SEMICONDUCTOR DEVICE

摘要

A vertical MOSFET includes: a semiconductor substrate comprising a drain layer, a drift layer, a body layer, and a source layer; and a trench gate penetrating through the source layer and the body layer from an upper surface of the semiconductor substrate and reaching the drift layer. The trench gate includes a gate electrode; a first insulating film disposed on a bottom surface of a trench formed in the semiconductor substrate; a second insulating film disposed at least on a side surface of the trench, and in contact with the body layer; and a third insulating film disposed between the gate electrode and the second insulating film, and formed of a material of which dielectric constant is higher than a dielectric constant of the second insulating film.

主权项

1. A vertical MOSFET comprising:
a semiconductor substrate comprising a first conductivity type drain layer, a first conductivity type drift layer formed on an upper surface of the drain layer, a second conductivity type body layer formed on an upper surface of the drift layer, and a first conductivity type source layer formed on a part of an upper surface of the body layer; and a trench gate penetrating through the source layer and the body layer from an upper surface of the semiconductor substrate and reaching the drift layer;wherein
the trench gate comprises:
a gate electrode;a first insulating film disposed on a bottom surface of a trench formed in the semiconductor substrate and in contact with the drift laver;a second insulating film disposed on a side surface of the trench and upper surface of the first insulating film, and in contact with the body layer; anda third insulating film disposed between the gate electrode and the second insulating film, and formed of a material of which dielectric constant is higher than a dielectric constant of the second insulating film.