US 12,463,030 B2
Selective oxidation of a substrate
Hansel Lo, Santa Clara, CA (US); and Chris Olsen, Santa Clara, CA (US)
Assigned to Applied Materials, Inc, Santa Clara, CA (US)
Filed by Applied Materials, Inc., Santa Clara, CA (US)
Filed on Sep. 29, 2022, as Appl. No. 17/956,157.
Prior Publication US 2024/0112903 A1, Apr. 4, 2024
Int. Cl. H01L 21/02 (2006.01)
CPC H01L 21/02236 (2013.01) [H01L 21/02164 (2013.01); H01L 21/0217 (2013.01); H01L 21/02247 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A method comprising:
forming a non-conformal layer on at least one side wall of a trench or a hole formed on a substrate, wherein the non-conformal layer forms on an upper portion of the at least one side wall and decreases in thickness with increased depth into the trench or the hole, and wherein the non-conformal layer comprises nitrogen; and
oxidizing the at least one side wall of the trench or the hole comprising the non-conformal layer, wherein oxidation of the non-conformal layer and an exposed portion of the at least one side wall not covered by the non-conformal layer occurs to form an oxide layer, wherein the oxide layer is thicker at a lower portion of the at least one side wall than the upper portion of the at least one side wall.