Barrier seals for segmented electrodes with floating segments

Abstract

A barrier seal configured to seal adjacent segments of a segmented electrode of a plasma processing system includes an annular body made of a plasma resistant material. The annular body extends circumferentially in a plane and includes a bottom portion extending parallel to the plane, a first leg extending from the bottom portion at a first angle relative to a line perpendicular to the plane, a second leg extending from the bottom portion at a second angle relative to a line perpendicular to the plane, and an annular groove defined between the first leg and the second leg.

Description

BARRIER SEALS FOR SEGMENTED ELECTRODES WITH FLOATING SEGMENTSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present disclosure claims the benefit of U.S. Provisional Patent Application No. 63 / 674,568, filed on July 23, 2024, which is related to U.S. Provisional Patent Application No. 63 / 534,950, filed on August 28, 2023, and U.S. Provisional Patent Application No. 63 / 625,240, filed on January 25, 2024. The entire disclosures of the applications referenced above are incorporated herein by reference.FIELD

[0002] The present disclosure relates to plasma processing systems for substrates, and more particularly to barrier seals for preventing passage of plasma radicals between adjacent segments of a segmented electrode of a plasma processing system.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, plasma density varies as a radial distance of the substrate varies. The plasma density variations cause processing non-uniformities.SUMMARY

[0006] A barrier seal configured to seal adjacent segments of a segmented electrode of a plasma processing system includes an annular body made of a plasma resistant material. The annular body extends circumferentially in a plane and includes a bottom portion extending parallel to the plane, a first leg extending from the bottom portion at a first angle relative to a line perpendicular to the plane, a second leg extending from the bottom portion at a second angle relative to a line perpendicular to the plane, and an annular groove defined between the first leg and the second leg.

[0007] In other features, the plasma resistant material is selected from a group consisting of perfluoroelastomer (FFKM), polytetrafluoroethylene (PTFE), and fluorinated ethylene propylene (FEP). The first and second angles are in a range from 0Qto 30Q. The annular body has a “U”-shaped cross section. The first leg and the second leg have a thickness in a range from 0.25 mm to 2 mm. A width of upper ends of the first leg and the second leg is greater than the bottom portion in an uninstalled state.

[0008] In other features, the bottom portion has a width in a range from 1 .5 mm to 5 mm, and upper ends of the first leg and the second leg have a width in a range from 1 .5 mm to 7.5 mm in an uninstalled state.

[0009] In other features, the first leg and the second leg are configured to bias opposing walls of an annular cavity defined between the adjacent segments of the segmented electrode.

[0010] A segmented electrode assembly includes S segments that are arranged concentrically and include gaps located therebetween, where S is an integer greater than one. B of the barrier seals are arranged between adjacent ones of the S segments, where B is an integer greater than one.

[0011] A plasma processing system includes the segmented electrode assembly. A segment control circuit including M impedances is connected to M of the S segments, 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 generate and maintain plasma in the processing chamber.

[0012] A barrier seal configured to seal adjacent segments of a segmented electrode of a plasma processing system includes an annular body made of a plasma resistantmaterial. The annular body extends circumferentially in a plane and includes a horizontal bottom portion extending parallel to the plane, a first leg extending from the horizontal bottom portion at a first angle relative to a line perpendicular to the plane, a second leg extending from the horizontal bottom portion at a second angle relative to the line perpendicular to the plane, and an annular groove defined between the first leg and the second leg.

[0013] In other features, the plasma resistant material is selected from a group consisting of perfluoroelastomer (FFKM), polytetrafluoroethylene (PTFE), and fluorinated ethylene propylene (FEP). The first angle is in a range from 30 to 80Qrelative to the plane and the second angle is in a range from 80Qto 100Qrelative to the plane. The first leg transitions from the first angle to the second angle. The annular body has a ‘V”-shaped cross section.

[0014] In other features, the first leg and the second leg have a thickness in a range from 0.25 mm to 2 mm. The horizontal bottom portion has a width in a range from 1 mm to 4 mm. Upper ends of the first leg and the second leg have a width in a range from 1 .5 mm to 7.5 mm in an uninstalled state. The first leg and the second leg are configured to bias opposing walls of an annular cavity defined between the adjacent segments of the segmented electrode.

[0015] A segmented electrode assembly includes S segments that are arranged concentrically and include gaps located therebetween, where S is an integer greater than one. B of the barrier seals are arranged between adjacent ones of the S segments, where B is an integer greater than one.

[0016] A plasma processing system includes the segmented electrode assembly. A segment control circuit includes M impedances connected to M of the S segments, 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 generate and maintain plasma.

[0017] A barrier seal configured to seal adjacent segments of a segmented electrode of a plasma processing system includes an annular body made of a plasma resistant material. The annular body extends circumferentially in a plane and includes a rounded base portion, a first leg extending from the rounded base portion at a first angle relative to a line perpendicular to the plane, a second leg extending from the rounded base portionat a second angle relative to the line perpendicular to the plane, and an annular groove defined between the first leg and the second leg.

[0018] In other features, the plasma resistant material is selected from a group consisting of perfluoroelastomer (FFKM), polytetrafluoroethylene (PTFE), and fluorinated ethylene propylene (FEP). The first angle is in a range from 20Qto 70Qrelative to the plane. The annular body has a ‘V”-shaped cross section. The first leg and the second leg have a thickness in a range from 0.25 mm to 2 mm. The rounded base portion has a width in a range from 1 to 5 mm. Upper ends of the first leg and the second leg have a width in a range from 1 .5 mm to 7.5 mm in an uninstalled state. A height of the barrier seal is in a range from 1 .5 mm to 6 mm.

[0019] In other features, the first leg and the second leg are configured to bias opposing walls of an annular cavity defined between the adjacent segments of the segmented electrode.

[0020] A segmented electrode assembly includes S segments that are arranged concentrically and include gaps located therebetween, where S is an integer greater than one. B of the barrier seals are arranged between adjacent ones of the S segments, where B is an integer greater than one.

[0021] A plasma processing system includes the segmented electrode assembly. A segment control circuit including M impedances connected to M of the S segments, 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. A plasma generator is configured to supply RF voltage to generate and maintain plasma.

[0022] A barrier seal configured to seal adjacent segments of a segmented electrode of a plasma processing system includes an annular body made of a plasma resistant material and extending circumferentially in a plane. The annular body has a “C”-shaped cross section, wherein an opening of the “C”-shaped cross section is positioned 90Qrelative to the plane. A first end of the annular body is spaced from a second end of the annular body. An annular groove is arranged between the first end and the second end.

[0023] In other features, the plasma resistant material is selected from a group consisting of perfluoroelastomer (FFKM), polytetrafluoroethylene (PTFE), and fluorinated ethylene propylene (FEP). A wall of the annular body has a thickness in a range from0.25mm to 2 mm. The annular body has a width in direction parallel to the plane in a range from 1 .5 mm to 7.5 mm. The annular body has a height in a range from 1 .5 mm to 6 mm. The annular body is configured to bias opposing walls of an annular cavity in direction parallel to the plane between the adjacent segments of the segmented electrode.

[0024] In other features, a filler material arranged in the annular groove. The filler material comprises a material having a durometer less than 60 Shore A. The filler material has a circular cross section. The filler material extends through an opening between the first end and the second end. The filler material is selected from a group consisting of fluoroelastomer (FKM), perfluoroelastomer (FFKM), fluorosilicone, and silicone.

[0025] A segmented electrode assembly includes S segments that are arranged concentrically and include gaps located therebetween, where S is an integer greater than one. B of the barrier seals are arranged between adjacent ones of the S segments, where B is an integer greater than one.

[0026] A plasma processing system includes the segmented electrode assembly. A segment control circuit includes M impedances connected to M of the S segments, 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 generate and maintain plasma.

