METHOD FOR FORMING TRENCH ISOLATION

摘要

PURPOSE: A trench isolation formation method is provided to prevent a damage of silicon lattices, such as a dislocation and a stress of a silicon substrate by forming a thermal oxide layer on a trench and by rounding edge portions of the trench. CONSTITUTION: A semiconductor substrate(10) is vertically etched by using a trench formation pattern as a mask to form an opening, and the substrate of the lower portion of the opening is etched to form a trench, thereby rounding the edge portions of the trench. A thermal oxide layer(16) is formed at both sidewalls and the bottom of the trench so as to remove a damage and a stress of the substrate(10). An oxidation barrier layer made of SiON is formed on the thermal oxide layer(16). An insulating substance is filled into the trench and annealed in order to densify the insulating substance.