Plasma processing system including segmented electrode with floating segments

Abstract

A plasma processing system for processing substrates includes a substrate support arranged in a processing chamber and including a first electrode. A second electrode is arranged above the substrate support and includes S segments that are arranged concentrically and include gaps located therebetween, where S is an integer greater than one. A segment control circuit includes M impedances connected to M of the S segments of the second electrode, where M is an integer greater than zero and less than or equal to S. The M impedances are selected from a group consisting of at least one of a resistor, an inductor, a capacitor, and combinations thereof. A plasma generator is configured to supply RF voltage to the first electrode to generate and maintain plasma in the processing chamber.

Description

PLASMA PROCESSING SYSTEM INCLUDING SEGMENTED ELECTRODE WITH FLOATING SEGMENTSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 534,950, filed on August 28, 2023, and the benefit of U.S. Provisional Application No. 63 / 625,240, filed on January 25, 2024. The entire disclosures of the above applications are incorporated herein by reference.FIELD

[0002] The present disclosure relates to plasma processing systems for substrates, and more particularly to plasma processing systems including a segmented electrode having an adjustable impedance to ground for DC or AC current and other plasma excitation frequencies.BACKGROUND

[0003] The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

[0004] Substrate processing systems may be used to treat substrates such as semiconductor wafers. The substrate treatments may include deposition, etching, cleaning, and / or other treatments. During processing, a substrate is arranged on a substrate support in a processing chamber of the substrate processing system. Gas mixtures are introduced into the processing chamber using a gas delivery device. In some processes, radio frequency (RF) plasma may be used to initiate chemical reactions.

[0005] When generating plasma, the substrate processing system may include an RF plasma generator including an RF source and a matching network that supply RF voltage / power to a first electrode in the substrate support. The substrate is arranged on the substrate support between the first electrode and a second electrode. The second electrode includes a plate that is grounded. When using a grounded electrode, plasmadensity varies as a radial distance of the substrate varies. The plasma density variations cause processing non-uniformities.SUMMARY

[0006] A plasma processing system for processing substrates includes a substrate support arranged in a processing chamber and including a first electrode. A second electrode is arranged above the substrate support and includes S segments that are arranged concentrically and include gaps located therebetween, where S is an integer greater than one. A segment control circuit includes M impedances connected to M of the S segments of the second electrode, where M is an integer greater than zero and less than or equal to S. The M impedances are selected from a group consisting of a resistor, an inductor, a capacitor, and combinations thereof. A plasma generator is configured to supply RF voltage to the first electrode to generate and maintain plasma in the processing chamber.

[0007] In other features, at least one of the M impedances comprises a fixed impedance. At least one of the M impedances comprises a variable impedance. A plasma density controller is configured to adjust the variable impedance of the at least one of the M impedances. At least one of a photon probe and a thermocouple is configured to sense a temperature of at least one of the S segments. The plasma density controller is configured to adjust the variable impedance of the at least one of the S segments in response to the temperature.

[0008] In other features, S is greater than two and less than or equal to six. M is greater than two and less than or equal to six. M is equal to S. M switches are connected in parallel to the M impedances to selectively short a corresponding one of the M impedances to ground a corresponding one of the S segments. The M impedances of corresponding ones of the M of the S segments are adjusted independently for DC and at least one plasma excitation frequency. The plasma generator includes a plurality of power settings for pulsed plasma. The M impedances of corresponding ones of the M of the S segments are adjusted for at least two of the plurality of power settings.

[0009] In other features, sides of the S segments are configured to prevent line of sight from the plasma through the gaps. Sides of the S segments are one of stair-stepped or sloped. The S segments include gas through holes. The M impedances include theresistor and at least one of the inductor and the capacitor. The S segments include a plurality of gas through holes.

[0010] In other features, the plasma processing system includes a cooling plate and a heating plate arranged adjacent to the cooling plate. A thermal gasket is arranged adjacent to an upper surface of the S segments and includes holes for gas through holes and for receiving fasteners connected to the S segments a gas distribution plate. A barrier layer is arranged adjacent to the thermal gasket. A gas distribution plate is arranged between the barrier layer and the heating plate and in fluid communication with the plurality of gas through holes in the S segments.

[0011] In other features, the thermal gasket includes a plurality of zones. At least two of the zones are at least one of made of different materials or have different thicknesses. The S segments are made of a material selected from a group consisting of silicon, polysilicon, silicon carbide, ceramic, and quartz. At least one of the S segments includes a substrate made of a first material and a plasma-resistant layer arranged on the substrate and made of a second material different than the first material. The substrate is made of a material selected from a group consisting of stainless steel, aluminum, and silicon.

[0012] In other features, the plasma-resistant layer is made of a material selected from a group consisting of silicon, polysilicon, silicon carbide, ceramic, and quartz. The plasma-resistant layer has a thickness in a range from 20 pm to 500 pm. An insulating material is arranged in the gaps between adjacent ones of the S segments. A voltage changing circuit includes M voltage sources connected to M of the S segments, respectively. A current changing circuit includes M current sources connected to M of the S segments, respectively. At least one of the S segments has a different thickness than another one of the S segments. The S segments include bottom surfaces that are coplanar. A bottom surface of at least one of the S segments is not coplanar with a bottom surface of another one of the S segments. A bottom surface of at least one of the S segments is non-planar. Substrate facing edges of at least one of the S segments are tapered.

[0013] A method for processing substrate includes arranging a substrate on a substrate support in a processing chamber; supplying RF voltage to a first electrode in the substrate support; arranging a second electrode above the substrate support that includes S segments that are arranged concentrically and that include gaps located therebetween,where S is an integer greater than one; connecting M impedances to M of the S segments of the second electrode, where M is an integer greater than zero and less than or equal to S, wherein the M impedances are selected from a group consisting of a resistor, an inductor, a capacitor, and combinations thereof; and supplying RF voltage to the first electrode to generate and maintain plasma in the processing chamber.

[0014] In other features, at least one of the M impedances comprises a fixed impedance. At least one of the M impedances comprises a variable impedance. The method includes sensing a parameter of at least one of the S segments and adjusting the variable impedance of the at least one of the M impedances based on the parameter. The method includes using the parameter to detect a hardware failure. The method includes using the parameter to detect deposition of film on the second electrode. The parameter comprises a temperature of the at least one of the S segments.

[0015] In other features, S is greater than two and less than or equal to six. M is greater than two and less than or equal to six. M is equal to S.

[0016] In other features, the method includes using M switches connected in parallel to the M impedances to selectively short a corresponding one of the M impedances to ground a corresponding one of the S segments. Sides of the S segments are configured to prevent line of sight from the plasma through the gaps. Sides of the S segments are stair-stepped. Sides of the S segments are sloped. The S segments include gas through holes. The M impedances include the resistor and at least one of the inductor and the capacitor. The S segments are made of a material selected from a group consisting of silicon, polysilicon, silicon carbide, ceramic, and quartz. At least one of the S segments includes a substrate made of a first material and a plasma-resistant layer arranged on the substrate.

[0017] In other features, the plasma-resistant layer is made of a material selected from a group consisting of silicon, polysilicon silicon carbide, and ceramic. The plasmaresistant layer has a thickness in a range from 20 pm to 500 pm. The method includes arranging a filler material between adjacent ones of the S segments. The method includes arranging an insulating coating layer on a side surface of at least one of the S segments. The side surface is arranged transverse to a plane including the substrate.

[0018] In other features, the method includes connecting M voltage sources to M of the S segments, respectively. The method includes connecting M current sources to M of the S segments, respectively. At least one of the S segments has a different thickness thananother one of the S segments. The S segments include bottom surfaces that are coplanar. A bottom surface of at least one of the S segments is not coplanar with a bottom surface of another one of the S segments. A bottom surface of at least one of the S segments includes one of a convex portion or concave portion. The method includes tapering substrate facing edges of at least one of the S segments.

[0019] A plasma processing system for processing substrates includes a processing chamber. A substrate support is arranged in the processing chamber and includes a first electrode. A second electrode is arranged above the substrate support and includes S segments that are arranged concentrically and include gaps located therebetween, where S is an integer greater than one. A segment control circuit includes M changing circuits connected to M of the S segments of the second electrode, where M is an integer greater than zero and less than or equal to S. The M changing circuits are configured to vary at least one of an impedance, a voltage, and a current of the M of the S segments relative to ground. A plasma generator is configured to supply RF voltage to the first electrode to generate and maintain plasma in the processing chamber.

[0020] In other features, a plasma density controller is configured to adjust the at least one of the impedance, the voltage, and the current. A sensor is configured to sense a parameter of at least one of the M of the S segments. A corresponding one of the M changing circuits is configured to adjust the at least one of the impedance, the voltage, and the current in response to the parameter.

[0021] A segmented electrode for a substrate processing system includes S electrode segments, where S is an integer greater than one. S-1 of the S electrode segments have an annular shape. An Sthone of the S electrode segments has a circular shape. The S electrode segments are arranged concentrically and include gaps located therebetween. Each of the S electrode segments includes a first set of gas through holes and a plurality of fasteners attached to a top side thereof and arranged adjacent to the first set of gas through holes.

[0022] In other features, each of the S electrode segments further comprise a second set of gas through holes arranged radially inside of the first set of gas through holes, and the plurality of fasteners are arranged between the first set of gas through holes and the second set of gas through holes. S is equal to 4.

[0023] In other features, each of the S electrode segments includes a plurality of pin alignment holes. The plurality of pin alignment holes are arranged between the first setof gas through holes and the second set of gas through holes. Each of the S electrode segments includes an electrical feed contact. The electrical feed contact is arranged between the first set of gas through holes and the second set of gas through holes. S-2 of the S electrode segments include a plurality of electrical feed contacts. The electrical feed contacts of each of the S-2 of the S electrode segments are rotated relative to others of the S-2 of the S electrode segments. The gaps are in a range from 1 mm to 3 mm.

