Abstract: In an embodiment, a system includes: a gas distributor assembly configured to dispense gas into a chamber; and a chuck assembly configured to secure a wafer within the chamber, wherein at least one of the gas distributor assembly and the chuck assembly includes: a first portion comprising a convex protrusion, and a second portion comprising a concave opening, wherein the convex protrusion is configured to engage the concave opening.

Abstract: A system to deposit a film on a substrate using atomic layer deposition includes a pedestal arranged in a processing chamber to support the substrate on a top surface of the pedestal when depositing the film on the substrate. A first annular recess in the pedestal extends downwardly from the top surface of the pedestal and radially inwardly from an outer edge of the pedestal towards an outer edge of the substrate. The first annular recess has an inner diameter that is greater than a diameter of the substrate. An annular ring is made of a dielectric material and is arranged around the substrate in the first annular recess. A second annular recess in the pedestal is located under the annular ring. The second annular recess has a height and extends radially inwardly from the outer edge of the pedestal towards the outer edge of the substrate.

Abstract: A substrate processing apparatus may include a vacuum chamber, a substrate supporting unit disposed at lower portion of an inside of the vacuum chamber, and an electric field forming unit forming an electric field inside the vacuum chamber. The electric field forming unit may include an upper electrode disposed at an upper portion of the inside of the vacuum chamber, a lower electrode disposed in the substrate supporting unit, and a middle electrode disposed between the upper electrode and the lower electrode.

Abstract: Embodiments of process kits for use in a process chamber are provided herein. In some embodiments, a process kit for use in a process chamber includes: a chamber liner having a tubular body with an upper portion and a lower portion; a confinement plate coupled to the lower portion of the chamber liner and extending radially inward from the chamber liner, wherein the confinement plate includes a plurality of slots; a shield ring disposed within the chamber liner and movable between the upper portion of the chamber liner and the lower portion of the chamber liner; and a plurality of ground straps coupled to the shield ring at a first end of each ground strap of the plurality of ground straps and to the confinement plate at a second end of each ground strap to maintain electrical connection between the shield ring and the chamber liner when the shield ring moves.

Abstract: A plasma reactor includes: a process chamber, at the inner bottom of the process chamber being provided a base, the base being connected to a RF power source via a RF match network, wherein a to-be-processed wafer is held above the base, an upper electrode assembly is provided at the inner top of the process chamber, and a plasma processing space is arranged between the base and the upper electrode assembly; a first conductive ground ring surrounding the outer periphery of the base; a second conductive ground ring connected between the outer sidewall of the first conductive ground ring and the inner sidewall of the process chamber, a plurality of gas channels being provided on the second conductive ground ring such that gas in the plasma processing space can be exhausted through the plurality of gas channels; an insulating ring provided between the base and the first conductive ground ring, wherein dielectric constant of the insulating ring is less than 3.5.

Abstract: A capacitively coupled Plasma Enhanced Chemical Vapour Deposition (PE-CVD) apparatus has a chamber, a first electrode with a substrate support positioned in the chamber, a second electrode with a gas inlet structure positioned in the chamber, and an RF power source connected to the gas inlet structure for supplying RF power thereto. The gas inlet structure has an edge region, a central region which depends downwardly with respect to the edge region, and one or more precursor gas inlets for introducing a PE-CVD precursor gas mixture to the chamber. The edge region and the central region both constitute part of the second electrode. The precursor gas inlets are disposed in the edge region and the central region is spaced apart from the substrate support to define a plasma dark space channel.

Abstract: A substrate treating apparatus includes a housing, treating space and support unit to support a substrate, dielectric plate, gas supply unit, and plasma source to generate a plasma and including a top edge electrode above the edge region supported by the support unit and bottom edge electrode below the edge region supported by the support unit, which includes a support plate having an inner space and vacuum hole that communicates with the inner space and sucking the substrate on the top surface. A lift pin assembly can transfer the substrate between an outside transfer unit and the support plate. A decompression unit can apply negative pressure to the inner space. The lift pin assembly includes a base plate and through hole penetrating the base plate to provide negative pressure in a region under the base plate to a region over the base plate. Lift pins protrude from the base plate and support a bottom substrate surface. A driver can lift/lower the base plate within the inner space.

