Lam Research Corporation
TIN OXIDE MANDRELS IN PATTERNING

Abstract:

Tin oxide films are used as mandrels in semiconductor device manufacturing. In one implementation the process starts by patterning a tin oxide layer using at least one of a hydrogen-based etch chemistry and a chlorine-based etch chemistry, and using patterned photoresist as a mask, thereby providing a substrate having a plurality of protruding tin oxide features (mandrels). Next, a conformal layer of spacer material is formed both on the horizontal surfaces and on the sidewalls of the mandrels. The spacer material is then removed from the horizontal surfaces exposing the tin oxide material of the mandrels, without fully removing the spacer material residing at the sidewalls of the mandrels. Next, mandrels are selectively removed (e.g., using hydrogen-based etch chemistry), while leaving the spacer material that resided at the sidewalls of the mandrels. The resulting spacers can be used for patterning underlying layers on the substrate.