[0024] In other features, each of the S electrode segments includes a plurality of pin alignment holes and at least one electrical feed contact. The plurality of pin alignment holes and the at least one electrical feed contact of each of the S electrode segments are arranged between corresponding ones of the first set of gas through holes and the second set of gas through holes.

[0025] In other features, a radially inner surface and a radially outer surface of at least one of the S electrode segments includes a first radial projection and a second radial projection, respectively. The first radial projection on the radially inner surface vertically overlaps a radial projection on a first adjacent one of the S electrode segments. The second radial projection on the radially outer surface vertically overlaps a radial projection on a second adjacent one of the S electrode segments.

[0026] In other features, an outer ring arranged around a radially outer edge of the segmented electrode. The outer ring includes a radial projection extending beneath a radial projection extending radially outwardly from a radially outer one of the S electrode segments. The outer ring includes a downward projection extending downwardly from a radially inner end of the outer ring.

[0027] A system comprising the segmented electrode and further includes a shroud ring including an annular body including a radially inner side including a radial projection, wherein the downward projection of the outer ring rests on the radial projection on the radially inner side of the annular body of the shroud.

[0028] An electrode segment for a segmented electrode of a plasma processing system includes one of an annular body and a circular body. A first set of gas through holes is arranged on the one of the annular body and the circular body. A second set of gas through holes is arranged on the one of the annular body and the circular body. A plurality of fasteners are attached to a top side of the one of the annular body and the circular body and arranged between the first set of gas through holes and the second set of gas through holes.

[0029] In other features, a plurality of pin alignment holes arranged on the one of the annular body and the circular body. The plurality of pin alignment holes are arranged between the first set of gas through holes and the second set of gas through holes. An electrical feed contact is arranged on the one of the annular body and the circular body. The electrical feed contact is arranged between the first set of gas through holes and the second set of gas through holes. A plurality of electrical feed contacts arranged on the one of the annular body and the circular body. A plurality of pin alignment holes and at least one electrical feed contact arranged on the one of the annular body and the circular body.

[0030] In other features, the plurality of pin alignment holes and the at least one electrical feed contact are arranged between the first set of gas through holes and the second set of gas through holes. The one of the annular body and the circular body includes the annular body, and a radially inner surface and a radially outer surface of the annular body includes a first radial projection and a second radial projection, respectively. The first radial projection on the radially inner surface is configured to overlap a radial projection on a first adjacent electrode segment, and the second radial projection on the radially outer surface is configured to overlap a radial projection on a second adjacent electrode segment.

[0031] In other features, the one of the annular body and the circular body includes the circular body, and a radially outer surface of the circular body includes a radial projection. The radial projection on the radially outer surface of the circular body is configured to overlap a radial projection on an adjacent electrode segment.

[0032] Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims, and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0034] FIG. 1 A is a functional block diagram of an example of a processing chamber including an RF plasma generator, a grounded non-segmented upper electrode, and alower electrode that receives an RF voltage to generate plasma in the processing chamber;

[0035] FIG. 1 B is a functional block diagram of an example of a processing chamber including an RF plasma generator, a segmented upper electrode with one or more floating segments, and a lower electrode that receives an RF voltage to generate plasma in the processing chamber according to the present disclosure;

[0036] FIG. 1 C is a functional block diagram of the impedance, current, and / or voltage changing circuit according to the present disclosure;

[0037] FIGS. 2A to 2E show examples of variations in ions tilt and plasma density as a function of substrate radius when using electrodes with various combinations of floating and / or grounded segment(s) according to the present disclosure;

[0038] FIGS. 3A and 3B are functional block diagrams of examples of segmented electrodes with floating segments including fixed and variable impedances, respectively, according to the present disclosure;

[0039] FIG. 3C is a functional block diagram of examples of segmented electrodes with fixed or variable impedances, current sources, and / or voltage sources according to the present disclosure;

[0040] FIG. 3D show an example of a fixed impedance including multiple impedances that can be switched according to the present disclosure;

[0041] FIG. 3E show an example of a variable impedance including multiple fixed and / or variable impedances that can be switched according to the present disclosure;

[0042] FIG. 4 is a side cross sectional view of an example of a temperature-controlled, segmented electrode according to the present disclosure;

[0043] FIGS. 5A to 5M are side views showing examples of segmented electrodes and / or segments according to the present disclosure;

[0044] FIGS. 6 and 7 are graphs illustrating examples of plasma density of the segments as a function of radial distance when using a segmented electrode according to the present disclosure;

[0045] FIG. 8 is a graph illustrating examples of plasma density as a function of radial distance for a non-segmented electrode and a combined plasma density of a segmented electrode according to the present disclosure;

[0046] FIGS. 9 and 10 are perspective views of examples of segmented electrodes according to the present disclosure;

[0047] FIG. 1 1 is a perspective view of a thermal gasket with zones having different materials and / or thicknesses to vary coupling according to the present disclosure;

[0048] FIG. 12 is a plan view of another example of a plasma-facing surface of a segmented electrode assembly according to the present disclosure;

[0049] FIG. 13 is a plan view of an example of the top surface of a partially assembled segmented electrode assembly of FIG. 12 according to the present disclosure;

[0050] FIG. 14 is a plan view of an example of a top surface of the segmented electrode assembly of FIG. 12;

[0051] FIG. 15 is a side cross section of an example of the segmented electrode assembly according to the present disclosure; and

[0052] FIG. 16 is a partial side cross section of an example of segments of the segmented electrode assembly according to the present disclosure.

[0053] In the drawings, reference numbers may be reused to identify similar and / or identical elements.DETAILED DESCRIPTION

[0054] The present disclosure relates to electrodes for plasma processing systems that include multiple segments where one or more of the segments are floating, biased by a voltage source, and / or biased by a current source (rather than shorted to ground). The segments can also be connected to power generators. Rather than using a grounded, non-segmented electrode, the present disclosure uses an electrode that is segmented radially and includes segments that are arranged concentrically and spaced from one another by a gap.

[0055] As used herein, the term “floating” refers to a high direct current (DC) impedance to ground (e.g., greater than 100 ohms). The term “grounded” refers to a low direct current impedance to ground (e.g., less than 100 ohms). The electromagnetic state of the segments is adjustable for DC and / or other plasma excitation frequencies. In some examples, the segments of the segmented electrode are connected to passive or active, fixed, or variable impedances, voltage sources, current sources, and / or power sources.

[0056] Impedance is the opposition to alternating current presented by the combined effect of resistance and reactance in a circuit. Examples of sources of impedances include resistors, inductors, capacitors, and / or combinations thereof (e.g., serial and / or parallel combinations of resistors, inductors, and / or capacitors may be used). For example, the impedances can include different values of resistors, inductors, capacitors, resistors and inductors, resistors and capacitors, capacitors, and inductors, and / or resistors, capacitors, and inductors. The resistors affect direct current (DC) coupling and reactive components such as inductors and capacitors vary alternating current (AC) coupling between the segments and ground. In other examples, current or voltage sources can also be used to bias one or more of the segments of the segmented electrode.

[0057] Varying impedances, voltage sources, and / or current sources connected to the segmented electrodes allows plasma density to be tuned or adjusted in a radial direction to achieve a desired plasma density pattern during substrate processing. For example, the impedances connected to the radially segmented electrodes can be used to make the plasma density more uniform from a center of a substrate to a radially outer edge of the substrate (as compared to non-segmented electrodes that are grounded). However, in other examples, the impedances, current sources, and / or voltage sources can also be tuned for other non-uniform plasma profiles.

[0058] Referring now to FIG. 1 A, a substrate processing system 100 includes a processing chamber 102 including a gas distribution device 104 and a substrate support 106. In some examples, the substrate support 106 includes an electrostatic chuck (ESC). During operation, a substrate 108 is arranged on the substrate support 106. If an ESC is used, the substrate support 106 includes a baseplate 1 10. In some examples, the baseplate 110 is made of a conducting material such as aluminum. The baseplate 110 supports a top plate 1 12, which may be made of ceramic or material resistant to plasma. A bond layer 1 14 may be disposed between the top plate 1 12 and the baseplate 110 to bond the top plate 1 12 and the baseplate 110. The baseplate 1 10 may include one or more coolant channels 1 16 for flowing coolant through the baseplate 1 10. In some examples, an edge ring 1 18 is arranged around the substrate support 106 to shape the plasma.

[0059] A gas delivery system 130 includes one or more gas sources 132. The gas sources 132 supply one or more process gas mixtures. For an etching process, theprocess gas mixture may include carrier gas, inert gases, etching gas, etc. For a deposition process, the process gas mixture may include including carrier gas, inert gases, deposition precursor gases, etc. The gas sources 132 are connected by flow metering devices 134 (e.g., mass flow controllers and valves) to a manifold 140. An output of the manifold 140 is fed to the gas distribution device 104. In some examples, a vapor delivery system 170 includes one or more vapor delivery sources that supply vapor to the manifold 140 or connect to the gas distribution device 104 downstream from the manifold 140. In some examples, the vapor delivery system 170 includes one or more ampoules 174, vaporizers 176, and flow metering devices 178 to controllably supply the vapor to the processing chamber.

[0060] In some examples, a temperature controller 142 is connected to heating elements 144 (e.g., thermal control elements (TCEs) or resistive heaters) arranged in the top plate 1 12. The temperature controller 142 may be used to supply power to the heating elements 144 to control a temperature of the substrate support 106 and the substrate 108 during processing. The temperature controller 142 also operates a coolant assembly 146 that controls coolant flow through the coolant channels 116. For example, the coolant assembly 146 may include a coolant pump and coolant reservoir (not shown). The temperature controller 142 operates the coolant assembly 146 to selectively flow the coolant through the coolant channels 1 16 to cool the substrate support 106 and the substrate 108.

