Patent ID: 8486787

Claim:
A method of fabricating a semiconductor device, comprising: preparing a substrate having a first region and a second region; forming a first element on the first region of the substrate; forming a second element having an upper surface disposed at a higher level than the first element on the second region of the substrate; forming an insulating layer covering the first and second elements; forming a mask on the insulating layer; performing photolithography and etching processes on the mask to form a first mask opening passing through the mask and exposing the insulating layer on the first region, and to form a preliminary mask opening not exposing the insulating layer on the second region; etching the insulating layer exposed by the first mask opening to form a preliminary contact opening on the first region; etching the mask remaining under the preliminary mask opening to form a second mask opening on the second region to expose the insulating layer under the preliminary mask opening; and etching the insulating layer between a bottom region of the preliminary contact opening and the first element on the first region to form a first contact opening exposing the first element, and etching the insulating layer exposed by the second mask opening on the second region to form a second contact opening exposing the second element.