# US 8,785,935 B2 · Etchant, display device and method for manufacturing display device using the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,785,935 B2 - Document ID: US8785935B2 - Status: Granted - Kind: B2 - Application number: 13/168,408 - Filed: 2011-06-24 - Published: 2012-06-21 - Granted: 2014-07-22 - Earliest claimed: 2010-12-15 - Assignees: Samsung Display Co., Ltd. - Applicants: Hong-Sick Park; Wang-Woo Lee; Sang-Tae Kim; Joon-Woo Lee; Young-Chul Park; Young-Jun Jin; Kyong-Min Kang; Young-Jin Yoon; Suck-Jun Lee; O-Byoung Kwon; In-Ho Yu; Sang-Hoon Jang; Min-Ki Lim; Dong-Ki Kim - Inventors: Hong-Sick Park; Wang-Woo Lee; Sang-Tae Kim; Joon-Woo Lee; Young-Chul Park; Young-Jun Jin; Kyong-Min Kang; Young-Jin Yoon; Suck-Jun Lee; O-Byoung Kwon; In-Ho Yu; Sang-Hoon Jang; Min-Ki Lim; Dong-Ki Kim - Web page: https://patentgrep.com/patent/US8785935B2 ## CPC - C23F 1/02: Local etching - H10D 86/0221: {comprising manufacture, treatment or patterning of TFT semiconductor bodies} - C23F 1/18: for etching copper or alloys thereof - C23F 1/26: for etching refractory metals - H10D 86/021: {of multiple TFTs} - H10D 86/441: {Interconnections, e.g. scanning lines} - H10D 86/60: wherein the TFTs are in active matrices - H10P 50/667: {by liquid etching only} - H10D 30/6729: {characterised by the electrodes} - 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 - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract An etchant includes: 5 to 20 wt % of persulfate, 1 to 10 wt % of at least one compound of an inorganic acid, an inorganic acid salt, or a mixture thereof, 0.3 to 5 wt % of a cyclic amine compound, 1 to 10 wt % of at least one compound of an organic acid, an organic acid salt, or a mixture thereof, 0.1 to 5 wt % of p-toluenesulfonic acid, and water, based on the total weight of the etchant. A copper-titanium etchant further includes 0.01 to 2 wt % of a fluoride-containing compound. A method of forming a display device using the etchant, and a display device, are also disclosed. ## Claims ### Claim 1 An etchant, comprising: 7 to 18 wt % of persulfate, 1 to 10 wt % of at least one compound of an inorganic acid, an inorganic acid salt, or a mixture comprising at least one of the foregoing, 0.3 to 5 wt % of a cyclic amine compound, 1 to 10 wt % of at least one compound of an organic acid, an organic acid salt, or a mixture comprising at least one of the foregoing, 0.1 to 5 wt % of p-toluenesulfonic acid, and water, based on the total weight of the etchant. ### Claim 2 (depends on 1) The etchant of claim 1, wherein the persulfate is selected from ammonium persulfate, sodium persulfate, potassium persulfate, or a combination comprising at least one of the foregoing. ### Claim 3 (depends on 2) The etchant of claim 2, wherein the inorganic acid is selected from nitric acid, sulfuric acid, phosphoric acid, perchloric acid, or a combination comprising at least one of the foregoing, and the inorganic acid salt is selected from nitrate, sulfate, phosphate, perchlorate, or a combination comprising at least one of the foregoing. ### Claim 4 (depends on 3) The etchant of claim 3, wherein the cyclic amine compound is selected from 5-aminotetrazole, tolyltriazole, benzotriazole, methyltriazole, or a combination comprising at least one of the foregoing. ### Claim 5 (depends on 4) The etchant of claim 4, wherein the organic acid is selected from acetic acid, glycolic acid, citric acid, oxalic acid, or a combination comprising at least one of the foregoing, and the organic acid salt is selected from a potassium salt, a sodium salt, an ammonium salt, or a combination comprising at least one of the foregoing of a compound selected from acetic acid, glycolic acid, citric acid, oxalic acid, or a combination comprising at least one of the foregoing. ### Claim 6 (depends on 5) The etchant of claim 5, further comprising 0.01 to 2 wt % of a fluoride-containing compound, based on the total weight of the etchant. ### Claim 7 (depends on 6) The etchant of claim 6, wherein the fluoride-containing compound is selected from ammonium fluoride, sodium fluoride, potassium fluoride, ammonium bifluoride, sodium bifluoride, potassium bifluoride, or a combination comprising at least one of the foregoing. ### Claim 8 (depends on 1) The etchant of claim 1, further comprising 0.01 to 2 wt % of a fluoride-containing compound, based on the total weight of the etchant. ### Claim 9 (depends on 8) The etchant of claim 8, wherein the fluoride-containing compound is selected from ammonium fluoride, sodium fluoride, potassium fluoride, ammonium bifluoride, sodium bifluoride, potassium bifluoride, or a combination comprising at least one of the foregoing.