[0061] A valve 150 and a pump 152 are connected to a gas line 148 (e.g., an exhaust gas line) and are used to control pressure within the processing chamber 102 and / or to evacuate reactants from the processing chamber 102. A plasma generator 154 includes a radio frequency (RF) source 156 to output RF voltage / power to a matching network 158. The matching network 158 matches the impedance of the RF source 156 to the impedance of the load including the processing chamber and plasma. A controller 160 may be used to monitor system parameters and to control components of the substrate processing system 100 based on a recipe. One or more robots 161 may be used to deliver substrates onto, and remove substrates from, the substrate support 106.

[0062] The gas distribution device 104 includes a gas plenum 182 that distributes gas from the gas delivery system 130 and / or vapor from the vapor delivery system 170 to gas through holes 184 passing through a non-segmented electrode 186 that is grounded. In this example, the non-segmented electrode 186 comprises a circular plate made of aconducting material that is shorted to ground. The uniformity of the plasma that is generated between the non-segmented electrode 186 and the substrate 108 may vary from one radial location of the substrate 108 to another. For example, plasma density may be higher in a central region of the substrate 108 and lower in radially outer regions of the substrate 108. In some applications, the variation in plasma density causes processing non-uniformities.

[0063] Referring now to FIG. 1 B, a substrate processing system 200 according to the present disclosure includes an electrode 220 that is radially segmented and includes S segments 222-1 , 222-2, ..., and 222-S, where S is an integer greater than one. In some examples, the electrode 220 comprises an upper electrode. However, positions of the powered electrode and floating electrode can be swapped. In some examples, S is greater than or equal to 2 and less than or equal to 6. An RF plasma generator 240 includes an RF source 242 and a matching network 244 that supply RF voltage to the baseplate 1 10 to strike and maintain plasma.

[0064] A first one of the S segments 222-1 is arranged at a center location above the substrate support 106. The first one of the S segments 222-1 has a circular cross section. Remaining ones of the S segments 222-2, ..., and 222-S have annular cross sections and are arranged concentrically around the first one of the S segments 222-1 .

[0065] As will be described further below, the S segments 222-1 , 222-2, ..., and 222-S are connected to M impedances of a segment control circuit 256, respectively, where M is greater than zero and less than or equal to S. One or more of the S segments 222-1 , 222-2, ..., and 222-S is floating (rather than grounded) to allow adjustment of the plasma density in the processing chamber 102. In some examples, all of the S segments 222-1 , 222-2, ..., and 222-S are floating (and connected to the same impedance or two or more different impedance values) to allow adjustment of the plasma density in the substrate processing chamber. In some examples, at least one of the S segments 222-1 , 222-2, ..., and 222-S is grounded and the remaining segments are floating (and connected to the same impedance or two or more different impedance values) to allow adjustment of the plasma density in the processing chamber 102. In some examples, the plasma density is tuned using the impedances of the segment control circuit 256 to provide relatively uniform plasma density across the substrate in a radial direction. In other examples, other plasma density patterns are created using different combinations of grounded and / or floating segments.

[0066] For example, the impedance control circuit can be adjusted to desired impedance values at different frequencies to enhance specific physical phenomena. For example, the impedance control circuit can have a high impedance value for or at a high frequency range above 50 MHz and a low impedance value for DC (or vice versa).

[0067] The S impedances of the segment control circuit 256 can be configured to connect the S segments to a ground connection, a fixed impedance connected to ground, and / or a variable impedance connected to ground. Each of the S impedances of the segment control circuit 256 can include resistive, inductive, and / or capacitive impedances such as resistors, inductors, and / or capacitors that are connected in series and / or parallel combinations. In some examples, at least one of the S impedances of the segment control circuit 256 is a fixed or variable impedance (rather than a direct connection to ground). In some examples, at least one of the S impedances of the segment control circuit 256 is connected to ground (e.g., the center segment is connected to ground).

[0068] In some examples, values of the S impedances of the segment control circuit 256 are determined for a particular configuration and remain static once calibration is performed. In other examples, one or more of the S impedances of the segment control circuit 256 are variable impedances that can be adjusted during calibration, maintenance, or in response to feedback from sensors (e.g., sensed or estimated current, voltage, temperature, etc. of the segment, or in response to other chamber parameters).

[0069] When variable impedances, current sources, and / or voltage sources are used, a plasma density controller 248 is configured to receive one or more sensed signals such as current, voltage, and / or temperature measurements for the corresponding segment (and / or other measured chamber parameters) and to adjust the impedance, voltage source, and / or current source in response thereto. For example, the impedance adjustment can be made during calibration, maintenance, and / or during or between substrate processing cycles. In some examples, a temperature sensor described below senses a temperature of the segment (e.g., using a photon probe or insulated thermocouple having low RF coupling coefficient). In some examples, heat flux and / or plasma density of the segment is estimated in response to the measurement.

[0070] In some examples, the sensed signals can be used to detect system faults and flag hardware failures. For example, the sensed signals are compared to predetermined thresholds and / or ranges to detect the hardware failures. In other examples, the sensedsignals are stored and used to detect process repeatability issues between cycles. In other examples, the sensor signals are used to estimate a thickness of film (e.g., etching chemicals or polymer) on the segments of the electrode. For example, the thickness can be estimated based on continuous or transient sensed signals measured during impedance changes. For example, changes in thickness can be determined in response to lower frequency amplitude variations.

[0071] In some examples, the segments of the segmented electrode have increasing or decreasing radial widths and / or thicknesses from a center to an edge of the segmented electrode. In other examples, the segments of the segmented electrode do not have increasing or decreasing radial widths and / or thicknesses from a center to an edge of the segmented electrode. The segments radial thickness variation may be used to change the radial length scale of the plasma density modulation through impedance control.

[0072] Referring now to FIG. 1 C, the segment control circuit 256 is shown to include an impedance changing circuit 270, a voltage changing circuit 274, and / or a current changing circuit 278. The impedance changing circuit 270 is configured to connect and / or disconnect fixed and / or variable impedances 272 to one or more of the segments of the electrode to vary the impedance value. The voltage changing circuit 274 is configured to connect and / or disconnect fixed and / or variable voltage sources 276 to one or more of the segments of the electrode to vary the voltage value. The current changing circuit 278 is configured to connect and / or disconnect fixed and / or current sources 280 to one or more of the segments to vary the current value.

[0073] Referring now to FIGS. 2A to 2E, examples of variations in plasma density (and plasma density modulation with respect to a grounded electrode) as a function of substrate radius is shown for electrodes with various combinations of floating and / or grounded segment(s). In FIGS. 2A to 2B, a non-segmented electrode is grounded (represented by solid blocks) or floating (represented by open blocks), respectively. In FIGS. 2C to 2E, electrodes with both grounded and floating segments in various combinations have tunable plasma density profiles and plasma density modulation profiles with respect to grounded electrodes. In some examples, the segments of the electrode are symmetrical about a center of the substrate. In FIG. 2C, the electrode includes an annular grounded segment arranged around a floating segment. In FIG. 2D, the electrode includes a first floating segment, an annular grounded segment arranged around the first floating segment, and a second floating segment arranged around theannular grounded segment. In FIG. 2E, the electrode includes an annular floating segment are arranged around a grounded segment.

[0074] Referring now to FIGS. 3A and 3B, a segmented electrode 310 is arranged above the substrate 108 on the substrate support 106. The segmented electrode 310 includes a plurality of segments 312-1 , 312-2, ..., and 312-S separated by gaps 313, where S is an integer greater than one. The shape and / or size of each of the gaps 313 may be same as, or different than, each other. In FIG. 3A, one or more of the plurality of segments 312-1 , 312-2, ..., and 312-S is connected to corresponding electrical path or circuit exhibiting one of fixed impedance 330-1 , 330-2, ..., and 330-S (corresponding to Z1 , Z2, ..., and ZS). In some examples, one or more of the impedances (such the fixed impedance 330-1 for the segment 312-1 ) may be omitted and the corresponding segment may be grounded. In other examples, all of the impedances Z1 , Z2, ..., and ZS are connected to a fixed impedance. In some examples, the fixed impedances Z1 , Z2, ..., and ZS are different from one another. In other examples, one or more of the fixed impedance Z1 , Z2, ..., and ZS are the same. In some examples, switches 332-1 , 332-2, ..., and 332-S are arranged in parallel with one or more of the impedances 330-1 , 330-2, ..., and 330-S to allow the segment to be switched between grounded and floating during operation. In some examples, the switches 332 include relays.

[0075] In FIG. 3B, one or more of the plurality of segments 312-1 , 312-2, ..., and 312-S is connected to a variable impedance Z1 , Z2, ..., and ZS. In this example, at least one of the impedances Z1 , Z2, ..., and ZS is a variable impedance. In some examples, all of the impedances Z1 , Z2, ..., and ZS are variable (e.g., corresponding to impedances 340-1 , 340-2, ..., and 340-S). In some examples, one or more of the impedances Z1 , Z2, ..., and ZS is omitted and the segment is grounded. In some examples, one or more of the impedances Z1 , Z2, ..., and ZS is fixed. In some examples, switches can be used to switch the segments between floating and grounded (or between different impedances) as shown above.

[0076] The impedance of each segment can also be modulated to achieve a different value for each RF generator power setting in a pulsed plasma. For example, a fast switch or relay can be used to switch connections between different positions corresponding to different impedances using either an independent synchronization signal or a voltage sensor connected to the electrode segment.

[0077] The floating segmented electrode allows impedance adjustment to be made in independent radial zones of the electrode to vary plasma density across the substrate. In some examples, a four zone floating, segmented electrode is able to control plasma density modulation up to 10% (e.g., 7%) across the substrate (as compared to a nonsegmented, grounded electrode). In some examples, the floating segmented electrode allows compensation of plasma non-uniformity from center to edge to provide a relatively flat electrode plasma density. The floating segmented electrode also enables a wider range of process conditions to be used in recipes (powers, pressure, etc.).

