extending radially outward from a lower end of the vertical portion. The vertical portion of the interlocking outer support flange is concentrically disposed outside the vertical portion of the fixed outer support flange. The interlocking outer support flange is spaced from the fixed outer support flange such that the interlocking outer support flange is movable along the vertical portion of the fixed outer support flange. The ground return assembly also includes a plurality of conductive straps. Each of the plurality of conductive straps has a first end connected to the interlocking outer support flange and a second end connected to the fixed outer support flange.

[0007] In an exemplary embodiment, a plasma processing system is disclosed. The plasma processing system includes an electrode formed of a conductive material. The electrode has a substantially cylindrical shape defined by a top surface, a bottom surface, and an outer surface. The plasma processing system also includes a ceramic layer formed on a top surface of the electrode. The ceramic layer is configured to receive and support a semiconductor wafer. The plasma processing system also includes a facility plate formed of a conductive material. The bottom surface of the electrode is physically and electrically connected to the top surface of the facility plate. The plasma processing system also includes an RF signal feed shaft formed of a conductive material. An upper end of the RF signal feed shaft is physically and electrically connected to the bottom surface of the facility plate. The plasma processing system also includes an RF signal feed rod formed of a conductive material. A lower end of the RF signal feed shaft is physically and electrically connected to a feed end of the RF signal feed rod. The plasma processing system also includes an RF signal generator electrically connected to a feed end of the RF signal feed rod via an impedance matching system. The plasma processing system also includes a tube disposed around the RF signal feed rod. The tube is formed of a conductive material. The tube has an inner wall separated from the RF signal delivery rod by air along the entire length of the tube.

[0008] In one exemplary embodiment, an RF signal feed structure for a plasma processing system is disclosed. The RF signal feed structure includes an RF signal feed rod formed of a conductive material. The RF signal feed rod has a feed end and a delivery end. The feed end of the RF signal feed rod is configured for connection to an impedance matching system disposed between the RF signal feed rod and an RF signal generator. The RF signal feed structure also includes a tube disposed around the RF signal feed rod. The tube is formed of a conductive material. The tube has an inner wall separated from the RF signal feed rod by air along the entire length of the tube. [Brief description of the drawings]

[0009] [Figure 1A]FIG. 1A illustrates a vertical cross-sectional view of a plasma processing system for use in semiconductor chip manufacturing, according to some embodiments.

[0010] [Figure 1B] FIG. 1B illustrates the system of FIG. 1A with the cantilever arm assembly moved downward to allow movement of a wafer W through the door, according to some embodiments.

[0011] [Diagram 2] FIG. 2 shows a top view of ceramic layers and electrodes according to some embodiments.

[0012] [Diagram 3] FIG. 3 illustrates an electrical schematic of an impedance matching system according to some embodiments.

[0013] [Figure 4A] FIG. 4A shows a close-up vertical cross-sectional view of a fixed outer support flange and a connecting outer support flange, according to some embodiments.

[0014] [Figure 4B] FIG. 4B illustrates a variation of FIG. 4A in which a first end of each of a plurality of conductive straps is connected to an upper surface of the horizontal portion of the interlocking outer support flange by a clamp ring, according to some embodiments.

[0015] [Diagram 5] FIG. 5 illustrates a top view of a connecting outer support flange and a fixed outer support flange, according to some embodiments, showing a number of conductive straps connected between the connecting outer support flange and the fixed outer support flange.

[0016] [Figure 6] FIG. 6 illustrates a perspective view of the top of a connecting outer support flange and a fixed outer support flange, according to some embodiments, showing a number of conductive straps connected between the connecting outer support flange and the fixed outer support flange.

[0017] [Figure 7] FIG. 7 illustrates an isometric view of a conductive strap, according to some embodiments.

[0018] [Figure 8A] FIG. 8A illustrates a vertical cross-sectional view of a top electrode according to some embodiments.

[0019] [Figure 8B] FIG. 8B illustrates a top view of the upper electrode, according to some embodiments.

[0020] [Figure 9] FIG. 9 shows a close-up view of the area near the edge ring, also shown in FIG. 1A, illustrating an electrode having an extended diameter, according to some embodiments.

[0021] [Figure 10] FIG. 10 is an alternative to FIG. 4A and shows conductive straps configured to bend inwardly toward a fixed outer support flange, according to some embodiments.

[0022] [Figure 11] FIG. 11 is an alternative to FIG. 4A and shows a conductive strap configured to bend in an S-shape between a connecting outer support flange and a fixed outer support flange, according to some embodiments.

[0023] [Figure 12] FIG. 12 illustrates an example schematic diagram of the control system of FIG. 1A, according to some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] In the following description, numerous specific details are set forth in order to provide an understanding of the embodiments of the present disclosure. However, it will be apparent to one skilled in the art that the embodiments of the present disclosure can be practiced without some or all of these specific details. In other instances, detailed descriptions of well-known processing operations are omitted in order to avoid unnecessarily obscuring the present disclosure.

[0025] In plasma etching systems for semiconductor wafer manufacturing, the spatial variation of the etching results across the semiconductor wafer is characterized by radial etch uniformity and azimuthal etch uniformity. Radial etch uniformity can be characterized by the variation of the etch rate as a function of radial position on the semiconductor wafer extending outward from the center of the semiconductor wafer to the edge of the semiconductor wafer at a given azimuthal position on the semiconductor wafer. Also, azimuthal etch uniformity can be characterized by the variation of the etch rate as a function of azimuthal position on the semiconductor wafer about the center of the semiconductor wafer at a given radial position on the semiconductor wafer. In some plasma processing systems, such as the system described herein, the semiconductor wafer is placed on an electrode from which an RF signal is emitted to generate a plasma in a plasma generating region over the semiconductor wafer. The plasma has controlled characteristics to produce a predetermined etching process on the semiconductor wafer.

[0026] An RF signal originating from an electrode beneath the semiconductor wafer travels through the plasma generating region overlying the semiconductor wafer to a peripheral electrical reference ground potential return path. The spatial arrangement and configuration of these peripheral electrical reference ground potential return paths can affect how the RF signal travels spatially through the plasma generating region and can affect the impedance seen by the RF signal, which in turn affects both the RF signal power delivered to the plasma and the spatial variation of plasma characteristics across the plasma generating region. Disclosed herein are various systems that enable improvements in both the configuration and control of the RF signal reference ground return paths within a plasma processing system, thereby improving uniformity of semiconductor processing results across a wafer, including improvements in both radial and azimuthal etch uniformity across a semiconductor wafer.

[0027] FIG. 1A illustrates a vertical cross-sectional view of a plasma processing system 100 for use in semiconductor chip manufacturing, according to some embodiments. The system 100 includes a chamber 101 formed by walls 101A, a top member 101B, and a bottom member 101C. The walls 101A, the top member 101B, and the bottom member 101C collectively form an interior region 103 within the chamber 101. The bottom member 101C includes an exhaust port 105 through which exhaust gases of a plasma processing operation are directed. In some embodiments, during operation, a suction force is applied to the exhaust port 105, such as by a turbo pump or other vacuum device, to draw process exhaust gases from the interior region 103 of the chamber 101. In some embodiments, the chamber 101 is formed of aluminum. However, in various embodiments, the chamber 101 can be formed of essentially any material, such as stainless steel, that has sufficient mechanical strength, acceptable thermal performance, and is chemically compatible with other materials that are in contact with and exposed to during plasma processing operations within the chamber 101. At least one wall 101A of the chamber 101 includes a door 107 through which semiconductor wafers W are transferred in and out of the chamber 101. In some embodiments, the door 107 is configured as a slit valve door.

[0028] In some embodiments, the semiconductor wafer W is a semiconductor wafer in a manufacturing process. For ease of description, the semiconductor wafer W is hereinafter referred to as a wafer W. However, in various embodiments, the wafer W can be essentially any type of substrate that is subjected to a plasma-based manufacturing process. For example, in some embodiments, the wafer W referred to herein can be a substrate formed of silicon, sapphire, GaN, GaAs, or SiC, or other substrate materials, and can include glass panels / substrates, metal foils, metal sheets, polymeric materials, and the like. Also, in various embodiments, the wafer W referred to herein can vary in form, shape, and / or size. For example, in some embodiments, the wafer W referred to herein can be a circular semiconductor wafer on which integrated circuit devices are fabricated. In various embodiments, the circular wafer W can have a diameter of 200 mm (millimeters), 300 mm, 450 mm, or other sizes. Also, in some embodiments, the wafer W referred to herein can be a non-circular substrate, such as a rectangular substrate for a flat panel display.

[0029] The plasma processing system 100 includes an electrode 109 disposed on a facility plate 111. In some embodiments, the electrode 109 and the facility plate 111 are formed of aluminum. However, in other embodiments, the electrode 109 and the facility plate 111 can be formed of other conductive materials that have sufficient mechanical strength and compatible thermal and chemical performance characteristics. A ceramic layer 110 is formed on a top surface of the electrode 109. In some embodiments, the ceramic layer has a vertical thickness of about 1.25 millimeters (mm) when measured perpendicular to the top surface of the electrode 109. However, in other embodiments, the ceramic layer 110 can have a vertical thickness greater than or less than 1.25 mm. The ceramic layer 110 is configured to receive and support the wafer W while plasma processing operations are performed on the wafer W. In some embodiments, the top surface of the electrode 190 and the peripheral side of the electrode 109, which are radially outward of the ceramic layer 110, are covered with a ceramic spray coat.

[0030] The ceramic layer 110 includes an arrangement of one or more clamping electrodes 112 for generating an electrostatic force that holds the wafer W on the top surface of the ceramic layer 110. In some embodiments, the ceramic layer 110 includes an arrangement of two clamping electrodes 112 operating in a bipolar manner to provide a clamping force to the wafer W. The clamping electrodes 112 are connected to a direct current (DC) power supply 117 that generates a controlled clamping voltage to hold the wafer W on the top surface of the ceramic layer 110. Electrical wires 119A, 119B are connected between the DC power supply 117 and the facility plate 111. Electrical wires / conductors are routed through the facility plate 111 and the electrodes 109 to electrically connect the wires 119A, 119B to the clamping electrodes 112. The DC power supply 117 is connected to a control system 120 via one or more signal conductors 121.

[0031] The electrode 109 also includes a configuration of temperature control fluid channels 123 through which a temperature control fluid flows to control the temperature of the electrode 109, and in turn, the temperature of the wafer W. The temperature control fluid channels 123 are plumbed (fluidically connected) to ports on the facility plate 111. Temperature control fluid supply and return lines are connected to these ports on the facility plate 111 and to a temperature control fluid circulation system 125, as indicated by arrows 126. The temperature control fluid circulation system 125 includes a temperature control fluid supply, a temperature control fluid pump, and heat exchangers and other devices, and controls the flow of temperature control fluid through the electrode 109 to set and maintain a predetermined wafer W temperature. The temperature control fluid circulation system 125 is connected to the control system 120 via one or more signal conductors 127. In various embodiments, various types of temperature control fluids can be used, such as water or a refrigerant liquid / gas. Additionally, in some embodiments, the temperature control fluid channels 123 are configured to allow for spatially varying control of the temperature of the wafer W, for example, in two dimensions (x and y) across the wafer W.

[0032] The ceramic layer 110 also includes an arrangement of backside gas supply ports 108 (see FIG. 2) fluidly connected to corresponding backside gas supply channels in the electrode 109. The backside gas supply channels in the electrode 109 are routed through the electrode 109 to an interface between the electrode 109 and the facility plate 111. One or more backside gas supply lines are connected to ports on the facility plate 111, as indicated by arrows 130, and to a backside gas supply system 129. The facility plate 111 is configured to supply backside gas from one or more backside gas supply lines to the backside gas supply channels in the electrode 109. The backside gas supply system 129 includes a backside gas source, mass flow controllers, flow control valves and other devices to provide a controlled backside gas flow through the arrangement of backside gas supply ports 108 in the ceramic layer 110. In some embodiments, the backside gas supply system 129 also includes one or more components for controlling the temperature of the backside gas. In some embodiments, the backside gas is helium. Also in some embodiments, a backside gas supply system 129 can be used to supply clean dry air (CDA) to the arrangement of backside gas supply ports 108 in the ceramic layer 110. The backside gas supply system 129 is connected to the control system 120 via one or more signal conductors 131.