[0027] A barrier seal configured to seal adjacent segments of a segmented electrode of a plasma processing system includes an annular body extending circumferentially in a plane, defining an annular groove, and made of a plasma resistant material. A spring is arranged in the annular groove of the annular body. An upper body portion of the annular body is configured for arrangement in a first cavity defined in a plate arranged above the adjacent segments of the segmented electrode. A lower body portion of the annular body is configured for arrangement in a second cavity defined between the adjacent segments of the segmented electrode.

[0028] In other features, the lower body portion includes a rounded portion. Radially inner and outer convex portions extending upwardly from inner and outer ends of the rounded portion, respectively. Radially inner and outer tapered portions extending upwardly from the radially inner and outer convex portions, respectively.

[0029] In other features, the upper body portion includes radially inner and outer vertical walls sloping outwardly from the radially inner and outer tapered portions of the lower portion, respectively. Radially inner and outer horizontal walls extend towards one another from the radially inner and outer vertical walls. An opening is located between the radially inner and outer horizontal walls.

[0030] In other features, radially inner and outer flanges extend downwardly from the radially inner and outer horizontal walls. The inner spring includes first openings that extend from a top of the spring on a radially inner side of the spring to a radially outer side of the spring below a radially outer connecting portion. Second openings that extend from the top of the spring on the radially outer side of the spring to the radially inner side of the spring below a radially inner connecting portion. The first openings and the second openings alternate around a circumference of the spring.

[0031] In other features, the plasma resistant material is selected from a group consisting of perfluoroelastomer (FFKM), polytetrafluoroethylene (PTFE), and fluorinated ethylene propylene (FEP). The upper body portion of the annular body has a width in a range from 1 .5 mm to 7.5 mm. The lower body portion of the annular body has a width in direction parallel to the plane in a range from 1 .5 mm to 6 mm. Outer sides of the lower body portion of the annular body are configured to bias opposing walls of the adjacent segments in the second cavity.

[0032] In other features, the annular body has a height in a range from 3 mm to 12 mm.

[0033] A segmented electrode assembly includes S segments that are arranged concentrically and include gaps located therebetween, where S is an integer greater than one. B of the barrier seals are arranged between adjacent ones of the S segments, where B is an integer greater than one.

[0034] A plasma processing system includes the segmented electrode assembly. A segment control circuit including M impedances connected to M of the S segments, 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 generate and maintain plasma.

[0035] A barrier seal configured to seal adjacent segments of a segmented electrode of a plasma processing system includes an annular body made of a plasma resistantmaterial and defining an annular groove. A spring is arranged in the annular groove of the annular body. The barrier seal is configured to be arranged between and bias the adjacent segments of the segmented electrode.

[0036] In other features, the annular body includes a bottom horizontal portion and radially inner and outer first walls extending upwardly from the bottom horizontal portion. Radially inner and outer convex portions extending upwardly from the radially inner and outer first walls. Radially inner and outer second walls extending upwardly from the radially inner and outer convex portions. Radially inner and outer horizontal wall portions extend towards one another from upper ends of the radially inner and outer second walls. An opening is located between the radially inner and outer horizontal wall portions.

[0037] In other features, radially inner and outer flanges extend downwardly from the radially inner and outer horizontal wall portions. The spring has a shape that is configured to nest within the annular body. The spring includes first openings that extend from a top of the spring on a radially inner side of the spring to a radially outer side of the spring below a radially outer connecting portion of the spring. Second openings extend from the top of the spring on the radially outer side of the spring to the radially inner side of the spring below a radially inner connecting portion of the spring. The first openings and the second openings alternate around a circumference of the spring.

[0038] In other features, the plasma resistant material is selected from a group consisting of perfluoroelastomer (FFKM), polytetrafluoroethylene (PTFE), and fluorinated ethylene propylene (FEP). The annular body has a height in a range from 1.5 mm to 6 mm. The annular body has a width in a range from 1 .5 mm to 7 mm.

[0039] A segmented electrode assembly includes S segments that are arranged concentrically and include gaps located therebetween, where S is an integer greater than one. B of the barrier seals are arranged between adjacent ones of the S segments, where B is an integer greater than one.

[0040] A plasma processing system includes the segmented electrode assembly. A segment control circuit includes M impedances connected to M of the S segments, 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 generate and maintain plasma.

[0041] A barrier seal configured to seal adjacent segments of a segmented electrode of a plasma processing system includes an annular body including an annular spring having a hollow body with an elliptical cross section and a plasma resistant material on an outer surface of the annular spring. The annular body has a diameter configured to fit between the adjacent segments of the segmented electrode.

[0042] In other features, the plasma resistant material is selected from a group consisting of perfluoroelastomer (FFKM), polytetrafluoroethylene (PTFE), and fluorinated ethylene propylene (FEP). A wall of the annular body has a thickness in a range from 0.25mm to 2mm. The annular body has a width in a range from 1 mm to 6.5 mm. The annular body is configured to bias opposing walls of an annular cavity between the adjacent segments of the segmented electrode.

[0043] A barrier seal configured to seal adjacent segments of a segmented electrode of a plasma processing system, includes an annular body having a solid body with a circular cross section and a plasma resistant material. The annular body has a diameter configured to fit between the adjacent segments of the segmented electrode.

[0044] In other features, the plasma resistant material is selected from a group consisting of perfluoroelastomer (FFKM), polytetrafluoroethylene (PTFE), and fluorinated ethylene propylene (FEP).

[0045] In other features, the plasma resistant material is discontinuous.

[0046] In other features, the annular body includes two opposing endpoints that overlap each other when arranged in an annular cavity between the adjacent segments of the segmented electrode.

[0047] 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

[0048] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0049] FIG. 1 is a functional block diagram of an example of a processing chamber including an RF plasma generator, a segmented upper electrode with one or morefloating segments, and a lower electrode that receives an RF voltage to generate plasma in the processing chamber according to the present disclosure;

[0050] FIG. 2 is a functional block diagram of an example of the impedance, current, and / or voltage changing circuit according to the present disclosure;

[0051] 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;

[0052] FIGS. 3C is a functional block diagram of an example of a segmented electrodes with fixed or variable impedances, current sources, and / or voltage sources according to the present disclosure;

[0053] FIG. 4 is a side cross sectional view of an example of a temperature-controlled, segmented electrode according to the present disclosure;

[0054] FIG. 5 is a side view showing an example of a segmented electrode including multiple radial segments according to the present disclosure;

[0055] FIG. 6 is a perspective view of an example of segmented electrode according to the present disclosure;

[0056] FIG. 7 is a side view showing an example of a segmented electrode including multiple radial segments according to the present disclosure;

[0057] FIG. 8 is a side view showing portions of first and second segments of a segmented electrode with a barrier seal arranged therebetween according to the present disclosure;

[0058] FIG. 9A is a side cross section of another example of an annular body of a barrier seal according to the present disclosure;

[0059] FIG. 9B is a side view showing portions of first and second segments of a segmented electrode with the barrier seal of FIG. 9A arranged therebetween according to the present disclosure;

[0060] FIG. 10A is a side cross section of another example of an annular body of a barrier seal according to the present disclosure;

[0061] FIG. 10B is a side view showing portions of first and second segments of a segmented electrode with the barrier seal of FIG. 10A arranged therebetween according to the present disclosure;

[0062] FIG. 1 1 A is a side cross section of another example of an annular body of a barrier seal according to the present disclosure;

[0063] FIG. 1 1 B is a side view showing portions of first and second segments of a segmented electrode with the barrier seal of FIG. 11 A arranged therebetween according to the present disclosure;

[0064] FIG. 12A is a side cross section of another example of an annular body of a barrier seal according to the present disclosure;

[0065] FIG. 12B is a side view showing portions of first and second segments of a segmented electrode with the barrier seal of FIG. 12A arranged therebetween according to the present disclosure;

[0066] FIG. 13A is a side cross section of another example of an annular body of a barrier seal according to the present disclosure;

