Power MOSFET with metal-filled deep source contact

摘要

A planar gate power MOSFET (100) has a gate stack (111a / 112, 111b / 112) on a substrate (105) having a semiconductor surface (108) doped to a first conductivity type and a body region (113). A plurality of transistor cells (cells) each including a first cell (110a) and at least a second cell (110b) are included. A source contact (SCT) from a source (127) to a substrate doped with a second conductivity type with a trench having an aspect ratio greater than 3 and extending downward from the top side of the semiconductor surface between the gate stacks (120) is provided. A field plate (FP) (128) is above the gate stack and provides a liner for the trench. The trench has a refractory metal or platinum group metal (PGM) metal filler (122) therein. A drain (132) doped to the second conductivity type is on the opposite side of the semiconductor surface from the trench of the gate stack.