# US 5,708,556 A · Electrostatic chuck assembly > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,708,556 A - Document ID: US5708556A - Status: Granted - Kind: A - Application number: 08/500,480 - Filed: 1995-07-10 - Granted: 1998-01-13 - Earliest claimed: 1995-07-10 - Assignees: Watkins-Johnson Company - Inventors: Ron van Os; Eric D. Ross - Web page: https://patentgrep.com/patent/US5708556A ## CPC - H10P 72/0432: {mainly by conduction} - C23C 16/4586: {Elements in the interior of the support, e.g. electrodes, heating or cooling devices} - H02N 13/00: Clutches or holding devices using electrostatic attraction, e.g. using Johnson-Rahbek effect - H10P 72/72: using electrostatic chucks - Y10T 279/23: with magnetic or electrostatic means - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) - H02N: ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract An electrostatic support system for retaining a wafer. The support system generally includes a support body having a support surface for retaining said wafer, a voltage source coupled to the support body for electrostatically coupling the wafer to the support surface, and a cooling system for cooling the wafer. A plurality of arm members extend from the support body to a carriage assembly for releasably mounting the support body to the processing chamber with the support body and the arm members separated from the chamber floor. This invention also includes the method of supporting a wafer in a processing chamber which includes the steps of positioning the wafer on a wafer supporting surface, applying a voltage to an electrode assembly to electrostatically attract the wafer to the support surface and, after processing the wafer, substantially grounding the electrode assembly to sufficiently deactivate the electrostatic charge for release of the wafer from the support surface. ## Claims ### Claim 1 An electrostatic support system for supporting a wafer comprising: a support body positionable in a processing chamber and having a support surface for retaining said wafer, said support body including protective means for preventing catastrophic separation of said wafer from said support surface, a voltage source coupled to said support surface for electrostatically coupling said wafer to said support surface, and a cooling system for cooling said wafer, said cooling system including a source of a gaseous substance, a plurality of gas distribution grooves formed in said support surface and configured for uniformly distributing a gaseous substance between said wafer and said support surface, and a conduit connecting said gas source to said gas distribution grooves for flow of said gaseous substance from said gas source to said gas distribution grooves, said conduit including an inner plenum coupled to said gas source and an outer plenum coupled to said gas distribution grooves, and said protective means including means for restricting the flow of said gaseous substance between said inner plenum and said outer plenum. ### Claim 2 (depends on 1) The support system of claim 1 in which said gas distribution grooves divide said support surface into a plurality of segments having a substantially uniform surface area. ### Claim 3 (depends on 2) The support system of claim 2 in which said segments have a substantially planar surface. ### Claim 4 (depends on 2) The support system of claim 2 in which said segments each have a surface area of about 1.5 to 2.5 square inches. ### Claim 5 (depends on 1) The support system of claim 1 in which said gas distribution grooves have a depth of about 0.015 inch and a width of about 0.062 inch. ### Claim 6 (depends on 1) The support system of claim 1 in which said gas distribution grooves have a substantially curved cross-sectional shape. ### Claim 7 (depends on 1) The support system of claim 1 in which said flow restricting means controls the flow of said gaseous substance between said inner plenum and said outer plenum at a rate such that when a portion of said wafer becomes separated from said support surface, the pressure of said gaseous substance in said gas distribution rings and said inner plenum is insufficient to disengage the remainder of said wafer from said support surface. ### Claim 8 An electrostatic support system for supporting a wafer comprising; a support body positionable in a processing chamber and having a support surface for retaining said wafer, said support surface having a plurality of circumferentially spaced holes formed therethrough, said support body including protective means for preventing catastrophic separation of said wafer from said support surface; a voltage source coupled to said support surface for electrostatically coupling said wafer to said support surface; a cooling system for cooling said wafer, said cooling system including a source of a gaseous substance, a plurality of gas distribution grooves formed in said support surface and configured for uniformly distributing a gaseous substance between said wafer and said support surface, and a conduit connecting said gas source to said gas distribution grooves for flow of said gaseous substance from said gas source to said gas distribution grooves, said conduit including a plurality of passageways each coupled to one of said holes extending through said support surface; a lifting mechanism for moving said wafer relative to said support surface, said lifting mechanism including a plurality of vertically extending lifting pins each extending through a different one of said holes formed through said support surface, said lifting pins being movable relative to said support surface between an extended position with said lifting pins extending through said hole in said support surface for supporting said wafer above said support surface and a retracted position with said lifting pins retracted beneath said support surface; said conduit including an inner plenum coupled to said gas source and an outer plenum coupled to said gas distribution grooves, and said protective means including means for restricting the flow of said gaseous