Power mosfet device with reduced snap-back and being capable of increasing avalanche-breakdown current endurance, and method of manafacturing the same

Abstract

The invention disclosed a power MOSFET with reduced snap-back and being capable increasing avalanche-breakdown current endurance, which has sequentially a drain with N+ silicon substrate, an N− epitaxial layer formed on said N+ silicon substrate, a source contact region formed of N+ doped well and P+ doped well implanted after etching in a P− well formed on said N− epitaxial layer, and a gate electrode with deposition of polysilicon above a channel between said N− epitaxial layer and N+ source contact region, said device is characterized in that: Said source contact region is formed by etching into said P− well first and implanting P+ dopant to the interface between said N− epitaxial layer and P− well, and the source contact region of said N+ well and that of said P+ well are not at the same level, by which it is possible to increase the avalanche-breakdown current endurance of the power MOSFET device.

Dependencies are inferred from the claim text.