METHOD FOR FABRICATING A POWER SEMICONDUCTOR DEVICE HAVING A FLOATING ISLAND VOLTAGE SUSTAINING LAYER

摘要

A power semiconductor device and a method of forming the same by providing a substrate 402 and then forming a voltage sustaining region on the substrate 402 by depositing an epitaxial layer 401 on the substrate 402 and forming at least one trench in the epitaxial layer 401. A barrier material is deposited along the walls of the trench and a dopant is implanted through the barrier material into a portion of the epitaxial layer 401 adjacent to and beneath the bottom of the trench. The dopant is diffused to a form a first doped layer and the barrier material is removed from at least the bottom of the trench. The trench is etched through the first doped layer and substantially filled to complete the voltage sustaining region. At least one region is formed over the voltage sustaining region to define a junction therebetween.