[0078] The radial modulation of the plasma density can also be used to achieve specific on wafer responses. In some examples, radial modulation can be used to compensate for other sources of non-uniformities. In some examples, the plasma generator includes a plurality of power settings for pulsed plasma. In some examples, the M impedances of corresponding ones of the M of the S segments are adjusted for each the plurality of power settings.

[0079] In FIG. 3C, each of the plurality of segments 312-1 , 312-2, ..., and 312-S is connected to an adjusting circuit 350-1 , 350-2, ..., and 350-S including at least one of a variable impedance circuit, a voltage source, and / or a current source providing a variable impedance, voltage, and / or a current to adjust the plasma density or other plasma parameters.

[0080] Referring now to FIGS. 3D and 3E, the impedance corresponding to each segment can include two or more impedances that can be connected and / or disconnected to provide different impedance values. For example, the impedance vales can be adjusted for different plasma frequencies and / or switched in response to different modes during RF plasma pulsing.

[0081] In FIG. 3D, each of the impedances Z1 , Z2, ..., and ZS (e.g., of FIGS. 3A-C) includes one or more fixed impedances that may be switched to provide different impedances. For example, impedance Z1 may include one or more impedances Z1 A, Z1 B, ... and corresponding switches SWA, SWB, ... that can be used to select an impedance value (e.g., Z1 A or Z1 B or a parallel combination of Z1 A and Z1 B). In some examples, one of the impedances (e.g., Z1 A) is selected for operation at a first RF plasma frequency (e.g., 400 kHz), another one of the impedances (e.g., Z1 B) is selected for operation at a second RF plasma frequency (e.g., 60 MHz), etc. For example, the switches SWA, SWB, ... can include a fast switch or relay that switches connectionsbetween different positions corresponding to different impedances in response to an independent synchronization signal or feedback from a voltage sensor connected to the electrode segment.

[0082] In FIG. 3E, each of the variable impedances Z1 , Z2, ..., and ZS (e.g., of FIGS. 3A-C) includes one or more fixed and / or variable impedances that may be switched or adjusted to provide different impedances. For example, the variable impedance Z1 may include one or more fixed or variable impedances Z1 A, Z1 B, Z1 C ... and corresponding switches SWA, SWB, SWC ... that can be used to select one of the impedances or a combination of impedances. In some examples, one of the impedances (e.g., Z1 A) is selected for operation at a first plasma frequency (e.g., DC), another one of the impedances (e.g., Z1 B) is selected for operation at a second plasma frequency (e.g., 400kHz), another one of the impedances (e.g., Z1 C) is selected for operation at a third plasma frequency (e.g., 60MHz), etc.

[0083] Referring now to FIG. 4, an example of a temperature-controlled upper electrode is shown. A cooling plate 414 including cooling channels 415 is arranged adjacent to a heating plate 418 including one or more resistive heaters 419. Thermal interface layers 416 are arranged between the cooling plate 414 and the heating plate 418 and between the heating plate 418 and a gas distribution plate 422.

[0084] The gas distribution plate 422 may include one or more gas plenums in fluid communication with gas through holes (not shown) extending through the gas distribution plate 422 to supply process gas to an upper surface of the electrode 440. A barrier layer 426 and a thermal gasket layer 430 are arranged between the gas distribution plate 422 and an electrode 440 including S segments 440-1 , 440-2, ..., and 440-S. The thermal gasket layer 430 provides electrical insulation while allowing heat exchange to occur between the segments of the electrode that are exposed to plasma and the cooling plate 414 and / or the heating plate 418.

[0085] Referring now to FIGS. 5A and 5M, the S segments 440-1 , 440-2, ..., and 440-S of the electrode 440 are spaced from one another and define gaps 439 to prevent shorting between adjacent segments. In some examples, side surfaces of the segments can have various different configurations to reduce arcing, plasma light up, and / or accumulation of any unwanted products or undesirable residues. In some examples, substrate facing surfaces of the segments can be sloped to change the radial length scale of the plasma density modulation through impedance control. In other words, varying the slope of thesegments can be used to increase or decrease a radial width of a Gaussian response of the plasma for the segment.

[0086] In FIG. 5A, radially facing surfaces of the S segments 440-1 , 440-2, ..., and 440- S include one or more stair steps 450 to prevent line of sight paths and to reduce Voltage breakdown.

[0087] In FIG. 5B, the S segments 440-1 , 440-2, ..., and 440-S may have different radial widths and / or numbers of stair steps (e.g., three stair steps at 480 and two stair steps at 484). In FIG. 5C, facing surfaces 490 of the S segments 440-1 , 440-2, ..., and 440-S can be sloped relative to a direction transverse to a plane including the substrate to prevent line of sight paths associated with arcing and light-up, or to reduce manufacturing costs. In some examples, O-rings are used between one or more pairs of adjacent segments (as shown in FIG. 10 below).

[0088] In FIG. 5D, filler material 441 can be arranged in gaps 443 located between adjacent segments (e.g., segments 440-1 and 440-2 in FIG. 5D) of an electrode. In some examples, the filler material 441 includes an insulating material. The insulating material can be varied between adjacent segments. For example, insulating material having different dielectric constants and can be used to tune coupling between the adjacent segments. In some examples, side surfaces of the electrode segments (arranged transverse to a plane including the substrate) are coated with an insulating material to increase arc margin or to control adhesion of chemical species to edges of the electrode segment. For example, the filler or insulating material can be used to increase breakdown voltage (e.g., alumina coating) or to improve polymer adhesion (e.g., yttrium oxide (Y2O3) coating). In some examples, filler material 441 may comprise of one material or a plurality of different materials. Different mixtures or compositions of materials may be used to fill different gaps. Filler material 441 may fill the gaps 443 completely or partially.

[0089] In some examples, the segments of the electrode are made of silicon (e.g., high resistance silicon, low resistance silicon), polysilicon, silicon carbide, quartz, ceramic, or other plasma resistant materials. In FIG. 5E, two or more materials can be used to manufacture the segments to reduce cost. For example, the segment 440-2 includes a substrate 447 made of a substrate material such as stainless steel, aluminum alloy, and / or silicon (e.g., lower cost and lower purity silicon than is used for a plasma-resistant layer). A plasma-resistant layer 449 (made of a plasma resistant material (e.g., silicon)) is formed, deposited, coated, and / or applied on an outer surface of the substrate 447. Insome examples, the plasma-resistant layer 449 has a thickness in a range from 20pm to 500pm (e.g., 100pm). By limiting the use of the more-expensive and harder to manufacture plasma resistant layer using a thin layer rather than a monolithic approach, the cost of manufacturing the segments can be reduced.

[0090] In FIGS. 5F and 5G, a substrate facing surface 451 of the segment 440-2 can have other profiles in addition to planar. In FIG. 5F, the substrate facing surface 451 includes a concave cavity (and / or outer planar portions and an inner concave portion). In FIG. 5G, a substrate facing surface 453 includes a convex projection (and / or outer planar portions and inner convex portion). In FIG. 5H, edges of the segment 440-2 are tapered at 455 to adjust the plasma density. One or more edges of the segment may be chamfered and / or rounded to facilitate alignment and / or assembly with the other components and / or to further adjust the plasma density.

[0091] In FIG. 5I, the segment 440-2 is shown with an insulating layer 457 arranged on radial side surfaces of the segment 440-2. The insulating layer 457 can be used to adjust the radial shape of the plasma for the segment. The insulating material can be used to tune coupling between the adjacent segments, to increase arc margin, and / or to control adhesion of chemical species to edges of the electrode segment.

[0092] In still other variations, the S segments have different thicknesses in a direction transverse to a plane including the substrate. In some examples, the S segments have substrate facing surfaces that are coplanar. In other examples, one or more of the substrate facing surfaces can be non-coplanar.

[0093] In other examples, the S segments have substrate facing surfaces that are sloped relative to a plane parallel to an upper surface of the substrate support. For example in FIG. 5J, substrate facing surfaces 462 and 464 of the segment 440-2 are sloped or inclined in opposite directions. The slope or incline of the substrate facing surfaces 462 and 464 is relative to a plane 466 that is parallel to a plane including a top surface of the substrate support. In some examples, the substrate facing surfaces slope in opposite directions from a mid-portion 465 of the segment 440-2 to a radial side surface of the segment (e.g., at 462). In some examples, the substrate facing surfaces 462 and 464 slope from the mid-portion 465 to a location spaced from one or both radial sides of the segment (e.g., at 464). In some examples, sloping of the substrate facing surfaces 462 and 464 is the same or symmetric (a mirror image relative to the middle portion of the segment).

[0094] In some examples, sloping of the substrate facing surfaces 462 and 464 is not the same or asymmetric. In FIG. 5K, only one side of the segment 440-2 includes a substrate facing surface that is sloped. In FIG. 5L, a substrate facing surface 474 slopes in one direction from one radial side surface to the other radial side surface.

[0095] Referring now to FIG. 5M, the segment 440-2 includes substrate facing surfaces 478 and 480 that are sloped relative to the plane 466 and a middle portion 482 that is parallel to the plane 466. In some examples, the middle portion 482 corresponds to at least 10%, 20%, 30% or more of a radial width of the segment 440-2. The substrate facing surfaces 478 and 480 that are sloped correspond to at least 10%, 20%, 30% or more of a radial width of the segment 440-2.

[0096] Referring now to FIGS. 6 to 8, the fixed or variable impedances connected to S segments may be used to adjust or tune plasma density in radial regions below the S segments. In FIGS. 6 and 7, a central one of the S segments is centered above a center of the substrate and generates a peak plasma density above the center of the substrate. The plasma density associated with the central one of the S segments fades with radial distance from the center of the substrate. Adjacent ones of the S segments have an annular shape and generate first and second peaks below opposite sides of the annular segment. The density fades in radially inward and radially outward directions from the respective peaks. The values of the impedances connected to the S segments (along with their widths, shapes, materials, etc.) can be used to vary the response of that segment. When the S segments are used together, the plasma densities of each of the segments add to form a combined plasma density.

