Patent ID: 7303999
Filing Date: 2007-12-04
Classification: H01L

Abstract:
1. A method for etching a silicon layer disposed on a substrate, said silicon layer having thereon a plurality of spacer features disposed so as to create openings to said silicon layer, comprising: etching in a first plasma etch step into said silicon layer through said openings, thereby forming etched features in said silicon layer; after terminating said first plasma etch step, forming deposition at the bottom of said etched features using a deposition recipe that is different from a recipe employed during said first plasma etch step; and after terminating said deposition recipe, etching in a second plasma etch step said silicon layer through said etched features using a second etch recipe, wherein said second etch recipe is configured to etch sidewalls of said etched features at a faster rate than downward into said silicon layer.