Patent application number | Description | Published |
20080257261 | PLASMA PROCESSING APPARATUS - Embodiments of the present invention relate to plasma processing apparatus and methods of use thereof. In some embodiments, a plasma control magnet assembly includes a plurality of magnets arranged in a predetermined pattern that generate a magnetic field having a strength greater than 10 Gauss in a region proximate the assembly and less than 10 Gauss in a region remote from the assembly. | 10-23-2008 |
20080260966 | PLASMA PROCESSING METHOD - Embodiments of the present invention relate to plasma processing apparatus and methods of use thereof. In some embodiments, a method of controlling a plasma in a process chamber includes providing a chamber for processing a substrate and having a processing volume defined therein wherein a plasma is to be formed during operation, the chamber further having a plasma control magnet assembly comprising a plurality of magnets that provide a magnetic field having a magnitude is greater than about 10 Gauss in an upper region of the processing volume and less than about 10 Gauss in a lower region of the processing volume proximate a substrate to be processed; supplying a process gas to the chamber; and forming a plasma in the processing volume from the process gas. | 10-23-2008 |
20080314522 | APPARATUS AND METHOD TO CONFINE PLASMA AND REDUCE FLOW RESISTANCE IN A PLASMA REACTOR - An apparatus configured to confine a plasma within a processing region in a plasma processing chamber. In one embodiment, the apparatus includes a ring that has a baffle having a plurality of slots and a plurality of fingers. Each slot is configured to have a width less than the thickness of a plasma sheath contained in the processing region. | 12-25-2008 |
20080314571 | ANNULAR BAFFLE - A baffle assembly for an etching apparatus is disclosed. The baffle assembly comprises a ring and a lower baffle portion having a curved wall extending between a flange portion and a lower frame portion. A heating assembly may be present within the lower frame portion to control the temperature of the baffle. The baffle assembly may help confine the plasma within the processing space in the chamber. The ring may comprise silicon carbide and the lower baffle portion may comprise aluminum. | 12-25-2008 |
20090025878 | PLASMA REACTOR WITH REDUCED ELECTRICAL SKEW USING ELECTRICAL BYPASS ELEMENTS - RF ground return current flow is diverted away from asymmetrical features of the reactor chamber by providing bypass current flow paths. One bypass current flow path avoids the pumping port in the chamber floor, and comprises a conductive symmetrical grill extending from the side wall to the grounded pedestal base. Another bypass current flow path avoids the wafer slit valve, and comprises an array of conductive straps bridging the section of the sidewall occupied by the slit valve. | 01-29-2009 |
20090025879 | PLASMA REACTOR WITH REDUCED ELECTRICAL SKEW USING A CONDUCTIVE BAFFLE - RF ground return current flow is diverted away from asymmetrical features of the reactor chamber by providing a bypass current flow path. The bypass current flow path avoids the pumping port in the chamber floor and avoids the wafer slit valve, and is provided by a conductive annular baffle grounded to and extending from the wafer pedestal. Current flow below the level of the annular baffle can be blocked by providing one or more insulating rings in the sidewall or by providing a dielectric sidewall. | 01-29-2009 |
20090081876 | METHOD OF PREVENTING ETCH PROFILE BENDING AND BOWING IN HIGH ASPECT RATIO OPENINGS BY TREATING A POLYMER FORMED ON THE OPENING SIDEWALLS - High aspect ratio contact openings are etched while preventing bowing or bending of the etch profile by forming a highly conductive thin film on the side wall of each contact opening. The conductivity of the thin film on the side wall is enhanced by ion bombardment carried out periodically during the etch process. | 03-26-2009 |
20090140828 | METHODS AND APPARATUS FOR CONTROLLING CHARACTERISTICS OF A PLASMA - Methods and apparatus for controlling characteristics of a plasma, such as the spatial distribution of RF power and plasma uniformity, are provided herein. In some embodiments, an apparatus for controlling characteristics of a plasma includes a resonator for use in conjunction with a plasma reactor, the resonator including a source resonator for receiving an RF signal having a first frequency; a return path resonator disposed substantially coaxially with, and at least partially within, the source resonator; and an outer conductor having the source resonator and the return path resonator disposed substantially coaxially with, and at least partially within, the outer conductor, the outer conductor for providing an RF ground connection. | 06-04-2009 |
