Method of manufacturing a semiconductor device including a seamless shallow trench isolation step

摘要

A trench is formed. A first TEOS film is deposited in the trench. Thereafter, the first TEOS film is etched back by a wet etching method up to a planarized surface of a substrate. In this way, seams and a void generated during the first TEOS film deposition step are exposed. This is attained by performing the etching under the conditions that an etching rate for the TEOS film of the upper portion of the trench is larger than that for the TEOS film of the bottom portion of the trench. Thereafter, a second TEOS film is deposited in the trench.