Abstract: In a shower plate, a plasma processing apparatus, and a plasma processing method, improvement of in-plane uniformity of plasma on a stage is required. The shower plate according to an exemplary embodiment includes an upper dielectric disposed to face a stage and an upper electrode embedded in the upper dielectric. A distance between a bottom surface of the upper dielectric and the upper electrode is shorter in a peripheral portion than in a central portion.

Abstract: A plasma etching apparatus may include a first source electrode, a first bias electrode, and a second bias electrode configured to generate a plasma by supplying energy to a process gas injected into a chamber; and a controller. The controller may be configured to supply a first high-frequency RF power, a first low-frequency RF power, and a second low-frequency RF power to the chamber during a first period from a first time to a second time; ramp down and turn off the first high-frequency RF power to the chamber during a second period from the second time to a third time; and ramp down and turn off the first low-frequency RF power to the chamber during a third period from the second time to a fourth time different from the third time. The third period may be smaller than ½ of the first period and greater than the second period.

Abstract: A shower plate includes a plate-shaped dielectric main body having gas holes, and a plurality of sealed areas formed in the dielectric main body. Each of the sealed areas has a permittivity lower than a permittivity of the dielectric main body. A volume density of the sealed areas at a central region of the dielectric main body is higher than a volume density of the sealed areas at a peripheral region of the dielectric main body.

Abstract: An electrostatic chuck according to an exemplary embodiment includes a first region and a second region. The first region has a first upper surface. The first region is configured to hold a substrate disposed on the first upper surface. The second region has a second upper surface. The second region extends in a circumferential direction to surround the first region. The second region is configured to support a focus ring mounted on the second upper surface. The first upper surface and the second upper surface extend along a single flat surface. The first region and the second region provide a space therebetween to separate the first upper surface and the second upper surface from each other.

Abstract: A disclosed plasma processing apparatus includes a chamber, a substrate support, an electric path, and a measuring device. The substrate support is accommodated in the chamber. The electric path is coupled to or capacitively coupled to an edge ring on the substrate support. The measuring device measures an electrical characteristic value of the edge ring with a voltage applied to the edge ring on the substrate support through the electric path. The electrical characteristic value measured by the measuring device is variable in accordance with a thickness of the edge ring.

Abstract: An edge ring includes a ramp surface of which a height decreases from an outer edge-side portion toward an inner edge-side portion. The edge ring is configured to satisfy the relation of T2/T1>T4/T3. Where, T1 is a thickness of the edge ring, before plasma treatment, at a first position on the ramp surface of the inner edge-side portion, and T2 is a thickness of the edge ring, before plasma treatment, at a second position on the ramp surface of the outer edge-side portion. T3 is a thickness of the edge ring, after plasma treatment, at the first position, and T4 is a thickness of the edge ring, after plasma treatment, at the second position.

Abstract: A plasma processing apparatus includes a processing chamber; a placing table disposed in the processing chamber to place a substrate thereon; an upper electrode facing the placing table; a member configured to adjust a temperature of the upper electrode; a first sensor provided within the member configured to adjust the temperature of the upper electrode, and configured to measure the temperature of the upper electrode; and a first sheet member, disposed between the upper electrode and the first sensor, having a relative dielectric constant of 2.4 or higher at a frequency of 1 MHz.

Abstract: The present disclosure is directed to an in situ closed-loop radio frequency (RF) power management on RF processes such as a plasma etch process, a plasma chemical vapor deposition process, a plasma physical vapor deposition process, a plasma clean process, or the like. An RF power measurement device according to one or more embodiments of the present disclosure assists the in situ closed-loop RF power management on RF processes. In some embodiments, the RF power measurement device includes a coil-shaped current sensor that is wound around the path between an RF generator and a chamber. The coil-shaped current sensor senses the current flowing through this path so that the power of the RF generator may be calibrated without having to separate the RF generator for separate analysis and calibration. The RF power measurement device allows management of RF power in an in situ closed-loop manner.

Abstract: Exemplary semiconductor processing chamber showerheads may include a dielectric plate characterized by a first surface and a second surface opposite the first surface. The dielectric plate may define a plurality of apertures through the dielectric plate. The dielectric plate may define a first annular channel in the first surface of the dielectric plate, and the first annular channel may extend about the plurality of apertures. The dielectric plate may define a second annular channel in the first surface of the dielectric plate. The second annular channel may be formed radially outward from the first annular channel. The showerheads may also include a conductive material embedded within the dielectric plate and extending about the plurality of apertures without being exposed by the apertures. The conductive material may be exposed at the second annular channel.

