Disclosed is a method for forming multi-layer interconnection of semiconductor device, which allows a contact hole to be formed at a size smaller than a resolution limit of the exposing system. The method comprises the steps of: providing a semiconductor substrate on which a first interconnection layer is formed; forming a first interlayer insulating film on the first interconnection layer and the semiconductor substrate; forming a patterned etch stopper layer on the first interlayer insulating film such that the etch stopper layer is overlapped with a portion of the first interconnection layer; forming a second interlayer insulating film on the etch stopper layer and the first interlayer insulating film; forming a photoresist pattern on the second interlayer insulating film in such a manner that a portion of the second interlayer insulating film, which is vertically overlapped with a portion of the first interconnection layer and a portion of the etch stopper layer including the portion overlapped with the first interconnection layer, is exposed; etching the second and first interlayer films using the photoresist pattern and the etch stopper layer such that a contact hole is formed through which the first interconnection layer and a portion of the etch stopper layer are exposed; removing the photoresist pattern; depositing a conductive film at a uniform thickness on the second interlayer insulating film, side walls of the contact hole, the first interconnection layer, and the etch stopper layer; and patterning the conductive film such that a second interconnection layer is formed that is in contact with the first interconnection layer.
A semiconductor device includes a conductive pattern disposed on a substrate, a first interlayer dielectric layer disposed on the substrate and the conductive pattern, a first dummy pattern disposed on the first interlayer dielectric layer and partially overlapping the conductive pattern, a second interlayer dielectric layer disposed on the first interlayer dielectric layer and the first dummy pattern, a second dummy pattern disposed on the second interlayer dielectric layer and partially overlapping the conductive pattern, a third interlayer dielectric layer disposed on the second interlayer dielectric layer and the second dummy pattern, and a contact plug that penetrates the third interlayer dielectric layer, the second interlayer dielectric layer, and the first interlayer dielectric layer to contact the conductive pattern, the contact plug arranged between the first dummy pattern and the second dummy pattern, the contact plug abutting the first dummy pattern and the second dummy pattern.
