Patent ID: 7846827

Claim:
A method for manufacturing a semiconductor device, comprising the: forming a plug on a semiconductor substrate; forming an insulation layer on the semiconductor substrate the plug formed thereon; conducting a first etching of the insulation layer to remove a partial thickness of the insulation layer so as to define a line type trench therein, wherein the line type trench is capable of receiving a bit line; conducting a second etching of a portion of the insulation layer corresponding to a bottom of the line type trench so as to define a contact hole exposing the plug, wherein the contact hole is capable of receiving a bit line contact plug; after conducting the second etching, forming a barrier layer on surfaces of the contact hole and trench; forming a first conductive layer on the barrier layer to fill the contact hole and the trench; removing portions of the first conductive layer and the barrier layer formed in the trench so as to form a bit line contact plug in the contact hole; and forming a bit line in the trench by forming a second conductive layer on the bit line contact plug.