[0033] The three lift pins 132 extend through the facility plate 111, the electrode 109, and the ceramic layer 110 to allow vertical movement of the wafer W relative to the top surface of the ceramic layer 110. In some embodiments, the vertical movement of the lift pins 132 is controlled by respective electromechanical and / or pneumatic lift devices 133 connected to the facility plate 111. The three lift devices 133 are connected to the control system 120 via one or more signal conductors 134. In some embodiments, the three lift pins 132 are positioned to have substantially equal azimuthal spacing with respect to a vertical centerline of the electrode 109 / ceramic layer 110 that extends perpendicular to the top surface of the ceramic layer 110. Note that the lift pins 132 rise to accept and remove the wafer W into and from the chamber 101. Also, the lift pins 132 lower to place the wafer W on the top surface of the ceramic layer 110 during processing of the wafer W.

[0034] FIG. 2 illustrates a top view of the ceramic layer 110 and the electrode 109, according to some embodiments. An exemplary placement of the clamping electrode 112 within the ceramic layer 110 is shown. Note that the clamping electrode 112 is located within the vertical thickness of the ceramic layer 110 such that a portion of the ceramic layer 110 resides above the clamping electrode 112. FIG. 2 also illustrates an exemplary placement of the backside gas supply ports 108. Note that the number and spatial placement of the backside gas supply ports 108 may vary in different embodiments. In some embodiments, the backside gas supply ports 108 are filled with a porous ceramic material that allows for backside gas flow through the backside gas supply ports 108 while simultaneously providing a solid surface at the backside gas supply ports 108. FIG. 2 also illustrates an exemplary placement of three lift pins 132.

[0035] Also, in various embodiments, one or more of the electrodes 109, facility plate 111, ceramic layer 110, clamping electrodes 112, lift pins 132, or essentially any other components associated therewith, may include one or more sensors, such as sensors for measuring temperature, voltage, and current, etc. Any sensors located on the electrodes 109, facility plate 111, ceramic layer 110, clamping electrodes 112, lift pins 132, or essentially any other components associated therewith, are connected to the control system 120 via electrical wires, optical fibers, or wireless connections.

[0036] The facility plate 111 is set within an opening in, and supported by, the ceramic support 113. The ceramic support 113 is disposed on a support surface 114 of the cantilever arm assembly 115. In some embodiments, the ceramic support 113 has a substantially annular shape such that the ceramic support 113 substantially surrounds the radial periphery of the facility plate 111 while also providing a support surface 116 on which a bottom peripheral surface of the facility plate 111 rests. The cantilever arm assembly 115 extends through the wall 101A of the chamber 101. In some embodiments, a sealing mechanism 135 is provided within the wall 101A of the chamber 101 in which the cantilever arm assembly 115 is disposed to seal the interior region 103 of the chamber 101 while allowing the cantilever arm assembly 115 to move up and down in the z-direction in a controlled manner.

[0037] The cantilever arm assembly 115 has an open area 118 through which various devices, wires, cables, and tubes are routed to support the operation of the system 100. The open area 118 in the cantilever arm assembly is exposed to the atmospheric conditions outside the chamber 101, such as air composition, temperature, pressure, and relative humidity. Also disposed within the cantilever arm assembly 115 is an RF signal supply rod 137. More specifically, the RF signal supply rod 137 is disposed within a conductive tube 139, and the RF signal supply rod 137 is spaced from an inner wall of the tube 139. In some embodiments, the tube 139 has an inner diameter within a range of about 1.5 inches to about 6 inches. In some embodiments, the RF signal supply rod 137 has an outer diameter within a range of about 0.75 inches to about 2 inches. In some embodiments, the difference between the inner diameter of the tube 139 and the outer diameter of the RF signal supply rod 137 is within a range of about 0.25 inches to about 4 inches. The size of the RF signal feed rod 137 and the tube 139 can vary. The area inside the tube 139 between the inner wall of the tube 139 and the RF signal feed rod 137 is occupied by air along the entire length of the tube 139. In some embodiments, the outer diameter (D rod ) and the inner diameter of the tube 139 (D tube ) is ln(D tube / D rod )>=e 1 is set so as to satisfy the relationship:

[0038] In some embodiments, the RF signal feed rod 137 is substantially centrally located within the tube 139, and a substantially uniform radial thickness of air exists between the RF signal feed rod 137 and the inner wall of the tube 139 along the length of the tube 139. However, in some embodiments, the RF signal feed rod 137 is not centrally located within the tube 139. There is still air space along the length of the tube 139 at all locations within the tube 139 between the RF signal feed rod 137 and the inner wall of the tube 139. The delivery end of the RF signal feed rod 137 is electrically and physically connected to the bottom end of the RF signal feed shaft 141. In some embodiments, the delivery end of the RF signal feed rod 137 is bolted to the bottom end of the RF signal feed shaft 141. The top end of the RF signal feed shaft 141 is electrically and physically connected to the bottom of the facility plate 111. In some embodiments, the top end of the RF signal feed shaft 141 is bolted to the bottom of the facility plate 111. In some embodiments, both the RF signal feed rod 137 and the RF signal feed shaft 141 are made of copper. In some embodiments, the RF signal feed rod 137 is made of copper, aluminum, or anodized aluminum. In some embodiments, the RF signal feed shaft 141 is made of copper, aluminum, or anodized aluminum. In other embodiments, the RF signal feed rod 137 and / or the RF signal feed shaft 141 are made of another conductive material that allows for the transmission of RF electrical signals. In some embodiments, the RF signal feed rod 137 and / or the RF signal feed shaft 141 are coated with a conductive material (such as silver or other conductive material) that allows for the transmission of RF electrical signals. Also, in some embodiments, the RF signal feed rod 137 is a solid rod. However, in other embodiments, the RF signal feed rod 137 is a tube. It should be noted that the area 140 surrounding the connection between the RF signal feed rod 137 and the RF signal feed shaft 141 is occupied by air.

[0039] The feed end of the RF signal feed rod 137 is electrically and physically connected to an impedance matching system 143. The impedance matching system 143 is connected to a first RF signal generator 147 and a second RF signal generator 149. The impedance matching system 143 is also connected to the control system 120 via one or more signal conductors 144. The first RF signal generator 147 is also connected to the control system 120 via one or more signal conductors 148. The second RF signal generator 149 is also connected to the control system 120 via one or more signal conductors 150. The impedance matching system 143 includes an arrangement of inductors and capacitors sized and connected to enable impedance matching so that RF power can be transmitted along the RF signal feed rod 137 and the RF signal feed shaft 141, through the facility plate 111 and the electrode 109, and to the plasma processing region 182 above the ceramic layer 110. In some embodiments, the first RF signal generator 147 is a high frequency RF signal generator and the second RF signal generator 149 is a low frequency RF signal generator. In some embodiments, the first RF signal generator 147 generates an RF signal in a range of about 50 megahertz (MHz) to about 70 MHz, or in a range of about 54 MHz to about 63 MHz, or at about 60 MHz. In some embodiments, the first RF signal generator 147 provides RF power in a range of about 5 kilowatts (kW) to about 25 kW, or in a range of about 10 kW to about 20 kW, or in a range of about 15 kW to about 20 kW, or at about 10 kW or about 16 kW. In some embodiments, the second RF signal generator 149 generates an RF signal in a range of about 50 kilohertz (kHz) to about 500 kHz, or in a range of about 330 kHz to about 440 kHz, or at about 400 kHz. In some embodiments, the second RF signal generator 149 provides RF power in the range of about 15 kW to about 100 kW, or in the range of about 30 kW to about 50 kW, or at about 34 kW or about 50 kW. In one exemplary embodiment, the first RF signal generator 147 is configured to generate an RF signal of about 60 MHz and the second RF signal generator 149 is configured to generate an RF signal of about 400 kHz.

[0040] FIG. 3 shows an electrical schematic diagram of the impedance matching system 143 according to some embodiments. The impedance matching system 143 includes a first branch 302A (high frequency branch) and a second branch 302B (low frequency branch). The first branch 302A includes circuit components such as an inductor L4, a capacitor C2, a capacitor C7, and a capacitor C3. The second branch 302B includes circuit components such as an inductor L1, an inductor L2, a capacitor C1, a capacitor C4, a capacitor C5, a capacitor C6, and an inductor L3. In some embodiments, the capacitors C1, C2, and C3 are variable capacitors. The capacitors C1 and C2 are main capacitors and the capacitor C3 is a reserve capacitor. The inductors L1, L2, L3, and L4 are each formed as a coil made of a conductive material, for example copper. The first branch 302A has an input I1 connected to the output of the first RF signal generator 147. The second branch 302B has an input I2 connected to the output of the second RF signal generator 149. The input I2 is connected to an inductor L1.

[0041] As an example, the RF straps referred to herein are flat, elongated pieces of conductive material such as copper. Thus, the RF straps have a length, a width, and a thickness. The length of the RF strap is greater than the width of the RF strap. Additionally, the width of the RF strap is greater than the thickness of the RF strap. In some embodiments, the RF straps are flexible to allow them to bend or reshape themselves.

[0042] The first branch 302A includes RF strap portion 304A (represented as inductor LA), RF strap portion 304B (represented as inductor LB), RF strap 304C (represented as inductor LC), RF strap 304D (represented as inductor LD), and RF strap 304E (represented as inductor LE). In some embodiments, RF strap portions 304A and 304B are separate parts of one RF strap, i.e., inductors LA and LB represent separate parts of one RF strap. However, in some embodiments, instead of one RF strap including two RF strap portions 304A and 304B, two separate RF straps are used as RF strap portions 304A and 304B, respectively. For example, a first RF strap having an inductance of RF strap portion 304A is connected to a second RF strap having an inductance of RF strap portion 304B via a conductive connector.

[0043] The capacitor C3 is coupled to a predetermined position P1 on the RF strap including both RF strap portions 304A and 304B via the RF strap 304C. Thus, the predetermined position P1 where the RF strap 304C is connected to the RF strap including both RF strap portions 304A and 304B determines the length of each of the RF strap portions 304A and 304B. The capacitor C7 is also coupled to the end of the RF strap portion 304A opposite to the predetermined position P1. The predetermined position P1 is coupled to the RF signal supply rod 137 via the RF strap portion 304B. The RF straps 304D and 304E are coupled to each other at the predetermined position P2. The terminal of the capacitor C2 is also connected to the predetermined position P2. The RF strap 304D is coupled to the inductor L4 and the input I1 of the impedance matching system 143. Each of the RF strap portions 304A and 304B, and each of the RF straps 304C, 304D, and 304E has an inductance. For example, RF strap portion 304A has an inductance LA, RF strap portion 304B has another inductance LB, RF strap 304C has another inductance LC, RF strap 304D has an inductance LD, and RF strap 304E has an inductance LE. Note that any of the RF straps such as RF straps 304A-304E described herein are not wound into a coil to form an inductor, but rather are formed as a flat strip of metal.

[0044] In various embodiments, any of the capacitors and / or non-strap inductors shown in FIG. 3 may be fixed or variable. For example, in various embodiments, any one or more of capacitors C4-C7 are fixed capacitors, meaning that their inductance cannot be changed or adjusted. Also, in some embodiments, any one or more of capacitors C4-C7 are variable capacitors, meaning that their capacitance can be changed / adjusted. In various embodiments, any one or more of inductors L1-L4 are fixed inductors, meaning that their inductance cannot be changed or adjusted. Also, in various embodiments, any one or more of inductors L1-L4 are variable inductors, meaning that their inductance can be changed or adjusted.

[0045] 1A, the ceramic ring 161 is configured and positioned to extend around the radial circumference of the electrode 109. Also, in some embodiments, the first quartz ring 163 is configured and positioned to extend around the radial circumference of both the ceramic ring 161 and the ceramic support 113. In some embodiments, the ceramic ring 161 and the first quartz ring 163 are configured to have substantially aligned top surfaces when the first quartz ring 163 is disposed around both the ceramic ring 161 and the ceramic support 113. Also, in some embodiments, the substantially aligned top surfaces of the ceramic ring 161 and the first quartz ring 163 are substantially aligned with the top surface of the electrode 109 that is outside the radial circumference of the ceramic layer 110. Also, in some embodiments, the second quartz ring 165 is configured and positioned to extend around the radial circumference of the top surface of the first quartz ring 163. Also, in some embodiments, the second quartz ring 165 is configured to extend vertically above the top surface of the first quartz ring 163. In this manner, the second quartz ring 165 provides a peripheral boundary around which the edge ring 167 is disposed.

