Semiconductor device and method for fabricating the same

Abstract

A method for fabricating a semiconductor device is provided. The method includes forming a pad oxide layer on a semiconductor substrate, forming a pad nitride layer on the pad oxide layer, forming a capping layer on the pad nitride layer, patterning the capping layer, the pad nitride layer, and the pad oxide layer by a photolithography method to expose portions of the semiconductor substrate, forming a field oxidation layer having bird's beaks, the bird's beaks being formed under the pad nitride layer, forming trenches in the semiconductor substrate by anisotropically etching the field oxide layer and the semiconductor substrate using the pad nitride layer as a mask, removing the capping layer, the pad nitride layer, the pad oxide layer, and the bird's beaks, and forming an isolation region in the trenches.

Dependencies are inferred from the claim text.