[0067] FIG. 13B is a side view showing portions of first and second segments of a segmented electrode with the barrier seal of FIG. 13A arranged therebetween according to the present disclosure;

[0068] FIG. 14A is a side cross section of another example of an annular body of a barrier seal according to the present disclosure;

[0069] FIG. 14B is a side view showing portions of first and second segments of a segmented electrode with the barrier seal of FIG. 14A arranged therebetween according to the present disclosure;

[0070] FIG. 14C is a perspective view of another example of an inner spring according to the present disclosure;

[0071] FIG. 15A is a side cross section of an example of an annular body of a barrier seal according to the present disclosure;

[0072] FIG. 15B is a side view showing portions of first and second segments of a segmented electrode with the barrier seal of FIG. 15A arranged therebetween according to the present disclosure;

[0073] FIG. 16A is a side cross section of another example of an annular body of a barrier seal according to the present disclosure;

[0074] FIG. 16B is a side view showing portions of first and second segments of a segmented electrode with the barrier seal of FIG. 16A arranged therebetween according to the present disclosure;

[0075] FIG. 17A is a side cross section of another example of an annular body of a barrier seal according to the present disclosure; and

[0076] FIG. 17B is a side view showing portions of first and second segments of a segmented electrode with the barrier seal of FIG. 17A arranged therebetween according to the present disclosure.

[0077] In the drawings, reference numbers may be reused to identify similar and / or identical elements.DETAILED DESCRIPTION

[0078] The present disclosure relates barrier seals arranged in gaps defined between adjacent segments of a segmented electrode for plasma processing systems. The barrier seals prevent passage of plasma radicals between the adjacent segments.

[0079] Many substrate processing systems include a grounded, non-segmented electrode arranged above the substrate support. The substrate support includes an electrode such as a baseplate or an electrode embedded in a dielectric material. The non-segmented electrode above the substrate support may be grounded while the electrode in the substrate support is biased by RF power.

[0080] Substrate processing systems according to the present disclosure include an upper electrode that is segmented in a radial direction. The segmented electrode includes a plurality of segments that are arranged concentrically and spaced from one another by a gap. The segments are grounded, floating, connected to power generators, biased by a voltage source, and / or biased by a current source (rather than shorted to ground) to adjust a shape of the plasma that is generated. The barrier seals are arranged in the gaps between the adjacent segments to prevent passage of plasma radicals between the adjacent segments.

[0081] In other plasma processing systems, the plasma radicals are controlled by minimizing gaps between components. When using the segmented electrode, larger gaps are required to maintain electrical isolation between the segments of the segmented electrodes. However, the gaps between the segmented electrodes create a path for plasma radicals to pass through and attack / erode components located above thesegmented electrode. For example, a thermal interface material may be used above the segmented electrode to thermally connect the segments to a gas distribution plate (GDP). If the gaps between the segments remain open, the plasma radicals travel through the gaps and erode the thermal interface material. The eroded thermal interface material generates particles that fall onto the substrate. The particles cause defects and require a shorter mean time between cleaning (MTBC).

[0082] The barrier seals include an annular body having various predetermined cross sections (described further below) that are configured to fit between adjacent segments and to provide a seal against vertical surfaces of adjacent segments. The barrier seals include an outer surface made of a plasma radical resistant material that is electrically non-conductive. In some examples, the barrier seals also include an annular spring arranged or embedded inside of the plasma resistant material. In some examples, the plasma radical resistant material is selected from a group consisting of perfluoroelastomer (FFKM), polytetrafluoroethylene (PTFE), and fluorinated ethylene propylene (FEP), although other materials can be used.

[0083] In some examples, the barrier seals are installed at room temperature. In some examples, the barrier seals are operated at processing temperatures in a range from 50QC to 260QC. In other examples, the barrier seals are operated at processing temperatures in a range from 80QC to 180QC. In some examples, the barrier seals can be installed by hand or using minimal tooling. In some examples, the barrier seals exert a minimal to zero vertical residual load after installation. In some examples, the barrier seals provide a horizontal sealing load (a vacuum seal may or may not be formed).

[0084] Referring now to FIG. 1 , 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 1 10 supports a top plate 112, which may be made of ceramic or another plasma resistor material. A bond layer 1 14 bonds the top plate 1 12 to the baseplate 1 10. 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.

[0085] A gas delivery system 130 includes one or more gas sources 132-1 , 132-2, 132- N (collectively referred to as gas sources 132). The gas sources 132 supply one or more process gas mixtures. For an etching process, the process gas mixture may include including 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 134-1 , 134-2, 134-N (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.

[0086] 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.

[0087] A valve 150 and a pump 152 are connected to a gas line (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 240 includes a radio frequency (RF) source 242 to output RF voltage / power to a matching network 244. The matching network 244 matches the impedance of the RF source 242 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.

[0088] The gas distribution device 104 includes a gas plenum 210 that distributes gas from the gas delivery system 130 or vapor from the vapor delivery system 170 to gasthrough holes passing through a segmented electrode 220 that is grounded. The segmented electrode 220 is radially segmented and includes S segments 222-1 , 222-2, and 222-S that are arranged concentrically, 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. The RF plasma generator 240 supplies RF voltage to the baseplate 1 10 to strike and maintain plasma.

[0089] 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 .

[0090] 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 via a plasma density controller 248. 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 102 via the plasma density controller 248. 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 via the plasma density controller 248. In some examples, the plasma density is tuned using the impedances 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.

[0091] For example, an impedance changing circuit of the segment control circuit 256 can be adjusted to desired impedance values at different frequencies to enhance specific physical phenomena. For example, the impedance changing circuit can have a high impedance value above 50 MHz and a low impedance value for DC (or vice versa).

[0092] 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).

[0093] 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 during operation in response to feedback from sensors in, for example, a sensing circuit 252 (e.g., sensed or estimated current, voltage, temperature, etc. of the segment, or in response to other chamber parameters).

[0094] 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.

[0095] Referring now to FIG. 2, 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 vary, connect and / or disconnect fixed and / or variable impedances 272 to one or more of the segments of the electrode. The voltage changing circuit 274 is configured to vary, connect and / or disconnect fixed and / or variable voltage sources 276 to one or more of the segments of the electrode. 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.

[0096] 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. In FIG. 3A, one or more of the plurality ofsegments 312-1 , 312-2, ..., and 312-S is connected to corresponding 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 ) is omitted and the corresponding segment is 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.

[0097] In FIG. 3B, one or more of the plurality of segments 312-1 , 312-2, ..., and 312-S is connected to a variable impedance 340-1 , 340-2, ..., and 340-S (corresponding to 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. 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.

[0098] 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.

[0099] 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.).

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] Referring now to FIG. 5, 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 and plasma light up. 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 some examples, 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.

[0105] 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 some examples, 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. In some 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 plasma resistant layer using a thin layer rather than a monolithic approach, the cost of manufacturing the segments can be reduced.

[0106] Referring now to FIG. 6, 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.

[0107] Referring now to FIGS. 7 and 8, 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. In some embodiments, the outer ring 820 corresponds to an outer electrode disposed between the segmented 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.

[0108] 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 that are arranged along a circle located radially inside of and adjacent to the radially outer edge of the outer ring 820. The gas through holes extend vertically through the outer ring 820.

[0109] The segmented electrode 830 includes electrode segments 830-1 , 830-2, 830- 3, and 830-4 that are shaped to allow nesting. Nesting refers to complementary surfaces on adjacent facing edges of the electrode segments 830-1 , 830-2, 830-3, and 830-4 to allow partial overlap. 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).

[0110] 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.

[0111] 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 segmented 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 .

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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 90Q). 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 911 includes a projection 916 (or lip) extending from a radially inner and lower edge of the upper portion 91 1 .