[0046] The edge ring 167 is configured to facilitate extending the plasma sheath radially outward beyond the periphery of the wafer W to improve processing results near the periphery of the wafer W. In various embodiments, the edge ring 167 is formed from a conductive material, such as crystalline silicon, polycrystalline silicon (polysilicon), boron-doped single crystal silicon, aluminum oxide, quartz, aluminum nitride, silicon nitride, silicon carbide, or a silicon carbide layer on an aluminum oxide layer, or an alloy of silicon, or a combination thereof, or other materials. It should be noted that the edge ring 167 is formed as an annular structure, such as a ring structure. The edge ring 167 can perform many functions, such as shielding components below the edge ring 167 to prevent damage from ions of the plasma 180 formed in the plasma processing region 182. The edge ring 167 also enhances the uniformity of the plasma 180 at and along the peripheral edge region of the wafer W.

[0047] A fixed outer support flange 169 is attached to the cantilever arm assembly 115. FIG. 4A shows a close-up view of a vertical cross section of the fixed outer support flange 169, according to some embodiments. The fixed outer support flange 169 is configured to extend around the outer vertical side 113A of the ceramic support 113, around the outer vertical side 163A of the first quartz ring 163, and around the lower outer vertical side 165A of the second quartz ring 165. The fixed outer support flange 169 has an annular shape that surrounds the assembly of the ceramic support 113, the first quartz ring 163, and the second quartz ring 165. The fixed outer support flange 169 has an L-shaped vertical cross section that includes a vertical portion 169A and a horizontal portion 169B. The L-shaped cross-sectional vertical portion 169A of the fixed outer support flange 169 has an inner vertical surface 169C disposed relative to the outer vertical side 113A of the ceramic support 113, the outer vertical side 163A of the first quartz ring 163, and the lower outer vertical side 165A of the second quartz ring 165. In some embodiments, the L-shaped cross-sectional vertical portion 169A of the fixed outer support flange 169 extends over the entire outer vertical side 113A of the ceramic support 113, the entire outer vertical side 163A of the first quartz ring 163, and the lower outer vertical side 165A of the second quartz ring 165. In some embodiments, the second quartz ring 165 extends radially outward above the top surface 169E of the L-shaped cross-sectional vertical portion 169A of the fixed outer support flange 169. In some embodiments, the upper outer vertical side surface 165B of the second quartz ring 165 (located above the top surface 169E of the vertical portion 169A of the L-shaped cross section of the fixed outer support flange 169) is substantially vertically aligned with the outer vertical surface 169D of the vertical portion 169A of the L-shaped cross section of the fixed outer support flange 169. The horizontal portion 169B of the L-shaped cross section of the fixed outer support flange 169 is disposed on and fixed to the support surface 114 of the cantilever arm assembly 115. The fixed outer support flange 169 is formed of a conductive material. In some embodiments, the fixed outer support flange 169 is formed of aluminum or anodized aluminum. However, in other embodiments, the fixed outer support flange 169 can be formed of other conductive materials, such as copper or stainless steel.In some embodiments, the horizontal portion 169 B of the L-shaped cross section of the fixed outer support flange 169 is bolted to the support surface 114 of the cantilever arm assembly 115 .

[0048] The connecting outer support flange 171 is configured and positioned to extend around at least a portion of the outer vertical surface 169D of the vertical portion 169A of the L-shaped cross section of the fixed outer support flange 169, and to extend around the upper outer vertical side surface 165B of the second quartz ring 165. The connecting outer support flange 171 has an annular shape that surrounds both at least a portion of the vertical portion 169A of the L-shaped vertical cross section of the fixed outer support flange 169 and the upper outer vertical side surface 165B of the second quartz ring 165. The connecting outer support flange 171 has an L-shaped vertical cross section that includes a vertical portion 171A and a horizontal portion 171B. The L-shaped cross-sectional vertical portion 171A of the connecting outer support flange 171 has an inner vertical surface 171C that is adjacent to and spaced apart from both at least a portion of the outer vertical side surface 169D of the L-shaped cross-sectional vertical portion 169A of the fixed outer support flange 169 and the upper outer vertical side surface 165B of the second quartz ring 165. In this manner, the connecting outer support flange 171 is movable in the vertical direction (z-direction) along both the L-shaped vertical cross-sectional vertical portion 169A of the fixed outer support flange 169 and the upper outer vertical side surface 165B of the second quartz ring 165, as indicated by arrow 172. The connecting outer support flange 171 is formed of a conductive material. In some embodiments, the connecting outer support flange 171 is formed of aluminum or anodized aluminum. However, in other embodiments, the connecting outer support flange 171 may be formed of other conductive materials, such as copper or stainless steel.

[0049] A number of conductive straps 173 are connected between the connecting outer support flange 171 and the fixed outer support flange 169 around the radial circumference of both the connecting outer support flange 171 and the fixed outer support flange 169. FIG. 5 shows a top view of the connecting outer support flange 171 and the fixed outer support flange 169, according to some embodiments, illustrating a number of conductive straps 173 connected between the connecting outer support flange 171 and the fixed outer support flange 169. FIG. 6 shows a perspective view of the top of the connecting outer support flange 171 and the fixed outer support flange 169, according to some embodiments, illustrating a number of conductive straps 173 connected between the connecting outer support flange 171 and the fixed outer support flange 169. In some embodiments, the conductive straps 173 are formed of stainless steel. However, in other embodiments, the conductive straps 173 may be formed of other conductive materials, such as aluminum or copper.

[0050] In the example of FIGS. 1A, 1B, 5, and 6, 48 conductive straps 173 are substantially equally spaced around the radial circumference of the connecting outer support flange 171 and the fixed outer support flange 169. It should be noted, however, that the number of conductive straps 173 can vary in different embodiments. In some embodiments, the number of conductive straps 173 is in a range of about 24 to about 80, or in a range of about 36 to about 60, or in a range of about 40 to about 56. In some embodiments, the number of conductive straps 173 is less than 24. In some embodiments, the number of conductive straps 173 is greater than 80. The number of conductive straps 173 can affect the uniformity of process results across the wafer W because the number of conductive straps 173 affects the ground return path of the RF signal near the periphery of the plasma processing region 182. Also, the size of the conductive straps 173 can vary in different embodiments. FIG. 7 illustrates an isometric view of a conductive strap 173, according to some embodiments. Conductive strap 173 has a rectangular prism shape defined by a width (d1), a length (d2), and a thickness (d3). In some embodiments, the width (d1) of conductive strap 173 is in the range of about 0.125 inches to about 2 inches. In some embodiments, the length (d2) of conductive strap 173 is in the range of about 2 inches to about 10 inches. In some embodiments, the thickness (d3) of conductive strap 173 is in the range of up to about 0.125 inches.

[0051] 5 also illustrates the azimuthal spacing (d4) between adjacent conductive straps 173 when connected between the connecting outer support flange 171 and the fixed outer support flange 169. In some embodiments, the conductive straps 173 are substantially equally spaced around the circumference of the connecting outer support flange 171 and similarly around the circumference of the fixed outer support flange 169. Thus, in these embodiments, the azimuthal spacing (d4) between adjacent conductive straps 173 around the circumference of the horizontal portion 171B of the L-shaped vertical cross section of the connecting outer support flange 171 depends on the number of conductive straps 173, the width dimension (d1) of the conductive straps 173, and the outer diameter of the horizontal portion 171B of the L-shaped vertical cross section of the connecting outer support flange 171. Similarly, the azimuthal spacing (d4) between adjacent conductive straps 173 around the circumference of the horizontal portion 169B of the L-shaped vertical cross section of the fixed outer support flange 169 depends on the number of conductive straps 173, the width dimension (d1) of the conductive straps 173, and the outer diameter of the horizontal portion 169B of the L-shaped vertical cross section of the fixed outer support flange 169. In some embodiments, the azimuthal spacing (d4) between adjacent conductive straps 173 is within a range from about 0.125 inches to about 4 inches.

[0052] In some embodiments, the conductive straps 173 are connected to the fixed outer support flange 169 by a clamping force applied by fastening the clamp ring 175 to the top surface 169F of the horizontal portion 169B of the L-shaped cross section of the fixed outer support flange 169. In some embodiments, the clamp ring 175 is bolted to the fixed outer support flange 169. In some embodiments, the bolts fastening the clamp ring 175 to the fixed outer support flange 169 are disposed at a location between the conductive straps 173. However, in some embodiments, the bolt or bolts fastening the clamp ring 175 to the fixed outer support flange 169 may be disposed to extend through the conductive straps 173. In some embodiments, the clamp ring 175 is formed of the same material as the fixed outer support flange 169. However, in other embodiments, the clamp ring 175 and the fixed outer support flange 169 may be formed of different materials.

[0053] In some embodiments, as shown in FIG. 4A , the conductive straps 173 are connected to the interlocking outer support flange 171 by a clamping force applied by fastening a clamp ring 177 to a bottom surface 171D of the horizontal portion 171B of the L-shaped cross section of the interlocking outer support flange 171. FIG. 4B illustrates a variation of FIG. 4A in which a first end of each of the plurality of conductive straps 173 is connected to a top surface 171F of the horizontal portion 171B of the interlocking outer support flange 171 by a clamp ring 177, according to some embodiments. In some embodiments, the clamp ring 177 is bolted to the interlocking outer support flange 171. In some embodiments, the bolts that secure the clamp ring 177 to the interlocking outer support flange 171 are located between the conductive straps 173. However, in some embodiments, the bolt or bolts that secure the clamp ring 177 to the interlocking outer support flange 171 may be positioned to extend through the conductive straps 173. In some embodiments, the clamp ring 177 is formed of the same material as the interlocking outer support flange 171. However, in other embodiments, the clamp ring 177 and the associated outer support flange 171 may be formed from different materials.

[0054] A set of support rods 201 are disposed around the cantilever arm assembly 115 and extend vertically through the horizontal portion 169B of the L-shaped section of the fixed outer support flange 169. The upper ends of the support rods 201 are configured to engage with the bottom surface 171D of the horizontal portion 171B of the L-shaped section of the connecting outer support flange 171. In some embodiments, the lower ends of each of the support rods 201 are engaged with a resistance mechanism 203. The resistance mechanism 203 is configured to provide an upward force to the corresponding support rod 201, which resists downward movement of the support rod 201 while allowing some downward movement of the support rod 201. In some embodiments, the resistance mechanism 203 includes a spring for providing an upward force to the corresponding support rod 201. In some embodiments, the resistance mechanism 203 includes a material, such as, for example, a spring and / or rubber, having a spring constant sufficient to provide an upward force to the corresponding support rod 201. It should be noted that as the interlocking outer support flange 171 moves downward to engage the set of support rods 201, the set of support rods 201 and corresponding resistance mechanisms 203 exert an upward force on the interlocking outer support flange 171. In some embodiments, the set of support rods 201 includes three support rods 201 and corresponding resistance mechanisms 203. In some embodiments, the support rods 201 are positioned to have substantially equal azimuthal spacing relative to the vertical centerline of the electrode 109. However, in other embodiments, the support rods 201 are positioned to have unequal azimuthal spacing relative to the vertical centerline of the electrode 109. Also, in some embodiments, more than three support rods 201 and corresponding resistance mechanisms 203 are provided to support the interlocking outer support flange 171.

[0055] 1A, the plasma processing system 100 further includes a C-shroud member 185 disposed above the electrode 109. The C-shroud member 185 is configured to interface with the associated outer support flange 171. Specifically, a seal 179 is disposed on the top surface 171E of the horizontal portion 171B of the L-shaped cross section of the associated outer support flange 171 such that the seal 179 is engaged by the C-shroud member 185 when the associated outer support flange 171 moves upward toward the C-shroud member 185. In some embodiments, the seal 179 is electrically conductive to facilitate establishing electrical conduction between the C-shroud member 185 and the associated outer support flange 171. In some embodiments, the C-shroud member 185 is formed of polysilicon. However, in other embodiments, the C-shroud member 185 is formed of another type of electrically conductive material that is chemically compatible with processes to be performed in the plasma processing region 182 and has sufficient mechanical strength.

[0056] The C-shroud is configured to extend around the plasma processing region 182, radially extending the extent of the plasma processing region 182 into an area defined within the C-shroud member 185. The C-shroud member 185 includes a bottom wall 185A, an outer vertical wall 185B, and an upper wall 185C. In some embodiments, the outer vertical wall 185B and the upper wall 185C of the C-shroud member 185 are solid, non-perforated members, and the bottom wall 185A of the C-shroud member 185 includes a number of vents 186 that channel process gases from within the plasma processing region 182. In some embodiments, a throttle member 196 is disposed below the vents 186 of the C-shroud member 185 to control the flow of process gases through the vents 186. More specifically, in some embodiments, the throttle member 196 is configured to move vertically up and down in the z-direction relative to the C-shroud member 185 to control the flow of process gas through the vents 186. In some embodiments, the throttle member 196 is configured to engage and / or enter the vents 186.

