# US 8,772,170 B2 · Enhanced stripping of implanted resists > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,772,170 B2 - Document ID: US8772170B2 - Status: Granted - Kind: B2 - Application number: 12/981,073 - Filed: 2010-12-29 - Published: 2012-03-01 - Granted: 2014-07-08 - Earliest claimed: 2010-09-01 - Assignees: Arizona Board of Regents on Behalf of the University of Arizona - Applicants: Srini Raghavan; Rajkumar Govindarajan; Manish Keswani - Inventors: Srini Raghavan; Rajkumar Govindarajan; Manish Keswani - Web page: https://patentgrep.com/patent/US8772170B2 ## CPC - H10P 50/287: {by chemical means} - G03F 7/423: {containing mineral acids or salts thereof, containing mineral oxidizing substances, e.g. peroxy compounds} - G03F 7/428: {using ultrasonic means only} - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - 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 benign all-wet process for stripping photoresist after an implantation process performed to fabricate a device is provided. A method of stripping implanted resist includes a first step of disrupting a crust formed on the surface of the resist during the implantation process and then removing the underlying resist. In accordance with embodiments of the invention, a catalyzed hydrogen peroxide (CHP) chemical system is used to disrupt the crust and allow for low temperature (<180° C.) removal of the underlying resist. ## Claims ### Claim 1 A method of stripping implanted resist, the method comprising: disrupting a crust on a resist to expose at least a portion of underlying resist by applying a catalyzed hydrogen peroxide propagation (CHP) chemical system, wherein the CHP chemical system comprises about 5-25% H2O2; and removing the underlying resist by applying an etchant to the resist after disrupting the crust. ### Claim 2 (depends on 1) The method according to claim 1, wherein the resist is a deep UV resist. ### Claim 3 (depends on 1) The method according to claim 1, wherein a catalyst of the CHP chemical system is iron. ### Claim 4 (depends on 1) The method according to claim 1, wherein a catalyst of the CHP chemical system is UV radiation. ### Claim 5 (depends on 1) The method according to claim 1, wherein a catalyst of the CHP chemical system is sonic waves. ### Claim 6 (depends on 1) The method according to claim 1, wherein the CHP chemical system is applied at room temperature. ### Claim 7 (depends on 1) The method according to claim 1, wherein the application of the CHP chemical system comprises immersing a wafer having the resist into the CHP chemical system. ### Claim 8 (depends on 1) The method according to claim 1, wherein the application of the CHP chemical system comprises applying the CHP chemical system while a wafer having the resist is moving. ### Claim 9 (depends on 8) The method according to claim 8, wherein the applying of the CHP chemical system uses an aerosolized spray. ### Claim 10 (depends on 1) The method according to claim 1, wherein the application of the CHP chemical system comprises applying a solution comprising the about 5-25% hydrogen peroxide by a spin processing method while irradiating with UV light or applying sonic waves. ### Claim 11 (depends on 1) The method according to claim 1, wherein removing the underlying resist by applying the etchant to the resist after disrupting the crust comprises: applying a sulfuric acid-peroxide mixture (SPM) after applying the CHP chemical system. ### Claim 12 (depends on 11) The method according to claim 11, wherein the SPM is applied by immersion. ### Claim 13 (depends on 11) The method according to claim 11, wherein the SPM is applied while a wafer having the underlying resist is moving. ### Claim 14 (depends on 11) The method according to claim 11, wherein the SPM is heated to a temperature of less than 180° C. before applying the SPM. ### Claim 15 (depends on 11) The method according to claim 11, wherein sulfuric acid of the SPM is heated to a temperature of about 80° C. before applying the SPM. ### Claim 16 A method of fabricating a semiconductor device using deep UV lithography, the method comprising: implanting ions at a dose of at least 1015/cm2 into a wafer having a deep UV resist pattern thereon; and stripping the implanted deep UV resist pattern, wherein stripping the implanted deep UV resist pattern comprises: using a CHP chemical system to disrupt a crust formed on the deep UV resist during the implanting of the ions, wherein the CHP chemical system comprises about 5-25% H2O2; and removing the deep UV resist underlying the disrupted crust by applying a sulfuric acid-peroxide mixture (SPM) after disrupting the crust using the CHP chemical system. ### Claim 17 (depends on 16) The method according to claim 16, wherein using the CHP chemical system comprises applying a solution comprising the about 5-25% H2O2 and 0-10 mM Fe2+ to the wafer. ### Claim 18 (depends on 17) The method according to claim 17, wherein using the CHP chemical system further comprises irradiating the wafer with UV light or sonic waves. ### Claim 19 (depends on 17) The method according to claim 17, wherein using the CHP chemical system further comprises irradiating the wafer with UV light before and during applying the solution to the wafer.