[0116] The outer ring 820 includes an annular body 920 including an upper surface 922 and a lower surface 924. A projection 926 extends radially outwardly from the lowersurface 924 at a radially outer edge of the annular body 920. A projection 928 extends radially inwardly from a lower and radially inner edge of the annular body 920.

[0117] 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 a middle or 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.

[0118] 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 barrier seals 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.

[0119] 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 barrier 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.

[0120] 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.

[0121] Referring now to FIG. 8, 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 electrodesegment 830-1 . In some examples, g2 is greater than g1. In some examples, g2 is in a range from 1 to 5 mm. 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. A height hi from the top of the projection 956 to the upper surface 952 is in a range from 2.5 mm to 6 mm.

[0122] 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 segment 830-1 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.

[0123] As can be seen in FIGS. 7 and 8, facing surfaces of the electrode segments 830- 1 , 830-2, 830-3, and 830-4 define tortuous paths (e.g., a tortuous path 998 in FIG. 8) 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).

[0124] Referring now to FIGS. 9A and 9B, a barrier seal 1010 according to an embodiment of the present disclosure is shown to include an annular body 1012 that extends circumferentially in a plane. In some examples, the annular body 1012 has a “U”-shaped cross section. The cross section, height, width, and diameter of the annular body 1012 allows fitment between an inner diameter of an outer segment and an outer diameter of an inner segment. As can be appreciated, the barrier seals have larger or smaller diameters depending upon which pair(s) of adjacent segments of the segmented electrode are being sealed. In some examples, the diameters of the barrier seals are in a range from 70 mm to 500 mm.

[0125] In FIG. 9A, the annular body 1012 includes first and second arms 1014 and 1016 defining an annular groove 1018 (having an inner surface 1020) therebetween and radially inner and outer surfaces 1022 and 1028. The first and second arms 1014 and 1016 extend at first and second angles a and p from a base portion 1024 (relative to a direction approximately perpendicular to the plane), respectively. In some examples, the first and second angles a and p are the same. In some examples, the first and second angles a and p are different. In some examples, the first and second angles a and p are in a range from 0Qto 30Q, although other angles can be used. In some examples, the first and second angles a and p are in a range from 5Qto 20Q, although other angles can be used.

[0126] In some examples, the barrier seal 1010 has a vertical height hi in a range from 1 .5 mm to 6 mm. In some examples, the base portion 1024 has a width w1 in a range from 1 .5 mm to 5 mm. In some examples, a width w2 is defined between radially inner and radially outer edges of the first and second arms 1014 and 1016, respectively. In some examples, the width w2 of the first and second arms 1014 and 1016 is in a range from 1 .5 mm to 7.5 mm (when unbiased). In some examples, the width w2 is greater than the width w1 when the barrier seal 1010 is in an uninstalled or unbiased state. In some examples, the width w2 decreases relative to the width w1 when the barrier seal 1010 is in an installed or biased state. In some examples, one or both of the first and second arms 1014 and 1016 have a thickness t1 in a range from 0.25 mm to 2 mm. In some examples, the first and second arms 1014 and 1016 have the same thickness. In other examples, the first and second arms 1014 and 1016 have different thicknesses to provide different horizontal loads.

[0127] In FIG. 9B, the barrier seal 1010 is arranged in an annular cavity 1044 defined between adjacent segments 1040 and 1042. In some examples, the segment 1042 includes a vertical wall 1052. In some examples, the segment 1040 includes a vertical wall 1050 having an upper end connected to one side of a horizontal surface 1054. The horizontal surface 1054 is connected to a vertical wall 1056. A vertical annular passage 1053 is defined between the vertical walls 1050 and 1052 and connects with a lower side of the annular cavity 1044. In some examples, a horizontal width w3 in an annular volume defined between the vertical walls 1056 and 1052 of the segments 1040 and 1042 is in a range from 1.5 mm to 5 mm. In some examples, a height h2 of the annular volume defined between the segments 1040 and 1042 is in a range from 1 .5 mm to 6 mm.

[0128] When the width w2 of the first and second arms 1014 and 1016 is greater than the width w3 of the annular volume defined between the segments 1040 and 1042, the annular body 1012 produces an outwardly-directed a horizontal load to form a seal that prevents passage of plasma radicals. In other words, the outer surface 1022 of the barrier seal 1010 is biased against the vertical wall 1052 of the segment 1042. In some embodiments, the base portion 1024 does not deform (e.g., cave or bulge in the middle) when arms 1014 and 1016 are biasing against the vertical wall 1052 and 1042. Likewise, the outer surface 1028 of the barrier seal 1010 is biased against the vertical wall 1056 of the segment 1040. In some examples, at least part of the base portion 1024 of the barrier seal 1010 lies adjacent to and / or abuts the horizontal surface 1054 of the segment 1040 when the barrier seal 1010 is in the installed state. In some examples, the height h2 defined between the horizontal surface 1054 and an upper horizontal surface of one or both of the segments 1040 and 1042 is greater than or equal to the height hi of the barrier seal 1010 to prevent vertical loading. In other words, since the height hi of the barrier seal 1010 is less than the height h2 of the corresponding opening, the barrier seal 1010 will not be loaded vertically when installed.

[0129] As can be appreciated, the barrier seal 1010 is easier to install between the adjacent segments as compared to prior barrier seals using more rigid materials and is capable of preventing plasma radicals from passing through the gap between the segments 1040 and 1042. The first and second arms 1014 and 1016 of the barrier seal 1010 compress towards one another to allow easier installation while providing a robust seal. The radial biases provided by the first and second arms 1014 and 1016 of the barrier seal 1010 against adjacent surfaces may be used to prevent vertical or rotational movement of the barrier seal 1010 during use.

[0130] Referring now to FIGS. 10A and 10B, a barrier seal 1 110 according to the present disclosure is shown to include an annular body 1 1 12. The diameter of the annular body 1 1 12 allows fitment between an inner diameter of an outer segment and an outer diameter of an inner segment. In some examples, the annular body 1 1 12 has a “V”- shaped cross section defined by first and second arms 1 114 and 1 1 16 that are connected at first ends. Opposite ends of the first and second arms 11 14 and 1 1 16 are spaced from one another.

[0131] The first and second arms 11 14 and 11 16 define an annular groove 1 1 18 on a top surface of the barrier seal 1 1 10. In some examples, the first and second arms 11 14and 1 1 16 are symmetric. In other examples, the first and second arms 11 14 and 1 1 16 are asymmetric. For example, the first arm 1 1 14 includes a first sloped portion 1 123 that extends at an angle 0 relative to a bottom surface of a base portion 1 124. The first arm 1 1 14 transitions to a vertical or approximately vertical portion 1 122. In some examples, the angle 0 is in a range from 30Qto 80Q. In some examples, the angle 0 is in a range from 45Qto 70Q. In some examples, the second arm 1 116 extends vertically from a bottom connection location 1 127 while the first arm 1 114 extends at the angle 0 before transitioning to vertical or near vertical direction or a direction approximately parallel to or a mirror image of the second arm 1 1 16. In other examples, the second arm 1 116 is similar to the first arm 1 1 14 shown in FIG. 10A or vice versa.

[0132] In some examples, the barrier seal 1 1 10 has a height hi and the base portion 1024 has a width w1. In some examples, the barrier seal 11 10 has a width w2 between a radially inner edge of the first arm 1 114 and a radially outer edge of the second arm 1 1 16. The first and second arms 1 1 14 and 1 1 16 have thicknesses of t1 and t2. In some examples, the thicknesses t1 and t2 are the same. In other examples, the thickness t1 and t2 are different. In some examples, the thickness t1 is less than the thickness t2 to allow increased flexibility of the first arm 1 114 relative to the second arm 1 1 16.

