Top-drain trench based resurf DMOS transistor structure

摘要

A top drain trench based RESURF DMOS (reduced surface field double diffused MOS) transistor structure provides improved RDSon performance by minimizing transistor cell pitch. The transistor includes a gate, a source and drain. The trench may include a nonuniform dielectric lining. A drain drift region partially surrounds the trench. Current flows laterally enabling multiple trench based RESURF DMOS transistors to be formed on a single semiconductor die. The addition of an isolation region to electrically isolate the source from the substrate allows the power transistor to be incorporated into high side driver applications as well as other application mandating electrical isolation between the source and ground.