Method for fabricating semiconductor device

摘要

Disclosed is a method for fabricating a semiconductor device. The method includes: forming a first inter-layer insulation layer on a substrate provided with a plurality of cell contact plugs; selectively etching the first inter-layer insulation layer to form a plurality of first contact holes; performing a cleaning process to remove etch residues on lower portions of the first contact holes; forming insulating fences on inner walls of the first contact holes; forming a plurality of bit lines in contact with a group of the cell contact plugs through the respective first contact holes; forming a second inter-layer insulation layer over the plurality of bit lines; planarizing the second inter-layer insulation layer until an upper portion of each of the bit lines is exposed; and selectively etching the second inter-layer insulation layer in alignment with the bit lines, thereby obtaining a plurality of second contact holes.