SEMICONDUCTOR DEVICE AND PRODUCTION METHOD FOR SAME

摘要

A semiconductor device (100), comprising: a substrate (1) having a semiconductor layer (102); a trench (12) in the semiconductor layer (102); a gate insulating film (11) that covers the periphery and the inside surfaces of the trench (12); a gate electrode (8) upon the gate insulating film (11), having a peripheral section and a section that buries the trench (12); an interlayer insulating film (13) upon the gate electrode (8); and a cavity (50) sandwiched between the gate electrode (8) and the gate insulating film (11) in the periphery and upper ridge sections of the trench (12). In the upper section of the trench (12), the cavity (50) protrudes to the inside of the trench (12) in the gate insulating film (11) from an extension surface of the upper surface of the section that flatly covers the side surface of the trench (12).