[0133] In some examples, the height hi is in a range from 1 .5 mm to 6.5 mm. In some examples, the height h2 is in a range from 1.5 mm to 6.5 mm. In some examples, the width w1 of the base portion 1124 is in a range from 1 mm to 4 mm. In some examples, the width w2 of the first and second arms 1 1 14 and 1 1 16 is in a range from 1 .5 mm to 7.5 mm. The thicknesses t2 and t3 of the first and second arms 1 114 and 1 1 16 are in a range from in a range from 0.25 to 2mm.

[0134] In some examples, the width w2 of the first and second arms 1014 and 1016 is greater than the width w3 of the annular volume defined between the segments 1040 and 1042. As a result, the barrier seal 1 1 10 creates a seal against the vertical wall 1052 of the segment 1042 and the vertical wall 1056 of the segment 1040 preventing passage of plasma radicals. In some examples, the base portion 1 124 of the barrier seal 1 1 10 abuts or is adjacent to the horizontal surface 1054. In some examples, the height h2 defined between the horizontal surface 1054 and the upper horizontal surface of at least one of the segments 1040 and 1042 is greater than or equal to the height hi of the barrier seal 11 10.

[0135] The first arm 1 1 14 of the barrier seal 1 1 10 compresses to allow easier installation while providing a robust seal. The radial bias provided by the first and second arms 1 1 14 and 11 16 of the barrier seal 1 1 10 against adjacent surfaces may be used to prevent vertical or rotational movement of the barrier seal 11 10 during use.

[0136] Referring now to FIGS. 1 1 A and 1 1 B, a barrier seal 1210 according to the present disclosure is shown to include an annular body 1212 having a diameter to allow fitment between an inner diameter of an outer segment and an outer diameter of an inner segment. In some examples, the annular body 1212 includes a base portion 1220 and first and second arms 1214 and 1216 that extend from the base portion 1220. The first and second arms 1214 and 1216 define an annular groove 1218 on the top surface of the barrier seal 1210. In some examples, the first and second arms 1214 and 1216 are symmetric. In other examples, the first and second arms 1214 and 1216 are asymmetric. In some examples, the base portion 1220 has a rounded or elliptical shape, although other shapes can be used.

[0137] The first and second arms 1214 and 1216 extend from the base portion 1220 at first and second angles a and p relative to a vertical direction. In some examples, the first and second angles a and p are the same. In other examples, the first and second angles a and p are different. In some examples, the first and second angles a and p are in a range from 20Qto 70Q, although other angles can be used. In some examples, the first and second angles a and p are in a range from 30Qto 60Q, although other angles can be used.

[0138] In some examples, the barrier seal 1210 has a height hi and the base portion has a height h3. In some examples, the height hi is in a range from 1 .5 mm to 6.5 mm. In some examples, the height h3 is in a range from 25%* hi to 75%* hi. In some examples, the base portion 1220 has a width w2 in a range from 1.5 mm to 5 mm. In some examples, a width w1 is defined between radially inner and radially outer edges of the first and second arms 1214 and 1216, respectively. In some examples, the width w1 of the first and second arms 1214 and 1216 is in a range from 1 .5 mm to 7.5 mm. In some examples, the width w1 is greater than the width w2when the barrier seal 1210 is in an uninstalled or unbiased state. In some examples, the width \N2 decreases relative to the width w1 when the barrier seal 1210 is in an installed or biased state due to horizontal loading.

[0139] In some examples, the first and second arms 1214 and 1216 have thicknesses t1 and t2 in a range from 0.25 to 2mm. In some examples, the first and second arms 1214 and 1216 have the same thickness. In other examples, the first and second arms 1214 and 1216 have different thicknesses to provide different horizontal loads.

[0140] The width w1 defined at outer edges of the first and second arms 1214 and 1216 is greater than the width w3 of the annular volume defined between the segments 1040 and 1042. Outer surfaces 1222 and 1228 of the barrier seal 1210 create a seal against the vertical wall 1052 of the segment 1042 and the vertical wall 1056 of the segment 1040. In some examples, a bottom surface of the base portion 1220 of the barrier seal 1210 abuts the horizontal surface 1054. In some examples, the height h2 defined between the horizontal surface 1054 and the upper horizontal surface of at least one of the segments 1040 and 1042 is greater than or equal to the height hi of the barrier seal 1210.

[0141] The barrier seal 1210 provides four separate contact points against the two adjacent surfaces of the segments, which provides a more robust and redundant seal. In other words, one of the contact points may be lost on one or both sides and the seal may be maintained by the other contact point on that side.

[0142] Referring now to FIGS. 12A to 13B, a barrier seal 1310 according to the present disclosure is shown to include an annular body 1312 having a diameter allowing fitment between an inner diameter of an outer segment and an outer diameter of an inner segment. The annular body 1312 is “C”-shaped and is inverted 90Qwith opposite ends 1314 and 1316. An annular groove 1324 is defined between the opposite ends 1314 and 1316 and is arranged in an upwardly-facing direction. In some examples, the annular body 1312 comprises an arcuate surface extending through an arc greater than 220Qand less than 340Q. In some examples, the annular body 1312 comprises an arcuate surface extending through an arc greater than 280Qand less than 320Q. In some examples, the annular body 1312 has an outer diameter w1 in a horizontal plane in a range from 1.5 mm to 7.5 mm. In some examples, the annular body 1312 has a height hi in a vertical plane in a range from 1 .5 mm to 6 mm.

[0143] In some examples, the width w1 is greater than the width w3 of the annular volume defined between the segments 1040 and 1042. The barrier seal 1310 creates a seal against the vertical wall 1052 of the segment 1042 and the vertical wall 1056 of the segment 1040. In some examples, a bottom surface of the barrier seal 1310 abuts or isadjacent to the horizontal surface 1054. In some examples, the height h2 defined between the horizontal surface 1054 and the upper horizontal surface of at least one of the segments 1040 and 1042 is greater than or equal to the height hi of the barrier seal 1 1 10.

[0144] The first and second arms 1314 and 1316 of the barrier seal 1310 compress towards one another to allow easier installation while providing a robust seal. The radial biases provided by the first and second arms 1314 and 1316 of the barrier seal 1310 against adjacent surfaces may be used to prevent vertical or rotational movement of the barrier seal 1310 during use.

[0145] In FIGS. 13A and 13B, the annular groove 1324 of the barrier seal 1310’ includes a filler material 1350. In some examples, the filler material 1350 has a circular cross section. In some examples, the filler material 1350 has a durometer that is less than 60 Shore A. In some examples, the filler material 1350 is selected from a group consisting of fluoroelastomer (FKM), perfluoroelastomer (FFKM), fluorosilicone, and silicone.

[0146] The barrier seal 1310’ allows the annular body 1312 to be made of PTFE. The annular body is exposed to radicals. The filler material 1350 allows the barrier seal 1310’ to be soft enough to press into the annular groove 1324. The filler material 1350 tends to have greater friction than the annular body 1312. In other words, the annular body 1312 has greater radical resistance while lowering friction for installation.

[0147] Referring now to FIGS. 14A to 14C, a barrier seal 1410 includes an annular body 1412 including a lower body portion 1422 and an upper body portion 1424. The lower body portion 1422 is arranged in the annular cavity 1044 defined between the segment 1040 and the segment 1042. The upper body portion 1424 is arranged in an annular cavity 1432 defined in a plate 1430 arranged above the segments 1040 and 1042. Vertical walls 1431 of the annular cavity 1432 slope outwardly from an opening 1433 into the annular cavity 1432. In some examples, the annular cavity 1432 is centered over the annular cavity 1044. The upper body portion 1424 is arranged in the annular cavity 1432 of the plate 1430.

[0148] The lower body portion 1422 includes a rounded lower portion 1425, a middle convex portion 1426, and an upper tapered portion 1427. In some examples, the middle convex portion 1426 has a width w1 that is greater than a width of the upper tapered portion 1427 and the rounded lower portion 1425. In some examples, the width w1 is greater than the width w3 when in an unbiased state. In some examples, the width w1 isin a range from 1 .5mm to 6 mm. In some examples, the rounded lower portion 1425 abuts or is adjacent to the horizontal surface 1054. The middle convex portion 1426 is biased by the vertical walls 1052 and 1056.

