TRENCH DMOS TRANSISTOR HAVING LIGHTLY DOPED SOURCE STRUCTURE

摘要

A trench DMOS transistor cell includes a substrate of a first conductivity type and a body region located on the substrate, which has a second conductivity type. At least one trench extends through the body region and the substrate. An insulating layer lines the trench and a conductive electrode is placed in the trench overlying the insulating layer. A source region of the first conductivity type is located in the body region adjacent to the trench. The source region includes a first layer and a second layer disposed over th first layer. The first layer has a lower dopant concentration of the first conductivity type relative to the dopant concentration of the second layer.