# US 7,744,769 B2 · Gas for removing deposit and removal method using same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,744,769 B2 - Document ID: US7744769B2 - Status: Granted - Kind: B2 - Application number: 11/543,968 - Filed: 2006-10-06 - Published: 2007-02-08 - Granted: 2010-06-29 - Earliest claimed: 1997-12-18 - Assignees: Central Glass Company, Limited - Inventors: Isamu Mouri; Tetsuya Tamura; Mitsuya Ohashi - Web page: https://patentgrep.com/patent/US7744769B2 ## CPC - C03C 15/00: Surface treatment of glass, not in the form of fibres or filaments, by etching (etching or surface-brightening compositions, in general C09K13/00) - C03C 17/00: Surface treatment of glass, not in the form of fibres or filaments, by coating (optical coatings of optical elements G02B1/10) - C09K 13/00: Etching, surface-brightening or pickling compositions (for glass C03C15/00, {C03C25/66; for mortars, concrete, artificial or natural stone or ceramics C04B41/5338}; for metallic material C23F, C23G1/00, C25F1/00; {for semi-conductors H10P52/40}) - C23F 4/00: Processes for removing metallic material from surfaces, not provided for in group C23F1/00 or C23F3/00 - H10P 50/267: {using plasmas} - H10P 50/283: {by chemical means} - C03C 2218/33: by etching - Y10S 438/905: Cleaning of reaction chamber - Y10S 438/906: Cleaning of wafer as interim step - C03C: CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - C23F: NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE (working metal by laser beams B23K26/00; desurfacing by applying flames B23K7/00; working of metal by electro-erosion B23H; producing decorative effects by removing surface material, e.g. by engraving, by etching, B44C1/22; electrolytic etching or polishing C25F); INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25 - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract The invention relates to a gas for removing deposits by a gas-solid reaction. This gas includes a hypofluorite that is defined as being a compound having at least one OF group in the molecule. Various deposits can be removed by the gas, and the gas can easily be made unharmful on the global environment after the removal of the deposits, due to the use of a hypofluorite. The gas may be a cleaning gas for cleaning, for example, the inside of an apparatus for producing semiconductor devices. This cleaning gas comprises 1-100 volume % of the hypofluorite. Alternatively, the gas of the invention may be an etching gas for removing an unwanted portion of a film deposited on a substrate. The unwanted portion can be removed by this etching gas as precisely as originally designed, due to the use of a hypofluorite. The invention further relates to a method for removing a deposit by the gas. This method includes the step (a) bringing the gas into contact with the deposit, thereby to remove the deposit by a gas-solid reaction. ## Claims ### Claim 1 A method for removing a portion of a film deposited on a substrate for producing thin film devices, said method comprising bringing an etching gas into contact with said portion of said film, thereby removing said portion by a gas-solid reaction, wherein said etching gas comprises a hypofluorite and at least one first gas component selected from the group consisting of hydrogen, CH4, NH3, HI, HBr, C2H2, and HCl, and a ratio by volume of said hypofluorite to said at least one first gas component is at least 1:10, wherein said film is made of SiO2, and said substrate is made of Si. ### Claim 2 (depends on 1) A method according to claim 1, wherein said hypofluorite is a compound having at least one OF group in the molecule and optionally having at least one group selected from the group consisting of halogen atoms, ether groups, alcohol groups, carbonyl groups, carboxyl groups, ester groups, amine groups, and amide groups. ### Claim 3 (depends on 1) A method according to claim 1, wherein said etching gas further comprises an inert gas. ### Claim 4 (depends on 1) A method according to claim 1, wherein said etching gas further comprises at least one second gas component selected from the group consisting of oxygen and oxygen-containing gases. ### Claim 5 (depends on 4) A method according to claim 4, wherein said oxygen-containing gases are selected from the group consisting of CO, NO, N2O and NO2. ### Claim 6 (depends on 4) A method according to claim 4, wherein a volume ratio of said hypofluorite to said at least one second as component is at least 1:4. ### Claim 7 (depends on 1) A method according to claim 1, wherein said etching gas has a pressure from 0.001 Torr to 5 Torr. ### Claim 8 (depends on 1) A method according to claim 1, wherein said etching gas is at a temperature of not higher than 400° C. ### Claim 9 (depends on 1) A method according to claim 1, wherein said etching gas has a flow rate of from 10 to 10,000 standard cubic centimeters per minute. ### Claim 10 (depends on 2) A method according to claim 2, wherein said hypofluorite is selected from the group consisting of CF3OF, CF2(OF)2, CF3CF2OF, CH3COOF, (CF3)3COF, CF2HCF2OF, (CF3CF2)(CF3)2COF, CH3OF, CFH2OF, CF2HOF, CF3CF2CF2OF, and (CF3)2CFOF. ### Claim 11 (depends on 10) A method according to claim 10, wherein said hypofluorite is selected from the group consisting of CF3OF, CF2(OF)2, CF3CF2OF, CH3COOF, (CF3)3COF, CF2HCF2OF, (CF3CF2)(CF3)2COF, CH3OF, CFH2OF, CF3CF2CF2OF, and (CF3)2CFOF. ### Claim 12 (depends on 11) A method according to claim 11, wherein said hypofluorite is selected from the group consisting of CF3OF, CF2(OF)2, CF3CF2OF, (CF3)3COF, (CF3CF2)(CF3)2COF, CF3CF2CF2OF, and (CF3)2CFOF. ### Claim 13 (depends on 1) A method according to claim 1, wherein said at least one first gas component is selected from the group consisting of hydrogen, NH3, HI, HBr, C2H2, and HCl. ### Claim 14 (depends on 1) A method according to claim 1, wherein said hypofluorite is selected from the group consisting of CF3OF, CF2HOF, CFH2OF, and CF2(OF)2. ### Claim 15 (depends on 1) A method according to claim 1, wherein said hypofluorite is CF3OF. ### Claim 16 (depends on 1) A method according to claim 1, wherein said at least one first gas component is selected from the group consisting of hydrogen, CH4, NH3, and HCl.