[0149] The upper body portion 1424 includes vertical walls 1434 that slope outwardly from the upper tapered portion 1427 of the lower body portion 1422. The upper body portion 1424 has a width \N2 adjacent to upper ends of the vertical walls 1434. In some examples, the width w2 is greater than the width w1. In some examples, the width w2 is in a range from 1.5mm to 7.5 mm. The vertical walls 1434 are connected to horizontal portions 1435 extending inwardly towards one another in a horizontal direction. In some examples, inner ends of the horizontal portions 1435 include flanges 1437 projecting downwardly and are spaced from one another to create an annular groove 1438. In some examples, a height hi of the barrier seal is in a range from 3 mm to 12 mm. In some examples, a height h2 between the upper body portion 1424 and the lower body portion 1422 is in a range from 1 .5 mm to 6.5 mm.

[0150] An inner spring 1450 is arranged inside of the annular body 1412 and is configured to nest inside of the annular body 1412. In FIG. 14C, the inner spring 1450 includes lower body portion 1452 and upper body portion 1454. The lower body portion 1452 similarly includes a rounded lower portion 1455, a middle convex portion 1456, and an upper tapered portion 1457 that have shapes matching inner surfaces of the rounded lower portion 1425, the middle convex portion 1426, and the upper tapered portion 1427 of the annular body 1412. The upper body portion 1454 includes walls 1458 extending outwardly from the upper tapered portion 1457.

[0151] The inner spring 1450 includes openings 1462 that extend from one side, around the rounded lower portion and upwardly on the opposite side below a connecting portion 1464. The openings 1462 and connecting portions 1464 alternate on opposite sides of the inner spring 1450 in an interleaved manner allow the inner spring to flex and bend into an annular shape inside of the annular body 1412. The upper body portion 1424 is retained in the annular cavity 1432 of the plate 1430 such that the segments 1040 and 1042 can be removed and replaced without removing the barrier seal 1410.

[0152] In FIG. 14C, the openings 1462 have a width w7 and a height h5. In some examples, the height h5 is greater than or equal to 40%*h1 and less than or equal to 90%* hi. The openings 1462 are spaced apart by a width w8. In some examples, w7 is in a range from (w7 + w8). In some examples, (w7 + w8) spans 0.5Qto 10Q. In someexamples, the spring includes S of the openings 1462 on both the radially inner and radially outer sides where S is an integer in a range from 36 to 720. In some examples, (w7 + w8) spans 1 - to 3Qand S is an integer in a range from 120 to 360.

[0153] The barrier seal 1410 can be inserted into the annular cavity 1432 where it is retained. When replacing the segments, the barrier seal 1410 remains in the same position since it is held by spring force between lower openings of the annular cavity 1432 (which are narrower). The segments are removed and reinstalled without requiring the barrier seal 1410 to be removed.

[0154] In some examples, the annular body 1412 and the inner spring 1450 are manufactured separately. In some examples, the annular body 1412 is molded and / or machined using the plasma resistant material. In some examples, the inner spring 1450 is punched from a sheet of spring metal and stamped / pressed into the shape that is shown. Then the inner spring 1450 is inserted into the annular groove 1438 in the annular body 1412. Once installed, the flanges 1437 retain the inner spring 1450 in the annular body 1412. In some examples, a width w6 of the barrier seal 1410 (at a location corresponding to w4) is less than or equal to w4 to allow the barrier seal 1410 to allow float due to mechanical tolerances as well as thermal expansion differences of the annular cavity 1432, the segment 1040, and / or the segment 1042.

[0155] Referring now to FIGS. 15A and 15B, a barrier seal 1510 includes an annular body 1512. The barrier seal 1510 is arranged in the annular cavity 1044 defined between the segment 1040 and the segment 1042. The annular body 1512 includes a bottom horizontal portion 1520. Vertical walls 1522 extend upwardly from the bottom horizontal portion 1520. Convex portions 1526 extend upwardly from the vertical walls 1522. Vertical walls 1528 extend upwardly from the convex portions 1526. Horizontal wall portions 1532 extend inwardly from upper ends of the vertical walls 1528. Flanges 1534 extend downwardly from the horizontal wall portions 1532.

[0156] An inner spring 1550 has a shape that is configured to nest inside of the annular body 1512. The inner spring 1550 includes a bottom horizontal portion 1560. Vertical walls 1562 extend upwardly from the bottom horizontal portion 1560. Convex portions 1566 extend upwardly from the vertical walls 1562. Vertical walls 1568 extend upwardly from the convex portions 1566. Horizontal wall portions 1572 extend inwardly from upper ends of the vertical walls 1568. In some examples, the inner spring 1550 includes openings and connecting portions (not shown) that are similar to the openings 1462 andconnecting portions 1464 of the inner spring 1450 shown in FIG. 14C. The convex portions 1526 apply pressure on the vertical walls 1052 and 1056 of the segments 1040 and 1042. In some examples, a height h2 of the barrier seal 1510 is in a range from 1 .5 mm to 6 mm. In some examples, a width w1 of the barrier seal 1510 is in a range from 1 .5mm to 7 mm. In some examples, the height h2 is less than the height h3 of the annular cavity and the width w1 is greater than the width of the annular cavity.

[0157] The convex portions 1526 and 1566 of the barrier seal 1510 compress towards one another to allow easier installation while providing a robust seal. The bias provided by the convex portions 1526 and 1566 of the barrier seal 1510 against adjacent surfaces may be used to prevent vertical or rotational movement of the barrier seal 1510 during use.

[0158] Referring now to FIGS. 16A and 16B, a barrier seal 1610 is shown to include an annular body 1612 made of a plasma resistant material 1615 and an inner annular spring 1618 arranged in the annular body 1612. In some examples, the annular body 1612 has a circular or elliptical cross section. In some examples, a diameter w1 of the annular body 1612 is greater than the width w3 and less than the height hi of the annular cavity 1044. In some examples, a width w1 of the barrier seal 1610 is in a range from 1 .5 mm to 6.5 mm. In some examples, a shape of the barrier seal 1610 is distorted (e.g., from circular to elliptical) when installed in the annular cavity.

[0159] The inner annular spring 1618 provides spring force against facing surfaces of the segments. The plasma resistant material 1615 surrounds the inner annular spring 1618 to protect the inner annular spring 1618 to increase durability. The sides of the barrier seal 1610 compress inwardly towards one another to allow easier installation while providing a robust seal. The bias provided by the sides of the barrier seal 1610 against adjacent surfaces of the segment may be used to prevent vertical or rotational movement of the barrier seal 1610 during use.

[0160] Referring now to FIGS. 17A and 17B, a barrier seal 1710 is shown to include an annular body 1712 made of a plasma resistant material 1715. In the example of FIGS. 17A and 17B, the annular body 1712 has a solid circular cross section. In some examples, a diameter (or width of the cross section) w1 of the annular body 1712 is in a range from 1 .5 mm to 6.5 mm, such as 1 .5 mm, 1 .8 mm, 2 mm, 2.3 mm , 2.5 mm, 2.8 mm, 3 mm, 3.3 mm, 3.5 mm, 3.8 mm, 4 mm , 4.3 mm, 4.5 mm, 4.8 mm, 5 mm, 5.3 mm, 5.5 mm, 5.8, 6 mm, 6.3 mm, 6.5 mm, or another other distance therebetween.

