# US 4,585,920 A · Plasma reactor removable insert > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,585,920 A - Document ID: US4585920A - Status: Granted - Kind: A - Application number: 06/658,468 - Filed: 1984-10-09 - Granted: 1986-04-29 - Earliest claimed: 1982-05-21 - Assignees: Tegal Corporation - Inventors: Josef T. Hoog; James W. Mitzel - Web page: https://patentgrep.com/patent/US4585920A ## CPC - H01J 37/32605: {Removable or replaceable electrodes or electrode systems} - H01J 37/32: Gas-filled discharge tubes (heating by discharge H05B) - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract An improved plasma reaction chamber is described in which the interior electrode is readily removed. The interior electrode may comprise a variety of materials, including metallized plastic, thus enabling a disposable electrode and a greater variety of plasmas to be used. ## Claims ### Claim 1 Planar RF plasma reactor apparatus comprising: a frame member having an aperture therein; a shell secured to said frame about said aperture; an upper electrode which fits within said shell, at least a portion of said electrode being electrically coupled to said shell; retaining means attached to said shell for holding said electrode in place; and wherein said aperture is larger than said electrode in at least one dimension for enbaling removal of said electrode through said aperture without separating said shell and said frame. ### Claim 2 (depends on 1) The aparatus of claim 1 wherein said electrode comprises metal. ### Claim 3 (depends on 2) The apparatus of claim 2 wherein said electrode is coated with a non-metallic layer on at least the major surface exposed to plasma. ### Claim 4 (depends on 3) The apparatus of claim 3 wherein said non-metallic layer comprises glass. ### Claim 5 (depends on 3) The apparatus of claim 3 wherein said non-metallic layer comprises a polymer. ### Claim 6 (depends on 1) The apparatus of claim 1 wherein said electrode comprises a non-metallic material coated with a metallic layer on at least the major surface exposed to plasma. ### Claim 7 (depends on 6) The apparatus of claim 6 wherein said electrode comprises a ceramic. ### Claim 8 (depends on 6) The apparatus of claim 6 wherein said electrode comprises a polymer. ### Claim 9 (depends on 1) The apparatus of claim 1 wherein said shell defines a first plenum having a plurality of passageways communicating therewith and defines a counterbore having a shoulder portion, wherein said electrode rests on and is located within said shell by said shoulder; and wherein said counterbore and said electrode defines a second plenum. ### Claim 10 (depends on 9) The apparatus as set forth in claim 9 wherein said electrode comprises a plurality of through-bores in the central portion thereof for communicating with said second plenum. ### Claim 11 (depends on 10) The apparatus as set forth in claim 10 wherein said electrode comprises a second plurality of through-bores about the periphery thereof for communicating with said passageway. ### Claim 12 (depends on 11) The apparatus as set forth in claim 11 wherein said electrode comprises a reduced thickness portion about the periphery thereof to define an annular chamber between said reduced thickness portion and said shell, said annular chamber interconnecting said passageway and said second plurality of through-bores. ### Claim 13 (depends on 9) The apparatus as set forth in claim 9 wherein said shoulder portion includes sealing means for engaging a major surface of said electrode thereby sealing said second plenum. ### Claim 14 (depends on 13) The apparatus as set forth in claim 13 wherein said retaining means comprises: a first ring of electrially non-conductive material for electrically isolating said electrode; a second ring, larger in diameter than said first ring and having a plurality of holes therethrough; and fastening means passing through said holes for attaching said second ring to said shell. ### Claim 15 (depends on 14) The apparatus as set forth in claim 14 wherein said frame comprises clearance means for access to said fastening means without separating said shell from said frame. ### Claim 16 (depends on 15) The apparatus as set forth in claim 15 wherein said shell includes second sealing means for engaging said electrode and said first ring, whereby said fastening means are outside the seal therebetween. ### Claim 17 (depends on 1) The plasma reactor apparatus as set forth in claim 1 and further comprising: non-metallic sealing means between said retaining means and said shell. ### Claim 18 An easily removed electrode for a planar RF plasma reactor comprising: a plain electrode member having a first and second major surfaces; said member defining a first and a second plurality of bores; said first plurality of bores extending from one major surface to the other, in a predetermined pattern in the central portion of said members, for gas flow in a first direction; a reduced thikcness portion about the periphery of said member; and said second pluraltiy of bores being disposed about the periphery of said member in said reduced thickness portion for gas flow in a second direction. ### Claim 19 (depends on 18) The electrode as set forth in claim 18 wherein said second plurality of bores extend through said reduced thickness portion. ### Claim 20 (depends on 19) The electrode as set forth in claim 19 wherein said second plurality of bores are distributed uniformly. ### Claim 21 (depends on 18) An electrode as set forth in claim 18 wherein said first plurality of bores comprise a reduced diameter portion at the exit end thereof.