US 12,437,986 B2
Wafer cleaning method and method for manufacturing semiconductor device
Ruijing Han, Guangdong (CN); and Hui Zeng, Guangdong (CN)
Assigned to CANSEMI TECHNOLOGY INC., Guangdong (CN)
Appl. No. 18/691,373
Filed by CANSEMI TECHNOLOGY INC., Guangdong (CN)
PCT Filed Jan. 28, 2022, PCT No. PCT/CN2022/074721
§ 371(c)(1), (2) Date Mar. 12, 2024,
PCT Pub. No. WO2023/035546, PCT Pub. Date Mar. 16, 2023.
Claims priority of application No. 202111066032.8 (CN), filed on Sep. 13, 2021.
Prior Publication US 2024/0387164 A1, Nov. 21, 2024
Int. Cl. H01L 21/02 (2006.01)
CPC H01L 21/02057 (2013.01) 16 Claims
OG exemplary drawing
 
1. A method for manufacturing semiconductor device, comprising:
cleaning a surface of a wafer according to a wafer cleaning method, the wafer cleaning method, comprising:
protonating a cleaning solution with a protonator comprising a cathodic electrode having a surface covered with an inert film, the protonator further comprising an anodic electrode and an anion exchange membrane, under the action of an electric field, anions in the cleaning solution passing through the anion exchange membrane and then being adsorbed to the anodic electrode and hydrogen ions in the cleaning solution moving towards the cathodic electrode and then being output in the protonated cleaning solution rich in hydrogen ions;
cleaning a wafer surface with the protonated cleaning solution which has a pH greater than 2.45 and less than 7, wherein a silicon dioxide film is formed on the wafer surface, and after the cleaning, silanol groups on a surface of the silicon dioxide film are deprotonated to make the wafer surface negatively charged, so that compared with using a non-protonated cleaning solution, cleaning the wafer surface with the protonated cleaning solution results in a reduced amount of negative charge, wherein the cleaned wafer surface is covered with a liquid film of the protonated cleaning solution and the liquid film is positively charged;
purging the wafer surface with a drying gas to remove the liquid film from a center of the wafer surface towards a periphery thereof, wherein as the liquid film retreats from the center of the wafer surface to the periphery, a concentration of hydrogen ions in the liquid film gradually increases and the same amount of positive charge of the liquid film accumulate; and
forming a film layer structure on the cleaned wafer surface.