20090159566 | METHOD AND APPARATUS FOR CONTROLLING TEMPERATURE OF A SUBSTRATE - A pedestal assembly and method for controlling temperature of a substrate during processing is provided. In one embodiment, method for controlling a substrate temperature during processing includes placing a substrate on a substrate pedestal assembly in a vacuum processing chamber, controlling a temperature of the substrate pedestal assembly by flowing a heat transfer fluid through a radial flowpath within the substrate pedestal assembly, the radial flowpath including both radially inward and radially outward portions, and plasma processing the substrate on the temperature controlled substrate pedestal assembly. In another embodiment, plasma processing may be at least one of a plasma treatment, a chemical vapor deposition process, a physical vapor deposition process, an ion implantation process or an etch process, among others. | 06-25-2009 |
20090179085 | HEATED SHOWERHEAD ASSEMBLY - The present invention generally comprises a heated showerhead assembly that may be used to supply processing gases into a processing chamber. The processing chamber may be an etching chamber. When processing gas is evacuated from the processing chamber, the uniform processing of the substrate may be difficult. As the processing gas is pulled away from the substrate and towards the vacuum pump, the plasma, in the case of etching, may not be uniform across the substrate. Uneven plasma may lead to uneven etching. To prevent uneven etching, the showerhead assembly may be separated into two zones each having independently controllable gas introduction and temperature control. The first zone corresponds to the perimeter of the substrate while the second zone corresponds to the center of the substrate. By independently controlling the temperature and the gas flow through the showerhead zones, etching uniformity of the substrate may be increased. | 07-16-2009 |
20090188624 | METHOD AND APPARATUS FOR ENHANCING FLOW UNIFORMITY IN A PROCESS CHAMBER - Methods and apparatus for processing substrates are provided herein. In some embodiments, an apparatus for processing a substrate may include a process chamber having an inner volume and an exhaust system coupled thereto, wherein the exhaust system includes a plurality of first conduits, each first conduit having an inlet adapted to receive exhaust from the inner volume of the process chamber. A pumping plenum is coupled to each of the plurality of first conduits. The pumping plenum has a pumping port adapted to pump the exhaust from the chamber. The conductance between each inlet of the plurality of first conduits and the pumping port is substantially equivalent. | 07-30-2009 |
20090188625 | ETCHING CHAMBER HAVING FLOW EQUALIZER AND LOWER LINER - A plasma processing chamber having a lowered flow equalizer and a lower chamber liner. In an etching process, the processing gases may be unevenly drawn from the processing chamber which may cause an uneven etching of the substrate. By equalizing the flow of the processing gases evacuated from the chamber, a more uniform etching may occur. By electrically coupling the flow equalizer to the chamber liners, the RF return path from the flow equalizer may run along the chamber liners and hence, reduce the amount of plasma drawn below the substrate during processing. | 07-30-2009 |
20090230089 | ELECTRICAL CONTROL OF PLASMA UNIFORMITY USING EXTERNAL CIRCUIT - A method and apparatus for controlling plasma uniformity is disclosed. When etching a substrate, a non-uniform plasma may lead to uneven etching of the substrate. Impedance circuits may alleviate the uneven plasma to permit more uniform etching. The impedance circuits may be disposed between the chamber wall and ground, the showerhead and ground, and the cathode can and ground. The impedance circuits may comprise one or more of an inductor and a capacitor. The inductance of the inductor and the capacitance of the capacitor may be predetermined to ensure the plasma is uniform. Additionally, the inductance and capacitance may be adjusted during processing or between processing steps to suit the needs of the particular process. | 09-17-2009 |
20100065213 | ETCHING CHAMBER HAVING FLOW EQUALIZER AND LOWER LINER - A plasma processing chamber having a lowered flow equalizer and a lower chamber liner. In an etching process, the processing gases may be unevenly drawn from the processing chamber which may cause an uneven etching of the substrate. By equalizing the flow of the processing gases evacuated from the chamber, a more uniform etching may occur. By electrically coupling the flow equalizer to the chamber liners, the RF return path from the flow equalizer may run along the chamber liners and hence, reduce the amount of plasma drawn below the substrate during processing. | 03-18-2010 |
