Patent ID: 9006820
Filing Date: 2015-04-14
Classification: H01L

Abstract:
1. A transistor, comprising: a semiconductor body; a body region of a first conductivity type formed in the semiconductor body; a gate electrode formed partially overlapping the body region and insulated from the semiconductor body by a gate dielectric layer; a source diffusion region of a second conductivity type formed in the body region on a first side of the gate electrode; a trench formed in the semiconductor body on a second side, opposite the first side, of the gate electrode, the trench being lined with a sidewall dielectric layer; a doped sidewall region of the second conductivity type formed in the semiconductor body along the sidewall of the trench outside of the trench, the doped sidewall region forming a vertical drain current path for the transistor, the drain current of the transistor flowing in the doped sidewall region in the semiconductor body outside of the trench; a trench bottom doped region of the second conductivity type formed in the semiconductor body beneath the trench and in electrical contact with the doped sidewall region formed in the semiconductor body along the sidewall of the trench; and a first conductive layer formed in the trench and in electrical contact with the trench bottom doped region, the sidewall dielectric layer of the trench has a thickness sufficient to electrically isolate the first conductive layer from the doped sidewall region along the sidewall of the trench, the first conductive layer forming a trench drain electrode, wherein the drain current of the transistor flowing in the vertical drain current path is directed to the trench bottom doped region and to the trench drain electrode.