Power MOSFET semiconductor device and method of manufacturing the same

摘要

A semiconductor device includes a semiconductor substrate (11) of a first conductivity type, on which a semiconductor layer (12) having a trench (15) extending in the depth direction toward the semiconductor substrate (11) is formed. A first region (19) of the first conductivity type is formed in the depth direction along one side of the trench (15) in the semiconductor layer (12) and contacts the semiconductor substrate (11). A second region (25) of the first conductivity type is formed in a surface area of the semiconductor layer (12) and close to the trench (15) and contacts the first region (19). A third region (26) of the second conductivity type is formed in the surface area of the semiconductor layer (12). A fourth region (27) of the first conductivity type is formed in a surface area of the third region (26). A gate insulation film and a gate electrode (29) are provided on the surface of the third region (26) between the second region (25) and the fourth region (27). <IMAGE>