20100300621 | METHOD OF COOLING A WAFER SUPPORT AT A UNIFORM TEMPERATURE IN A CAPACITIVELY COUPLED PLASMA REACTOR - A method of transferring heat from or to a workpiece support in an RF coupled plasma reactor includes placing coolant in an internal flow channel that is located inside the workpiece support and transferring heat from or to the coolant by circulating the coolant through a refrigeration loop in which the internal flow channel of the workpiece support constitutes an evaporator of the refrigeration loop. The method further includes maintaining thermal conditions of the coolant inside the evaporator within a range in which heat exchange between the workpiece support and the coolant is primarily or exclusively through the latent heat of vaporization of the coolant. | 12-02-2010 |
20100303680 | CAPACITIVELY COUPLED PLASMA REACTOR HAVING VERY AGILE WAFER TEMPERATURE CONTROL - A plasma reactor for processing a workpiece includes a reactor chamber, an electrostatic chuck within the chamber having a top surface for supporting a workpiece and having indentations in the top surface that form enclosed gas flow channels whenever covered by a workpiece resting on the top surface. The reactor further includes thermal control apparatus thermally coupled to the electrostatic chuck, an RF plasma bias power generator coupled to apply RF power to the electrostatic chuck, a pressurized gas supply of a thermally conductive gas, a controllable gas valve coupling the pressurized gas supply to the indentations to facilitate filling the channels with the thermally conductive gas for heat transfer between a backside of a workpiece and the electrostatic chuck at a heat transfer rate that is a function of the pressure against the backside of the workpiece of the thermally conductive gas. The reactor further includes an agile workpiece temperature control loop including (a) a temperature probe in the electrostatic chuck, and (b) a backside gas pressure controller coupled to an output of the temperature probe and responsive to a specified desired temperature, the controller governing the gas valve in response to a difference between the output of the temperature probe and the desired temperature. | 12-02-2010 |
20100314046 | PLASMA REACTOR WITH A MULTIPLE ZONE THERMAL CONTROL FEED FORWARD CONTROL APPARATUS - A plasma reactor having a reactor chamber and an electrostatic chuck having a surface for holding a workpiece inside the chamber includes inner and outer zone backside gas pressure sources coupled to the electrostatic chuck for applying a thermally conductive gas under respective pressures to respective inner and outer zones of a workpiece-surface interface formed whenever a workpiece is held on the surface, and inner and outer evaporators inside respective inner and outer zones of the electrostatic chuck and a refrigeration loop having respective inner and cuter expansion valves for controlling flow of coolant through the inner and outer evaporators respectively. The reactor further includes inner and outer zone temperature sensors in inner and outer zones of the electrostatic chuck and a thermal model capable of simulating heat transfer through the inner and outer zones, respectively, between the evaporator and the surface based upon measurements from the inner and outer temperature sensors, respectively. Inner and outer zone agile control processors coupled to the thermal model govern the inner and outer zone backside gas pressure sources, respectively, in response to predictions from the model of changes in the respective pressures that would bring the temperatures measured by the inner and outer zone sensors, respectively, closer to a desired temperature. | 12-16-2010 |
20100319851 | PLASMA REACTOR WITH FEED FORWARD THERMAL CONTROL SYSTEM USING A THERMAL MODEL FOR ACCOMMODATING RF POWER CHANGES OR WAFER TEMPERATURE CHANGES - A plasma reactor having a reactor chamber and an electrostatic chuck with a surface for holding a workpiece inside the chamber includes a backside gas pressure source coupled to the electrostatic chuck for applying a thermally conductive gas under a selected pressure into a workpiece-surface interface formed whenever a workpiece is held on the surface and an evaporator inside the electrostatic chuck and a refrigeration loop having an expansion valve for controlling flow of coolant through the evaporator. The reactor further includes a temperature sensor in the electrostatic chuck and a memory storing a schedule of changes in RF power or wafer temperature. The reactor further includes a thermal model capable of simulating heat transfer between the evaporator and the surface based upon measurements from the temperature sensor, and a control processor coupled to the thermal model and to the memory and governing the backside gas pressure source in response to a prediction from the model of a change in the selected pressure that would compensate for the next scheduled change in RF power or implement the next scheduled change in wafer temperature. | 12-23-2010 |
