# US 12,603,256 B2 · Conductive member for cleaning focus ring of a plasma processing apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,603,256 B2 - Document ID: US12603256B2 - Status: Granted - Kind: B2 - Application number: 17/563,560 - Filed: 2021-12-28 - Published: 2023-03-09 - Granted: 2026-04-14 - Earliest claimed: 2021-12-28 - Assignees: Beijing E-Town Semiconductor Technology Co., Ltd.; Mattson Technology, Inc. - Applicants: Beijing E-Town Semiconductor Technology Co., Ltd.; Mattson Technology, Inc. - Inventors: Maolin Long; Changle Guan - Web page: https://patentgrep.com/patent/US12603256B2 ## CPC - H01J 37/32642: {Focus rings} - H01J 37/32715: {Workpiece holder} - H10P 72/72: using electrostatic chucks - H10P 72/722: {Details of electrostatic chucks} - H10P 72/7611: {characterised by edge profile or support profile} - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract A pedestal assembly is provided. The pedestal assembly includes an electrostatic chuck configured to support a workpiece. The pedestal assembly includes a focus ring have a top surface and a bottom surface. The focus ring can be configured to surround a periphery of the workpiece when the workpiece is positioned on the electrostatic chuck. The pedestal assembly includes a plurality of insulators. The pedestal assembly further includes a conductive member positioned between at least a portion of the bottom surface of the focus ring and at least a portion of one of the plurality of insulators. ## Claims ### Claim 1 A pedestal assembly comprising: an electrostatic chuck configured to support a workpiece, the electrostatic chuck defining a plurality of stepped surfaces, each of the plurality of stepped surfaces comprises a different horizontal depth; a focus ring having a top surface and a bottom surface, the focus ring configured to surround a periphery of the workpiece when the workpiece is positioned on the electrostatic chuck; an inner insulator ring configured to surround a portion of a periphery of the electrostatic chuck; an outer insulator ring configured to surround a periphery of the inner insulator ring, the electrostatic chuck, and a conductive member, the focus ring being on the outer insulator ring such that the bottom surface of the focus ring is on a top surface of the outer insulator ring; and the conductive member positioned vertically between at least a portion of the bottom surface of the focus ring, a top surface of the inner insulator ring, and positioned horizontally between a portion of the inner insulator ring and the outer insulator ring, the conductive member is spaced apart from the periphery of the electrostatic chuck along a first axis by a first distance and the conductive member is spaced apart from the periphery of the electrostatic chuck along a second axis by a second distance, the first axis intersecting with the second axis in a plane, and the first axis and the second axis forming an angle that differs from 90 degrees by less than 15 degrees. ### Claim 2 (depends on 1) The pedestal assembly of claim 1, wherein the conductive member comprises a semiconductor material. ### Claim 3 (depends on 1) The pedestal assembly of claim 1, wherein the conductive member comprises a metal. ### Claim 4 (depends on 1) The pedestal assembly of claim 1, wherein the first distance is different than the second distance. ### Claim 5 (depends on 1) The pedestal assembly of claim 1, wherein the first distance ranges from about 2 millimeters to about 5 millimeters. ### Claim 6 (depends on 1) The pedestal assembly of claim 1, wherein the conductive member comprises a conductive ring. ### Claim 7 (depends on 1) The pedestal assembly of claim 1, wherein the inner insulator ring comprises: a first portion positioned on a first stepped surface of the plurality of stepped surfaces; and a second portion positioned on a second stepped surface of the plurality of stepped surfaces. ### Claim 8 (depends on 1) The pedestal assembly of claim 1, wherein the conductive member is positioned between the stepped surface defined by the inner insulator ring and a first portion of the bottom surface of the focus ring. ### Claim 9 (depends on 8) The pedestal assembly of claim 8, wherein: the conductive member is spaced apart from the periphery of the electrostatic chuck along a first axis by a first distance; and the conductive member is spaced apart from the periphery of the electrostatic chuck along a second axis by a second distance, the second axis being substantially perpendicular to the first axis. ### Claim 10 (depends on 9) The pedestal assembly of claim 9, wherein the first distance is different than the second distance. ### Claim 11 A plasma processing apparatus comprising: a processing chamber; and a pedestal assembly disposed within the processing chamber, the pedestal assembly comprising: an electrostatic chuck configured to support a workpiece, the electrostatic chuck defining a plurality of stepped surfaces, each of the plurality of stepped surfaces comprises a different horizontal depth; a focus ring having a top surface and a bottom surface, the focus ring configured to surround a periphery of the workpiece when the workpiece is positioned on the electrostatic chuck; an inner insulator ring configured to surround a portion of a periphery of the electrostatic chuck; an outer insulator ring configured to surround a periphery of the inner insulator ring, the electrostatic chuck, and a conductive member, the focus ring being on the outer insulator ring such that the bottom surface of the focus ring is on a top surface of the outer insulator ring; and the conductive member positioned vertically between at least a portion of the bottom surface of the focus ring, a top surface of the inner insulator ring, and positioned horizontally between a portion of the inner insulator ring and the outer insulator ring, the conductive member is spaced apart from the periphery of the electrostatic chuck along a first axis by a first distance and the conductive member is spaced apart from the periphery of the electrostatic chuck along a second axis by a second distance, the first axis intersecting with the second axis in a plane, and the first axis and the second axis forming an angle that differs from 90 degrees by less than 15 degrees. ### Claim 12 (depends on 11) The plasma processing apparatus of claim 11, wherein the conductive member comprises a conductive ring.