Patent ID: 6444575
Filing Date: 2002-09-03
Classification: H01L

Abstract:
A method for forming a contact via comprising:providing a substrate; forming over the substrate a pair of topographic structures which is separated by a contact region formed within the substrate; forming upon the substrate and the pair of topographic structures a blanket conformal isolation layer having an upper region formed upon the pair of topographic structures and a lower region formed interposed between the pair of topographic structures and over the contact region; forming upon the blanket conformal isolation layer a blanket variable thickness masking layer having a greater thickness over the upper region of the blanket conformal isolation layer than over the lower region of the blanket conformal isolation layer; etching completely through the blanket variable thickness masking layer and the blanket conformal isolation layer at the lower region of the blanket conformal isolation layer but not the upper region of the blanket conformal isolation layer to form a pair of patterned conformal isolation layers and a pair of patterned variable thickness masking layers which define a contact via exposing the contact region.