[0057] The top wall 185C of the C-shroud member 185 is configured to support the top electrodes 187A / 187B. In some embodiments, the top electrodes 187A / 187B include an inner top electrode 187A and an outer top electrode 187B. Alternatively, in some embodiments, the inner top electrode 187A is present but the outer top electrode 187B is not present, with the inner top electrode 187A extending radially to the location that the outer top electrode 187B should occupy. In some embodiments, the inner top electrode 187A is formed of single crystal silicon and the outer top electrode 187B is formed of polysilicon. However, in other embodiments, the inner top electrode 187A and the outer top electrode 187B may be formed of other materials that are structurally, chemically, electrically, and mechanically compatible with the processes performed in the plasma processing region 182. The inner top electrode 187A includes a number of through ports 197, defined as holes that extend through the entire vertical thickness of the inner top electrode 187A. Through ports 197 are distributed throughout the inner upper electrode 187A, relative to the xy plane, and provide a flow of process gas from the plenum region 188 above the upper electrodes 187A / 187B to the plasma processing region 182 below the upper electrodes 187A / 187B.

[0058] 8A illustrates a vertical cross-sectional view of the top electrodes 187A / 187B according to some embodiments. In some embodiments, the inner top electrode 187A includes a plate 211 formed of a semiconductor material, such as single crystal silicon. In some embodiments, a highly conductive layer 213 is formed on the top surface of the plate 211 and is integral with the plate 211. The highly conductive layer 213 has a lower electrical resistance than the semiconductor material of the plate 211. Each through port 197 extends through the entire thickness of the inner top electrode 187A from the top surface 215 of the inner top electrode 187A to the bottom surface 217 of the inner top electrode 187A. As previously described, the inner top electrode 187A is configured to physically separate the process gas plenum region 188 from the plasma processing region 182 and provide a flow of process gas from the process gas plenum region 188 to the plasma processing region 182 through a distribution of the through ports 197.

[0059] FIG. 8B illustrates a top view of the upper electrodes 187A / 187B, according to some embodiments. FIG. 8B illustrates an example distribution of through ports 197 across the inner upper electrode 187A. It should be noted that the distribution of through ports 197 across the inner upper electrode 187A may be configured differently in other embodiments. For example, the total number of through ports 197 in the inner upper electrode 187A and / or the spatial distribution of through ports 197 in the inner upper electrode 187A may vary in other embodiments. The diameter of the through ports 197 may also vary in other embodiments. In general, it is important to reduce the diameter of the through ports 197 to a size small enough to prevent the ingress of plasma 180 from the plasma processing region 182 into the through ports 197. In some embodiments, if the diameter of the through ports 197 is reduced, the total number of through ports 197 in the inner upper electrode 187A is increased to maintain a predetermined total flow rate of process gas from the process gas plenum region 188 through the inner upper electrode 187A to the plasma processing region 182. Also, in some embodiments, the top electrodes 187A / 187B are electrically connected to a reference ground potential, but in other embodiments, the inner top electrode 187A and / or the outer top electrode 187B are electrically connected to either a respective direct current (DC) power source or a respective RF power source by corresponding impedance matching circuits.

[0060] 1A, the plenum region 188 is defined by a top member 189. One or more gas supply ports 192 are formed through the chamber 101 and the top member 189 and are in fluid communication with the plenum region 188. The one or more gas supply ports 192 are fluidly connected (plumbed) to a process gas supply system 191. The process gas supply system 191 may include, for example, one or more process gas sources, one or more mass flow controllers, one or more flow control valves or other devices, and provides a controlled flow of one or more process gases through the one or more gas supply ports 192 to the plenum region 188, as indicated by arrows 193. In some embodiments, the process gas supply system 191 also includes one or more components for controlling the temperature of the process gas. The process gas supply system 191 is connected to the control system 120 via one or more signal conductors 194.

[0061] The process gap (g1) is defined as the vertical (z-direction) distance measured between the top surface of the ceramic layer 110 and the bottom surface of the inner upper electrode 187A. The size of the process gap (g1) can be adjusted by moving the cantilever arm assembly 115 in the vertical (z-direction). As the cantilever arm assembly 115 moves upward, the linked outer support flange 171 eventually engages the bottom wall 185A of the C-shroud member 185, at which point the linked outer support flange 171 moves along the fixed outer support flange 169 as the cantilever arm assembly 115 continues to move upward until the set of support rods 201 engages the linked outer support flange 171, achieving a predetermined process gap (g1) size. Then, to reverse this movement to remove the wafer W from the chamber, the cantilever arm assembly 115 moves downward until the linked outer support flange 171 clears the bottom wall 185A of the C-shroud member 185. FIG 1B illustrates the system 100 of FIG 1A with the cantilever arm assembly 115 moved downward to allow movement of the wafer W through the door 107, according to some embodiments. In various embodiments, the size of the process gap (g1) during plasma processing of the wafer W is controlled to a range of up to about 10 centimeters, up to about 8 centimeters, or up to about 5 centimeters. Also in FIG 1B, the wafer W is shown in an elevated position by lift pins 133. Note that FIG 1A illustrates the system 100 in a closed configuration with the wafer W positioned on the ceramic layer 110 for plasma processing.

[0062] During plasma processing operations in the plasma processing system 100, one or more process gases are supplied to the plasma processing region 182 via the process gas supply system 191, the plenum region 188, and the through port 197 in the inner upper electrode 187A. RF signals are also transmitted into the plasma processing region 182 by the first and second RF signal generators 147, 149, the impedance match system 143, the RF signal supply rod 137, the RF signal supply shaft 141, the facility plate 111, the electrode 109, and through the ceramic layer 110. The RF signals convert the process gases into a plasma 180 in the plasma processing region 182. The ions and / or reactive components of the plasma interact with one or more materials on the wafer W to change the composition and / or shape of certain materials present on the wafer W. Exhaust gases from the plasma processing region 182 are influenced by the suction force applied to the exhaust port 105 as shown by arrows 195 and flow through vents 186 in the C-shroud member 185 and through the interior region 103 within the chamber 101 to the exhaust port 105.

[0063] In various embodiments, the electrode 109 may be configured to have different diameters. However, in some embodiments, the diameter of the electrode 109 is extended to increase the surface of the electrode 109 on which the edge ring 167 rests. For example, FIG. 9 shows a close-up view of the area 220 near the edge ring 167, as also shown in FIG. 1A, illustrating the electrode 109 having an extended diameter, according to some embodiments. Prior to the extension of the diameter of the electrode 109, the outer edge of the electrode 109 is shown by dashed line 222. With the outer edge of the electrode 109 shown in dashed line 222, the edge ring 167 rests on a portion of the electrode 109 having a radial distance (d5) that is less than half the radial distance (d7) of the edge ring 167. With the extension of the diameter of the electrode 109, the outer edge 224 of the electrode 109 is positioned farther toward the outer diameter of the edge ring 167, and the edge ring 167 rests on a portion of the electrode 109 having a radial distance (d6). In some embodiments, the radial distance (d6) is greater than or equal to ½ the radial distance (d7) of the edge ring 167. In some embodiments, the radial distance (d6) is greater than or equal to ¾ the radial distance (d7) of the edge ring 167. In some embodiments, the conductive gel 226 is disposed between the bottom of the edge ring 167 and the top of the electrode 109. In these embodiments, the diameter of the electrode 109 is extended to increase the surface area of ​​the conductive gel disposed between the edge ring 167 and the electrode 109.

[0064] It should be noted that the combination of the coupled outer support flange 171, the conductive straps 173, and the fixed outer support flange 169 are electrically at a reference ground potential, and collectively they form a ground return path for the RF signal transmitted from the electrode 109 through the ceramic layer 110 to the plasma processing region 182. The azimuthal uniformity of this ground return path around the periphery of the electrode 109 may affect the uniformity of the process results on the wafer W. For example, in some embodiments, the etch rate uniformity across the wafer W may be affected by the azimuthal uniformity of the ground return path around the periphery of the electrode 109. It should be noted, therefore, that the number, configuration, and placement of the conductive straps 173 around the periphery of the electrode 109 may affect the uniformity of the process results across the wafer W.

[0065] In the exemplary embodiments shown in Figures 1A, 1B, 4A, 4B, 5, and 6, the conductive straps 173 are shown having an "outward" configuration, in which the conductive straps 173 are curved outwardly, away from the fixed outer support flange 169. In other embodiments, the conductive straps 173 are configured to curve inwardly towards the fixed outer support flange 169. Figure 10 is an alternative to Figure 4A, showing conductive straps 173 configured to curve inwardly towards the fixed outer support flange 169, according to some embodiments. B 10. Conductive strap 173 in FIG. B This configuration is referred to as an "inward" configuration. In other embodiments, the conductive strap 173B is configured to bend in an S-shape between the connecting outer support flange 171 and the fixed outer support flange 169. FIG. 11 is an alternative to FIG. 4A and shows a conductive strap 173B configured to bend in an S-shape between the connecting outer support flange 171 and the fixed outer support flange 169 according to some embodiments. C 11. Conductive strap 173 in FIG. C This configuration is called an "S-shaped" configuration.

[0066] In addition, conductive straps 173, 173 B , 173 CThe outward, inward, and S-shaped configurations of the conductive straps 173, 173 have different performance characteristics with respect to the ground return path for the RF signals in the system 100. B , 173 C The impedance characteristics of the outward, inward, and S-shaped configurations of the conductive straps 173, 173 B , 173 C The difference in the proximity of the connecting outer support flange 171 to the outer vertical surface 169D of the vertical portion 169A of the fixed outer support flange 169 changes, particularly as the connecting outer support flange 171 moves in the vertical direction (z-direction). As the process gap (g1) increases, the connecting outer support flange 171 becomes higher in the z-direction relative to the fixed outer support flange 169, and in some cases the conductive straps 173, 173 B , 173 C 169A of the fixed outer support flange 169. In addition, as the process gap (g1) decreases, the connecting outer support flange 171 becomes lower in the z-direction relative to the fixed outer support flange 169, and in some cases, the conductive straps 173, 173 B , 173 C The curvature of the conductive straps 173, 173 tends to increase toward or away from the vertical portion 169A of the fixed outer support flange 169. B , 173 C These changes in curvature of the conductive straps 173, 173 relative to the vertical portion 169A of the fixed outer support flange 169 B , 173 C With the change in proximity of the conductive strap 173, 173 B , 173 C This can cause an impedance change along the RF signal ground return path formed by

[0067] Conductive strap 173, 173 B , 173 CA study of the outward, inward, and S-shaped configurations of the conductive straps 173 (as shown in FIGS. 1A, 1B, 4A, 4B, 5, and 6) has shown that the outward configuration of the conductive straps 173 (as shown in FIGS. 1A, 1B, 4A, 4B, 5, and 6) provides 1) better etch rate uniformity across the radial direction of the wafer W, and 2) allows for higher RF power to be delivered to the plasma 180 at higher frequencies, e.g., 60 MHz, over an operable range of process gap (g1) sizes. B Conductive strap 173 B It has been shown that the inward configuration of the conductive straps 173 results in larger amplitudes of higher harmonics (4th, 5th, 6th, 7th, 10th, 11th, 12th harmonics) in the RF signal delivered from the impedance matching system 143 to the RF signal feed rod 137. Therefore, it is beneficial to use an outward configuration of the conductive straps 173 to avoid amplification of these higher harmonics in the RF signal delivered to the plasma. In some embodiments, all of the conductive straps 173 have an outward configuration. However, in some embodiments, a subset of the conductive straps 173 has an outward configuration, and one or more other subsets of the conductive straps 173 have another shape, such as an inward configuration or an S-shaped configuration. In some of these embodiments, the conductive straps 173 having an outward configuration are substantially uniformly distributed around the connecting outer support flange 171 and the fixed outer support flange 169. Also, in some of these embodiments, the subset of conductive straps 173 having an outward configuration is a majority subset of the total number of conductive straps 173.

[0068] In an exemplary embodiment, the plasma processing system 100 includes an electrode 109, a ceramic layer 110, an RF signal generator 147 / 149, a fixed outer support flange 169, a connecting outer support flange 171, and a plurality of conductive straps 173. The electrode 109 has a substantially cylindrical shape defined by a top surface, a bottom surface, and an outer surface. The top surface of the electrode 109 corresponds to a reference horizontal plane (xy plane), and a reference vertical direction (z direction) is perpendicular to the reference horizontal plane. A ceramic layer 110 is formed on the top surface of the electrode 109. The ceramic layer 110 is configured to receive and support a wafer W. The RF signal generators 147, 149 are electrically connected to the electrode 109 via an impedance matching system 143. The RF signal generators 147, 149 are configured to generate and supply RF signals to the electrode 109.

