	US 12,266,537 B2
	Selective barrier metal etching
Jonathan Shaw, Oakland, CA (US); and Gene Lee, San Jose, CA (US)
Assigned to Applied Materials, Inc., Santa Clara, CA (US)
Filed by Applied Materials, Inc., Santa Clara, CA (US)
Filed on Feb. 3, 2022, as Appl. No. 17/592,365.
Claims priority of provisional application 63/155,911, filed on Mar. 3, 2021.
Prior Publication US 2022/0285167 A1, Sep. 8, 2022
Int. Cl. H01L 21/311 (2006.01); H01J 37/32 (2006.01); H01L 21/768 (2006.01)

CPC H01L 21/31116 (2013.01) [H01J 37/321 (2013.01); H01L 21/76849 (2013.01); H01J 2237/334 (2013.01)]

15 Claims

1. A method for selective barrier metal etching, the method comprising:

performing a hydrogen implantation process to chemically reduce an oxidized portion of a barrier metal layer on a foot structure formed at a bottom of a feature in a metal layer on the barrier metal layer;

performing a first etch process to remove the hydrogen implanted portion of the barrier metal layer; and

performing a second etch process to remove at least a portion of the foot structure,

wherein the hydrogen implantation process, the first etch process, and the second etch process are repeated.