20100319852 | CAPACITIVLEY COUPLED PLASMA REACTOR HAVING A COOLED/HEATED WAFER SUPPORT WITH UNIFORM TEMPERATURE DISTRIBUTION - A plasma reactor for processing a workpiece includes a reactor chamber, an electrostatic chuck within the chamber for supporting a workpiece, an RF plasma bias power generator coupled to apply RF power to the electrostatic chuck and a refrigeration loop having an evaporator inside the electrostatic chuck with a refrigerant inlet and a refrigerant outlet. Preferably, the evaporator includes a meandering passageway distributed in a plane beneath a top surface of the electrostatic chuck. Preferably, refrigerant within the evaporator is apportioned between a vapor phase and a liquid phase. As a result, heat transfer between the electrostatic chuck and the refrigerant within the evaporator is a constant-temperature process. This feature improves uniformity of temperature distribution across a diameter of the electrostatic chuck. | 12-23-2010 |
20110065279 | METHOD OF PROCESSING A WORKPIECE IN A PLASMA REACTOR USING FEED FORWARD THERMAL CONTROL - A method of processing a workpiece in a plasma reactor having an electrostatic chuck for supporting the workpiece within a reactor chamber, the method including circulating a coolant through a refrigeration loop that includes an evaporator inside the electrostatic chuck, while pressurizing a workpiece-to-chuck interface with a thermally conductive gas, sensing conditions in the chamber including temperature near the workpiece and simulating heat flow through the electrostatic chuck in a thermal model of the chuck based upon the conditions. The method further includes obtaining the next scheduled change in RE heat load on the workpiece and using the model to estimate a change in thermal conditions of the coolant in the evaporator that would hold the temperature nearly constant by compensating for the next scheduled change in RF heat load, and making the change in thermal conditions of the coolant in the evaporator prior to the time of the next scheduled change by a head start related to the thermal propagation delay through the electrostatic chuck. | 03-17-2011 |
20110068085 | METHOD OF PROCESSING A WORKPIECE IN A PLASMA REACTOR USING MULTIPLE ZONE FEED FORWARD THERMAL CONTROL - A method of controlling wafer temperature in a plasma reactor by obtaining the next scheduled change in RF heat load on the workpiece, and using thermal modeling to estimate respective changes in wafer backside gas pressure and in coolant flow through a wafer support pedestal that would compensate for the next scheduled change in RF heat load, and making the respective changes in the backside gas pressure or in the coolant flow prior to the time of the next scheduled change. | 03-24-2011 |
20110180233 | APPARATUS FOR CONTROLLING TEMPERATURE UNIFORMITY OF A SHOWERHEAD - An apparatus for controlling thermal uniformity of a substrate-facing surface of a showerhead is provided herein. In some embodiments, the thermal uniformity of the substrate facing surface of the showerhead may be controlled to be more uniform. In some embodiments, the thermal uniformity of the substrate facing surface of the showerhead may be controlled to be non-uniform in a desired pattern. In some embodiments, an apparatus for controlling thermal uniformity of a substrate-facing surface of a showerhead may include a showerhead having a substrate facing surface and one or more plenums for providing one or more process gases through a plurality of gas distribution holes formed through the substrate facing surface of the showerhead; and a plurality of flow paths having a substantially equivalent fluid conductance disposed within the showerhead to flow a heat transfer fluid. | 07-28-2011 |
20110180243 | APPARATUS FOR CONTROLLING TEMPERATURE UNIFORMITY OF A SUBSTRATE - Apparatus for controlling thermal uniformity of a substrate is provided herein. In some embodiments, the thermal uniformity of the substrate may be controlled to be more uniform. In some embodiments, the thermal uniformity of the substrate may be controlled to be non-uniform in a desired pattern. In some embodiments, an apparatus for controlling thermal uniformity of a substrate may include a substrate support having a support surface to support a substrate thereon; and a plurality of flow paths having a substantially equivalent fluid conductance disposed within the substrate support to flow a heat transfer fluid beneath the support surface. | 07-28-2011 |
20110303641 | TEMPERATURE CONTROLLED PLASMA PROCESSING CHAMBER COMPONENT WITH ZONE DEPENDENT THERMAL EFFICIENCIES - Components and systems for controlling a process or chamber component temperature as a plasma process is executed by plasma processing apparatus. A first heat transfer fluid channel is disposed in a component subjacent to a working surface disposed within a plasma processing chamber such that a first length of the first channel subjacent to a first temperature zone of the working surface comprises a different heat transfer coefficient, h, or heat transfer area, A, than a second length of the first channel subjacent to a second temperature zone of the working surface. In embodiments, different heat transfer coefficients or heat transfer areas are provided as a function of temperature zone to make more independent the temperature control of the first and second temperature zones. | 12-15-2011 |
