Patent ID: 7384846

Claim:
A method of fabricating a semiconductor device, comprising the steps of: (a) stacking a buffer film, an anti-polish film and a hard mask film on a semiconductor substrate including a cell region; (b) coating a first photoresist on the entire surface, then patterning the first photoresist to define the isolation region of the cell region, and then patterning the hard mask film using the patterned first photoresist as a mask; (c) etching the anti-polish film and the buffer film using a patterned hard mask film as a mask; (d) forming a second photoresist on the entire surface including the cell region and a peripheral region other than the cell region; (e) patterning the second photoresist to define an isolation region of the peripheral region; (f) etching the hard mask film, the anti-polish film and the buffer film using the patterned second photoresist as a mask; (g) etching the semiconductor substrate using the patterned hard mask film as a mask, forming a plurality of trenches; and (h) forming isolation films within the trenches.