US 12,341,021 B2
Selective etch using deposition of a metalloid or metal containing hardmask
Samantha Siamhwa Tan, Newark, CA (US); Daniel Peter, Sunnyvale, CA (US); Arunima Deya Balan, Mountain View, CA (US); Younghee Lee, Pleasanton, CA (US); and Yang Pan, Los Altos, CA (US)
Assigned to Lam Research Corporation, Fremont, CA (US)
Appl. No. 17/914,296
Filed by Lam Research Corporation, Fremont, CA (US)
PCT Filed Apr. 6, 2021, PCT No. PCT/US2021/026063
§ 371(c)(1), (2) Date Sep. 23, 2022,
PCT Pub. No. WO2021/207286, PCT Pub. Date Oct. 14, 2021.
Claims priority of provisional application 63/007,201, filed on Apr. 8, 2020.
Prior Publication US 2023/0118701 A1, Apr. 20, 2023
Int. Cl. H01L 21/311 (2006.01)
CPC H01L 21/31116 (2013.01) [H01L 21/31144 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method for selectively etching at least one feature in a silicon oxide region with respect to a lower oxygen containing region, wherein the lower oxygen containing region and the silicon oxide region form a structure, wherein the silicon oxide region is adjacent to the lower oxygen containing region and wherein a mask is above at least part of the silicon oxide region and the lower oxygen containing region and wherein the mask provides an exposed part of the lower oxygen containing region and an exposed part of the silicon oxide region, comprising:
providing an etch gas comprising a metalloid halide and/or a metal halide;
forming the etch gas into a plasma; and
simultaneously selectively etching at least one feature in the exposed part of the silicon oxide region with respect to the lower oxygen containing region and forming a metalloid or metal containing hardmask on the exposed part of the lower oxygen containing region, wherein a portion of the silicon oxide region below the mask is not etched and the metalloid or metal containing hardmask is not formed on a portion of the lower oxygen containing region below the mask.