20120091104 | MULTI-ZONED PLASMA PROCESSING ELECTROSTATIC CHUCK WITH IMPROVED TEMPERATURE UNIFORMITY - An electrostatic chuck assembly including a dielectric layer with a top surface to support a workpiece. A cooling channel base disposed below the dielectric layer includes a plurality of inner fluid conduits disposed beneath an inner portion of the top surface, and a plurality of outer fluid conduits disposed beneath an outer portion of the top surface. A chuck assembly includes a thermal break disposed within the cooling channel base between the inner and outer fluid conduits. A chuck assembly includes a fluid distribution plate disposed below the cooling channel base and the base plate to distribute a heat transfer fluid delivered from a common input to each inner or outer fluid conduit. The branches of the inner input manifold may have substantially equal fluid conductance. | 04-19-2012 |
20120193456 | GAS DISTRIBUTION PLATE WITH DISCRETE PROTECTIVE ELEMENTS - Embodiments of the present invention provide a gas distribution plate assembly having protective elements for plasma processing. The gas distribution plate assembly includes a base plate having a front side and a backside, and a plurality of protective elements in direct contact with the base plate. The protective elements cover the front side of the base plate to protect the base plate from a plasma processing environment during use. | 08-02-2012 |
20130008604 | METHOD AND APPARATUS FOR ENHANCING FLOW UNIFORMITY IN A PROCESS CHAMBER - Methods and apparatus for processing substrates are provided herein. In some embodiments, an apparatus for processing a substrate may include a process chamber having an inner volume and an exhaust system coupled thereto, wherein the exhaust system includes a plurality of first conduits, each first conduit having an inlet adapted to receive exhaust from the inner volume of the process chamber. A pumping plenum is coupled to each of the plurality of first conduits. The pumping plenum has a pumping port adapted to pump the exhaust from the chamber. The conductance between each inlet of the plurality of first conduits and the pumping port is substantially equivalent. | 01-10-2013 |
20130098553 | ELECTRON BEAM PLASMA SOURCE WITH PROFILED CHAMBER WALL FOR UNIFORM PLASMA GENERATION - A plasma reactor that generates plasma in a workplace processing chamber by an electron beam, has an electron beam source chamber with a wall opposite to the electron beam propagation direction, the wall being profiled to compensate for a non-uniformity in electron beam density distribution. | 04-25-2013 |
20130098555 | ELECTRON BEAM PLASMA SOURCE WITH PROFILED CONDUCTIVE FINS FOR UNIFORM PLASMA GENERATION - In a plasma reactor employing a planar electron beam as a plasma source, the electron beam source chamber has an internal conductive fin that is profiled along a direction transverse to the beam propagation diction and parallel to the plane of the electron beam, in order to correct electron beam density distribution. | 04-25-2013 |
20130098873 | OVERHEAD ELECTRON BEAM SOURCE FOR PLASMA ION GENERATION IN A WORKPIECE PROCESSING REGION - A plasma reactor has a main chamber for processing a workpiece in a processing region bounded between an overhead ceiling and a workpiece support surface, the reactor having an overhead electron beam source that produces an electron beam flowing into the processing region through the ceiling of the main chamber. | 04-25-2013 |
20130098883 | ELECTRON BEAM PLASMA SOURCE WITH PROFILED MAGNET SHIELD FOR UNIFORM PLASMA GENERATION - A plasma reactor employs an e-beam source to generate plasma, and the e-beam source has a configurable magnetic shield. | 04-25-2013 |
20130105085 | PLASMA REACTOR WITH CHAMBER WALL TEMPERATURE CONTROL | 05-02-2013 |
20130118686 | TEMPERATURE CONTROLLED CHAMBER LINER - A liner for a semiconductor processing chamber and a semiconductor processing chamber are provided. In one embodiment, a liner for a semiconductor processing chamber includes a body having an outwardly extending flange. A plurality of protrusions extend from a bottom surface of the flange. The protrusions have a bottom surface defining a contact area that is asymmetrically distributed around the bottom surface of the flange. | 05-16-2013 |
20130284369 | TWO-PHASE OPERATION OF PLASMA CHAMBER BY PHASE LOCKED LOOP - Plasma distribution is controlled in a plasma reactor by controlling the phase difference between opposing RF electrodes, in accordance with a desired or user-selected phase difference, by a phase-lock feedback control loop. | 10-31-2013 |
