POWER MOSFET AND MANUFACTURE THEREOF

摘要

PURPOSE: To prevent a strong field from being generated in a power MOSFET device by dividing a single crystal semiconductor into a main active region and a peripheral termination region thereby obtaining a novel terminal structure. CONSTITUTION: An annular BPSG part 2012E and an underlying thin oxide section 2008C2 isolate a termination metal part 2015B from a polysilicon section 2003C1 extending along the inner edge of an opening 2013E. The polysilicon section 2003C1 of a field plate is isolated from an underlying epitaxial layer by an thin oxide 2002. When it is biased reversely with high voltage, a depletion region is formed along the upper side face of the epitaxial layer 2000 under influence of the underlying polysilicon section 2003C1. According to the structure, generation of undesired strong field is prevented and the performance of MOSFET can be enhanced.