# US 9,436,094 B2 · Stripping solution for photolithography and pattern formation method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,436,094 B2 - Document ID: US9436094B2 - Status: Granted - Kind: B2 - Application number: 14/026,407 - Filed: 2013-09-13 - Published: 2014-03-27 - Granted: 2016-09-06 - Earliest claimed: 2012-09-24 - Assignees: Tokyo Ohka Kogyo Co., Ltd. - Applicants: Tokyo Ohka Kogyo Co., Ltd. - Inventors: Naohisa Ueno; Daijiro Mori; Takayuki Haraguchi - Web page: https://patentgrep.com/patent/US9436094B2 ## CPC - G03F 7/425: {containing mineral alkaline compounds; containing organic basic compounds, e.g. quaternary ammonium compounds; containing heterocyclic basic compounds containing nitrogen} - G03F 7/426: {containing organic halogen compounds; containing organic sulfonic acids or salts thereof; containing sulfoxides} - 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) ## Abstract A stripping solution for photolithography which can effectively strip away residual materials of a photoresist pattern and etching residual materials, and has excellent anticorrosion properties on SiO2 and a variety of metal materials; and a method for forming a pattern using the stripping solution. A prescribed basic compound is used as a counter amine of the hydrofluoric acid contained in the stripping solution for photolithography, and the stripping solution for photolithography is adjusted to a pH measured at 23° C. of not more than 6.0 or 8.5 or more. ## Claims ### Claim 1 A stripping solution for photolithography comprising (A) hydrofluoric acid, (B) a basic compound represented by the following general formula (b-1), and (C) water, and having a pH at 23° C. of not more than 6.0, or 8.5 or more: wherein R1b to R5b each independently represent a hydrogen atom or an alkyl group having from 1 to 6 carbon atoms, which may be substituted with a hydroxyl group, a carboxyl group, an amino group, or a phosphonic acid group, provided that at least one of R1b to R5b represents a hydrogen atom, and one of R1b to R4b may bind with R5b to form a ring structure; Y1b and Y2b each independently represent an alkylene group having from 1 to 3 carbon atoms; n is an integer of from 1 to 5; and when n is 2 or greater, a plurality of R5bs may be the same as or different from each other, a plurality of Y1bs may be the same as or different from each other, and R5bs may bind with each other to form a ring structure, wherein a content of (B) the basic compound in the stripping solution is from 0.01 to 2.00% by mass. ### Claim 2 (depends on 1) The stripping solution for photolithography according to claim 1, further comprising (D) a pH adjuster. ### Claim 3 (depends on 1) The stripping solution for photolithography according to claim 1, further comprising (E) a water-soluble organic solvent. ### Claim 4 (depends on 1) The stripping solution for photolithography according to claim 1, wherein a ratio of the normality of the basic compound to the normality of the hydrofluoric acid is from 0.1 to 3.0. ### Claim 5 (depends on 1) The stripping solution for photolithography according to claim 1, wherein the stripping solution is used for forming a metal wiring pattern on a substrate provided with an insulating film made of SiO2. ### Claim 6 (depends on 1) The stripping solution for photolithography according to claim 1, wherein R1b to R5b each independently represent a hydrogen atom or an alkyl group having from 1 to 6 carbon atoms, which may be substituted with a hydroxyl group or an amino group. ### Claim 7 (depends on 1) The stripping solution for photolithography according to claim 1, wherein (B) the basic compound represented by the general formula (b-1) is a compound represented by the following general formula (b-2): wherein, Y1b, Y2b and n are as defined in the general formula (b-1). ### Claim 8 (depends on 1) A method of forming a pattern, comprising etching a substrate using a photoresist pattern provided on the substrate as a mask; then ashing the photoresist pattern; and thereafter stripping away residual materials of the photoresist pattern and etching residual materials using the stripping solution for photolithography according to claim 1. ### Claim 9 A stripping solution for photolithography comprising (A) hydrofluoric acid, (B) a basic compound represented by the following general formula (b-1), and (C) water and having a pH at 23° C. of not more than 6.0 or 8.5 or more: wherein R1b to R5b each independently represent a hydrogen atom or an alkyl group having from 1 to 6 carbon atoms, which may be substituted with a hydroxyl group, a carboxyl group, or an amino group, provided that at least one of R1b to R5b represents a hydrogen atom, and one of R1b to R4b may bind with R5b to form a ring structure; Y1b and Y2b each independently represent an alkylene group having from 1 to 3 carbon atoms; n is an integer of from 1 to 5; and when n is 2 or greater, a plurality of R5bs may be the same as or different from each other, a plurality of Y1bs may be the same as or different from each other, and R5bs may bind with each other to form a ring structure, and a content of (B) the basic compound in the stripping solution is from 0.01 to 2.00% by mass. ### Claim 10 (depends on 9) A method of forming a pattern, comprising etching a substrate using a photoresist pattern provided on the substrate as a mask; then ashing the photoresist pattern; and thereafter stripping away residual materials of the photoresist pattern and etching residual materials using the stripping solution for photolithography according to claim 9.