[0097] In FIG. 8, the plasma density of the segmented electrode is compared to the plasma density of a non-segmented electrode. The segmented electrode is connected to fixed or variable impedances to adjust the plasma density of each of the individual segments. As can be seen, the segmented electrode provides more uniform plasma density with fixed or variable impedances as compared to a non-segmented electrode that is grounded.

[0098] Referring now to FIG. 9 and 10, additional details relating to the segmented electrode are shown. In FIG. 9, a segmented electrode 500 is shown to include a plurality of electrode segments 510-1 , 510-2, 510-3, and 510-4 arranged concentrically with gaps therebetween. Some or all of the plurality of electrode segments 510-1 , 510-2, 510-3, and 510-4 are connected to fixed or variable impedances. Each of the segments 510-1 ,510-2, 510-3, and 510-4 is spaced from an adjacent segment by a predetermined gap to prevent shorting. In some examples, the segmented electrode 500 includes a pattern 520 of gas through holes 522 that pass vertically through at least one of the electrode segments 510-1 , 510-2, 510-3, and 510-4. In some examples, one or more cavities 524 (that does not pass through the corresponding electrode segment) may be used for receiving a threaded fastener to fasten the segmented electrode to another component of the processing chamber.

[0099] In FIG. 10, a portion of a segmented electrode 600 is shown to include the electrode segments 510-2, 510-3, and 510-4. A thermal gasket 610 is arranged on a surface of the electrode segments 510-1 , 510-2, 510-3, and 510-4 and over the gaps located therebetween. The thermal gasket 610 includes openings 612 having various different shapes to provide clearance for the cavities 524 and / or for the pattern 520 of the gas through holes 522. A barrier layer 620 is arranged above the thermal gasket 610. In some examples, one or more O-rings 630 can be used in gaps 632 between adjacent ones of the electrode segments 510-1 , 510-2, 510-3, and 510-4 to reduce plasma arcing and light up.

[0100] Referring now to FIGS. 4, 10, and 1 1 , capacitive coupling between the segments of segmented electrode 600 and the gas distribution plate 422 can be varied uniformly (all segments are the same) or individually by segment. For example, coupling can be varied by adjusting a thickness of the entire surface of the thermal gasket 610 or portions of the thermal gasket (e.g., portions aligned with each of the segments). In some examples, the thermal gasket 610 includes different zones 610-1 , 610-2, 610-3, and 610- 4 that are aligned with the S segments. In some examples, at least two of the zones use a different material (e.g., ml , m2, m3, m4 for each of the zones) and / or have a different thickness (e.g., t1 , t2, t3, or t4 for each of the zones) to vary capacitive coupling between the segmented electrode 600 and the gas distribution plate 422. The amount of coupling can be used to vary the plasma density in the corresponding regions.

[0101] It can be challenging to design a segmented electrode with multiple electrode segments (having a range of variable inner and / or outer diameters to allow adjustability for different applications) while maintaining process uniformity. More particularly, the radial locations of edges of the electrode segments and the gas through hole locations on the segments are designed to create the desired plasma profile while supplying gas flows for a particular application.

[0102] The top surface of each of the annular or circular electrode segments of the segmented electrode needs to provide sufficient physical space to allow attachment of mechanical fasteners, space for pin alignment holes to properly align the electrode segments relative to the processing chamber (and one another), space to provide electrical connections to the electrode segments, and space for sets of gas through holes to deliver gas uniformly through each of the segmented electrodes. In addition, the segmented electrodes provide flexibility with respect to varying the inner and / or outer diameters of each of the electrode segments (within predetermined ranges) to allow control and adjustment of the plasma profiles and / or gas flows for a particular application, while providing sufficient gap (or separation) between each neighboring electrode segment to be electrically isolated and be controlled individually under the high RF operating conditions of the process chamber.

[0103] In some examples, mechanical fasteners, pin alignment holes, and / or electrical contact points of each of the electrode segments are located in an annular area between inner and outer sets of gas through holes of each of the electrode segments.

[0104] Radially facing edges of the segmented electrodes are designed with overlapping projections that define tortuous paths (e.g., preventing a direct line of sight to the plasma) to block ions that are generated by the plasma from passing through gaps defined between the electrode segments. The tortuous paths help to protect a barrier seal arranged adjacent to and below on a top surface between adjacent pairs of the segmented electrodes. As can be appreciated, if the tortuous paths are not used, the barrier seal and / or other components above the segmented electrode can be damaged by ions generated by the plasma.

[0105] Referring now to FIG. 12, a plasma-facing surface of a segmented electrode assembly 800 including an outer ring 820 and a segmented electrode 830 is shown. The segmented electrode assembly 800 may also include a shroud ring 810, which is arranged to surround the segmented electrode 830 and the outer ring 820. The outer ring 820 corresponds to an outer electrode disposed between the segment electrode 830 and the shroud ring 810. A radially outer edge of the outer ring 820 is arranged on a radially inner edge of an upper surface of the shroud ring 810. A radially outer edge of the segmented electrode 830 is arranged over (e.g., with a gap) a radially inner edge of the outer ring 820.

[0106] The radially inner edge of the shroud ring 810 extends radially inside of a radially outer edge of the outer ring 820 to support the radially outer edge of the outer ring 820. In some examples, the outer ring 820 includes a plurality of gas through holes 822 that are arranged along a circle 824 located radially inside of and adjacent to the radially outer edge of the outer ring 820. The gas through holes 822 extend vertically through the outer ring 820. As can be appreciated, some but not all of the gas through holes 822 are shown for purposes of illustration.

[0107] The segmented electrode 830 includes electrode segments 830-1 , 830-2, 830- 3, and 830-4 that have complementary shapes to allow nesting. The electrode segments 830-1 , 830-2, and 830-3 include an annular body and the electrode segment 830-4 has a circular body. The electrode segment 830-2 is arranged radially inside of the electrode segment 830-1 (including some overlap between the two). The electrode segment 830- 3 is arranged radially inside of the electrode segment 830-2 (including some overlap between the two). The electrode segment 830-4 is arranged radially inside of the electrode segment 830-3 (including some overlap between the two).

[0108] Top surfaces of the electrode segments 830-1 , 830-2, 830-3, and 830-4 are mounted with gaps between radially facing edges of the electrode segments 830-1 , 830- 2, 830-3, and 830-4 to electrically isolate the electrode segments. The gaps allow the electrode segments to be electrically isolated from one another (since they be connected to ground and / or different impedances) and to prevent arcing between the electrode segments.

[0109] The segments of the segmented electrode 830 each may include one or more of rings of gas through holes to supply process gases to the process chamber. Each individual segment of the segment electrode 830 may include the same or different number of rings of gas through holes or the same or different distribution patterns of gas through holes. For example, each segment of the segmented electrode 830 may include two rings of gas through holes to supply process gas in a uniform manner above different radial regions of the substrate. The electrode segment 830-1 includes first and second sets of gas through holes 832 that are arranged around circles 834-1 and 836-1 . In some examples, the circles 834-1 and 836-1 are concentric with each other (and / or with radially inner and outer edges of the electrode segment 830-1 ). The gas through holes 832 extend vertically through the electrode segments. The circle 834-1 of gas through holes 832 is located radially inwardly from a radially outer edge of the electrode segment 830-1 . The circle 836-1 of gas through holes 832 is located radially outwardly from a radially inner edge of the electrode segment 830-1 .

[0110] The electrode segment 830-2 includes gas through holes 832 arranged along circles 834-2 and 836-2 that are concentric. In some examples, the circles 834-2 and 836-2 are concentric with each other and with radially inner and outer edges of the electrode segment 830-2. The circle 834-2 of gas through holes 832 is arranged adjacent to a radially outer edge of the electrode segment 830-2. The circle 836-2 of gas through holes 832 is arranged adjacent to the radially inner edge of the electrode segment 836-2.

[0111] The electrode segment 830-3 includes gas through holes 832 arranged along circles 834-3 and 836-3 that are concentric. In some examples, the circles 834-3 and 836-3 are concentric with each other and with radially inner and outer edges of the electrode segment 830-3. The circle 834-3 of gas through holes 832 is arranged adjacent to a radially outer edge of the electrode segment 830-3. The circle 836-3 of gas through holes 832 is arranged adjacent to the radially inner edge of the electrode segment 836-3.

[0112] The electrode segment 830-4 includes gas through holes 832 arranged along concentric circles 834-4 and 836-4. In some examples, the circles 834-4 and 836-4 are concentric with each other and with a radially outer edge of the electrode segment 830-4. The circle 834-4 of gas through holes 832 is arranged adjacent to a radially outer edge of the electrode segment 830-4. The circle 836-4 of gas through holes 832 is arranged radially inside of the circle 834-4 of gas through holes 832.

[0113] In some examples, a radially outer edge of the substrate may be arranged below or radially inwardly from a radially outer edge of the segmented electrode 830.

[0114] Referring now to FIGS. 13 and 14, a top surface of the segmented electrode assembly 800 of FIG. 12 is shown. In FIG. 13, the segmented electrode assembly 800 is shown partially assembled. The segmented electrode assembly 800 includes a plurality of threaded cavities 840 that are configured to receive mechanical fasteners (e.g., 850 and 860 shown in FIG. 14). The fasteners are used to mount and maintain positions of the shroud ring 810, the outer ring 820, and the electrode segments 830-1 , 830-2, 830- 3, and 830-4 during substrate processing. The location and number of fasteners are selected to prevent relative movement of the respective components during expansionand / or contraction due to temperature changes (from room temperature to plasma processing temperatures) and / or temperature gradients between various components.