[0069] The fixed outer support flange 169 is formed to surround the outer surface of the electrode 109. The fixed outer support flange 169 has a fixed spatial relationship with respect to the electrode 109. The fixed outer support flange 169 has a vertical portion 169A and a horizontal portion 169B extending radially outward from a lower end of the vertical portion 169A. The fixed outer support flange 169 is electrically connected to a reference ground potential, for example, by the cantilever arm assembly 115. The connecting outer support flange 171 is formed to surround the fixed outer support flange 169. The connecting outer support flange 171 has a vertical portion 171A and a horizontal portion 171B extending radially outward from a lower end of the vertical portion 171A. The vertical portion 171A of the connecting outer support flange 171 is concentrically disposed outside at least a portion of the vertical portion 169A of the fixed outer support flange 169. The connecting outer support flange 171 is spaced from the fixed outer support flange 169 so as to be vertically movable relative to the fixed outer support flange 169 .

[0070] Each of the plurality of conductive straps 173 has a first end connected to the horizontal portion 171B of the connecting outer support flange 171 and a second end connected to the horizontal portion 169B of the fixed outer support flange 169. Each of the plurality of conductive straps 173 bends outwardly in a direction away from the vertical portion 169A of the fixed outer support flange 169. In some embodiments, the plurality of conductive straps 173 are arranged in a substantially equally spaced configuration around both the connecting outer support flange 171 and the fixed outer support flange 169. The plurality of conductive straps 173 are configured to bend as the connecting outer support flange 171 moves relative to the fixed outer support flange 169. Each of the plurality of conductive straps 173 has a bendable length between the first end connected to the connecting outer support flange 171 and the second end connected to the fixed outer support flange 169. According to the outward bending of the plurality of conductive straps 173, the entire bendable length of each of the plurality of conductive straps 173 is disposed outside the connecting outer support flange 171 and / or the fixed outer support flange 169. In some embodiments, a first end of each of the plurality of conductive straps 173 is connected to the lower surface 171D of the horizontal portion 171B of the connecting outer support flange 171 (see FIG. 4A). In some embodiments, a first end of each of the plurality of conductive straps 173 is connected to the upper surface 171F of the horizontal portion 171B of the connecting outer support flange 171 (see FIG. 4B). In some embodiments, a second end of each of the plurality of conductive straps 173 is connected to the upper surface 169F of the horizontal portion 169B of the fixed outer support flange 169 (see FIGS. 4A and 4B).

[0071] In some embodiments, the clamp ring 177 (first clamp ring) is connected to the horizontal portion 171B of the connecting outer support flange 171. A first end of the plurality of conductive straps 173 is disposed between the clamp ring 177 and the horizontal portion 171B of the connecting outer support flange 171. The clamp ring 177 secures the physical and electrical connection of the plurality of conductive straps 173 to the horizontal portion 171B of the connecting outer support flange 171. Additionally, the clamp ring 175 (second clamp ring) is connected to the horizontal portion 169B of the fixed outer support flange 169. A second end of the plurality of conductive straps 173 is disposed between the clamp ring 175 and the horizontal portion 169B of the fixed outer support flange 169. The clamp ring 175 secures the physical and electrical connection of the plurality of conductive straps 173 to the horizontal portion 169B of the fixed outer support flange 169. In some embodiments, clamp ring 177 is bolted to horizontal portion 171B of connecting outer support flange 171, and clamp ring 175 is bolted to horizontal portion 169B of fixed outer support flange 169. Also, in some embodiments, the bolts used to bolt clamp ring 177 to horizontal portion 171B of connecting outer support flange 171 are disposed between first ends of conductive straps 173. Similarly, in some embodiments, the bolts used to bolt clamp ring 175 to horizontal portion 169B of fixed outer support flange 169 are disposed between second ends of conductive straps 173.

[0072] In some embodiments, each of the connecting outer support flange 171, the fixed outer support flange 169, the clamp ring 177, and the clamp ring 175 are formed from aluminum. In some embodiments, each of the connecting outer support flange 171, the fixed outer support flange 169, the clamp ring 177, and the clamp ring 175 are formed from anodized aluminum. In some embodiments, each of the plurality of conductive straps 173 are formed from stainless steel. In some embodiments, each of the plurality of conductive straps 173 are formed from copper. In some embodiments, the number of the plurality of conductive straps 173 is in the range of about 6 to about 80.

[0073] In some embodiments, each of the plurality of conductive straps 173 has a rectangular prism shape, as described with respect to Figure 7. Also, in some embodiments, there is an azimuthal spacing between adjacent plurality of conductive straps 173 around the periphery of the horizontal portion 171B of the connecting outer support flange 171, as described with respect to Figure 5. The azimuthal spacing is measured relative to a central axis of the connecting outer support flange 171 that extends in the z-direction.

[0074] In some embodiments, the C-shroud member 185 is disposed above the electrode 109. The seal 179 is disposed at the upper end 171E of the vertical portion 171A of the connecting outer support flange 171. The seal 179 is configured to engage the C-shroud member 185 when the connecting outer support flange 171 moves upwardly to reach the C-shroud member 185. In some embodiments, the seal 179 is electrically conductive and provides electrical conductivity between the C-shroud member 185 and the connecting outer support flange 171.

[0075] In some embodiments, a ceramic structure, such as ceramic support 113, is disposed between electrode 109 and fixed outer support flange 169. The ceramic structure is formed to surround an outer surface of electrode 109. In some embodiments, a quartz structure, such as first quartz ring 163, is disposed between the ceramic structure and fixed outer support flange 169. The quartz structure is formed to surround a vertical portion of the ceramic structure. In some embodiments, an edge ring 167 is disposed between connecting outer support flange 171 and ceramic layer 110. In some embodiments, a quartz ring, such as second quartz ring 165, is disposed between edge ring 167 and connecting outer support flange 171.

[0076] In an exemplary embodiment, a ground return assembly for a plasma processing system 100 is disclosed. The ground return assembly includes a fixed outer support flange 169, a connecting outer support flange 171, and a plurality of conductive straps 173. The fixed outer support flange 169 is formed to surround an electrode 109 in the plasma processing system 100 and has a fixed spatial relationship with respect to the electrode 109. The fixed outer support flange 169 has a vertical portion 169A and a horizontal portion 169B extending radially outward from a lower end of the vertical portion 169A. The connecting outer support flange 171 is formed to surround the fixed outer support flange 169. The connecting outer support flange 171 has a vertical portion 171A and a horizontal portion 171B extending radially outward from a lower end of the vertical portion 171A. The vertical portion 171A of the connecting outer support flange 171 is concentrically disposed outside at least a portion of the vertical portion 169A of the fixed outer support flange 169. The connecting outer support flange 171 is spaced from the fixed outer support flange 169 such that the connecting outer support flange 171 is movable along the vertical portion 169A of the fixed outer support flange 169. Each of the plurality of conductive straps 173 has a first end connected to the connecting outer support flange 171 and a second end connected to the fixed outer support flange 169. Each of the plurality of conductive straps 173 bends outwardly in a direction away from the vertical portion 169A of the fixed outer support flange 169.

[0077] In an exemplary embodiment, the plasma processing system 100 includes an electrode 109, a ceramic layer 110, a facility plate 111, an RF signal feed shaft 141, an RF signal feed rod 137, RF signal generators 147, 149, an impedance matching system 143, and a tube 139. The electrode 109 is formed of a conductive material. The electrode 109 has a substantially cylindrical shape defined by a top surface, a bottom surface, and an outer surface. The ceramic layer 110 is formed on the top surface of the electrode 109 and is configured to receive and support a wafer W. The facility plate 111 is formed of a conductive material. The bottom surface of the electrode 109 is physically and electrically connected to the top surface of the facility plate 111. The RF signal feed shaft 141 is formed of a conductive material. The upper end of the RF signal feed shaft 141 is physically and electrically connected to the bottom surface of the facility plate 111. The RF signal feed rod 137 is formed of a conductive material. The lower end of the RF signal feed shaft 141 is physically and electrically connected to the delivery end of the RF signal feed rod 137. The RF signal generators 147 and / or 149 are electrically connected to the feed end of the RF signal feed rod 137 via an impedance matching system 143. A tube 139 is disposed around the RF signal feed rod 137. The tube 139 is formed of a conductive material. The tube 139 has an inner wall separated from the RF signal feed rod 137 by air along the entire length of the tube 139.

[0078] In some embodiments, the physical and electrical connections between the RF signal feed rod 137 and the RF signal feed shaft 141 are separated from the surrounding conductive material by air. In some embodiments, the physical connections between the feed end of the RF signal feed rod 137 and the impedance match system 143, the physical connections between the send end of the RF signal feed rod 137 and the bottom end of the RF signal feed shaft 141, and the physical connections between the top end of the RF signal feed shaft 141 and the bottom surface of the facility plate 111 collectively maintain the physical dimensions of the air gap between the RF signal feed rod 137 and the inner wall of the tube 139 along the entire length of the tube 139. In some embodiments, the tube 139 forms part of a ground potential return path for the RF signal transmitted through the RF signal feed rod 137. Considering that the top surface of the electrode 109 corresponds to a reference horizontal plane (xy plane) and the reference vertical direction (z direction) g extends perpendicular to the reference horizontal plane, in some embodiments, the RF signal supply rod 137 extends in a straight line substantially parallel to the reference horizontal plane, and the RF signal supply shaft 141 has a central axis substantially parallel to the reference vertical direction.

[0079] In some embodiments, the RF signal supply rod 137 is made of copper, aluminum, or anodized aluminum. In some embodiments, the RF signal supply rod 137 is a solid rod. In some embodiments, the RF signal supply rod 137 is a tube. In some embodiments, the RF signal supply rod 137 has an outer diameter in the range of about 0.75 inches to about 2 inches. In some embodiments, the tube 139 has an inner diameter in the range of about 1.5 inches to about 6 inches. In some embodiments, the difference between the inner diameter of the tube 139 and the outer diameter of the RF signal supply rod 137 is in the range of about 0.25 inches to about 4 inches.

[0080] In some embodiments, the tube 139 is a first tube, and the plasma processing system 100 includes a second tube 139A disposed around at least a lower portion of the RF signal supply shaft 141. The first tube 139 is connected to the second tube 139A, and the interior volume of the first tube 139 is open to the interior volume of the second tube 139A (see FIG. 1A). The interior volumes of the first tube 139 and the second tube 139A form a continuous air region around both the RF signal supply rod 137 and the RF signal supply shaft 141 at a location 140 (see FIG. 1A) where the lower end of the RF signal supply shaft 141 is physically and electrically connected to the delivery end of the RF signal supply rod 137.

[0081] In an exemplary embodiment, an RF signal feed structure for a plasma processing system 100 is disclosed. The RF signal feed structure includes an RF signal feed rod 137 and a tube 139. The RF signal feed rod 137 is formed of a conductive material and includes a feed end and a send end. The feed end is configured for connection to an impedance matching system 143 disposed between the RF signal feed rod 137 and an RF signal generator 147, 149. The tube 139 is disposed near the RF signal feed rod 137. The tube 139 is formed of a conductive material and has an inner wall separated from the RF signal feed rod 137 by air along the entire length of the tube 139. In some embodiments, the tube 139 extends from a position proximate the impedance matching system 143 to a position proximate the send end of the RF signal feed rod 137. In some embodiments, the tube 139 forms part of a ground potential return path for an RF signal transmitted through the RF signal feed rod 137.

[0082] FIG. 12 illustrates an exemplary schematic diagram of the control system 120 of FIG. 1A according to some embodiments. In some embodiments, the control system 120 is configured as a process controller for controlling a semiconductor manufacturing process performed in the plasma processing system 100. In various embodiments, the control system 120 includes a processor 1201, a storage hardware unit (HU) 1203 (e.g., memory), an input HU 1205, an output HU 1207, an input / output (I / O) interface 1209, an I / O interface 1211, a network interface controller (NIC) 1213, and a data communication bus 1215. The processor 1201, the storage HU 1203, the input HU 1205, the output HU 1207, the I / O interface 1209, the I / O interface 1211, and the NIC 1213 are in data communication with each other via the data communication bus 1215. The input HU 1205 is configured to receive data communication from a number of external devices. Examples of the input HU 1205 include a data acquisition system, a data acquisition card, and the like. The output HU 1207 is configured to transmit data to a number of external devices. An example of the output HU 1207 includes a device controller. An example of the NIC 1213 includes a network interface card, a network adapter, etc. Each of the I / O interfaces 1209 and 1211 is defined to provide compatibility between different hardware units coupled to the I / O interface. For example, the I / O interface 1209 may be defined to convert signals received from the input HU 1205 to a format, amplitude, and / or speed compatible with the data communication bus 1215. Also, the I / O interface 1207 may be defined to convert signals received from the data communication bus 1215 to a format, amplitude, and / or speed compatible with the output HU 1207.It should be noted that although various operations are described herein as being performed by processor 1201 of control system 120, in some embodiments, various operations may be performed by multiple processors of control system 120 and / or by multiple processors of multiple computing systems in data communication with control system 120.