20130284372 | ESC COOLING BASE FOR LARGE DIAMETER SUBSRATES - Embodiments include a base for an electrostatic chuck (ESC) assembly for supporting a workpiece during a manufacturing operation in a processing chamber, such as a plasma etch, clean, deposition system, or the like. Inner and outer fluid conduits are disposed in the base to conduct a heat transfer fluid. In embodiments, a counter-flow conduit configuration provides improved temperature uniformity. The conduit segments in each zone are interlaced so that fluid flows are in opposite directions in radially adjacent segments. In embodiments, each separate fluid conduit formed in the base comprises a channel formed in the base with a cap e-beam welded to a recessed lip of the channel to make a sealed conduit. To further improve the thermal uniformity, a compact, tri-fold channel segment is employed in each of the outer fluid loops. In further embodiments, the base includes a multi-contact fitting RF and DC connection, and thermal breaks. | 10-31-2013 |
20130315795 | PLASMA REACTOR GAS DISTRIBUTION PLATE WITH RADIALLY DISTRIBUTED PATH SPLITTING MANIFOLD - In a showerhead assembly, a path splitting manifold comprises a gas supply inlet and a planar floor and plural gas outlets extending axially through the floor and azimuthally distributed about the floor. The path splitting manifold further comprises a plurality of channels comprising plural paths between the inlet and respective ones of the plural outlets. A gas distribution showerhead underlies the floor of the manifold and is open to the plural outlets. In certain embodiments, the plural paths are of equal lengths. | 11-28-2013 |
20140083978 | TEMPERATURE CONTROLLED PLASMA PROCESSING CHAMBER COMPONENT WITH ZONE DEPENDENT THERMAL EFFICIENCES - Components and systems for controlling a process or chamber component temperature as a plasma process is executed by plasma processing apparatus. A first heat transfer fluid channel is disposed in a component subjacent to a working surface disposed within a plasma processing chamber such that a first length of the first channel subjacent to a first temperature zone of the working surface comprises a different heat transfer coefficient, h, or heat transfer area, A, than a second length of the first channel subjacent to a second temperature zone of the working surface. In embodiments, different heat transfer coefficients or heat transfer areas are provided as a function of temperature zone to make more independent the temperature control of the first and second temperature zones. | 03-27-2014 |
20140130926 | ANNULAR BAFFLE - A baffle assembly for an etching apparatus is disclosed. The baffle assembly comprises a ring and a lower baffle portion having a curved wall extending between a flange portion and a lower frame portion. A heating assembly may be present within the lower frame portion to control the temperature of the baffle. The baffle assembly may help confine the plasma within the processing space in the chamber. The ring may comprise silicon carbide and the lower baffle portion may comprise aluminum. | 05-15-2014 |
20140346743 | MULTI-ZONED PLASMA PROCESSING ELECTROSTATIC CHUCK WITH IMPROVED TEMPERATURE UNIFORMITY - An electrostatic chuck assembly including a dielectric layer with a top surface to support a workpiece. A cooling channel base disposed below the dielectric layer includes a plurality of inner fluid conduits disposed beneath an inner portion of the top surface, and a plurality of outer fluid conduits disposed beneath an outer portion of the top surface. A chuck assembly includes a thermal break disposed within the cooling channel base between the inner and outer fluid conduits. A chuck assembly includes a fluid distribution plate disposed below the cooling channel base and the base plate to distribute a heat transfer fluid delivered from a common input to each inner or outer fluid conduit. The branches of the inner input manifold may have substantially equal fluid conductance. | 11-27-2014 |
20150053794 | HEATED SHOWERHEAD ASSEMBLY - The present disclosure generally comprises a heated showerhead assembly that may be used to supply processing gases into a processing chamber. The processing chamber may be an etching chamber. When processing gas is evacuated from the processing chamber, the uniform processing of the substrate may be difficult. As the processing gas is pulled away from the substrate and towards the vacuum pump, the plasma, in the case of etching, may not be uniform across the substrate. Uneven plasma may lead to uneven etching. To prevent uneven etching, the showerhead assembly may be separated into two zones each having independently controllable gas introduction and temperature control. The first zone corresponds to the perimeter of the substrate while the second zone corresponds to the center of the substrate. By independently controlling the temperature and the gas flow through the showerhead zones, etching uniformity of the substrate may be increased. | 02-26-2015 |