Patent ID: 7763544

Claim:
A method of forming a self-aligned contact of a semiconductor device comprising: forming a conductive line structure which comprises a conductive material layer, a hard mask layer, and a sidewall spacer on a substrate; forming a silicon germanium (Si 1-x Ge x ) sacrificial layer, which has a height equal to or higher than a height of at least the conductive line structure, on an entire surface of the substrate; forming a photoresist pattern for defining a contact hole on the sacrificial layer; dry-etching the sacrificial layer using the photoresist pattern as an etch mask, thereby forming the contact hole for exposing the substrate; forming a plurality of contacts for filling the contact hole with polysilicon; removing the remaining sacrificial layer by wet-etching; and filling the region where the removed sacrificial layer is located with silicon oxide, thereby forming a first interlayer insulating layer, wherein, x is from about 0.1 to about 0.8.