Patent ID: 9263320
Filing Date: 2016-02-16
CPC Classification: H01L

Claim Text:
1. A method of manufacturing a semiconductor device, comprising the steps of: (a) forming a trench portion in a main surface of a semiconductor substrate; (b) forming a first insulating film having a silicon oxide film in the trench portion and over the main surface of the semiconductor substrate by chemical vapor deposition with a first gas containing an ozone gas and a tetraethoxysilane gas; (c) forming a second insulating film having a silicon oxide film over the first insulating film by plasma chemical vapor deposition; and (d) forming a third insulating film having a silicon oxide film over the second insulating film by chemical vapor deposition with a second gas containing an ozone gas and a tetraethoxysilane gas, wherein in the step (b), the first insulating film covers therewith a first side surface of the trench portion, wherein in the step (c), the second insulating film covers therewith the first side surface of the trench portion via the first insulating film, and wherein in the step (d), the third insulating film closes therewith the trench portion while leaving a space in the trench portion.