Lam Research Corporation
Atomic layer clean for removal of photoresist patterning scum

Abstract:

Methods and apparatuses for removing photoresist patterning scum from patterning mandrel structures without damaging other features or structures on a semiconductor substrate are desirable for patterning precision. Methods involve cleaning carbon-containing features on a semiconductor substrate by an atomic layer cleaning (ALC) process to descum the carbon-containing features without substantially modifying feature critical dimensions. The ALC process involves exposing the carbon-containing features to an oxidant or reductant in absence of a plasma, or other energetic activation, to modify scum on the surface of the carbon-containing features. The modified scum on the surface of the carbon-containing features is then exposed to an inert gas along with a plasma ignited at a pressure between 0.1 Torr and 10 Torr and a power of less than 200 W to remove the modified scum from the surface of the carbon-containing features.