# US 11,298,796 B2 · Method for double-side polishing wafer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,298,796 B2 - Document ID: US11298796B2 - Status: Granted - Kind: B2 - Application number: 15/779,141 - Filed: 2016-11-22 - Published: 2018-09-27 - Granted: 2022-04-12 - Earliest claimed: 2015-12-11 - Assignees: Shin-Etsu Handotai Co., Ltd. - Applicants: Shin-Etsu Handotai Co., Ltd. - Inventors: Yuki Tanaka; Daichi Kitazume; Syuichi Kobayashi - Web page: https://patentgrep.com/patent/US11298796B2 ## CPC - B24B 37/28: for double side lapping of plane surfaces - B24B 37/042: {operating processes therefor} - B24B 37/044: {characterised by the composition of the lapping agent} - B24B 27/0076: {grinding machines comprising two or more grinding tools} - B24B 37/08: for double side lapping - H10P 90/129: {by polishing} - B24B: MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING (grinding of gear teeth B23F, of screw-threads B23G1/36; by electro-erosion B23H; abrasive or related blasting B24C; tools for grinding, buffing or sharpening B24D; polishing compositions C09G1/00; abrasives C09K3/14; electrolytic etching or polishing C25F3/00; grinding arrangements for use on assembled railway tracks E01B31/17); DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract A method for double-side polishing a wafer uses a double-side polishing machine wherein a carrier which is yet to be arranged in the double-side polishing machine is previously subjected to two-stage double-side polishing which uses a double-side polishing machine different from the double-side polishing machine adopted for double-side polishing the wafer and includes primary polishing using slurry containing abrasive grains and secondary polishing using an inorganic alkali solution containing no abrasive grain, the carrier subjected to the two-stage double-side polishing is arranged in the double-side polishing machine adopted for double-side polishing the wafer, and the double-side polishing of the wafer is performed. Consequently, the method for double-side polishing a wafer enables suppressing damages to wafers to be polished immediately after arranging the carrier between the upper and lower turntables. ## Claims ### Claim 1 A method for double-side polishing a wafer, comprising: double-side polishing a carrier, using a second double-side polishing machine, without a wafer disposed in the carrier, the double-side polishing of the carrier including two-stage double-side polishing which includes primary polishing using slurry containing abrasive grains and secondary polishing using an inorganic alkali solution containing no abrasive grain; after the double-side polishing of the carrier, arranging the carrier between upper and lower turntables having polishing pads attached thereto respectively in a first double-side polishing machine different from the second double-side polishing machine; holding the wafer in a holding hole formed in the carrier to be sandwiched between the upper and lower turntables; and double-side polishing the wafer using the first double-side polishing machine, wherein a plurality of batches of the double-side polishing the wafer using the first double-side polishing machine are performed, and the double-side polishing including the two-stage double-side polishing using the second double-side polishing machine is performed for each of the plurality of batches. ### Claim 2 (depends on 1) The method for double-side polishing a wafer according to claim 1, wherein the two-stage double-side polishing using the second double-side polishing machine is carried out before first arrangement for the double-side polishing of the wafer. ### Claim 3 (depends on 1) The method for double-side polishing a wafer according to claim 1, wherein the carrier used for the double-side polishing of the wafer is taken out from the first double-side polishing machine and temporarily stored, and the two-stage double-side polishing of the carrier using the second double-side polishing machine is performed before rearranging the carrier for the double-side polishing of a next wafer. ### Claim 4 (depends on 2) The method for double-side polishing a wafer according to claim 2, wherein the carrier used for the double-side polishing of the wafer is taken out from the first double-side polishing machine and temporarily stored, and the two-stage double-side polishing of the carrier using the second double-side polishing machine is performed before rearranging the carrier for the double-side polishing of a next wafer. ### Claim 5 (depends on 1) The method for double-side polishing a wafer according to claim 1, wherein the carrier is made of a metal. ### Claim 6 (depends on 2) The method for double-side polishing a wafer according to claim 2, wherein the carrier is made of a metal. ### Claim 7 (depends on 3) The method for double-side polishing a wafer according to claim 3, wherein the carrier is made of a metal. ### Claim 8 (depends on 4) The method for double-side polishing a wafer according to claim 4, wherein the carrier is made of a metal. ### Claim 9 (depends on 1) The method for double-side polishing a wafer according to claim 1, wherein the abrasive grains in the slurry used in the primary polishing of the carrier have a diameter of 70 nm or more. ### Claim 10 (depends on 8) The method for double-side polishing a wafer according to claim 8, wherein the abrasive grains in the slurry used in the primary polishing of the carrier have a diameter of 70 nm or more. ### Claim 11 (depends on 1) The method for double-side polishing a wafer according to claim 1, wherein polishing pads used in the two-stage double-side polishing of the carrier are urethane foam pads having Shore A hardness of 80 or more. ### Claim 12 (depends on 10) The method for double-side polishing a wafer according to claim 10, wherein polishing pads used in the two-stage double-side polishing of the carrier are urethane foam pads having Shore A hardness of 80 or more. ### Claim 13 (depends on 1) The method for double-side polishing a wafer according to claim 1, wherein a polishing stock removal in the primary polishing of the carrier is set to 30 nm or more on each side. ### Claim 14 (depends on 12) The method for double-side polishing a wafer according to claim 12, wherein a polishing stock removal in the primary polishing of the carrier is set to 30 nm or more on each side. ### Claim 15 (depends on 1) The method for double-side polishing a wafer according to claim 1, wherein a temperature of the inorganic alkali solution used in the secondary polishing of the carrier is set to 30° C. or more. ### Claim 16 (depends on 14) The method for double-side polishing a wafer according to claim 14, wherein a temperature of the inorganic alkali solution used in the secondary polishing of the carrier is set to 30° C. or more.