Method for self-aligned shallow trench isolation and method of manufacturing non-volatile memory device comprising the same

Abstract

A method of self-aligned shallow trench isolation and a method of manufacturing a non-volatile memory using the same are disclosed. An oxide layer, a first conductive layer and a nitride layer are successively formed on a semiconductor substrate. By using a single mask, the nitride layer, the first conductive layer and the oxide layer are etched to form an oxide layer pattern, a first conductive layer pattern and a nitride layer pattern. Subsequently, the upper portion of the substrate adjacent to the first conductive layer pattern is etched to form a trench. A CVD-oxide layer is deposited on the inner surface of the trench to form a trench inner-wall oxide layer, thereby preventing the formation of a positive profile at the sidewalls of the first conductive layer pattern. The trench inner-wall oxide layer is annealed in an N O or NO atmosphere to form an oxynitride layer at the interface between the substrate and trench inner-wall oxide layer. Finally, a field oxide layer that fills up the trench is formed. Because the trench inner-wall oxide layer is formed by a CVD method to prevent the sidewalls of the first conductive layer pattern from having positive slopes, a conductive residue does not remain during a subsequent gate etching process.