Patent ID: 7691741
Filing Date: 2010-04-06
Classification: H01L

Abstract:
1. A method of forming a bit line of a semiconductor device, the method comprising sequentially: (a) stacking an etch-stop nitride film on a semiconductor substrate in which a contact plug is formed, a trench oxide film on the etch-stop nitride film, and a hard mask nitride film on the trench oxide film; (b) forming a photo mask on a predetermined region of the hard mask nitride film, and etching the hard mask nitride film and a predetermined thickness of the trench oxide film using the photo mask as a mask; (c) stripping the photo mask; (d) etching the trench oxide film remaining on the etch-stop nitride film using the hard mask nitride film as a mask to form a trench, thereby exposing the etch-stop nitride film; (e) stripping the hard mask nitride film and the etch-stop nitride film below the trench, thereby exposing the contact plug; (f) forming wet etch barriers on entire sidewalls of the trench; and (g) forming a bit line within the trench, wherein the wet etch barriers are formed before the contact plug is exposed.