SEMICONDUCTOR DEVICE

摘要

The semiconductor device includes: a channel layer, a barrier layer, a first insulating film, and a second insulating film, each of which is formed above a substrate; a trench that penetrates the second insulating film, the first insulating film, and the barrier layer to reach the middle of the channel layer; and a gate electrode arranged in the trench and over the second insulating film via a gate insulating film. The bandgap of the second insulating film is smaller than that of the first insulating film, and the bandgap of the second insulating film is smaller than that of the gate insulating film GI. Accordingly, a charge (electron) can be accumulated in the second (upper) insulating film, thereby allowing the electric field strength at a corner of the trench to be improved. As a result, a channel is fully formed even at a corner of the trench, thereby allowing an ON-resistance to be reduced and an ON-current to be increased.

主权项

1. A semiconductor device comprising:
a first nitride semiconductor layer formed above a substrate; a second nitride semiconductor layer that is formed over the first nitride semiconductor layer and has a bandgap wider than that of the first nitride semiconductor layer; an insulating film formed above the second nitride semiconductor layer; a trench that penetrates the insulating film and the second nitride semiconductor layer to reach a middle of the first nitride semiconductor layer; and agate electrode formed in the trench and over the insulating film via a gate insulating film, wherein the insulating film has a first film and a second film formed over the first film, and wherein a bandgap of the second film is smaller than that of the first film.