Method for fabricating semiconductor device without damaging hard mask during contact formation process

Abstract

Disclosed is a method for fabricating a semiconductor device without damaging a hard mask of a conductive structure. The method includes the steps of: forming a plurality of conductive structures on a substrate, each conductive structure including a conductive layer and a hard mask; sequentially forming a first nitride layer, an oxide layer, a second nitride layer, and an etch stop layer on the plurality of conductive structures; forming an inter-layer insulation layer on the etch stop layer; removing a portion of the inter-layer insulation layer through a planarization process; performing a self-aligned etching (SAC) process selectively etching the inter-layer insulation layer, the second nitride layer and the oxide layer until the SAC etching process is stopped at the first nitride layer to thereby form a contact hole exposing the first nitride layer; and removing the first nitride layer by performing a blanket etch-back process to thereby expose the conductive layer.