METHOD OF FORMING SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a method of forming a semiconductor device by which a leakage current from a bottom surface of a bit line formed in a trench is reduced and a problem such as a decrease in processability due to a high aspect ratio of the trench is not caused by stably forming a film in a space in the trench in a subsequent process without greatly increasing the aspect ratio. SOLUTION: In the method of manufacturing the semiconductor device, the trench is formed in a semiconductor substrate. A first insulating film is formed on the bottom surface of a trench internal wall. A second insulating film larger in film thickness than the first insulating film is formed by thermal oxidation on a side face of the trench internal wall. The bit line 120b is formed on the first insulating film in the trench. COPYRIGHT: (C)2011,JPO&INPIT