[0083] In some embodiments, the control system 120 is used to control devices in various wafer fabrication systems based in part on the sensed values. For example, the control system 120 can control one or more of the valves 1217, the filter heater 1219, the wafer support structure heater 1221, the pump 1223, and other devices 1225 based on the sensed values ​​and other control parameters. The valves 1217 can include valves associated with controlling the backside gas supply system 129, the process gas supply system 191, and the temperature control fluid circulation system 125. The control system 120 receives sensed values ​​from, for example, a pressure gauge 1227, a flow meter 1229, a temperature sensor 1231, and / or other sensors 1233, such as, for example, voltage sensors, current sensors, etc. The control system 120 can also be used to control process conditions in the plasma processing system 100 while performing plasma processing operations on the wafer W. For example, the control system 120 can control the type and amount of process gas supplied from the process gas supply system 191 to the plasma processing region 182. The control system 120 may also control the operation of the first RF signal generator 147, the second RF signal generator 149, and the impedance matching system 143. The control system 120 may also control the operation of the DC power supply 117 for the clamp electrode 112. The control system 120 may also control the operation of the lift device 133 for the lift pins 132 and the operation of the door 107. The control system 120 also controls the operation of the backside gas supply system 129 and the temperature control fluid circulation system 125. The control system 120 also controls the vertical movement of the cantilever arm assembly 115. The control system 120 also controls the operation of the throttle member 196 and a pump that controls the suction at the exhaust port 105. It is noted that the control system 120 is equipped to allow programmatic and / or manual control of any function within the plasma processing system 100.

[0084] In some embodiments, the control system 120 is configured to execute computer programs that include sets of instructions for controlling process timing, process gas delivery system temperature, pressure differentials, valve positions, process gas mixture, process gas flow rates, backside cooling gas flow rates, chamber pressure, chamber temperature, wafer support structure temperature (wafer temperature), RF power levels, RF frequency, RF pulses, impedance match system 143 settings, cantilever arm assembly position, bias power, and other parameters of a particular process. In some embodiments, other computer programs stored in a memory device associated with the control system 120 may be used. In some embodiments, there is a user interface associated with the control system 120. The user interface may include a display 1235 (e.g., a display screen and / or a graphical software representation of the apparatus and / or process conditions) and user input devices 1237, such as a pointing device, keyboard, touch screen, microphone, etc.

[0085] The software directing the operation of the control system 120 can be designed or configured in many different ways. The computer programs directing the operation of the control system 120 to perform the various wafer fabrication processes in a process sequence can be written in any conventional computer readable programming language, such as assembly language, C, C++, Pascal, Fortran, etc. The compiled object code or script is executed by the processor 1201 to perform the tasks identified in the program. The control system 120 can be programmed to control various process control parameters related to process conditions, such as filter pressure differential, process gas composition and flow rate, backside cooling gas composition and flow rate, plasma conditions such as temperature, pressure, RF power level and RF frequency, bias voltage, cooling gas / fluid pressure, chamber wall temperature, etc. Examples of sensors that may be monitored during the wafer fabrication process include, but are not limited to, mass flow control modules, pressure sensors such as pressure gauge 1227, and temperature sensor 1231. Appropriately programmed feedback and control algorithms can be used with data from these sensors to control / adjust one or more process control parameters to maintain the desired process conditions.

[0086] In some implementations, the control system 120 is part of a broader manufacturing control system. Such manufacturing control systems may include semiconductor processing equipment, including processing tools, chambers, and / or platforms for wafer processing, and / or specific processing components such as wafer pedestals, gas flow systems, etc. These manufacturing control systems may be integrated with electronics for controlling their operation before, during, and after wafer processing. The control system 120 may control various components or subparts of the manufacturing control system. The control system 120 may be programmed to control any of the processes disclosed herein, including delivery of process gases, delivery of backside cooling gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow settings, fluid delivery settings, position and motion settings, wafer transport in and out of tools and other transport tools and / or load locks connected or interfaced to the particular system, depending on the wafer processing requirements.

[0087] Generally, the control system 120 can be defined as electronics having various integrated circuits, logic, memory, and / or software to receive and issue instructions, control operations, enable wafer processing operations, enable endpoint measurements, etc. The integrated circuits can include chips in firmware form that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers that execute the program instructions (e.g., software). The program instructions can be instructions communicated to the control system 120 in the form of various individual settings (or program files) that define operational parameters for performing a particular process on the wafer W within the system 100. In some embodiments, the operational parameters can be part of a recipe defined by a process engineer to accomplish one or more processing steps during the manufacture of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of the wafer.

[0088] In some implementations, the control system 120 may be integrated or coupled with the plasma processing system 100, or may be part of or coupled to a computer that is networked to the system 100, or a combination thereof. For example, the control system 120 may be in the "cloud" of all or part of a fab host computer system that allows remote access to the wafer processing. The computer may allow remote access to the system 100 to monitor the current progress of a manufacturing operation, examine the history of past manufacturing operations, examine trends or performance metrics from multiple manufacturing operations, change parameters of a current process, set processing steps to follow a current process, or start a new process. In some examples, a remote computer (e.g., a server) may provide process recipes to the system 100 over a network, which may include a local network or the Internet.

[0089] The remote computer may include a user interface that allows for entry or programming of parameters and / or settings, which are then communicated from the remote computer to the system 100. In some examples, the control system 120 receives instructions in the form of data, where the instructions specify parameters for each of the processing steps to be performed during one or more operations. It should be noted that the parameters may be specific to the type of process being performed within the plasma processing system 100. Thus, as noted above, the control system 120 may be distributed, such as with one or more discrete controllers, which are networked together and operate for a common purpose, such as the processing and control described herein. One example of a distributed controller for such purposes is one or more integrated circuits in the plasma processing system 100 that communicate with one or more integrated circuits located remotely (e.g., at the platform level or as part of the remote computer) and are coupled to control the processes performed on the plasma processing system 100.

[0090] Examples of systems with which control system 120 may interface include, without limitation, plasma etch chambers or modules, deposition chambers or modules, spin rinse chambers or modules, metal plating chambers or modules, clean chambers or modules, bevel edge etch chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, atomic layer deposition (ALD) chambers or modules, atomic layer etch (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, and any other semiconductor processing systems that may be associated with or used in the fabrication and / or manufacture of semiconductor semiconductor wafers. As noted above, depending on the process step or steps performed by the tool, control system 120 may communicate with one or more other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout the factory, a main computer, another controller, or tools used in material transport to or from tool locations and / or loading docks in a semiconductor manufacturing factory.

[0091] The embodiments described herein may be practiced with a variety of computer system configurations, including handheld hardware units, microprocessor systems, microprocessor-based or program-controlled consumer electronics, minicomputers, mainframe computers, and the like. The embodiments described herein may also be practiced with distributed computing environments in which tasks are performed by remote processing hardware units connected over a network. It should be noted that the embodiments described herein, particularly those relating to the control system 120, may employ various computer-implemented operations with data stored in computer systems. These operations involve physical manipulation of physical quantities. Any operations described herein that are part of the embodiments are useful machine operations. The embodiments also relate to hardware units or apparatus for performing these operations. An apparatus may be specially configured for a special purpose computer. When defined as a special purpose computer, it may perform other processes, program executions, or routines that are not part of the special purpose while still allowing operations for that special purpose. In some embodiments, operations may be processed by a general purpose computer selectively activated or configured by one or more computer programs stored in a computer memory, cache, or retrieved from a network. When data is obtained from the network, it may be processed by other computers on the network, for example, a cloud of computing resources.

[0092] Various embodiments described herein may be implemented via process control instructions instantiated as computer readable code on a non-transitory computer readable medium. A non-transitory computer readable medium is any data storage hardware unit that can store data and subsequently read the data by a computer system. Examples of non-transitory computer readable media include hard disks, network attached storage (NAS), ROM, RAM, compact disk ROM (CD-ROM), recordable CD (CD-R), rewritable CD (CD-RW), magnetic tape, and other optical and non-optical data storage hardware units. A non-transitory computer readable medium may include a computer readable tangible medium distributed over a network-coupled computer system, allowing the storage and execution of computer readable code in a distributed manner.