[0161] In some examples, a shape of the barrier seal 1610 is distorted (e.g., from circular to elliptical) when installed in the annular cavity. This distortion may be caused by the pliability (e.g., flexibility, elasticity, etc.) of the plasma resistant material 1715. As example only, the plasma resistant material 1715 may be any suitable material, such as perfluoroelastomer (FFKM), polytetrafluoroethylene (PTFE), and fluorinated ethylene propylene (FEP). In such examples, the pliability of the annular body 1712 provides spring force against facing surfaces of the segments. The sides of the barrier seal 1710 compress inwardly towards one another to allow easier installation while providing a robust seal. The bias provided by the sides of the barrier seal 1710 against adjacent surfaces of the segment may be used to prevent vertical or rotational movement of the barrier seal 1710 during use.

[0162] In some examples, the barrier seal 1710 may be a continuous or a discontinuous piece of the plasma resistant material 1715. For example, the barrier seal 1710 may form a continuous loop or segment without endpoints. In other examples, the barrier seal 1710 may be a continuous segment having two endpoints. In such examples, when installed in the annular cavity, one endpoint may overlap with the other endpoint by 1 .5 cm, 1 .75 cm, 2 cm, 2.25 cm, 2.5 cm, 2.75 cm, 3 cm, or another other distance. This continuous or a discontinuous configuration may be employed in any of the other barrier seals herein.

[0163] 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.

[0164] 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 relationship between 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.”

[0165] 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.

[0166] 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 operationalparameters may, in some embodiments, be part of a recipe defined by process engineers to 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.

[0167] 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.

[0168] 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.

[0169] 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

CLAIMSWhat is claimed is:1 . A barrier seal configured to seal adjacent segments of a segmented electrode of a plasma processing system, comprising: an annular body made of a plasma resistant material, wherein the annular body extends circumferentially in a plane and includes: a bottom portion extending parallel to the plane; a first leg extending from the bottom portion at a first angle relative to a line perpendicular to the plane; a second leg extending from the bottom portion at a second angle relative to a line perpendicular to the plane; and an annular groove defined between the first leg and the second leg.

2. The barrier seal of claim 1 , wherein the plasma resistant material is selected from a group consisting of perfluoroelastomer (FFKM), polytetrafluoroethylene (PTFE), and fluorinated ethylene propylene (FEP).

3. The barrier seal of claim 1 , wherein the first and second angles are in a range from 0Qto 30Q.

4. The barrier seal of claim 1 , wherein the annular body has a “U”-shaped cross section.

5. The barrier seal of claim 1 , wherein the first leg and the second leg have a thickness in a range from 0.25 mm to 2 mm.

6. The barrier seal of claim 1 , wherein a width of upper ends of the first leg and the second leg is greater than the bottom portion in an uninstalled state.

7. The barrier seal of claim 6, wherein: the bottom portion has a width in a range from 1 .5 mm to 5 mm, and upper ends of the first leg and the second leg have a width in a range from 1 .5 mm to 7.5 mm in an uninstalled state.

8. The barrier seal of claim 7, wherein the first leg and the second leg are configured to bias opposing walls of an annular cavity defined between the adjacent segments of the segmented electrode.

9. A segmented electrode assembly, comprising:S segments that are arranged concentrically and include gaps located therebetween, where S is an integer greater than one; andB of the barrier seal of claim 1 arranged between adjacent ones of the S segments, where B is an integer greater than one.

10. A plasma processing system comprising: the segmented electrode assembly of claim 9; a segment control circuit including M impedances connected to M of the S segments, 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 generate and maintain plasma.1 1. A barrier seal configured to seal adjacent segments of a segmented electrode of a plasma processing system, comprising: an annular body made of a plasma resistant material, wherein the annular body extends circumferentially in a plane and includes: a horizontal bottom portion extending parallel to the plane; a first leg extending from the horizontal bottom portion at a first angle relative to a line perpendicular to the plane; a second leg extending from the horizontal bottom portion at a second angle relative to the line perpendicular to the plane; and an annular groove defined between the first leg and the second leg.

12. The barrier seal of claim 10, wherein the plasma resistant material is selected from a group consisting of perfluoroelastomer (FFKM), polytetrafluoroethylene (PTFE), and fluorinated ethylene propylene (FEP).

13. The barrier seal of claim 11 , wherein: the first angle is in a range from 30 to 80Qrelative to the plane; and the second angle is in a range from 80Qto 100Qrelative to the plane.

14. The barrier seal of claim 13 wherein the first leg transitions from the first angle to the second angle.

15. The barrier seal of claim 11 , wherein the annular body has a ‘V”-shaped cross section.

16. The barrier seal of claim 11 , wherein the first leg and the second leg have a thickness in a range from 0.25 mm to 2 mm.

17. The barrier seal of claim 11 , wherein the horizontal bottom portion has a width in a range from 1 mm to 4 mm.

18. The barrier seal of claim 11 , wherein upper ends of the first leg and the second leg have a width in a range from 1 .5 mm to 7.5 mm in an uninstalled state.

19. The barrier seal of claim 15, wherein the first leg and the second leg are configured to bias opposing walls of an annular cavity defined between the adjacent segments of the segmented electrode.

20. A segmented electrode assembly comprising:S segments that are arranged concentrically and include gaps located therebetween, where S is an integer greater than one; andB of the barrier seal of claim 11 arranged between adjacent ones of the S segments, where B is an integer greater than one.21 . A plasma processing system comprising: the segmented electrode assembly of claim 20; a segment control circuit including M impedances connected to M of the S segments, 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 generate and maintain plasma.

22. A barrier seal configured to seal adjacent segments of a segmented electrode of a plasma processing system, comprising: an annular body made of a plasma resistant material, wherein the annular body extends circumferentially in a plane and includes: a rounded base portion; a first leg extending from the rounded base portion at a first angle relative to a line perpendicular to the plane; a second leg extending from the rounded base portion at a second angle relative to the line perpendicular to the plane; and an annular groove defined between the first leg and the second leg.

23. The barrier seal of claim 22, wherein the plasma resistant material is selected from a group consisting of perfluoroelastomer (FFKM), polytetrafluoroethylene (PTFE), and fluorinated ethylene propylene (FEP).

24. The barrier seal of claim 22, wherein the first angle is in a range from 20Qto 70Qrelative to the plane.

25. The barrier seal of claim 22, wherein the annular body has a ‘V”-shaped cross section.

26. The barrier seal of claim 22, wherein the first leg and the second leg have a thickness in a range from 0.25 mm to 2 mm.

27. The barrier seal of claim 22, wherein the rounded base portion has a width in a range from 1 to 5 mm.

28. The barrier seal of claim 22, wherein upper ends of the first leg and the second leg have a width in a range from 1 .5 mm to 7.5 mm in an uninstalled state.

29. The barrier seal of claim 22, wherein a height of the barrier seal is in a range from 1 .5 mm to 6 mm.

30. The barrier seal of claim 22, wherein the first leg and the second leg are configured to bias opposing walls of an annular cavity defined between the adjacent segments of the segmented electrode.31 . A segmented electrode assembly comprising:S segments that are arranged concentrically and include gaps located therebetween, where S is an integer greater than one; andB of the barrier seal of claim 22 arranged between adjacent ones of the S segments, where B is an integer greater than one.

32. A plasma processing system comprising: the segmented electrode assembly of claim 31 ; a segment control circuit including M impedances connected to M of the S segments, 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 generate and maintain plasma.

33. A barrier seal configured to seal adjacent segments of a segmented electrode of a plasma processing system, comprising: an annular body made of a plasma resistant material and extending circumferentially in a plane, wherein the annular body has a “C”-shaped cross section, wherein an opening of the “C”-shaped cross section is positioned 90Qrelative to the plane; a first end of the annular body is spaced from a second end of the annular body; and an annular groove arranged between the first end and the second end.

34. The barrier seal of claim 33, wherein the plasma resistant material is selected from a group consisting of perfluoroelastomer (FFKM), polytetrafluoroethylene (PTFE), and fluorinated ethylene propylene (FEP).

35. The barrier seal of claim 33, wherein a wall of the annular body has a thickness in a range from 0.25mm to 2 mm.

36. The barrier seal of claim 33, wherein the annular body has a width in direction parallel to the plane in a range from 1 .5 mm to 7.5 mm.

