# US 2008/0122367 A1 · Apparatus and method for plasma processing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2008/0122367 A1 - Document ID: US20080122367A1 - Status: Published application - Kind: A1 - Application number: 11/606,813 - Filed: 2006-11-29 - Published: 2008-05-29 - Earliest claimed: 2006-11-29 - Assignees: FOI Corporation - Inventors: Georgy K. Vinogradov; Vladimir M. Menagarishvili - Web page: https://patentgrep.com/patent/US20080122367A1 ## CPC - H05H 1/46: using applied electromagnetic fields, e.g. high frequency or microwave energy (H05H1/26 takes precedence) - H01J 37/321: {the radio frequency energy being inductively coupled to the plasma} - H01J 37/32174: {Circuits specially adapted for controlling the RF discharge} - H05H: PLASMA TECHNIQUE (apparatus or processes specially adapted for producing X-rays H05G2/00); PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract The present invention discloses an apparatus for plasma processing comprising of a chamber for plasma processing with an external wall, and at least one induction coil for providing a radio frequency induction field that is adjacent to the chamber. It further includes an end terminal of the induction coil that is connected to a radio frequency power supply, another end terminal of the induction coil that is open-ended, and a grounded terminal of the induction coil that is located at substantially central position of the induction coil. ## Claims ### Claim 1 An apparatus for plasma processing, comprising: a chamber for plasma processing with an external wall; at least one inductor for providing a radio frequency induction field that is adjacent to the chamber; an end terminal of the inductor that is connected to a radio frequency power supply; another end terminal of the inductor that is open-ended; and a grounded terminal of the inductor that is located at substantially central position of the inductor. ### Claim 2 (depends on 1) An apparatus for plasma processing as set forth in claim 1, wherein: the inductor is capacitively symmetric with respect to the central position. ### Claim 3 (depends on 2) An apparatus for plasma processing as set forth in claim 2, wherein: capacitance to plasma caused by the inductor between one end terminal and the grounded terminal, and capacitance to plasma of the inductor between the grounded terminal and another end terminal are substantially same. ### Claim 4 (depends on 1) An apparatus for plasma processing as set forth in claim 1, wherein: the inductor is geometrically symmetric with respect to the central position. ### Claim 5 (depends on 1) An apparatus for plasma processing as set forth in claim 1, wherein: the inductor is a cylindrical spiral coil. ### Claim 6 (depends on 1) An apparatus for plasma processing as set forth in claim 1, wherein: the inductor is a flat spiral coil. ### Claim 7 (depends on 1) An apparatus for plasma processing as set forth in claim 1, wherein: the chamber is dome-shape and the inductor is dome-shaped spiral coil. ### Claim 8 (depends on 1) An apparatus for plasma processing as set forth in claim 1, wherein: a plurality of the inductors is provided. ### Claim 9 (depends on 1) An apparatus for plasma processing as set forth in claim 1, wherein: the chamber comprising a flat roof made of dielectric or semiconductor material. ### Claim 10 (depends on 9) An apparatus for plasma processing as set forth in claim 9 wherein: the flat roof has at least one pair of an inside ring groove and an outside ring groove which is coaxial and adjacent to the inside ring groove. ### Claim 11 (depends on 10) An apparatus for plasma processing as set forth in claim 10 wherein: each of the inductors is inserted in each of the outer ring grooves. ### Claim 12 (depends on 8) An apparatus for plasma processing as set forth in claim 8 wherein: each of the radio frequency power supplies is provided by each of separate independently controlled RF generators. ### Claim 13 (depends on 10) An apparatus for plasma processing as set forth in claim 10 wherein: a plurality of gas inlets are penetrating at upper bottom of the inside grooves for providing process gases to the inside grooves. ### Claim 14 (depends on 8) An apparatus for plasma processing as set forth in claim 8 wherein: each of the radio frequency power supplies is provided by a single RF generator with a power splitter. ### Claim 15 (depends on 1) An apparatus for plasma processing as set forth in claim 1 wherein: the end terminal that is open-ended is connected to a relay switch connected to ground. ### Claim 16 An apparatus for plasma processing, comprising: a cylindrical chamber for plasma processing with an external wall; a gas inlet for introducing process gas into the cylindrical chamber; at least one induction coil for providing a radio frequency induction field that is cylindrical spiral and adjacently surrounds a part of the cylindrical chamber; an end terminal of the induction coil that is connected to a radio frequency power supply; another end terminal of the induction coil that is open-ended; and a grounded terminal of the induction coil that is located at geometrically central position of the induction coil. ### Claim 17 A method for plasma processing, comprising: generating plasma by an apparatus, comprising: a chamber for plasma processing with an external wall; at least one inductor for providing a radio frequency induction field that is adjacent to the chamber; an end terminal of the inductor that is connected to a radio frequency power supply; another end terminal of the inductor that is open-ended, a grounded terminal of the inductor that is located at substantially central position of the inductor; and processing a workpiece by using the plasma in the chamber.