Method of forming trench isolation regions

Abstract

To form isolation trenches on a semiconductor substrate, chemical mechanical polishing (CMP) stopping patterns are formed on the substrate, and the substrate is then etched using the CMP stopping patterns as a mask. Then an insulating material is deposited to fill the trenches and cover the CMP stopping patterns. The insulating material is etched using a CMP process until the CMP stopping patterns become exposed, and is then etched using a wet or dry etching process. The wet or dry etching is continued until protruding insulating material above a surface of the substrate is a predetermined thickness, which corresponds to an amount of the insulating material that is etched during removal of the CMP stopping patterns and during intermediate processes prior to formation of a gate oxide layer.