Abstract: A substrate processing apparatus includes a conductive enclosure having a gas passage, a conductive member having a gas passage, and a piping assembly including a hollow tube having an inner sidewall, a core block disposed in the hollow tube, the core block having an outer sidewall fitting the inner sidewall of the hollow tube, the core block having a first dielectric constant, and at least one dielectric member disposed in at least one of the hollow tube and the core block, the dielectric member having a second dielectric constant higher than the first dielectric constant.

Abstract: A capacitively coupled Plasma Enhanced Chemical Vapour Deposition (PE-CVD) apparatus has a chamber, a first electrode with a substrate support positioned in the chamber, a second electrode with a gas inlet structure positioned in the chamber, and an RF power source connected to the gas inlet structure for supplying RF power thereto. The gas inlet structure has an edge region, a central region which depends downwardly with respect to the edge region, and one or more precursor gas inlets for introducing a PE-CVD precursor gas mixture to the chamber. The edge region and the central region both constitute part of the second electrode. The precursor gas inlets are disposed in the edge region and the central region is spaced apart from the substrate support to define a plasma dark space channel.

Abstract: Disclosed is a plasma treatment apparatus that includes a cover attached to a body part, a plasma generation unit that generates plasma and provides the plasma to the cover, a gas supply unit that supplies a source gas for generating the plasma to the plasma generation unit, and an exhaust unit that exhausts an exhaust gas from the cover.

Abstract: A bevel etching apparatus includes a chuck plate that is configured to receive a substrate, a lower ring surrounding a circumference of the chuck plate, a cover plate on the chuck plate, and an upper ring surrounding a circumference of the cover plate. The lower ring includes a ring base and a protrusion that extends upwardly from an edge of the ring base and surrounds a lower portion of a sidewall of the substrate.

Abstract: A plasma processing apparatus includes an insertion member having a first surface facing a vacuum space, a second surface facing a non-vacuum space, and an insertion hole penetrating through the first and second surfaces. A pin is inserted into the insertion hole and moved vertically. A movable member is provided in a recess formed on a wall surface of the insertion hole facing the pin. The movable member has an opening into which the pin is inserted and is movable along a surface of the recess. A first sealing member is provided between the movable member and the pin. A second sealing member is provided between the movable body and the surface of the recess and allows, when a pressing force of the pin that locally compresses the first sealing member acts on the first sealing member, the movable member to move in a direction to release the pressing force.

Abstract: A deposition or cleaning apparatus including an outer vacuum chamber and a reaction chamber inside the outer chamber forming a double chamber structure.

Abstract: A plasma processing apparatus is for performing plasma processing in a depressurizable inner space. The apparatus includes a chamber having therein an inner space, a supporting table provided in the inner space and configured to support a substrate to be mounted thereon, one or more first members included in the chamber or separate from the chamber and partially exposed to a depressurized environment including the inner space, and one or more second members included in the chamber or separate from the chamber, each being in contact with a corresponding one of said one or more first members, and partially disposed in an atmospheric pressure environment. The apparatus further includes one or more feeders each of which is configured to supply a coolant to a cavity formed in a corresponding one of said one or more second members.

Abstract: The disclosure describes a plasma source assemblies comprising a differential screw assembly, an RF hot electrode, a top cover, an upper housing and a lower housing. The differential screw assembly is configured to provide force to align the plasma source assembly vertically matching planarity of a susceptor. More particularly, the differential screw assembly increases a distance between the top cover and the upper housing to align the gap with the susceptor. The disclosure also provides a better thermal management by cooling fins. A temperature capacity of the plasma source assemblies is extended by using titanium electrode. The disclosure provides a cladding material covering a portion of a first surface of RF hot electrode, a second surface of RF hot electrode, a bottom surface of RF hot electrode, a portion of a surface of the showerhead and a portion of lower housing surface.

Abstract: Polycrystalline silicon is produced in a chemical vapour deposition reactor, wherein, outside the reactor at at least one position on at least one reactor component, vibrations of the reactor are measured using a measurement device and optionally recorded. The vibrations may be used to identify rod fall over and other events occurring within the reactor.

