Patent ID: 7105442

Claim:
A method of forming an opening in a substituent layer of an integrated circuit comprising: a) coating said substituent layer with one or more masking layers; and, b) photolithographically patterning said one or more masking layers; and, c) coating said patterned one or more masking layers with a topmost masking layer wherein said topmost masking layer coats the exposed surfaces of said substituent layer and coats the vertical sidewalls and horizontal surfaces of said patterned one or more masking layers; and, d) etching said topmost masking layer so as to open said topmost masking layer, exposing thereby said substituent layer while leaving spacers on said vertical sidewalls of said patterned one or more masking layers; and, e) etching an opening in said substituent layer wherein the critical dimension of said opening is reduced from the critical dimension of said patterned one or more masking layers by the thickness of said spacers; and wherein at least one of said one or more masking layers and said topmost masking layers comprise amorphous carbon.