Vertical power devices having deep and shallow trenches and methods of forming same

摘要

Vertical power devices include a semiconductor substrate having a drift region of first conductivity type therein and first and second stripe-shaped trenches that extend in the semiconductor substrate and define a drift region mesa therebetween. First and second insulated source electrodes are provided in the first and second stripe-shaped trenches, respectively. A UMOSFET, comprising a third trench that is shallower than the first and second stripe-shaped trenches, is provided in the drift region mesa.