# US 9,519,221 B2 · Method for microwave processing of photosensitive polyimides > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,519,221 B2 - Document ID: US9519221B2 - Status: Granted - Kind: B2 - Application number: 14/544,482 - Filed: 2015-01-12 - Published: 2015-07-16 - Granted: 2016-12-13 - Earliest claimed: 2014-01-13 - Assignees: Applied Materials, Inc. - Applicants: Applied Materials, Inc. - Inventors: Robert L. Hubbard; Iftikhar Ahmad - Web page: https://patentgrep.com/patent/US9519221B2 ## CPC - G03F 7/0387: {Polyamides or polyimides} - C08J 7/123: {Treatment by wave energy or particle radiation (C08J7/18 takes precedence)} - G03F 7/16: Coating processes; Apparatus therefor (applying coatings to base materials in general B05; applying photosensitive compositions to base for photographic purposes G03C1/74) - G03F 7/20: Exposure; Apparatus therefor (photographic printing apparatus for making copies G03B27/00) - G03F 7/26: Processing photosensitive materials; Apparatus therefor (G03F7/12 - G03F7/24 take precedence) - G03F 7/38: Treatment before imagewise removal, e.g. prebaking {(G03F7/265 takes precedence)} - G03F 7/40: Treatment after imagewise removal, e.g. baking - H10P 14/6529: {by exposure to a gas or vapour} - H10P 14/683: {carbon-based polymeric organic materials, e.g. polyimides, poly cyclobutene or PVC} - H10P 50/28: of insulating materials - B05D 3/029: {with microwaves} - B05D 3/06: by exposure to radiation (B05D3/02 takes precedence {; plasma treatment B05D3/141}) - B05D 2505/50: Polyimides - C08J 2379/04: Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors - C08J 2379/08: Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors - G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G) - C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29) - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - B05D: PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL (conveying articles or workpieces through baths of liquid B65G, e.g. B65G49/02) ## Abstract A method for curing photosensitive polyimide (PSPI) films includes the steps of: depositing a PSPI film on a selected substrate, and curing the film by microwave heating at a selected temperature from about 200 to 340° C. in a selected atmosphere containing an oxygen concentration from about 20 to 200,000 ppm. The process atmosphere may be static or flowing. The addition of oxygen improves the removal of acrylate residue and improves the Tg of the cured film, while the low processing temperature characteristic of the microwave process prevents the oxygen from damaging the polyimide backbone. The method may further include the steps of photopatterning and developing the PSPI film prior to curing. The process is particularly suitable for dielectric films on silicon for electronic applications. ## Claims ### Claim 1 A method for curing photopolymer films comprising the steps of: depositing a photopolymer film on a selected substrate; and, curing the photopolymer film by microwave heating for a selected time at a selected temperature from about 200 to about 340° C. in a selected atmosphere containing an oxygen concentration in the range from about 20 to 200,000 ppm, wherein the oxygen concentration is maintained by at least one of supplying a known amount of oxygen gas (O2) to the atmosphere or adjusting the pressure of the atmosphere. ### Claim 2 (depends on 1) The method of claim 1, wherein the photopolymer is a photosensitive polyimide (PSPI). ### Claim 3 (depends on 2) The method of claim 2 wherein the PSPI comprises a polyamic acid (PAA) precursor resin modified with a photosensitive methacrylate alcohol to form a photosensitive polyamic ester (PAE). ### Claim 4 (depends on 3) The method of claim 3 wherein the methacrylate alcohol comprises one or more compositions in the methacrylate family (R—CH2CH2OC(O)CH═C(CH3)2) of monomers and oligomers, where R indicates any selected organic moiety attached at the indicated position. ### Claim 5 (depends on 2) The method of claim 2 wherein the selected time is from about 60 to about 180 minutes. ### Claim 6 (depends on 2) The method of claim 2 wherein the selected temperature ranges from about 200 to about 275° C. ### Claim 7 (depends on 2) The method of claim 2 wherein the selected atmosphere contains an oxygen concentration in the range from about 200 to 200,000 ppm. ### Claim 8 (depends on 1) The method of claim 1, wherein the photopolymer is a polybenzoxazole (PBO). ### Claim 9 A method for curing photopolymer films comprising the steps of: depositing a photopolymer film on a selected substrate; photopatterning the photopolymer film; developing the photopatterned photopolymer film; and, curing the developed photopolymer film by microwave heating for a selected time at a selected temperature from about 200 to 340° C. in a selected atmosphere containing an oxygen concentration from about 20 to 200,000 ppm, wherein the oxygen concentration is maintained by at least one of supplying a known amount of oxygen gas to the atmosphere or adjusting the pressure of the atmosphere. ### Claim 10 (depends on 9) The method of claim 9, wherein the photopolymer is a photosensitive polyimide (PSPI). ### Claim 11 (depends on 10) The method of claim 10 wherein the PSPI comprises a polyamic acid (PAA) precursor resin modified with a photosensitive methacrylate alcohol to form a photosensitive polyamic ester (PAE). ### Claim 12 (depends on 11) The method of claim 11 wherein the methacrylate alcohol comprises one or more compositions in the methacrylate family (R—CH2CH2OC(O)CH═C(CH3)2) of monomers and oligomers, where R indicates any selected organic moiety attached at the indicated position. ### Claim 13 (depends on 10) The method of claim 10 wherein the selected time is from about 60 to about 180 minutes. ### Claim 14 (depends on 10) The method of claim 10 wherein the selected temperature ranges from about 200 to about 275° C. ### Claim 15 (depends on 10) The method of claim 10 wherein the selected atmosphere contains an oxygen concentration in the range from about 200 to 200,000 ppm. ### Claim 16 (depends on 9) The method of claim 9, wherein the photopolymer is a polybenzoxazole (PBO).