METHOD OF FORMING ISOLATION LAYER OF SEMICONDUCTOR DEVICE FOR PREVENTING PROPERTY DEGRADATION OF TUNNEL OXIDE LAYER AT CORNER OF ACTIVE REGION

摘要

PURPOSE: A method of forming an isolation layer of a semiconductor device is provided to prevent property degradation of a tunnel oxide layer at a corner portion of an active region by depositing optimally a wall oxide layer on a sluggish trench. CONSTITUTION: A predetermined structure composed of a tunnel oxide pattern(12), a polysilicon pattern(14a) and a pad nitride pattern(16a) is formed on a semiconductor substrate(10). A spacer made of insulating layer is formed at both sidewalls of the predetermined structure. A plurality of trenches(22) are formed in the substrate by performing etching using the pad nitride pattern and the spacer as an etching mask. A corner portion of an active region is exposed by removing the spacer therefrom. A wall oxide layer(24) is formed thereon and an isolation layer is filled in each trench.