Patent ID: 7084069

Claim:
A method of forming a conductive path in a semiconductor device, comprising: forming an insulating layer on a semiconductor substrate, the insulating layer having a first conductive member and a second conductive member embedded therein spaced apart from each other, so that the second conductive member is below the first conductive member, and so that the first and second conductive members are covered by the insulating layer; forming an etching mask on the insulating layer, the etching mask having an opening over the first conductive member; etching the insulating layer using the etching mask in a reaction chamber, wherein a reaction chamber pressure is not less than about 100 mTorr, a reaction gas consists of CHF 3 and CO, a flow ratio of CHF 3 and CO is about 15/85, and a flow rate of the reaction gas is not less than about 300 sccm, so that the insulating layer under the opening of the etching mask is removed and an etch stop occurs in the insulating layer between the first and second conductive members without exposing the second conductive member; and filling a removed portion of the insulating layer with a conductive material to form the conductive path.