Abstract: Apparatus and methods for providing high velocity gas flow showerheads for deposition chambers are described. The showerhead has a faceplate in contact with a backing plate that has a concave portion to provide a plenum between the backing plate and the faceplate. A plurality of thermal elements is within the concave portion of the backing plate and extends to contact the faceplate.

Abstract: A semiconductor device manufacturing system is provided. In one embodiment, a load lock chamber of the semiconductor device manufacturing system comprises an internal cavity, a substrate carrier, configured to support and deliver a substrate and a cooling gas inlet module arranged in the internal cavity and adjacent to a first side of the internal cavity. The cooling gas inlet module is configured to discharge a gas toward a second side of the internal cavity to cool down the substrate supported and delivered by the substrate carrier, wherein the second side. The second side is opposite to the first side.

Abstract: A coating apparatus and movable electrode arrangement, movable support arrangement, and application thereof are disclosed. The coating apparatus includes a reactor chamber body and a movable support arrangement. The reactor chamber body has a reactor chamber. The movable support arrangement is received in the reactor chamber and includes one or more electrodes and a movable support. The movable support is adapted for rotating relative to the reactor chamber body. At least one of the electrodes is arranged on the movable support so as for rotating together with the movable support. One or more workpieces to be coated are adapted for being held on the movable support to move together with the movable support.

Abstract: Embodiments described herein relate to methods and apparatus for performing immersion field guided post exposure bake processes. Embodiments of apparatus described herein include a chamber body defining a processing volume. Electrodes may be disposed adjacent the process volume and process fluid is provided to the process volume via a plurality of fluid conduits to facilitate immersion field guided post exposure bake processes. A post process chamber for rinsing, developing, and drying a substrate is also provided.

Abstract: A plasma processing method according to an embodiment is performed in a state in which a substrate is placed on a support stage in an internal space of a chamber body. In the plasma processing method, a plasma treatment is performed on the substrate. Subsequently, a phase of a voltage of a lower electrode is relatively adjusted with respect to a phase of a voltage of an upper electrode by a phase adjustment circuit, such that a thickness of a sheath between the support stage and plasma without extinguishing the plasma generated in order to perform the plasma treatment. Thereafter, in a state in which supply of a high-frequency power is stopped, gases and particles in the internal space of the chamber body are discharged using an exhaust device.

Abstract: According to some embodiments, a semiconductor substrate processing apparatus includes a housing, a plasma source unit, an electrostatic chuck, and a ring unit. The housing encloses a process chamber. The plasma source unit is connected to the housing, and includes a shower head and a fixing ring positioned to support the shower head. The shower head includes an upper electrode mounted on the fixing ring, and includes injection holes passing through part of the upper electrode and configured to inject gas into the chamber. The electrostatic chuck is connected to the housing and includes a lower electrode, and is for mounting a semiconductor substrate thereon. The ring unit is mounted on an edge portion of the electrostatic chuck, and includes a focus ring and a cover ring surrounding the focus ring. One of the lower electrode and the upper electrode is connected to a high frequency power supply, and the other of the lower electrode and the upper electrode is connected to ground.

Abstract: The present disclosure provides an apparatus including a chamber body and a lid defining a volume therein. The apparatus includes a substrate support disposed in the volume opposite the lid. The substrate support includes a support body disposed on a stem, and a ground plate disposed between the support body and the stem. A top flange is coupled to a lower peripheral surface the ground plate and a bottom flange is coupled to a bottom of the chamber body. The bottom flange and the top flange is coupled to one another with a plurality of straps, each of the straps having a first end coupled to the bottom flange and a second end coupled to the top flange.

Abstract: A plasma processing apparatus includes a process chamber having an inner space, an electrostatic chuck in the process chamber and to which a substrate is mounted, a gas injection unit to inject a process gas into the process chamber at a side of the process chamber, a plasma applying unit to transform the process gas injected into the process chamber into plasma, and a plasma adjusting unit disposed around the electrostatic chuck and operative to adjust the density of the plasma across the substrate.

Abstract: A substrate processing apparatus capable of preventing deflection of exhaust flow which may occur when an asymmetric exhaust structure is introduced includes: an exhaust unit providing an exhaust space surrounding a reaction space; an exhaust port connected to the exhaust unit; and a flow control unit disposed in the exhaust space, wherein the exhaust port is arranged asymmetrically with respect to the reaction space, and the flow control unit may include: an upper flow control plate including a plurality of first through holes; and a lower flow control plate disposed below the upper flow control plate and including a plurality of second through holes.