[0093] The above disclosure includes detailed descriptions for a clearer understanding, but it is clear that certain changes and modifications are permitted within the scope of the appended claims. For example, one or more features from any embodiment disclosed herein can be combined with one or more features from any other embodiment disclosed herein. Therefore, it should be recognized that the present embodiment is merely illustrative and not restrictive, and the claims are not limited to the details described herein, but can be modified within the scope of the described embodiments and equivalents. The present disclosure may be realized in the following forms. [Form 1] 1. A plasma processing system comprising: an electrode having a substantially cylindrical shape defined by a top surface, a bottom surface, and an exterior surface; a ceramic layer formed on the top surface of the electrode, the ceramic layer being configured to receive and support a semiconductor wafer; an RF signal generator electrically connected to the electrode via an impedance matching system and configured to generate and supply an RF signal to the electrode; a fixed outer support flange formed around the outer surface of the electrode, in a fixed spatial relationship with respect to the electrode, having a vertical portion and a horizontal portion extending radially outward from a lower end of the vertical portion, the fixed outer support flange being electrically connected to a reference ground potential; a connecting outer support flange formed to surround the fixed outer support flange and having a vertical portion concentrically disposed outside the vertical portion of the fixed outer support flange and a horizontal portion extending radially outward from a lower end of the vertical portion, the connecting outer support flange being disposed spaced apart from the fixed outer support flange so as to be movable vertically relative to the fixed outer support flange; a plurality of conductive straps, each having a first end connected to the horizontal portion of the interlocking outer support flange and a second end connected to the horizontal portion of the fixed outer support flange; A plasma processing system comprising: [Form 2] 2. The plasma processing system according to claim 1, A plasma processing system, wherein each of the plurality of conductive straps bends outwardly away from the vertical portion of the stationary outer support flange. [Form 3] 2. The plasma processing system according to claim 1, The plurality of conductive straps are disposed in a substantially equally spaced configuration around a circumference of both the connecting outer support flange and the fixed outer support flange. [Form 4] 2. The plasma processing system according to claim 1, The plasma processing system, wherein the plurality of conductive straps are configured to flex with movement of the interlocking outer support flange relative to the fixed outer support flange. [Form 5] 2. The plasma processing system according to claim 1, 11. The plasma processing system of claim 10, wherein each of the plurality of conductive straps has a bendable length extending between the first end and the second end, and wherein an entirety of the bendable length of each of the plurality of conductive straps is disposed outside the connecting outer support flange and / or the fixed outer support flange. [Form 6] 2. The plasma processing system according to claim 1, The first end of each of the plurality of conductive straps is connected to a lower surface of the horizontal portion of the interlocking outer support flange. [Form 7] 2. The plasma processing system according to claim 1, The first end of each of the plurality of conductive straps is connected to an upper surface of the horizontal portion of the interlocking outer support flange. [Form 8] 2. The plasma processing system according to claim 1, The second end of each of the plurality of conductive straps is connected to an upper surface of the horizontal portion of the stationary outer support flange. [Form 9] 2. The plasma processing system according to claim 1, a first clamp ring connected to the horizontal portion of the interlocking outer support flange, the first ends of the plurality of conductive straps being disposed between the first clamp ring and the horizontal portion of the interlocking outer support flange, the first clamp ring securing the plurality of conductive straps in physical and electrical communication with the horizontal portion of the interlocking outer support flange; a second clamp ring connected to the horizontal portion of the fixed outer support flange, wherein the second ends of the plurality of conductive straps are disposed between the second clamp ring and the horizontal portion of the fixed outer support flange, the second clamp ring securing the plurality of conductive straps in physical and electrical connection with the horizontal portion of the fixed outer support flange. [Form 10] 10. The plasma processing system of claim 9, further comprising: The first clamp ring is bolted to the horizontal portion of the connecting outer support flange and the second clamp ring is bolted to the horizontal portion of the fixed outer support flange. [Form 11] 11. The plasma processing system of claim 10, further comprising: a bolt used to bolt the first clamp ring to the horizontal portion of the connecting outer support flange is disposed between the first ends of the conductive straps, and a bolt used to bolt the second clamp ring to the horizontal portion of the fixed outer support flange is disposed between the second ends of the conductive straps. [Form 12] 10. The plasma processing system of claim 9, further comprising: The plasma processing system, wherein each of the connecting outer support flange, the fixed outer support flange, the first clamp ring, and the second clamp ring are formed from aluminum or anodized aluminum. [Form 13] 2. The plasma processing system according to claim 1, The plasma processing system, wherein each of the plurality of conductive straps is formed from stainless steel. [Form 14] 2. The plasma processing system according to claim 1, The plasma processing system, wherein a number of the plurality of conductive straps is in a range from about 6 to about 80. [Form 15] 2. The plasma processing system according to claim 1, The plasma processing system, wherein each of the plurality of conductive straps has a rectangular prism shape defined by a length, a width, and a thickness. [Form 16] 2. The plasma processing system according to claim 1, a C-shroud member disposed above the electrode; a seal disposed at an upper end of the vertical portion of the connecting outer support flange and configured to engage the C-shroud member when the connecting outer support flange moves upwardly to reach the C-shroud member; The plasma processing system further comprises: [Form 17] 17. The plasma processing system of claim 16, wherein the seal is electrically conductive and provides electrical conductivity between the C-shroud member and the mating outer support flange. [Form 18] 2. The plasma processing system according to claim 1, The plasma processing system further comprising a ceramic structure formed and positioned between the electrode and the fixed outer support flange so as to surround the outer surface of the electrode. [Form 19] 19. The plasma processing system of claim 18, further comprising: The plasma processing system further comprising a quartz structure formed and positioned between the ceramic structure and the fixed outer support flange so as to surround a vertical portion of the ceramic structure. [Form 20] 2. The plasma processing system according to claim 1, The plasma processing system further comprises an edge ring disposed between the connecting outer support flange and the ceramic layer. [Form 21] 21. The plasma processing system of claim 20, further comprising: The plasma processing system further comprising a quartz ring disposed between the edge ring and the mating outer support flange. [Form 22] 1. A ground return assembly for a plasma processing system, comprising: a fixed outer support flange configured to surround an electrode within the plasma processing system and having a fixed spatial relationship to the electrode, the fixed outer support flange having a vertical portion and a horizontal portion extending radially outward from a lower end of the vertical portion; a connecting outer support flange formed to surround the fixed outer support flange, the connecting outer support flange having a vertical portion concentrically disposed outside the vertical portion of the fixed outer support flange and a horizontal portion extending radially outward from a lower end of the vertical portion, the connecting outer support flange being disposed at a distance from the fixed outer support flange so as to be movable along the vertical portion of the fixed outer support flange; a plurality of conductive straps, each having a first end connected to the interlocking outer support flange and a second end connected to the fixed outer support flange; A ground return assembly for a plasma processing system comprising: [Form 23] 23. A ground return assembly for a plasma processing system as recited in claim 22, comprising: A ground return assembly for a plasma processing system, wherein each of the plurality of conductive straps bends outwardly away from the vertical portion of the fixed outer support flange. [Form 24] 23. A ground return assembly for a plasma processing system as recited in claim 22, comprising: A ground return assembly for a plasma processing system, wherein the plurality of conductive straps are disposed in a substantially equally spaced configuration around a circumference of both the connecting outer support flange and the fixed outer support flange. [Form 25] 23. A ground return assembly for a plasma processing system as recited in claim 22, comprising: A ground return assembly for a plasma processing system, wherein the plurality of conductive straps are configured to flex with movement of the interlocking outer support flange relative to the fixed outer support flange. [Form 26] 23. A ground return assembly for a plasma processing system as recited in claim 22, comprising: 11. A ground return assembly for a plasma processing system, wherein each of the plurality of conductive straps has a bendable length extending between the first end and the second end, and wherein an entirety of the bendable length of each of the plurality of conductive straps is disposed outside the connecting outer support flange and / or the fixed outer support flange. [Form 27] 23. A ground return assembly for a plasma processing system as recited in claim 22, comprising: A ground return assembly for a plasma processing system, wherein the first end of each of the plurality of conductive straps is connected to a lower surface of the horizontal portion of the interlocking outer support flange. [Form 28] 23. A ground return assembly for a plasma processing system as recited in claim 22, comprising: A ground return assembly for a plasma processing system, wherein the first end of each of the plurality of conductive straps is connected to an upper surface of the horizontal portion of the interlocking outer support flange. [Form 29] 23. A ground return assembly for a plasma processing system as recited in claim 22, comprising: The second end of each of the plurality of conductive straps is connected to an upper surface of the horizontal portion of the stationary outer support flange. [Form 30] 23. A ground return assembly for a plasma processing system as recited in claim 22, comprising: a first clamp ring connected to the horizontal portion of the interlocking outer support flange, the first ends of the plurality of conductive straps being disposed between the first clamp ring and the horizontal portion of the interlocking outer support flange, the first clamp ring securing the plurality of conductive straps in physical and electrical communication with the horizontal portion of the interlocking outer support flange; 11. A ground return assembly for a plasma processing system, further comprising: a second clamp ring connected to the horizontal portion of the fixed outer support flange, the second ends of the plurality of conductive straps being disposed between the second clamp ring and the horizontal portion of the fixed outer support flange, the second clamp ring securing the plurality of conductive straps in physical and electrical connection with the horizontal portion of the fixed outer support flange. [Form 31] 31. A ground return assembly for a plasma processing system as recited in claim 30, comprising: A ground return assembly for a plasma processing system, wherein the first clamp ring is bolted to the horizontal portion of the connecting outer support flange and the second clamp ring is bolted to the horizontal portion of the fixed outer support flange. [Form 32] 32. A ground return assembly for a plasma processing system as recited in claim 31, comprising: a bolt used to bolt the first clamp ring to the horizontal portion of the connecting outer support flange is disposed between the first ends of the conductive straps, and a bolt used to bolt the second clamp ring to the horizontal portion of the fixed outer support flange is disposed between the second ends of the conductive straps. [Form 33] 31. A ground return assembly for a plasma processing system as recited in claim 30, comprising: A ground return assembly for a plasma processing system, wherein each of the interlocking outer support flange, the fixed outer support flange, the first clamp ring, and the second clamp ring are formed from aluminum. [Form 34] 23. A ground return assembly for a plasma processing system as recited in claim 22, comprising: A ground return assembly for a plasma processing system, wherein each of the plurality of conductive straps is formed from stainless steel. [Form 35] 23. A ground return assembly for a plasma processing system as recited in claim 22, comprising: The ground return assembly for a plasma processing system, wherein a number of the plurality of conductive straps is in a range from about 6 to about 80. [Form 36] 23. A ground return assembly for a plasma processing system as recited in claim 22, comprising: A ground return assembly for a plasma processing system, wherein each of the plurality of conductive straps has a rectangular prism shape defined by a length, a width, and a thickness. [Form 37] 23. A ground return assembly for a plasma processing system as recited in claim 22, comprising: A ground return assembly for a plasma processing system, wherein an upper end of the vertical portion of the interlocking outer support flange is configured to receive a conductive seal. [Form 38] 1. A plasma processing system comprising: an electrode formed of a conductive material having a substantially cylindrical shape defined by a top surface, a bottom surface and an exterior surface; a ceramic layer formed on the top surface of the electrode, the ceramic layer being configured to receive and support a semiconductor wafer; a facility plate formed of a conductive material and having a top surface to which the bottom surfaces of the electrodes are physically and electrically connected; an RF signal feed shaft formed of a conductive material and having an upper end physically and electrically connected to a bottom surface of the facility plate; an RF signal supply rod formed of a conductive material and having a transmission end physically and electrically connected to a lower end of the RF signal supply shaft; an RF signal generator electrically connected to the supply end of the RF signal supply rod through an impedance matching system; a tube disposed about said RF signal feed rod, said tube having an inner wall formed of a conductive material and separated from said RF signal feed rod by air along its entire length; A plasma processing system comprising: [Form 39] 39. The plasma processing system of claim 38, further comprising: A plasma processing system, wherein the physical and electrical connection between the RF signal supply rod and the RF signal supply shaft is separated from surrounding conductive material by air. [Form 40] 39. The plasma processing system of claim 38, further comprising: A plasma processing system, wherein the physical connection between the supply end of the RF signal supply rod and the impedance matching system, the physical connection between the delivery end of the RF signal supply rod and the lower end of the RF signal supply shaft, and the physical connection between the upper end of the RF signal supply shaft and the bottom surface of the facility plate collectively maintain the physical dimension of the gap between the RF signal supply rod and the inner wall of the tube along the entire length of the tube. [Form 41] 39. The plasma processing system of claim 38, further comprising: The tube forms part of a ground potential return path for an RF signal transmitted through the RF signal supply rod. [Form 42] 39. The plasma processing system of claim 38, further comprising: a top surface of the electrode corresponding to a reference horizontal plane, a reference vertical direction extending perpendicular to the reference horizontal plane, the RF signal supply rod extending in a linear direction substantially parallel to the reference horizontal plane, and the RF signal supply shaft having a central axis substantially parallel to the reference vertical direction. [Form 43] 39. The plasma processing system of claim 38, further comprising: A plasma processing system, wherein the RF signal distribution rod is formed of copper, aluminum, or anodized aluminum. [Form 44] 39. The plasma processing system of claim 38, further comprising: The plasma processing system, wherein the RF signal supply rod is a solid rod. [Form 45] 39. The plasma processing system of claim 38, further comprising: The plasma processing system, wherein the RF signal supply rod is a tube. [Form 46] 39. The plasma processing system of claim 38, further comprising: the tube is a first tube, and the plasma processing system includes a second tube disposed around at least a lower portion of the RF signal supply shaft, the first tube being connected to the second tube such that an internal volume of the first tube is open to an internal volume of the second tube, and the internal volumes of the first tube and the second tube form a continuous air region around both the RF signal supply rod and the RF signal supply shaft at a location where the lower end of the RF signal supply shaft is physically and electrically connected to the delivery end of the RF signal supply rod. [Form 47] 1. An RF signal supply structure for a plasma processing system, comprising: an RF signal feed rod formed of a conductive material and having a feed end and a delivery end, the feed end configured for connection to an impedance matching system disposed between the RF signal feed rod and an RF signal generator; a tube disposed about said RF signal feed rod, said tube having an inner wall formed of a conductive material and separated from said RF signal feed rod by air along its entire length; An RF signal supply structure for a plasma processing system comprising: [Form 48] 48. An RF signal supply structure for a plasma processing system according to claim 47, comprising: The tube extends from a location adjacent to the impedance match system to a location adjacent to the delivery end of the RF signal delivery rod. [Form 49] 48. An RF signal supply structure for a plasma processing system according to claim 47, comprising: The tube forms part of a ground potential return path for an RF signal transmitted through the RF signal supply rod. [Form 50] 48. An RF signal supply structure for a plasma processing system according to claim 47, comprising: The RF signal supply structure for a plasma processing system further comprises an RF signal supply shaft having a lower end physically and electrically connected to the delivery end of the RF signal supply rod. [Form 51] 51. An RF signal supply structure for a plasma processing system according to claim 50, comprising: an RF signal supply structure for a plasma processing system, wherein the tube is a first tube, the plasma processing system includes a second tube disposed around at least a lower portion of the RF signal supply shaft, the first tube being connected to the second tube such that an internal volume of the first tube is open to an internal volume of the second tube, and the internal volumes of the first tube and the second tube form a continuous air region near both the RF signal supply rod and the RF signal supply shaft at a location where the lower end of the RF signal supply shaft is physically and electrically connected to the delivery end of the RF signal supply rod. [Form 52] 48. An RF signal supply structure for a plasma processing system according to claim 47, comprising: The RF signal supply structure for a plasma processing system, wherein the RF signal supply rod is made of copper, aluminum, or anodized aluminum. [Form 53] 48. An RF signal supply structure for a plasma processing system according to claim 47, comprising: 2. An RF signal supply structure for a plasma processing system, wherein the RF signal supply rod is a solid rod. [Form 54] 48. An RF signal supply structure for a plasma processing system according to claim 47, comprising: The RF signal supply structure for a plasma processing system, wherein the RF signal supply rod is a tube.

