# US 2022/0033710 A1 · Compositions and methods for selectively etching silicon nitride films > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2022/0033710 A1 - Document ID: US20220033710A1 - Status: Published application - Kind: A1 - Application number: 17/388,990 - Filed: 2021-07-29 - Published: 2022-02-03 - Earliest claimed: 2020-07-30 - Assignees: Entegris, Inc. - Applicants: Entegris, Inc. - Inventors: Steven M. BILODEAU; Emanuel I. COOPER; Daniela WHITE - Web page: https://patentgrep.com/patent/US20220033710A1 ## CPC - C09K 13/06: with organic material - C09K 13/08: containing a fluorine compound - H10P 14/69433: {the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz} - H10P 50/28: of insulating materials - H10P 50/282: {of inorganic materials} - H10P 50/283: {by chemical means} - H10P 50/642: {Chemical etching} - H10P 50/667: {by liquid etching only} - H10P 50/683: {of inorganic materials} - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract Provided are wet etching compositions and methods for etching a surface of a microelectronic device that contains silicon nitride (SiN), silicon oxide, and polysilicon which in one embodiment is in contact with a surface comprising a compound which is electrochemically more noble than silicon, and optionally other materials which may include a conductive material, a semiconducting material, or an insulating material useful in a microelectronic device, or a processing material that is useful in preparing a microelectronic device. ## Claims ### Claim 1 A method of etching silicon nitride on a microelectronic device substrate, said substrate comprising a surface comprising silicon nitride, a surface comprising silicon oxide, and a surface comprising polysilicon, the method comprising: providing an etching composition comprising: a. concentrated phosphoric acid, in an amount of at least 60 weight percent, based on the total weight of the composition; b. a polysilicon corrosion inhibitor compound; c. an aminoalkyl silanol; and d. optionally a fluorine compound; providing a substrate having a surface that comprises silicon nitride and a surface which comprises polysilicon, and contacting the substrate with the composition under conditions effective to etch silicon nitride. ### Claim 2 (depends on 1) The method of claim 1, wherein said surface comprising polysilicon is in contact with a surface comprising a composition which is more electrochemically noble than silicon. ### Claim 3 (depends on 2) The method of claim 2, wherein the surface comprising a composition which is more noble than silicon is chosen from tungsten silicide, nickel silicide, platinum silicide, and titanium silicide. ### Claim 4 (depends on 1) The method of claim 1, wherein the fluorine compound is present and is chosen from HF, ammonium fluoride, tetrafluoroboric acid, hexafluorosilicic acid, tetrabutylammonium tetrafluoroborate, tetra(C1-C6 alkyl)ammonium fluorides, and combinations thereof. ### Claim 5 (depends on 1) The method of claim 1, wherein the fluorine compound is flourosurfactant. ### Claim 6 (depends on 4) The method of claim 4, wherein the fluorine compound is HF. ### Claim 7 (depends on 1) The method of claim 1, wherein the aminoalkyl silanol is chosen from 3-aminopropylsilanetriol, N-(6-aminohexyl)aminopropylsilanol, 3-aminopropyltriethoxide and 3-aminopropyltrimethoxide and (3-trimethoxysilylpropyl) diethylenetriamine. ### Claim 8 (depends on 6) The method of claim 6, wherein the aminoalkyl silanol is formed in situ from an aminoalkoxy silane. ### Claim 9 (depends on 1) The method of claim 1, wherein the polysilicon corrosion inhibitor is chosen from linear and branched C8-C16 alkylbenzenesulfonic acids. ### Claim 10 (depends on 1) The method of claim 1, wherein the polysilicon corrosion inhibitor is chosen from C6-C16 alkyldiphenyl oxide disulfonic acids, C6-C16 alkyldiphenyl sulfide disulfonic acids, and C6-C16 alkyldiphenylamine disulfonic acids. ### Claim 11 (depends on 1) The method of claim 1, wherein the polysilicon corrosion inhibitor is chosen from hexyl diphenyl oxide disulfonic acid, dodecyl diphenyl oxide disulfonic acid, and dodecylbenzenesulfonic acid. ### Claim 12 (depends on 1) The method of claim 1, wherein the substrate is contacted with the composition at a temperature of about 130° to about 180° C. ### Claim 13 (depends on 1) The method of claim 1, wherein the composition is comprised of a. concentrated phosphoric acid, in an amount of at least 60 weight percent, based on the total weight of the composition; b. dodecylbenzenesulfonic acid; and c. 3-aminopropylsilanetriol. ### Claim 14 (depends on 1) The method of claim 1, wherein the composition is comprised of a. concentrated phosphoric acid, in an amount of at least 60 weight percent, based on the total weight of the composition; b. a C6-C16 alkyldiphenyl oxide disulfonic acid, C6-C16 alkyldiphenyl sulfide disulfonic acid, or C6-C16 alkyldiphenylamine disulfonic acid; and c. 3-aminopropylsilanetriol. ### Claim 15 (depends on 1) The method of claim 1, further comprising a fluorine compound. ### Claim 16 A composition comprising: a. concentrated phosphoric acid, in an amount of at least 60 weight percent, based on the total weight of the composition; b. a polysilicon corrosion inhibitor compound chosen from chosen from linear and branched C8-C16 alkylbenzenesulfonic acids, and C6-C16 alkyldiphenyl oxide disulfonic acids, C6-C16 alkyldiphenyl sulfide disulfonic acids, or C6-C16 alkyldiphenylamine disulfonic acids; and c. an aminoalkyl silanol. ### Claim 17 (depends on 15) The composition of claim 15, wherein the aminoalkyl silanol is chosen from 3-aminopropylsilanetriol, N-(6-aminohexyl)aminopropylsilanol, 3-aminopropyltriethoxide and 3-aminopropyltrimethoxide and (3-trimethoxysilylpropyl) diethylenetriamine. ### Claim 18 (depends on 15) The composition of claim 15, wherein the polysilicon corrosion inhibitor is chosen from hexyl diphenyl oxide disulfonic acid, dodecyl diphenyl oxide disulfonic acid, and dodecylbenzenesulfonic acid. ### Claim 19 (depends on 15) The composition of claim 15, further comprising a fluorine compound. ### Claim 20 (depends on 18) The composition of claim 18, wherein the fluorine compound is HF. ### Claim 21 (depends on 15) The composition of claim 15, comprising: a. concentrated phosphoric acid, in an amount of at least 60 weight percent, based on the total weight of the composition; b. dodecylbenzenesulfonic acid; and c. 3-aminopropylsilanetriol. ### Claim 22 (depends on 20) The composition of claim 20, further comprising HF. ### Claim 23 (depends on 1) A kit including, in one or more containers, one or more components a. through d., as claimed in claim 1.