Abstract: A substrate processing apparatus includes a chamber, a susceptor provided in the chamber, a shower plate having a plate part provided with a plurality of through holes and formed of a conductor, a ring-shaped part connected to an outer edge of the plate part, surrounding the plate part and formed of a conductor and a lead wire embedded in the ring-shaped part and surrounding the plate part and the susceptor in plan view, the shower plate being provided so as to face the susceptor in the chamber, and a DC power supply that supplies a direct current to the lead wire.

Abstract: A plasma processing apparatus configured to perform plasma processing on a conductive workpiece having a flat plate shape includes: a conductive vacuum chamber having a recessed portion which is configured to cause a processing object portion of at least one side of the workpiece having a flat plate shape to be disposed in the recessed portion and a peripheral edge portion which is provided outside the recessed portion to be continuous with the recessed portion; a holding member configured to hold the workpiece to be separated and insulated from the peripheral edge portion; a voltage application unit configured to apply a voltage between the workpiece and the vacuum chamber; and an insulating layer configured to cover a portion of the peripheral edge portion facing the workpiece.

Abstract: Processing chambers with a plurality of processing stations and individual wafer support surfaces are described. The processing stations and wafer support surfaces are arranged so that there is an equal number of processing stations and heaters. An RF generator is connected to a first electrode in a first station and a second electrode in a second station. A bottom RF path is formed by a connection between the a first support surface and a second support surface.

Abstract: A plasma reactor includes a chamber body having an interior space that provides a plasma chamber, a gas distribution port to deliver a processing gas to the plasma chamber, a workpiece support to hold a workpiece, an antenna array comprising a plurality of monopole antennas extending partially into the plasma chamber, and an AC power source to supply a first AC power to the plurality of monopole antennas. The plurality of monopole antennas can extend through a first gas distribution plate. A grid filter can be positioned between the workpiece support and the plurality of monopole antennas.

Abstract: According to one embodiment, a substrate processing apparatus includes a table configured to place a substrate thereon and to connect the substrate to a positive electrode, an counter electrode located opposite to the table, having a plurality of holes, and connected to a negative electrode, and a holding unit located opposite to the table across the counter electrode and configured to supply a chemical liquid to the counter electrode while holding the counter electrode.

Abstract: A plasma confinement ring for a plasma chamber comprises a ring-shaped element and a cylindrical element. The ring-shaped element of the plasma confinement ring surrounds a substrate support assembly in the plasma chamber and is arranged along a plane in which a substrate is arranged on the substrate support assembly. The ring-shaped element includes a plurality of orifices. The cylindrical element of the plasma confinement ring extends from an outer edge of the ring-shaped element in a direction perpendicular to the plane in which the substrate is arranged on the substrate support assembly in the plasma chamber. The plasma confinement ring is monolithic.

Abstract: A process module including a chamber body having a lower chamber and an upper chamber is provided. The lower chamber is configured to mate with the upper chamber along a diagonal interface. An electrode assembly having a substrate support is provided. The electrode assembly is coupled to the upper chamber. A hinge connect couples a first side of the lower chamber to a first side of the upper chamber. The upper chamber is configured to split and open along the diagonal interface and rotate about the hinge connect. The electrode assembly is configured to rotate with the upper chamber in a direction that is away from the lower chamber.

Abstract: A showerhead assembly includes a support structure and a porous plate. The support structure includes a support feature. The porous plate has a thermal conductivity of at least about 50 W/(mK) and includes a plurality of pores having an average diameter of less than about 100 um, wherein at least a portion of a perimeter of the porous plate rests on the support feature. The showerhead may be included within a processing chamber that is utilized to process a substrate.

Abstract: A plasma etching method according to an exemplary embodiment comprises arranging a substrate on an electrostatic chuck in a region surrounded by a focus ring. The substrate, in a state of being held by the electrostatic chuck, is etched by means of ions from a plasma. The electrostatic chuck includes a plurality of electrodes including a first electrode and a second electrode. The first electrode extends under a central region of the substrate. The second electrode extends under an edge region of the substrate. A plurality of voltages are respectively applied to the plurality of electrodes, wherein the plurality of voltages are determined such that, in the state in which the substrate is held by the electrostatic chuck, the ions from the plasma are incident on both the central region and the edge region substantially vertically.

