METHOD FOR TRENCH ISOLATION, METHOD OF FORMING A GATE STRUCTURE USING THE METHOD FOR TRENCH ISOLATION AND METHOD OF FORMING A NON-VOLATILE MEMORY DEVICE USING THE METHOD FOR TRENCH ISOLATION

摘要

A trench isolation method, a method for forming a gate structure, and a method for manufacturing a non-volatile memory device are provided to suppress a leakage current at an edge portion of an active region by forming an oxide film with a constant thickness on center and edge portions. A mask pattern is formed on a substrate(100). A pad oxide film pattern(114) and a nitride film pattern(110) are laminated on the mask pattern, which defines a first aperture. The first aperture partially exposes the substrate. A portion of a substrate, which is exposed by the pad oxide film pattern, is removed, such that a second aperture is formed. The second aperture is coupled with the first aperture. A sidewall of the second aperture has a first slope. The exposed substrate is etched by using the mask pattern as an etch mask, such that a trench is formed. The trench is coupled with the second aperture and has a second slope, which is greater than the first slope. The second slope is wider than the first slope. An insulation film is formed to completely fill in the first and second apertures and the trench.