Semiconductor device and method for producing the semiconductor device

Abstract

In one embodiment, a semiconductor device includes a substrate; a gate insulating film; first trenches in a cell array region; first embedded insulating films in the first trenches; second trenches in a peripheral circuit region; second embedded insulating films in the second trenches; a third trench in an isolation region; a third embedded insulating film in the third trench; gate structures; and inter-gate insulating films between the gate structures covering the first, second and third embedded insulating films. An upper surface of the third embedded insulating film covered with the inter-gate insulating film is substantially flat. Upper surfaces of the first, second, and third embedded insulating films are higher than an upper surface of the gate insulating film. The upper surfaces of the first and third embedded insulating films are lower than the upper surfaces of the second embedded insulating films.