US 11,869,774 B2
Method for improving etching rate of wet etching
Nannan Zhang, Hefei (CN); and Yen-Teng Huang, Hefei (CN)
Assigned to CHANGXIN MEMORY TECHNOLOGIES, INC., Hefei (CN)
Filed by CHANGXIN MEMORY TECHNOLOGIES, INC., Hefei (CN)
Filed on Aug. 17, 2021, as Appl. No. 17/445,299.
Application 17/445,299 is a continuation of application No. PCT/CN2021/099825, filed on Jun. 11, 2021.
Claims priority of application No. 202011024298.1 (CN), filed on Sep. 25, 2020.
Prior Publication US 2022/0102157 A1, Mar. 31, 2022
Int. Cl. H01L 21/311 (2006.01); C09K 13/08 (2006.01); H01L 21/67 (2006.01)
CPC H01L 21/31111 (2013.01) [C09K 13/08 (2013.01); H01L 21/67086 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A method for improving an etching rate of wet etching used in an etching reaction chamber for etching work, the etching reaction chamber being connected with an etchant supply mechanism, the etchant supply mechanism being connected with a water supply mechanism, comprising:
injecting water into the etchant supply mechanism by the water supply mechanism according to a change range of pH of an etchant in the etchant supply mechanism to ensure that a hydrogen ion concentration and a fluoride ion concentration of the etchant in the etchant supply mechanism are stable;
wherein
the etchant is composed of water, ammonium fluoride, hydrogen fluoride, and a surfactant; and
illuminating in the etching reaction chamber with yellow light having a wavelength of 570 nm-590 nm.