US 12,341,017 B2
Etching methods with alternating non-plasma and plasma etching processes
Xiangyu Guo, Bear, DE (US); and Nathan Stafford, Bear, DE (US)
Assigned to American Air Liquide, Inc., Fremont, CA (US)
Filed by American Air Liquide, Inc., Fremont, CA (US)
Filed on Oct. 26, 2022, as Appl. No. 17/974,246.
Prior Publication US 2024/0162042 A1, May 16, 2024
Int. Cl. H01L 21/3065 (2006.01)
CPC H01L 21/30655 (2013.01) 19 Claims
OG exemplary drawing
 
1. A method for forming an aperture pattern in a substrate, the substrate including a film disposed thereon and a patterned mask layer disposed on the film, the method comprising the steps of:
1) exposing the substrate to a vapor of a passivation molecule in a non-plasma condition for a period to form a surface protective layer on the patterned mask layer;
2) exposing the substrate to a plasma activated etch gas and plasma dry etching the substrate to form apertures over the patterned mask layer in the film with the plasma activated etch gas; and
3) repeating step 1) to 2) until a desired aperture pattern is formed in the film,
wherein the surface protective layer is also formed on the sidewalls of the apertures formed in the film,
wherein the passivation molecule is selected from the group consisting of halogen-containing silanes, I-containing hydrofluorocarbons, N-containing hydrofluorocarbons and S-containing hydrofluorocarbons.