[0115] The plurality of threaded cavities 840 are arranged along concentric circles located on the shroud ring 810, the outer ring 820, and the electrode segments 830-1 , 830-2, 830-3, and 830-4. In some examples, the threaded cavities 840 on the outer ring 820 on the shroud ring 810 are arranged closer to the radially inner edge of the shroud ring 810 than to the radially outer edge of the shroud ring 810. On the outer ring 820, the threaded cavities 840 are arranged radially inside of the circle 824 of the gas through holes 822 and spaced from a radially inner edge of the outer ring 820. In some examples, the threaded cavities 840 are arranged closer to the radially outer edge of the outer ring 820 than to the radially inner edge of the outer ring 820. The circles of threaded cavities 840 of the electrode segments 830-1 , 830-2, 830-3, and 830-4 are located in annular regions approximately midway between the circles 834-1 and 836-1 , 834-2 and 836-2, 834-3 and 836-3, and 834-4 and 836-4 of gas through holes 832, respectively.

[0116] In some examples, the shroud ring 810 includes 16 of the threaded cavities 840, the outer ring 820 includes 16 of the threaded cavities 840, the electrode segments 830- 1 and 830-2 include 16 of the threaded cavities 840, the electrode segment 830-3 includes 8 of the threaded cavities 840, and the electrode segment 830-4 includes 4 of the threaded cavities 840. As can be appreciated, additional or fewer threaded cavities 840 can be used and / or the threaded cavities 840 can be arranged in different locations.

[0117] Pin alignment holes 842 are arranged on or near the concentric circles of the threaded cavities 840 on the outer ring 820 and the electrode segments 830-1 , 830-2, 830-3, and 830-4. In some examples, the shroud ring 810, the outer ring 820 and the electrode segments 830-1 , 830-2, and 830-3 include three pin alignment holes 842 spaced approximately 120ºapart (subject to adjustment for spacing of other components). The electrode segment 830-4 includes two pin alignment holes 842 (e.g., a central pin alignment holes and a radially spaced pin alignment hole to control the orientation (or clocking) of the electrode segment 830-4). In some examples, the pin alignment holes of the shroud ring 810, the outer ring 820 and the electrode segments are rotationally clocked. As can be appreciated, the outer ring 820 and the electrode segments can include additional or fewer pin alignment holes 842 and / or the pin alignment holes 842 can be arranged in different locations.

[0118] The outer ring 820 and the electrode segments 830-1 , 830-2, 830-3, and 830-4 each include one or more electrical feed contacts 844. In some examples, the outer ring 820 includes 3 electrical feed contacts 844 that are spaced approximately 120ºapart (subject to adjustment for spacing of other components). In some examples, the electrode segment 830-1 includes two electrical feed contacts 844 that are spaced approximately 180ºapart (subject to adjustment for spacing of other components). In some examples, the electrode segment 830-2 includes two electrical feed contacts 844 that are spaced approximately 180ºapart (subject to adjustment for spacing of other components). In some examples, the electrical feed contacts 844 of the electrode segment 830-2 are rotationally offset in a range from 60ºto 120ºrelative to a line through the electrical feed contacts 844 of the electrode segment 830-1 . As can be appreciated, the outer ring 820 and the electrode segments can include additional or fewer electrical feed contacts 844 and / or the electrical feed contacts 844 can be arranged in different locations.

[0119] In some examples, the electrode segment 830-3 includes one electrical feed contact 844. In some examples, a line through the electrical feed contact 844 of the electrode segment 830-3 and a center of the electrode segment 830-3 is rotationally offset by 30ºto 60ºrelative to a line through the electrical feed contacts of the electrode segment 830-2.

[0120] In some examples, the electrode segment 830-4 include one electrical feed contact 844. In some examples, a line through the electrical feed contact 844 of the electrode segment 830-4 and a center of the electrode segment 830-4 is rotationally offset by 60ºto 120ºrelative to a line through the electrical feed contact 844 of the electrode segment 830-3 and the center of the electrode segment 830-3.

[0121] Rotationally misaligning the electric feed contacts of the electrode segments 830- 1 , 830-2, 830-3, and 830-4 helps to reduce noise and / or crosstalk.

[0122] In FIG. 14, a plurality of fasteners 850 are arranged in the threaded cavities 840 located on the shroud ring 810. The outer ring 820 and the electrode segments 830-1 , 830-2, 830-3, and 830-4 include a plurality of fasteners 860 arranged in the threaded cavities 840 around circles 862, 864-1 , 864-2, 864-3, and 864-4, respectively. In some examples, the concentric circles 864-1 , 864-2, 864-3, and 864-4 are approximately radially centered between the circles 834-1 and 836-1 , 834-2 and 836-2, 834-3 and 836- 3, and 834-4 and 836-4, respectively, of gas through holes 832. In some examples, thepin alignment holes 842 and / or the electrical feed contacts 844 are also arranged on or near the circles 862, 864-1 , 864-2, 864-3, and 864-4.

[0123] As can be appreciated, the design of the segmented electrode is flexible and can be varied for different applications. For example, the radial distances from a center of the segmented electrode 830 to a radially outer edge on the bottom surface of the corresponding electrode segments 830-1 , 830-2, 830-3, and 830-4 can be varied. In some examples, the minimum plasma face center line D1 of the electrode segment 830- 4 is in a range from 37.755 mm to 49.34 mm. In some examples, the minimum plasma face center line D2 of the electrode segment 830-3 is in a range from 77.525 mm to 85.295 mm. In some examples, the minimum plasma face center line D3 of the electrode segment 830-2 is in a range from 1 12.57 mm to 121.545 mm. In some examples, the minimum plasma face center line D4 of the electrode segment 830-1 is in a range from 152.95 mm to 164.75 mm (e.g., for a substrate having a radius of 156.75 mm).

[0124] Referring now to FIG. 15, one side of the segmented electrode assembly 800 is shown in further detail. The shroud ring 810 includes an annular body 910 including an upper portion 91 1 defining an inner cavity 915 (for receiving the outer ring 820 and the segmented electrode 830), a side wall 912, and a lower portion 913. In some examples, the upper portion 91 1 , the side wall 912, and the lower portion 913 define a “U”-shaped cross section that is rotated 90º). The side wall 912 is connected to radially outer edges of the upper portion 91 1 and the lower portion 913. A radially inner edge of the lower portion 913 includes a downwardly-projecting extension 914. A radially inner edge of the upper portion 91 1 includes a projection 916 (or lip) extending from a radially inner and lower edge of the upper portion 91 1 .

[0125] The outer ring 820 includes an annular body 920 including an upper surface 922 and a lower surface 924. A projection 926 extends downwardly from the lower surface 924 at a radially outer edge of the annular body 920. A projection 928 (or lip) extends radially inwardly from a lower and radially inner edge of the annular body 920. In some examples, an arcuate surface 929 is arranged between the projection 926 and the lower surface 924.

[0126] The electrode segment 830-1 includes an annular body 940 including an upper surface 942 and a lower surface 944. A projection 946 projects radially outwardly from an upper and radially outer edge of the annular body 940. A projection 948 extends radially inwardly from a lower and radially inner edge of the annular body 940.

[0127] The electrode segment 830-2 includes an annular body 950 including an upper surface 952 and a lower surface 954. A projection 956 projects radially outwardly from a middle and radially outer edge of the annular body 950. The projection 956 is located adjacent and above the projection 948 of the electrode segment 830-1 . An upper edge of the projection 956 is spaced from the upper surface 952 to allow a barrier seal (FIG. 16) to be positioned between the radially facing surface of the electrode segment 830-2 and the electrode segment 830-1 . A projection 958 extends radially inwardly from a lower and radially inner edge of the annular body 950.

[0128] The electrode segment 830-3 includes an annular body 960 including an upper surface 962 and a lower surface 964. A projection 966 projects radially outwardly from a middle and radially outer edge of the annular body 960. The projection 966 is located above the projection 958 of the electrode segment 830-2. An upper edge of the projection 966 is spaced from the upper surface 962 to allow a seal to be positioned between the electrode segment 830-3 and the electrode segment 830-2. A projection 968 extends radially inwardly from a middle and radially inner edge of the annular body 960.

[0129] The electrode segment 830-4 includes an annular body 970 including an upper surface 972 and a lower surface 974. A projection 976 projects radially outwardly from a lower and radially outer edge of the annular body 970. The projection 976 extends below the projection 968 of the electrode segment 830-3. One of the fasteners 860 is shown attached in one of the threaded cavities 840.

[0130] Referring now to FIG. 16, an example of an interface region between the electrodes 830-1 and 830-2 is shown in more detail. The radially outer surface of the electrode segment 830-2 includes the projection 956. An upper and radially outer surface 990 of the annular body 950 located above the projection 956 defines a predetermined gap g2 relative to a radially inner surface 991 of the electrode segment 830-1 . A lower and radially outer surface 992 of the annular body 950 located below the projection 956 defines a predetermined gap g1 relative to a radially inner surface 993 of the electrode segment 830-1. In some examples, g2 is greater than g1. In some examples, the predetermined gap g1 is in a range from 1 mm to 3 mm. Controlling the gap provides several benefits including reduced arcing and similar capacitive coupling from one segment to another.

[0131] In some examples, an annular body of a barrier seal 994 is arranged in the predetermined gap g2 between the radially inner surface 991 of the electrode segment830-1 and the radially outer surface 990 of the electrode segment 830-2. While the barrier seal 994 is shown with a circular cross section (e.g., in a compressed state), the barrier seal 994 can have other cross sectional shapes. In some examples, the lower and radially inner surface 993 of the electrode segment 830-1 is located radially inwardly from the radially outer edge of the projection 956 to prevent line of sight from the plasma to the barrier seal 994.

