SEMICONDUCTOR DEVICE INCLUDING A FLOATING GATE

摘要

A semiconductor device includes a semiconductor layer with a trench dug downward from its surface, a source region formed on a surface layer portion adjacent to a first side of the trench in a prescribed direction, a drain region formed on the surface layer portion, adjacent to a second side of the trench opposite to the first side in the prescribed direction, a first insulating film on the bottom surface and the side surface of the trench, a floating gate stacked on the first insulating film and opposed to the bottom surface and the side surface of the trench through the first insulating film, a second insulating film formed on the floating gate, and a control gate at least partially embedded in the trench so that the portion embedded in the trench is opposed to the floating gate through the second insulating film.

主权项

1. A semiconductor device comprising:
a semiconductor layer; a trench dug downward from the surface of the semiconductor layer; a source region formed on the surface layer portion of the semiconductor layer adjacently to a first side of the trench in a prescribed direction; a drain region formed on the surface layer portion of the semiconductor layer adjacently to a second side of the trench opposite to the first side in the prescribed direction; a first insulating film formed on the bottom surface and the side surface of the trench, the first insulating film having a thin portion having a relatively small thickness and a thick portion having a relatively large thickness formed by the remaining portion of the first insulating film other than the thin portion; a floating gate stacked on the first insulating film and opposed to the bottom surface and the side surface of the trench through the first insulating film; a second insulating film formed on the floating gate; and a control gate at least partially embedded in the trench so that the portion embedded in the trench is opposed to the floating gate through the second insulating film.