US 11,702,751 B2
Non-conformal high selectivity film for etch critical dimension control
Bo Qi, San Jose, CA (US); Huiyuan Wang, Santa Clara, CA (US); Yingli Rao, Palo Alto, CA (US); and Abhijit Basu Mallick, Palo Alto, CA (US)
Assigned to Applied Materials, Inc., Santa Clara, CA (US)
Filed by Applied Materials, Inc., Santa Clara, CA (US)
Filed on Aug. 10, 2020, as Appl. No. 16/989,167.
Claims priority of provisional application 62/887,078, filed on Aug. 15, 2019.
Prior Publication US 2021/0047733 A1, Feb. 18, 2021
Int. Cl. C23C 16/30 (2006.01); C23C 16/56 (2006.01); C23C 16/455 (2006.01); H10B 12/00 (2023.01); H10B 41/20 (2023.01); H10B 41/35 (2023.01)
CPC C23C 16/56 (2013.01) [C23C 16/30 (2013.01); C23C 16/45529 (2013.01); H10B 12/02 (2023.02); H10B 12/30 (2023.02); H10B 41/20 (2023.02); H10B 41/35 (2023.02)] 20 Claims
OG exemplary drawing
 
1. A method comprising:
forming a film stack on a substrate, the film stack comprising a plurality of alternating layers of an oxide material and a nitride material and the film stack having a stack thickness;
etching the film stack to a first depth to form an opening with at least one sidewall and a bottom, the first depth being less than the thickness;
depositing a non-conformal liner on the at least one sidewall and the bottom of the opening, the non-conformal liner on the bottom of the opening having a thickness less than a thickness of the non-conformal liner on the at least one sidewall of the opening;
etching the non-conformal liner from the bottom of the opening to reduce the thickness of the non-conformal liner on the bottom of the opening;
selectively etching the film stack relative to the non-conformal liner to a second depth to form a hole; and
annealing the film stack in an oxidizing atmosphere to remove the non-conformal liner.