US 11,935,758 B2
Atomic layer etching for subtractive metal etch
Wenbing Yang, Campbell, CA (US); Mohand Brouri, Fremont, CA (US); Samantha SiamHwa Tan, Fremont, CA (US); Shih-Ked Lee, Fremont, CA (US); Yiwen Fan, Fremont, CA (US); Wook Choi, San Jose, CA (US); Tamal Mukherjee, Fremont, CA (US); Ran Lin, Fremont, CA (US); and Yang Pan, Los Altos, CA (US)
Assigned to Lam Research Corporation, Fremont, CA (US)
Appl. No. 17/600,999
Filed by Lam Research Corporation, Fremont, CA (US)
PCT Filed Apr. 27, 2020, PCT No. PCT/US2020/030054
§ 371(c)(1), (2) Date Oct. 1, 2021,
PCT Pub. No. WO2020/223152, PCT Pub. Date Nov. 5, 2020.
Claims priority of provisional application 62/840,253, filed on Apr. 29, 2019.
Prior Publication US 2022/0199422 A1, Jun. 23, 2022
Int. Cl. H01L 21/3213 (2006.01)
CPC H01L 21/32139 (2013.01) [H01L 21/32136 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A method for atomic layer etching a metal containing layer, wherein the metal containing layer fills features in a patterned mask and covers tops of the patterned mask, comprising:
a) modifying at least a region of a surface of the metal containing layer to form a modified metal containing region by exposing a surface of the metal containing layer to a modification gas, wherein adjacent to the modified metal containing region remains an unmodified metal containing region;
b) selectively removing the modified metal containing region with respect to the unmodified metal containing region by exposing the surface of the metal containing layer to an inert bombardment plasma generated from an inert gas; and
c) cyclically repeating steps a and b until the tops of the patterned mask are exposed.