[0132] As can be seen in FIGS. 15 and 16, facing surfaces of the electrode segments 830-1 , 830-2, 830-3, and 830-4 define tortuous paths that include both vertical and horizonal portions to prevent a direct line of sight from the plasma to the barrier seals 994 (e.g., to prevent ion erosion of the barrier seals and / or other damage once the seals are eroded). While specific examples of segmented electrodes show projections located in specific locations, the locations of the projections can be varied. In some examples, each of the segmented electrodes includes radial projections that radially overlap radial projections of adjacent electrode segments to prevent line of sight. For example, one facing radial surface includes a lower projection and the adjacent electrode segment includes a middle projection (or upper projection if barrier seals are not used).

[0133] The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Further, although each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of the disclosure can be implemented in and / or combined with features of any of the other embodiments, even if that combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments with one another remain within the scope of this disclosure.

[0134] Spatial and functional relationships between elements (for example, between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including “connected,” “engaged,” “coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and “disposed.” Unless explicitly described as being “direct,” when a relationshipbetween first and second elements is described in the above disclosure, that relationship can be a direct relationship where no other intervening elements are present between the first and second elements, but can also be an indirect relationship where one or more intervening elements are present (either spatially or functionally) between the first and second elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”

[0135] In some implementations, a controller is part of a system, which may be part of the above-described examples. Such systems can comprise semiconductor processing equipment, including a processing tool or tools, chamber or chambers, a platform, or platforms for processing, and / or specific processing components (a wafer pedestal, a gas flow system, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after processing of a semiconductor wafer or substrate. The electronics may be referred to as the “controller,” which may control various components or subparts of the system or systems. The controller, depending on the processing requirements and / or the type of system, may be programmed to control any of the processes disclosed herein, including the delivery of processing 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 rate settings, fluid delivery settings, positional and operation settings, wafer transfers into and out of a tool and other transfer tools and / or load locks connected to or interfaced with a specific system.

[0136] Broadly speaking, the controller may be defined as electronics having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operation, enable cleaning operations, enable endpoint measurements, and the like. The integrated circuits may include chips in the form of firmware 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 program instructions (e.g., software). Program instructions may be instructions communicated to the controller in the form of various individual settings (or program files), defining operational parameters for carrying out a particular process on or for a semiconductor wafer or to a system. The operational parameters may, in some embodiments, be part of a recipe defined by process engineersto accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0137] The controller, in some implementations, may be a part of or coupled to a computer that is integrated with the system, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller may be in the “cloud” or all or a part of a fab host computer system, which can allow for remote access of the wafer processing. The computer may enable remote access to the system to monitor current progress of fabrication operations, examine a history of past fabrication operations, examine trends or performance metrics from a plurality of fabrication operations, to change parameters of current processing, to set processing steps to follow a current processing, or to start a new process. In some examples, a remote computer (e.g., a server) can provide process recipes to a system over a network, which may include a local network or the Internet. The remote computer may include a user interface that enables entry or programming of parameters and / or settings, which are then communicated to the system from the remote computer. In some examples, the controller receives instructions in the form of data, which specify parameters for each of the processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process to be performed and the type of tool that the controller is configured to interface with or control. Thus, as described above, the controller may be distributed, such as by comprising one or more discrete controllers that are networked together and working towards a common purpose, such as the processes and controls described herein. An example of a distributed controller for such purposes would be one or more integrated circuits on a chamber in communication with one or more integrated circuits located remotely (such as at the platform level or as part of a remote computer) that combine to control a process on the chamber.

[0138] Without limitation, example systems may include a plasma etch chamber or module, a deposition chamber or module, a spin-rinse chamber or module, a metal plating chamber or module, a clean chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing systemsthat may be associated or used in the fabrication and / or manufacturing of semiconductor wafers.

[0139] As noted above, depending on the process step or steps to be performed by the tool, the controller might communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout a factory, a main computer, another controller, or tools used in material transport that bring containers of wafers to and from tool locations and / or load ports in a semiconductor manufacturing factory.

Claims

AMENDED CLAIMS received by the International Bureau on 30 January 2025 (30.01.2024)CLAIMSWhat is claimed is:

1. A plasma processing system for processing substrates, comprising: a substrate support arranged in a processing chamber and including a first electrode; a second electrode arranged above the substrate support and including S segments that are arranged concentrically and include gaps located therebetween, where S is an integer greater than one; a segment control circuit including M impedances connected to M of the S segments of the second electrode, where M is an integer greater than zero and less than or equal to S, and wherein the M impedances are selected from a group consisting of a resistor, an inductor, a capacitor, and combinations thereof; and a plasma generator configured to supply RF voltage to the first electrode to generate and maintain plasma in the processing chamber.

2. The plasma processing system of claim 1 , wherein at least one of the M impedances comprises a fixed impedance.

3. The plasma processing system of claim 1 , wherein at least one of the M impedances comprises a variable impedance.

4. The plasma processing system of claim 3, further comprising a plasma density controller configured to adjust the variable impedance of the at least one of the M impedances.

5. The plasma processing system of claim 4, further comprising at least one of a photon probe and a thermocouple configured to sense a temperature of at least one of the S segments, wherein the plasma density controller is configured to adjust the variable impedance of the at least one of the S segments in response to the temperature.

6. The plasma processing system of claim 1 , wherein S is greater than two and less than or equal to six.

7. The plasma processing system of claim 1 , wherein M is greater than two and less than or equal to six.

8. The plasma processing system of claim 1 , wherein M is equal to S.

9. The plasma processing system of claim 1 , further comprising M switches connected in parallel to the M impedances to selectively short a corresponding one of the M impedances to ground a corresponding one of the S segments.

10. The plasma processing system of claim 9, where the M impedances of corresponding ones of the M of the S segments are adjusted independently for DC and at least one plasma excitation frequency.

11. The plasma processing system of claim 9, where the plasma generator includes a plurality of power settings for pulsed plasma, and wherein the M impedances of corresponding ones of the M of the S segments are adjusted for at least two of the plurality of power settings.

12. The plasma processing system of claim 1 , wherein sides of the S segments are configured to prevent line of sight from the plasma through the gaps.

13. The plasma processing system of claim 1 , wherein sides of the S segments are one of stair-stepped or sloped.

14. The plasma processing system of claim 1 , wherein the S segments include gas through holes.

15. The plasma processing system of claim 1 , wherein the M impedances include the resistor and at least one of the inductor and the capacitor.

16. The plasma processing system of claim 1 , wherein the S segments include a plurality of gas through holes.

17. The plasma processing system of claim 16, further comprising: a cooling plate; a heating plate arranged adjacent to the cooling plate;a thermal gasket arranged adjacent to an upper surface of the S segments and including holes for gas through holes and for receiving fasteners connected to the S segments a gas distribution plate; a barrier layer arranged adjacent to the thermal gasket; and a gas distribution plate arranged between the barrier layer and the heating plate and in fluid communication with the plurality of gas through holes in the S segments.

18. The plasma processing system of claim 17, wherein the thermal gasket includes a plurality of zones and wherein at least two of the zones are at least one of made of different materials or have different thicknesses.

19. The plasma processing system of claim 1 , wherein the S segments are made of a material selected from a group consisting of silicon, polysilicon, silicon carbide, ceramic, and quartz.

20. The plasma processing system of claim 1 , wherein at least one of the S segments includes a substrate made of a first material and a plasma-resistant layer arranged on the substrate and made of a second material different than the first material.

21. The plasma processing system of claim 20, wherein the substrate is made of a material selected from a group consisting of stainless steel, aluminum, and silicon.

22. The plasma processing system of claim 20, wherein the plasma-resistant layer is made of a material selected from a group consisting of silicon, polysilicon, silicon carbide, ceramic, and quartz.

23. The plasma processing system of claim 22, wherein the plasma-resistant layer has a thickness in a range from 20 pm to 500 pm.

24. The plasma processing system of claim 1 , further comprising an insulating material arranged in the gaps between adjacent ones of the S segments.

25. The plasma processing system of claim 1 , further comprising a voltage changing circuit including M voltage sources connected to M of the S segments, respectively.

26. The plasma processing system of claim 1 , further comprising a current changing circuit including M current sources connected to M of the S segments, respectively.

27. The plasma processing system of claim 1 , wherein at least one of the S segments has a different thickness than another one of the S segments.

28. The plasma processing system of claim 1 , wherein the S segments include bottom surfaces that are co-planar.

29. The plasma processing system of claim 1 , wherein a bottom surface of at least one of the S segments is not coplanar with a bottom surface of another one of the S segments.

30. The plasma processing system of claim 1 , wherein a substrate facing surface of at least one of the S segments is inclined relative to a plane parallel to a plane including a top surface of the substrate support.

31. The plasma processing system of claim 1 , wherein substrate facing edges of at least one of the S segments are tapered.

32. A method for processing substrate, comprising: arranging a substrate on a substrate support in a processing chamber; supplying RF voltage to a first electrode in the substrate support; arranging a second electrode above the substrate support and including S segments that are arranged concentrically and that include gaps located therebetween, where S is an integer greater than one; connecting M impedances to M of the S segments of the second electrode, where M is an integer greater than zero and less than or equal to S, and wherein the M impedances are selected from a group consisting of a resistor, an inductor, a capacitor, and combinations thereof; and supplying RF voltage to the first electrode to generate and maintain plasma in the processing chamber.

33. The method of claim 32, wherein at least one of the M impedances comprises a fixed impedance.

34. The method of claim 32, wherein at least one of the M impedances comprises a variable impedance.

35. The method of claim 34, further comprising sensing a parameter of at least one of the S segments and adjusting the variable impedance of the at least one of the M impedances based on the parameter.