Claims

1. 1. A plasma processing system comprising: an electrode having a substantially cylindrical shape defined by a top surface, a bottom surface, and an exterior surface; a ceramic layer formed on the top surface of the electrode, the ceramic layer being configured to receive and support a semiconductor wafer; an RF signal generator electrically connected to the electrode through an impedance matching system and configured to generate and supply an RF signal to the electrode; a fixed outer support flange formed around the outer surface of the electrode, in a fixed spatial relationship with respect to the electrode, having a vertical portion and a horizontal portion extending radially outward from a lower end of the vertical portion, the fixed outer support flange being electrically connected to a reference ground potential; a connecting outer support flange formed to surround the fixed outer support flange, the connecting outer support flange having a vertical portion and a horizontal portion extending radially outward from a lower end of the vertical portion of the connecting outer support flange, the vertical portion of the connecting outer support flange being concentrically disposed outside the vertical portion of the fixed outer support flange, and the connecting outer support flange being disposed at a distance from the fixed outer support flange so as to be vertically movable relative to the fixed outer support flange; a plurality of conductive straps, each having a first end connected to the horizontal portion of the interlocking outer support flange and a second end connected to the horizontal portion of the fixed outer support flange; Equipped with a first clamp ring connected to the horizontal portion of the interlocking outer support flange, the first ends of the plurality of conductive straps being disposed between the first clamp ring and the horizontal portion of the interlocking outer support flange, the first clamp ring securing the plurality of conductive straps in physical and electrical connection with the horizontal portion of the interlocking outer support flange; a second clamp ring connected to the horizontal portion of the fixed outer support flange, the second ends of the conductive straps being disposed between the second clamp ring and the horizontal portion of the fixed outer support flange, the second clamp ring securing the conductive straps in physical and electrical connection with the horizontal portion of the fixed outer support flange; the first clamp ring is bolted to the horizontal portion of the connecting outer support flange and the second clamp ring is bolted to the horizontal portion of the fixed outer support flange; a bolt used to bolt the first clamp ring to the horizontal portion of the connecting outer support flange is disposed between the first ends of the conductive straps, and a bolt used to bolt the second clamp ring to the horizontal portion of the fixed outer support flange is disposed between the second ends of the conductive straps.

2. 10. The plasma processing system of claim 1 , A plasma processing system, wherein each of the plurality of conductive straps bends outwardly away from the vertical portion of the stationary outer support flange.

3. 10. The plasma processing system of claim 1 , The plurality of conductive straps are disposed in a substantially equally spaced configuration around a circumference of both the connecting outer support flange and the fixed outer support flange.

4. 10. The plasma processing system of claim 1 , The plasma processing system, wherein the plurality of conductive straps are configured to flex with movement of the interlocking outer support flange relative to the fixed outer support flange.

5. 10. The plasma processing system of claim 1 , 11. The plasma processing system of claim 10, wherein each of the plurality of conductive straps has a bendable length extending between the first end and the second end, and wherein an entirety of the bendable length of each of the plurality of conductive straps is disposed outside of the connecting outer support flange and / or the fixed outer support flange.

6. 10. The plasma processing system of claim 1 , The first end of each of the plurality of conductive straps is connected to a lower surface of the horizontal portion of the interlocking outer support flange.

7. A plasma processing system comprising: an electrode having a substantially cylindrical shape defined by a top surface, a bottom surface, and an exterior surface; a ceramic layer formed on the top surface of the electrode, the ceramic layer being configured to receive and support a semiconductor wafer; an RF signal generator electrically connected to the electrode through an impedance matching system and configured to generate and supply an RF signal to the electrode; a fixed outer support flange formed around the outer surface of the electrode, in a fixed spatial relationship with respect to the electrode, having a vertical portion and a horizontal portion extending radially outward from a lower end of the vertical portion, the fixed outer support flange being electrically connected to a reference ground potential; a connecting outer support flange formed to surround the fixed outer support flange, the connecting outer support flange having a vertical portion and a horizontal portion extending radially outward from a lower end of the vertical portion of the connecting outer support flange, the vertical portion of the connecting outer support flange being concentrically disposed outside the vertical portion of the fixed outer support flange, and the connecting outer support flange being disposed at a distance from the fixed outer support flange so as to be vertically movable relative to the fixed outer support flange; a plurality of conductive straps, each having a first end connected to the horizontal portion of the interlocking outer support flange and a second end connected to the horizontal portion of the fixed outer support flange; Equipped with The first end of each of the plurality of conductive straps is connected to an upper surface of the horizontal portion of the interlocking outer support flange.

8. 10. The plasma processing system of claim 1 , The second end of each of the plurality of conductive straps is connected to an upper surface of the horizontal portion of the stationary outer support flange.

9. 10. The plasma processing system of claim 1 , The plasma processing system, wherein each of the interlocking outer support flange, the fixed outer support flange, the first clamp ring, and the second clamp ring are formed from aluminum or anodized aluminum.

10. 10. The plasma processing system of claim 1 , The plasma processing system, wherein each of the plurality of conductive straps is formed from stainless steel.

11. 10. The plasma processing system of claim 1 , The plasma processing system, wherein a number of the plurality of conductive straps is in a range from about 6 to about 80.

12. 10. The plasma processing system of claim 1 , The plasma processing system, wherein each of the plurality of conductive straps has a rectangular prism shape defined by a length, a width, and a thickness.

13. 10. The plasma processing system of claim 1 , a C-shroud member disposed above the electrode; a seal disposed at an upper end of the vertical portion of the connecting outer support flange and configured to engage the C-shroud member when the connecting outer support flange moves upwardly into the C-shroud member; The plasma processing system further comprises:

14. 14. The plasma processing system of claim 13, wherein said seal is electrically conductive and provides electrical conductivity between said C-shroud member and said mating outer support flange.

15. 10. The plasma processing system of claim 1 , The plasma processing system further comprising a ceramic structure formed and positioned between the electrode and the fixed outer support flange so as to surround the outer surface of the electrode.

16. A plasma processing system comprising: an electrode having a substantially cylindrical shape defined by a top surface, a bottom surface, and an exterior surface; a ceramic layer formed on the top surface of the electrode, the ceramic layer being configured to receive and support a semiconductor wafer; an RF signal generator electrically connected to the electrode through an impedance matching system and configured to generate and supply an RF signal to the electrode; a fixed outer support flange formed around the outer surface of the electrode, in a fixed spatial relationship with respect to the electrode, having a vertical portion and a horizontal portion extending radially outward from a lower end of the vertical portion, the fixed outer support flange being electrically connected to a reference ground potential; a connecting outer support flange formed to surround the fixed outer support flange, the connecting outer support flange having a vertical portion and a horizontal portion extending radially outward from a lower end of the vertical portion of the connecting outer support flange, the vertical portion of the connecting outer support flange being concentrically disposed outside the vertical portion of the fixed outer support flange, and the connecting outer support flange being disposed at a distance from the fixed outer support flange so as to be vertically movable relative to the fixed outer support flange; a plurality of conductive straps, each having a first end connected to the horizontal portion of the interlocking outer support flange and a second end connected to the horizontal portion of the fixed outer support flange; Equipped with a ceramic structure formed and disposed between the electrode and the fixed outer support flange so as to surround the outer surface of the electrode; The plasma processing system further comprising a quartz structure formed and positioned between the ceramic structure and the fixed outer support flange so as to surround a vertical portion of the ceramic structure.

17. 10. The plasma processing system of claim 1 , The plasma processing system further comprises an edge ring disposed between the connecting outer support flange and the ceramic layer.

18. 20. The plasma processing system of claim 17, further comprising: The plasma processing system further comprising a quartz ring disposed between the edge ring and the mating outer support flange.

19. 1. A ground return assembly for a plasma processing system, comprising: a fixed outer support flange configured to surround an electrode within the plasma processing system and having a fixed spatial relationship to the electrode, the fixed outer support flange having a vertical portion and a horizontal portion extending radially outward from a lower end of the vertical portion; a connecting outer support flange formed to surround the fixed outer support flange, the connecting outer support flange having a vertical portion and a horizontal portion extending radially outward from a lower end of the vertical portion of the connecting outer support flange, the vertical portion of the connecting outer support flange being concentrically disposed outside the vertical portion of the fixed outer support flange, and the connecting outer support flange being disposed at a distance from the fixed outer support flange so as to be vertically movable relative to the fixed outer support flange; a plurality of conductive straps, each having a first end connected to the interlocking outer support flange and a second end connected to the fixed outer support flange; Equipped with a first clamp ring connected to the horizontal portion of the interlocking outer support flange, the first ends of the plurality of conductive straps being disposed between the first clamp ring and the horizontal portion of the interlocking outer support flange, the first clamp ring securing the plurality of conductive straps in physical and electrical connection with the horizontal portion of the interlocking outer support flange; a second clamp ring connected to the horizontal portion of the fixed outer support flange, the second ends of the conductive straps being disposed between the second clamp ring and the horizontal portion of the fixed outer support flange, the second clamp ring securing the conductive straps in physical and electrical connection with the horizontal portion of the fixed outer support flange; the first clamp ring is bolted to the horizontal portion of the connecting outer support flange and the second clamp ring is bolted to the horizontal portion of the fixed outer support flange; a bolt used to bolt the first clamp ring to the horizontal portion of the connecting outer support flange is disposed between the first ends of the conductive straps, and a bolt used to bolt the second clamp ring to the horizontal portion of the fixed outer support flange is disposed between the second ends of the conductive straps.

20. 20. The ground return assembly for a plasma processing system of claim 19, comprising: A ground return assembly for a plasma processing system, wherein each of the plurality of conductive straps bends outwardly away from the vertical portion of the fixed outer support flange.

21. 20. The ground return assembly for a plasma processing system of claim 19, comprising: A ground return assembly for a plasma processing system, wherein the plurality of conductive straps are disposed in a substantially equally spaced configuration around a circumference of both the connecting outer support flange and the fixed outer support flange.

22. 20. The ground return assembly for a plasma processing system of claim 19, comprising: A ground return assembly for a plasma processing system, wherein the plurality of conductive straps are configured to flex with movement of the interlocking outer support flange relative to the fixed outer support flange.

23. 20. The ground return assembly for a plasma processing system of claim 19, comprising:

11. A ground return assembly for a plasma processing system, wherein each of the plurality of conductive straps has a bendable length extending between the first end and the second end, and wherein an entirety of the bendable length of each of the plurality of conductive straps is disposed outside of the connecting outer support flange and / or the fixed outer support flange.

24. 20. The ground return assembly for a plasma processing system of claim 19, comprising: A ground return assembly for a plasma processing system, wherein the first end of each of the plurality of conductive straps is connected to a lower surface of the horizontal portion of the interlocking outer support flange.

25. A ground return assembly for a plasma processing system, comprising: a fixed outer support flange configured to surround an electrode within the plasma processing system and having a fixed spatial relationship to the electrode, the fixed outer support flange having a vertical portion and a horizontal portion extending radially outward from a lower end of the vertical portion; a connecting outer support flange formed to surround the fixed outer support flange, the connecting outer support flange having a vertical portion and a horizontal portion extending radially outward from a lower end of the vertical portion of the connecting outer support flange, the vertical portion of the connecting outer support flange being concentrically disposed outside the vertical portion of the fixed outer support flange, and the connecting outer support flange being disposed at a distance from the fixed outer support flange so as to be vertically movable relative to the fixed outer support flange; a plurality of conductive straps, each having a first end connected to the interlocking outer support flange and a second end connected to the fixed outer support flange; Equipped with A ground return assembly for a plasma processing system, wherein the first end of each of the plurality of conductive straps is connected to an upper surface of the horizontal portion of the interlocking outer support flange.

26. 20. The ground return assembly for a plasma processing system of claim 19, comprising: A ground return assembly for a plasma processing system, wherein the second end of each of the plurality of conductive straps is connected to an upper surface of the horizontal portion of the fixed outer support flange.

27. 20. The ground return assembly for a plasma processing system of claim 19, comprising: A ground return assembly for a plasma processing system, wherein each of the interlocking outer support flange, the fixed outer support flange, the first clamp ring, and the second clamp ring are formed from aluminum.

28. 20. The ground return assembly for a plasma processing system of claim 19, comprising: A ground return assembly for a plasma processing system, wherein each of the plurality of conductive straps is formed from stainless steel.

29. 20. The ground return assembly for a plasma processing system of claim 19, comprising: The ground return assembly for a plasma processing system, wherein a number of the plurality of conductive straps is in a range from about 6 to about 80.

30. 20. The ground return assembly for a plasma processing system of claim 19, comprising: A ground return assembly for a plasma processing system, wherein each of the plurality of conductive straps has a rectangular prism shape defined by a length, a width, and a thickness.

31. 20. The ground return assembly for a plasma processing system of claim 19, comprising: A ground return assembly for a plasma processing system, wherein an upper end of the vertical portion of the interlocking outer support flange is configured to receive a conductive seal.

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