Patent ID: 6723617
Filing Date: 2004-04-20
Classification: H01L

Abstract:
A method of manufacturing a semiconductor device, comprising steps in order of:(a) sequentially forming a pad oxide film, a pad nitride film and a screen oxide film on a semiconductor substrate in which an active region and a field region are defined; (b) removing the screen oxide film and the pad nitride film formed in the field region; (c) performing a wet etch process to remove a portion of the pad nitride film exposed at the boundary of the active region and the field region, in a lateral direction by a given width; (d) performing a dry etch process using the screen oxide film as an etch mask to remove portions of the pad oxide film and the semiconductor substrate formed in the field region, thus forming a trench; (e) removing the screen oxide film and simultaneously removing the exposed portion of the pad oxide film below said portion of the pad nitride film removed by the wet etch process; (f) performing an oxidation process to form a rounding oxide film in the exposed portion of the semiconductor substrate after simultaneously removing the screen oxide film and the exposed portion of the pad oxide film; (g) depositing a field oxide film of a thickness by which the trench is sufficiently buried and then polishing the field oxide film; and (h) removing the pad nitride film and the pad oxide film in the active region.