36. The method of claim 35, further comprising using the parameter to detect a hardware failure.

37. The method of claim 35, further comprising using the parameter to detect deposition of film on the second electrode.

38. The method of claim 35, wherein the parameter comprises a temperature of the at least one of the S segments.

39. The method of claim 32, wherein S is greater than two and less than or equal to six.

40. The method of claim 32, wherein M is greater than two and less than or equal to six.

41. The method of claim 32, wherein M is equal to S.

42. The method of claim 32, further comprising using M switches connected in parallel to the M impedances to selectively short a corresponding one of the M impedances to ground a corresponding one of the S segments.

43. The method of claim 32, configuring sides of the S segments to prevent line of sight from the plasma through the gaps.

44. The method of claim 32, wherein sides of the S segments are stair-stepped.

45. The method of claim 32, wherein sides of the S segments are sloped.

46. The method of claim 32, wherein the S segments include gas through holes.

47. The method of claim 32, wherein the M impedances includes the resistor and at least one of the inductor and the capacitor.

48. The method of claim 32, wherein the S segments are made of a material selected from a group consisting of silicon, polysilicon, silicon carbide, ceramic, and quartz.

49. The method of claim 32, wherein at least one of the S segments includes a substrate made of a first material and a plasma-resistant layer arranged on the substrate.

50. The method of claim 49, wherein the plasma-resistant layer is made of a material selected from a group consisting of silicon, polysilicon silicon carbide, and ceramic.

51. The method of claim 50, wherein the plasma-resistant layer has a thickness in a range from 20 pm to 500 pm.

52. The method of claim 32, further comprising arranging a filler material between adjacent ones of the S segments.

53. The method of claim 32, further comprising arranging an insulating layer on a side surface of at least one of the S segments, wherein the side surface is arranged transverse to a plane including the substrate.

54. The method of claim 32, further comprising connecting M voltage sources to M of the S segments, respectively.

55. The method of claim 32, further comprising connecting M current sources to M of the S segments, respectively.

56. The method of claim 32, wherein at least one of the S segments has a different thickness than another one of the S segments.

57. The method of claim 32, wherein the S segments include bottom surfaces that are co-planar.

58. The method of claim 32, wherein a bottom surface of at least one of the S segments is not coplanar with a bottom surface of another one of the S segments.

59. The method of claim 32, wherein a bottom surface of at least one of the S segments includes one of a convex portion or concave portion.

60. The method of claim 32, further comprising tapering substrate facing edges of at least one of the S segments.

61. The method of claim 32, wherein a substrate facing surface of at least one of the S segments is inclined relative to a plane parallel to a plane including a top surface of the substrate support.

62. A plasma processing system for processing substrates, comprising: a processing chamber; a substrate support arranged in the processing chamber and including a first electrode; a second electrode arranged above the substrate support and including S segments that are arranged concentrically and include gaps located therebetween, where S is an integer greater than one; a segment control circuit including M changing circuits connected to M of the S segments of the second electrode, where M is an integer greater than zero and less than or equal to S, and wherein the M changing circuits are configured to vary at least one of an impedance, a voltage, and a current of the M of the S segments relative to ground; and a plasma generator configured to supply RF voltage to the first electrode to generate and maintain plasma in the processing chamber.

63. The plasma processing system of claim 62, further comprising a plasma density controller configured to adjust the at least one of the impedance, the voltage, and the current.

64. The plasma processing system of claim 62, further comprising a sensor configured to sense a parameter of at least one of the M of the S segments, wherein a corresponding one of the M changing circuits is configured to adjust the at least one of the impedance, the voltage, and the current in response to the parameter.

65. A segmented electrode for a substrate processing system, comprising:S electrode segments, where S is an integer greater than one; and a gap located between each adjacent pair of the S electrode segments, wherein S-1 of the S electrode segments have an annular shape, wherein an Sthone of the S electrode segments has a circular shape, wherein the S electrode segments are arranged concentrically, and wherein each of the S electrode segments includes a first set of gas through holes.

66. The segmented electrode of claim 65, wherein: each of the S electrode segments further comprise a second set of gas through holes arranged radially inside of the first set of gas through holes.

67. The segmented electrode of claim 66, wherein each of the S electrode segments further comprise a third set of holes configured to receive fasteners.

68. The segmented electrode of claim 67, wherein the third set of holes of at least some of the S electrode segments is arranged between the first set of gas through holes and the second set of gas through holes.

69. The segmented electrode of claim 65, where S is equal to 4.

70. The segmented electrode of claim 66, wherein each of the S electrode segments includes a plurality of pin alignment holes.

71. The segmented electrode of claim 70, wherein the plurality of pin alignment holes are arranged between the first set of gas through holes and the second set of gas through holes.

72. The segmented electrode of claim 66, wherein each of the S electrode segments includes an electrical feed contact.

73. The segmented electrode of claim 72, wherein the electrical feed contact of at least one of the S electrode segments is arranged between the first set of gas through holes and the second set of gas through holes.

74. The segmented electrode of claim 65, wherein S is an integer equal to three or more and S-2 of the S electrode segments include a plurality of electrical feed contacts.

75. The segmented electrode of claim 74, wherein the electrical feed contacts of each of the S-2 of the S electrode segments are rotated relative to others of the S-2 of the S electrode segments.

76. The segmented electrode of claim 65, wherein the gap are in a range from 1 mm to 3 mm.

77. The segmented electrode of claim 66, wherein each of the S electrode segments includes a plurality of pin alignment holes and at least one electrical feed contact.

78. The segmented electrode of claim 77, wherein the plurality of pin alignment holes and the at least one electrical feed contact of at least one of the S electrode segments are arranged between corresponding ones of the first set of gas through holes and the second set of gas through holes.

79. The segmented electrode of claim 65, wherein a radially inner surface and a radially outer surface of at least one of the S electrode segments includes a first radial projection and a second radial projection, respectively.

80. The segmented electrode of claim 79, wherein: the first radial projection on the radially inner surface vertically overlaps a radial projection on a first adjacent one of the S electrode segments, and the second radial projection on the radially outer surface vertically overlaps a radial projection on a second adjacent one of the S electrode segments.

81. A segmented electrode assembly comprising the segmented electrode of claim 65 and an outer ring arranged around a radially outer edge of the segmented electrode.

82. The segmented electrode assembly of claim 81 , wherein the outer ring includes a radial projection extending beneath a radial projection extending radially outwardly from a radially outer one of the S electrode segments.

83. The segmented electrode assembly of claim 82, wherein the outer ring includes a downward projection extending downwardly from a radially inner end of the outer ring.

84. A system comprising the segmented electrode assembly of claim 83, and further comprising a shroud ring including an annular body including a radially inner side including a radial projection, wherein the downward projection of the outer ring rests on the radial projection on the radially inner side of the annular body of the shroud.

85. An electrode segment for a segmented electrode of a plasma processing system, comprising: one of an annular body or a circular body; a first set of gas through holes arranged on the one of the annular body or the circular body; and a second set of gas through holes arranged on the one of the annular body or the circular body.

86. The electrode segment of claim 85, further comprising a plurality of pin alignment holes arranged on the one of the annular body or the circular body.

87. The electrode segment of claim 86, wherein at least one of the plurality of pin alignment holes is arranged between the first set of gas through holes and the second set of gas through holes.

88. The electrode segment of claim 85, further comprising at least one electrical feed contact arranged on the one of the annular body or the circular body.

89. The electrode segment of claim 88, wherein the at least one electrical feed contact is arranged radially inside of the second set of gas through holes.

90. The electrode segment of claim 85, further comprising a plurality of electrical feed contacts arranged on the one of the annular body or the circular body.

91. The electrode segment of claim 85, further comprising a plurality of pin alignment holes and at least one electrical feed contact arranged on the one of the annular body or the circular body.

92. The electrode segment of claim 91 , wherein the plurality of pin alignment holes and the at least one electrical feed contact are arranged between the first set of gas through holes and the second set of gas through holes.

93. The electrode segment of claim 85, wherein: the one of the annular body or the circular body includes the annular body, and a radially inner surface and a radially outer surface of the annular body includes a first radial projection and a second radial projection, respectively.

94. The electrode segment of claim 93, wherein: the first radial projection on the radially inner surface is configured to overlap a radial projection on a first adjacent electrode segment, and the second radial projection on the radially outer surface is configured to overlap a radial projection on a second adjacent electrode segment.

95. The electrode segment of claim 85, wherein: the one of the annular body or the circular body includes the circular body, and a radially outer surface of the circular body includes a radial projection.

96. The electrode segment of claim 95, wherein the radial projection on the radially outer surface of the circular body is configured to overlap a radial projection on an adjacent electrode segment.

97. The electrode segment of claim 85, further comprising a third set of holes configured to receive fasteners.

98. The electrode segment of claim 97, wherein the third set of holes is arranged between the first set of gas through holes and the second set of gas through holes.

99. An electrode segment for a segmented electrode of a plasma processing system, comprising: one of an annular body or a circular body; a first set of gas through holes arranged on the one of the annular body or the circular body; a second set of gas through holes arranged on the one of the annular body or the circular body; a plurality of pin alignment holes arranged on the one of the annular body or the circular body between the first set of gas through holes and the second set of gas through holes; and at least one electrical feed contact arranged on the one of the annular body or the circular body radially inside of the second set of gas through holes.

100. An electrode segment for a segmented electrode of a plasma processing system, comprising: an annular body; a first set of gas through holes arranged on the annular body; a second set of gas through holes arranged on the one of the annular body; at least one of a pin alignment hole and an electrical feed contact arranged on the annular body between the first set of gas through holes and the second set of gas through holes; a first radial projection arranged on a radially inner surface of the annular body and configured to overlap a radial projection on a first adjacent electrode segment; and a second radial projection arranged on a radially outer surface of the annular body and configured to overlap a radial projection on a second adjacent electrode segment.

101. The electrode segment of claim 100, further comprising a third set of holes configured to receive fasteners.

102. The electrode segment of claim 101 , wherein the third set of holes is arranged between the first set of gas through holes and the second set of gas through holes.

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