Trench MOS gate semiconductor device and method of fabricating the same

摘要

A semiconductor device includes a substrate having a drift region doped to a first conductivity type. A trench is formed by vertically etching an upper surface of the substrate. A gate is arranged along side walls of the trench. A gate oxide layer is arranged between the side walls of the trench and the gate and between a portion of the bottom surface of the trench and the gate. A first source region of the first conductivity type is formed on the upper surface of the substrate. A second source region of the first conductivity type is formed under the central portion of the bottom surface of the trench. A first well region is formed between the first source region and the drift region, and a second well region is formed between the second source region and the drift region. The first and second well regions are doped to a second conductivity type which is electrically opposite to the first conductivity type.