Patent ID: 7645667

Claim:
A method for performing self-aligned source etching process comprising: providing a substrate material; forming a layer of etchable oxide material overlying at least a portion of the substrate material, the layer of etchable oxide material being characterized by a first thickness, the layer of etchable oxide material including a first portion, a second portion, and a third portion, the second portion being positioned between the first portion and the third portion; forming a plurality of structures overlying the layer of etchable oxide material, the plurality of structures including a first structure and a second structure, the first structure including a first sidewall and being positioned above the first portion, the second structure including a second sidewall and being positioned above the third portion, the first sidewall facing the second sidewall; forming a plurality of photoresist layers overlying the plurality of structures, the plurality of photoresist layers including a first photoresist layer overlying the first structure and a second photoresist layer overlying the second structure; performing a first dry etching process at a first depth, forming a first polymer layer overlying the first sidewall and a second polymer layer overlying the second sidewall, removing at least a second thickness of the second portion, the second thickness being less than the first thickness; performing a second dry etching process at a second depth, the second depth being greater than the first depth, removing at least a third thickness of the second portion; removing the plurality of photoresist layers; and removing the first and second sidewalls.