Patent ID: 7160789
Filing Date: 2007-01-09
Classification: H01L

Abstract:
1. A method of forming a semiconductor device including a STI structure for defining an active region on a semiconductor substrate, the active region being structured to have a recess channel trench therein, the method comprising: (a) forming a mask layer pattern that defines the active region on the semiconductor substrate; (b) anisotropically etching the semiconductor substrate to form a top portion of a STI trench in the semiconductor substrate, using the mask layer pattern as an etch mask; (c) forming a laterally curved middle portion of the STI trench by isotropically etching the semiconductor substrate at about the bottom height of the recess channel trench, using the mask layer pattern as an etch mask; (d) anisotropically etching the semiconductor substrate to form a bottom portion of the STI trench, using the mask layer pattern as an etch mask; and (e) forming an insulating layer that fills the STI trench.