37. The barrier seal of claim 33, wherein the annular body has a height in a range from 1 .5 mm to 6 mm.

38. The barrier seal of claim 33, wherein the annular body is configured to bias opposing walls of an annular cavity in direction parallel to the plane between the adjacent segments of the segmented electrode.

39. The barrier seal of claim 33 further comprising a filler material arranged in the annular groove.

40. The barrier seal of claim 39, wherein the filler material comprises a material having a durometer less than 60 Shore A.41 . The barrier seal of claim 39, wherein the filler material has a circular cross section.

42. The barrier seal of claim 39, wherein the filler material extends through an opening between the first end and the second end.

43. The barrier seal of claim 39, wherein the filler material is selected from a group consisting of fluoroelastomer (FKM), perfluoroelastomer (FFKM), fluorosilicone, and silicone.

44. A segmented electrode assembly comprising:S segments that are arranged concentrically and include gaps located therebetween, where S is an integer greater than one; andB of the barrier seal of claim 33 arranged between adjacent ones of the S segments, where B is an integer greater than one.

45. A plasma processing system comprising: the segmented electrode assembly of claim 44; a segment control circuit including M impedances connected to M of the S segments, 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 generate and maintain plasma.

46. A barrier seal configured to seal adjacent segments of a segmented electrode of a plasma processing system, comprising: an annular body extending circumferentially in a plane, defining an annular groove, and made of a plasma resistant material; a spring arranged in the annular groove of the annular body; an upper body portion of the annular body is configured for arrangement in a first cavity defined in a plate arranged above the adjacent segments of the segmented electrode; and a lower body portion of the annular body is configured for arrangement in a second cavity defined between the adjacent segments of the segmented electrode.M . The barrier seal of claim 46, wherein the lower body portion includes: a rounded portion; radially inner and outer convex portions extending upwardly from inner and outer ends of the rounded portion, respectively; and radially inner and outer tapered portions extending upwardly from the radially inner and outer convex portions, respectively.

48. The barrier seal of claim 47, wherein the upper body portion includes: radially inner and outer vertical walls sloping outwardly from the radially inner and outer tapered portions of the lower portion, respectively; radially inner and outer horizontal walls extending towards one another from the radially inner and outer vertical walls; and an opening between the radially inner and outer horizontal walls.

49. The barrier seal of claim 48, further comprising radially inner and outer flanges extending downwardly from the radially inner and outer horizontal walls.

50. The barrier seal of claim 49, wherein the inner spring includes first openings that extend from a top of the spring on a radially inner side of the spring to a radially outer side of the spring below a radially outer connecting portion; and second openings that extend from the top of the spring on the radially outer side of the spring to the radially inner side of the spring below a radially inner connecting portion.51 . The barrier seal of claim 50, wherein the first openings and the second openings alternate around a circumference of the spring.

52. The barrier seal of claim 46, wherein the plasma resistant material is selected from a group consisting of perfluoroelastomer (FFKM), polytetrafluoroethylene (PTFE), and fluorinated ethylene propylene (FEP).

53. The barrier seal of claim 46, wherein the upper body portion of the annular body has a width in a range from 1 .5 mm to 7.5 mm.

54. The barrier seal of claim 46, wherein the lower body portion of the annular body has a width in direction parallel to the plane in a range from 1 .5 mm to 6 mm.

55. The barrier seal of claim 46, wherein outer sides of the lower body portion of the annular body are configured to bias opposing walls of the adjacent segments in the second cavity.

56. The barrier seal of claim 46, wherein the annular body has a height in a range from 3 mm to 12 mm.

57. A segmented electrode assembly comprising:S segments that are arranged concentrically and include gaps located therebetween, where S is an integer greater than one; andB of the barrier seal of claim 46 arranged between adjacent ones of the S segments, where B is an integer greater than one.

58. A plasma processing system comprising: the segmented electrode assembly of claim 57; a segment control circuit including M impedances connected to M of the S segments, 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 generate and maintain plasma.

59. A barrier seal configured to seal adjacent segments of a segmented electrode of a plasma processing system, comprising: an annular body made of a plasma resistant material and defining an annular groove; and a spring arranged in the annular groove of the annular body, wherein the barrier seal is configured to be arranged between and bias the adjacent segments of the segmented electrode.

60. The barrier seal of claim 59, wherein the annular body includes: a bottom horizontal portion radially inner and outer first walls extending upwardly from the bottom horizontal portion; radially inner and outer convex portions extending upwardly from the radially inner and outer first walls; radially inner and outer second walls extending upwardly from the radially inner and outer convex portions; radially inner and outer horizontal wall portions extend towards one another from upper ends of the radially inner and outer second walls; and an opening between the radially inner and outer horizontal wall portions.61 . The barrier seal of claim 59, further comprising radially inner and outer flanges extending downwardly from the radially inner and outer horizontal wall portions.

62. The barrier seal of claim 59, wherein the spring has a shape that is configured to nest within the annular body.

63. The barrier seal of claim 59, wherein the spring includes: first openings that extend from a top of the spring on a radially inner side of the spring to a radially outer side of the spring below a radially outer connecting portion of the spring; and second openings that extend from the top of the spring on the radially outer side of the spring to the radially inner side of the spring below a radially inner connecting portion of the spring.

64. The barrier seal of claim 63, wherein the first openings and the second openings alternate around a circumference of the spring.

65. The barrier seal of claim 59, wherein the plasma resistant material is selected from a group consisting of perfluoroelastomer (FFKM), polytetrafluoroethylene (PTFE), and fluorinated ethylene propylene (FEP).

66. The barrier seal of claim 59, wherein the annular body has a height in a range from 1 .5 mm to 6 mm.

67. The barrier seal of claim 59, wherein the annular body has a width in a range from 1 .5 mm to 7 mm.

68. A segmented electrode assembly comprising:S segments that are arranged concentrically and include gaps located therebetween, where S is an integer greater than one; andB of the barrier seal of claim 59 arranged between adjacent ones of the S segments, where B is an integer greater than one.

69. A plasma processing system comprising: the segmented electrode assembly of claim 68; a segment control circuit including M impedances connected to M of the S segments, 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 generate and maintain plasma.

70. A barrier seal configured to seal adjacent segments of a segmented electrode of a plasma processing system, comprising: an annular body comprising: an annular spring having a hollow body with an elliptical cross section; and a plasma resistant material on an outer surface of the annular spring, wherein the annular body has a diameter configured to fit between the adjacent segments of the segmented electrode.71 . The barrier seal of claim 70, wherein the plasma resistant material is selected from a group consisting of perfluoroelastomer (FFKM), polytetrafluoroethylene (PTFE), and fluorinated ethylene propylene (FEP).

12. The barrier seal of claim 70, wherein a wall of the annular body has a thickness in a range from 0.25mm to 2mm.

73. The barrier seal of claim 70, wherein the annular body has a width in a range from 1 mm to 6.5 mm.

74. The barrier seal of claim 70, wherein the annular body is configured to bias opposing walls of an annular cavity between the adjacent segments of the segmented electrode.

75. A barrier seal configured to seal adjacent segments of a segmented electrode of a plasma processing system, comprising: an annular body comprising: a solid body with a circular cross section; and a plasma resistant material, wherein the annular body has a diameter configured to fit between the adjacent segments of the segmented electrode.

76. The barrier seal of claim 75, wherein the plasma resistant material is selected from a group consisting of perfluoroelastomer (FFKM), polytetrafluoroethylene (PTFE), and fluorinated ethylene propylene (FEP).

77. The barrier seal of claim 75, wherein the plasma resistant material is discontinuous.

78. The barrier seal of claim 77, wherein the annular body includes two opposing endpoints that overlap each other when arranged in an annular cavity between the adjacent segments of the segmented electrode.

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