# US 5,344,536 A · Method of and apparatus for processing a workpiece in plasma > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,344,536 A - Document ID: US5344536A - Status: Granted - Kind: A - Application number: 07/984,518 - Filed: 1992-12-02 - Granted: 1994-09-06 - Earliest claimed: 1991-12-03 - Assignees: Tokyo Ohka Kogyo Co., Ltd. - Inventors: Kazuto Obuchi; Satoshi Oya; Mitsuaki Minato; Akira Uehara; Kazutoshi Fujisawa; Kazuhisa Takao - Web page: https://patentgrep.com/patent/US5344536A ## CPC - H01J 37/32192: {Microwave generated discharge (H01J37/32357, H01J37/32366, H01J37/32394, H01J37/32403 take precedence)} - C23C 16/511: using microwave discharges - H01J 37/32623: {Mechanical discharge control means} - H01J 37/3266: {Magnetic control means} - H01J 37/32678: {Electron cyclotron resonance} - H01J 37/32706: {Polarising the substrate} - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) - 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) ## Abstract An electron cyclotron resonance plasma chemical vapor deposition system has a reaction chamber for introducing a reaction gas therein, the reaction chamber housing a table for supporting a semiconductor wafer. A microwave oscillator is connected to the reaction chamber through a waveguide for generating and introducing a microwave into the reaction chamber to produce a plasma in the reaction chamber for activating the reaction gas to etch or deposit a film on the semiconductor wafer in the reaction chamber. A pair of upper and lower coils is disposed around the reaction chamber for generating respective magnetic fields in opposite directions in the reaction chamber. The magnetic fields cancel out each other creating a region with substantially no flux density in the magnetic fields between the coils. A bias voltage is applied to the table to attract the plasma to the table in a uniform manner. ## Claims ### Claim 1 An apparatus for processing a workpiece in a plasma, comprising: a reaction chamber adapted to have a reaction gas introduced therein and exhausted therefrom; microwave generating means for generating and introducing a microwave into said reaction chamber to produce a plasma therein for activating the reaction gas to process a workpiece in said reaction chamber; and magnetic field generating means for generating a magnetic field in said reaction chamber while creating a region with substantially no flux density in said magnetic field wherein said plasma is uniformly applied to said workpiece. ### Claim 2 (depends on 1) An apparatus according to claim 1, wherein said magnetic field generating means comprises a pair of upper and lower coils for jointly generating said magnetic field, said region being positioned between said upper and lower coils. ### Claim 3 (depends on 2) An apparatus according to claim 2, wherein said lower coil is flatter than said upper coil. ### Claim 4 (depends on 1) An apparatus according to claim 1, further comprising a table disposed in said reaction chamber inside of said lower coil for supporting the workpiece thereon. ### Claim 5 (depends on 4) An apparatus according to claim 4, further comprising means for applying a bias voltage to said table. ### Claim 6 (depends on 4) An apparatus according to claim 4, further comprising a ring disposed around said table. ### Claim 7 (depends on 4) An apparatus according to claim 4, wherein said magnetic field generating means comprises a pair of upper and lower coils for jointly generating said magnetic field, and said table is positioned in a region below said lower coil where there is substantially no flux density. ### Claim 8 (depends on 2) An apparatus according to claim 2, wherein said upper and lower coils are energized to produce respective magnetic fields in opposite directions. ### Claim 9 An apparatus for processing a semiconductor device in a plasma, comprising: a reaction chamber for introducing a reaction gas therein; a table disposed in said reaction chamber for supporting a semiconductor device thereon; a microwave oscillator connected to said reaction chamber for generating and introducing a microwave into said reaction chamber to produce a plasma in said reaction chamber for activating the reaction gas to process the semiconductor device in said reaction chamber; magnetic means disposed around said reaction chamber for generating a magnetic field in said reaction chamber while creating a region with substantially no flux density in said magnetic field wherein said plasma is uniformly applied to said workpiece; and biasing means for applying a bias voltage to said table. ### Claim 10 (depends on 9) An apparatus according to claim 9, wherein said magnetic means comprises a pair of coils for generating respective oppositely directed magnetic fields which are combined into said magnetic field in said reaction chamber, said pair of coils being adapted to generate said oppositely directed magnetic fields such that they cancel out each other to create said region between said coils. ### Claim 11 (depends on 10) An apparatus according to claim 10, wherein one of said coils is flatter than the other of said coils. ### Claim 12 (depends on 11) An apparatus according to claim 11, wherein said table is positioned in a region below said one of the coils where there is substantially no flux density. ### Claim 13 (depends on 9) An apparatus according to claim 9, further comprising a ring disposed around said table. ### Claim 14 A method of processing a workpiece in a plasma, comprising the steps of: introducing a reaction gas into a reaction chamber; introducing a microwave into said reaction chamber to produce a plasma therein for activating the reaction gas; processing a workpiece supported on a table in said reaction chamber with the activated reaction gas; and generating a magnetic field in said reaction chamber while creating a region with substantially no flux density in said magnetic field wherein said plasma is uniformly applied to said workpiece. ### Claim 15 (depends on 14) A method according to claim 14, further comprising the step of: applying a bias voltage to said table. ### Claim 16 (depends on 14) A method according to claim 14, wherein said step of generating a magnetic field in said reaction chamber comprises generating oppositely directed magnetic fields which are combined into said magnetic field in said reaction chamber, said oppositely directed magnetic fields canceling out each other to create said region with substantially no flux density. ### Claim 17 A method of processing a workpiece in a plasma, comprising the steps of: introducing a reaction gas in a reaction chamber; introducing a microwave into said reaction chamber to produce a plasma therein for activating the reaction gas; processing a workpiece supported on a table in said reaction chamber with the activated reaction gas; and energizing a pair of coils disposed around said reaction chamber to generate respective magnetic fields in opposite directions in said reaction chamber, said magnetic fields cancelling out each other creating a region with substantially no flux density in said magnetic fields between said coils wherein said plasma is uniformly applied to said workpiece. ### Claim 18 (depends on 17) A method according to claim 17, further comprising the step of: applying a bias voltage to said table. ### Claim 19 (depends on 15) A method according to claim 15, comprising further a step of: electrically isolating said table from ground. ### Claim 20 (depends on 18) A method according to claim 18, comprising further a step of: electrically isolating said table from ground.