substance between said inner plenum and said outer plenum. ### Claim 9 An electrostatic support system for supporting a wafer comprising: a support body positionable in a processing chamber and having a support surface for retaining said wafer, said support surface having a plurality of circumferentially spaced holes formed therethrough, a voltage source coupled to said support surface for electrostatically coupling said wafer to said support surface, a cooling system for cooling said wafer, said cooling system including a source of a gaseous substance, a plurality of gas distribution grooves formed in said support surface and configured for uniformly distributing a gaseous substance between said wafer and said support surface, and a conduit connecting said gas source to said gas distribution grooves for flow of said gaseous substance from said gas source to said gas distribution grooves, said conduit including a plurality of passageways each coupled to one of said holes extending through said support surface, each of said passageways is formed with at least one flow restriction for restricting the flow of said gaseous substance between said gas distribution grooves and said gas source, and a lifting mechanism for moving said wafer relative to said support surface, said lifting mechanism including a plurality of vertically extending lifting pins each extending through a different one of said holes formed through said support surface, said lifting pins being movable relative to said support surface between an extended position with said lifting pins extending through said hole in said support surface for supporting said wafer above said support surface and a retracted position with said lifting pins retracted beneath said support surface. ### Claim 10 An electrostatic support system for retaining a wafer in a processing chamber having a chamber wall and a bottom, said support system comprising: a body portion having a support surface for retaining said wafer, a plurality of arm members extending outwardly from said body portion for supporting said body portion in said processing chamber with said body portion and said arm members spaced from the bottom of said chamber, and means for applying a charge to said support surface for electrostatically coupling said wafer to said support surface. ### Claim 11 (depends on 10) The support system of claim 10, and further comprising a carriage assembly mountable to said chamber, said arm members being mounted to said carriage assembly. ### Claim 12 (depends on 10) The support system of claim 10 in which said arm members are mountable to said chamber wall of said processing chamber. ### Claim 13 (depends on 12) The support system of claim 12 in which said chamber wall includes a plurality of side wall portions and in which said arm members are positioned on said body portion such that when said support system is installed in said processing chamber, said arm portions are mounted to one of said side wall portions. ### Claim 14 (depends on 10) The support system of claim 10 in which said support system includes two of said arm members. ### Claim 15 (depends on 10) The support system of claim 10 in which said means for applying a charge includes a voltage source remote from said body portion and at least one electrical connector coupled to said voltage source and extending through a passageway formed in one of said arm members. ### Claim 16 (depends on 10) The support system of claim 10 in which said means for applying a charge includes at least one electrode carded by said body portion and an electrode cooling system for cooling said electrode, said electrode cooling system including a liquid source remote from said body portion and a conduit extending through a passageway formed in one of said arm members. ### Claim 17 (depends on 16) The support system of claim 16 in which said means for applying a charge includes at least one electrical connector extending through a passageway formed in another of said arm members. ### Claim 18 (depends on 10) The support system of claim 10, and further comprising biasing means for applying an RF bias to said body portion. ### Claim 19 (depends on 18) The support system of claim 18 in which said biasing means includes a source remote from said body portion and at least one electrical connector extending through a passageway in one of said arm members. ### Claim 20 (depends on 10) The support system of claim 10, and further comprising a wafer cooling system for cooling said wafer. ### Claim 21 (depends on 20) The support system of claim 20 in which said wafer cooling system includes a source of a gaseous substance and a conduit coupling said gaseous substance source to said support surface, said conduit extending through a passageway formed in one of said arm members. ### Claim 22 (depends on 21) The support system of claim 21 in which said wafer cooling system includes a plurality of gas distribution grooves formed in said support surface. ### Claim 23 (depends on 21) The support system of claim 21 in which said support body includes protective means for preventing catastrophic separation of said wafer from said support surface. ### Claim 24 (depends on 23) The support system of claim 23 in which said conduit includes an inner plenum coupled to said gas source and an outer plenum coupled to said support surface, and in which said protective means includes means for restricting the flow of said gaseous substance between said inner plenum and said outer plenum. ### Claim 25 (depends on 21) The support system of claim 21 in which said conduit includes at least one hole extending through said support surface. ### Claim 26 (depends on 21) The support system of claim 21 in which said body portion includes at least one lifting member movable relative to said support surface between an extended position with said lifting member extending through said hole in said support surface for supporting said wafer above said support surface and a retracted position with said lifting member retracted beneath said support surface.