Abstract: A plasma processing method is provided that includes applying a radio frequency power to an upper electrode of a chamber, and performing a coating process by supplying a coating gas, including a carbon-containing gas, to an interior of the chamber to generate a plasma from the supplied coating gas, and coating the interior of the chamber with a carbon film using the plasma generated from the coating gas. The plasma processing method further includes performing an etching process after the coating process by supplying an etching gas, including a fluorocarbon-containing gas, to the interior of the chamber to generate a plasma from the supplied etching gas and etching a first silicon-containing film that is arranged on a second silicon-containing film covering an electrode formed on a workpiece using the plasma generated from the etching gas.

Abstract: A plasma processing apparatus includes a processing chamber, a high frequency power supply and a load variation stabilization circuit. The high frequency power supply is configured to supply a high frequency power to the processing chamber and generate plasma inside the processing chamber. The load variation stabilization circuit is connected in parallel with the processing chamber at a connection portion provided between the high frequency power supply and the processing chamber. The load variation stabilization circuit is configured to suppress variation in a load impedance when viewing a downstream side from the connection portion.

Abstract: Plasma source assemblies comprising an RF hot electrode having a body and at least one return electrode spaced from the RF hot electrode to provide a gap in which a plasma can be formed. An RF feed is connected to the RF hot electrode at a distance from the inner peripheral end of the RF hot electrode that is less than or equal to about 25% of the length of the RF hot electrode.

Abstract: A plasma processing apparatus includes a processing vessel, a lower electrode, an annular member, an inner upper electrode, an outer upper electrode, a processing gas supply, a first high frequency power supply and a first DC power supply. The lower electrode is configured to place a processing target substrate. The annular member is disposed on an outer peripheral portion of the lower electrode. The inner upper electrode is disposed to face the lower electrode. The outer upper electrode is disposed at an outside of the inner upper electrode. The first high frequency power supply applies a first high frequency power. The first DC power supply applies a first variable DC voltage to the outer upper electrode. At least a part of a surface of the outer upper electrode exposed to the processing space is located higher than a surface of the inner upper electrode exposed to the processing space.

Abstract: A lower plasma-exclusion-zone ring for a bevel etcher is provided that is configured to etch a bevel edge of a substrate. The lower plasma-exclusion-zone ring includes a ring-shaped body and a radially-outer stepped surface. The ring-shaped body of the lower plasma-exclusion-zone ring defines an upper surface, a lower surface, a radially inner surface, and a radially outer surface. The radially-outer stepped surface of the lower plasma-exclusion-zone ring extending inwardly into the ring-shaped body between the radially outer surface of the ring-shaped body and the upper surface of the ring-shaped body. The ring-shaped body is made of a material selected from a group consisting of aluminum oxide, aluminum nitride, silicon, silicon carbide, silicon nitride, and yttria.

Abstract: An upper plasma-exclusion-zone ring for a bevel etcher is provided that is configured to etch a bevel edge of a substrate. The upper plasma-exclusion-zone ring includes a ring-shaped body and a radially-inner stepped surface. The ring-shaped body of the upper plasma-exclusion-zone ring defines an upper surface, a lower surface, a radially inner surface, and a radially outer surface. The radially-inner stepped surface of the upper plasma-exclusion-zone ring extends inwardly into the ring-shaped body between the radially inner surface of the ring-shaped body and the lower surface of the ring-shaped body. The ring-shaped body is made of a material selected from a group consisting of aluminum oxide, aluminum nitride, silicon, silicon carbide, silicon nitride, and yttria.

Abstract: An electrostatic chuck assembly for processing a semiconductor substrate is provided. The electrostatic chuck assembly includes a first layer, a baseplate, a second layer, and at least one annular gasket. The first layer includes ceramic material and a first radio frequency (RF) electrode. The first RF electrode is embedded in the ceramic material. The second layer is disposed between the first layer and the baseplate. The at least one annular gasket extends along an upper surface of the baseplate and through the second layer. The at least one annular gasket electrically couples the upper surface of the baseplate to the first RF electrode. RF power passes from the baseplate to the first RF electrode through the at least one annular gasket.