US 12,261,054 B2
Substrate processing with material modification and removal
Ivo Otto, IV, Albany, NY (US); and Subhadeep Kal, Albany, NY (US)
Assigned to Tokyo Electron Limited, Tokyo (JP)
Filed by TOKYO ELECTRON LIMITED, Tokyo (JP)
Filed on Aug. 11, 2022, as Appl. No. 17/886,289.
Prior Publication US 2024/0055270 A1, Feb. 15, 2024
Int. Cl. H01L 21/311 (2006.01); H01J 37/32 (2006.01); H01L 21/02 (2006.01)
CPC H01L 21/31116 (2013.01) [H01J 37/32422 (2013.01); H01L 21/0234 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A substrate processing method comprising:
providing a substrate which includes a spacer layer formed of a spacer material;
performing an etch and surface modification step in which a surface of the spacer material is etched to remove a portion of the spacer material and a remaining surface of the spacer material is modified to provide a modified surface having an increased content of oxygen and fluorine compared to the spacer material before the etch and modification step, the etch and surface modification step including exposing the spacer material to a plasma which includes at least fluorine and oxygen; and
after the etch and surface modification step, performing a gas chemistry etch which is not in a plasma to remove the modified surface of the spacer material, the gas chemistry etch includes a first step and a second step, the first step using HF and NH3, the second step using Ar and/or N and not using HF or NH3, and the second step being performed at a higher temperature than the first step.