Patent ID: 6333274
Filing Date: 2001-12-25
Classification: H01L

Abstract:
A method of manufacturing a semiconductor device comprising the steps of:forming a trench in a semiconductor substrate;depositing a first TEOS film in the trench, said first TEOS film having a seam in an interface thereof, by which the first TEOS film is closed at an upper portion, thereby forming a void in the first TEOS film;etching back the first TEOS film by a wet etching method using hydrofluoric acid in such a way that an etching amount of the first TEOS film in an upper portion of the trench is larger than that in a bottom portion of the trench, so as to remove the seam and the void, thereby leaving the first TEOS film at bottom corner portions and on a side wall of the trench in the form of a two-stepped taper comprising a first stepped portion formed near a bottom of the trench and having a first angle with respect to a horizontal portion, and a second stepped portion formed above the first stepped portion and having a second angle with respect to the horizontal portion, said second angle being larger than the first angle; anddepositing a second TEOS film in the trench, whereby the trench is completely filled with the second TEOS film.