US Patent No. 9,881,805

SILICON SELECTIVE REMOVAL


Patent No. 9,881,805
Issue Date January 30, 2018
Title Silicon Selective Removal
Inventorship Zihui Li, Santa Clara, CA (US)
Ching-Mei Hsu, Stanford, CA (US)
Hanshen Zhang, Cupertino, CA (US)
Jingchun Zhang, Cupertino, CA (US)
Assignee Applied Materials, Inc., Santa Clara, CA (US)

Claim of US Patent No. 9,881,805

1. A method of etching a patterned substrate, the method comprising:
placing the patterned substrate in a substrate processing region of a substrate processing chamber, wherein the patterned
substrate comprises an exposed silicon portion and a second exposed portion and wherein the second exposed portion comprises
at least one element other than silicon;

producing plasma effluents by flowing a fluorine-containing precursor into a remote plasma region fluidly coupled to the substrate
processing region while forming a remote plasma in the remote plasma region;

flowing a hydrogen-containing precursor into the substrate processing region without first passing the hydrogen-containing
precursor through the remote plasma region; and

etching the exposed silicon portion by flowing the plasma effluents into the substrate processing region, wherein the exposed
silicon portion etches at a first etch rate and the second exposed portion etches at a second etch rate which is lower than
the first etch rate.