Patent ID: 6090669
Filing Date: 2000-07-18
Classification: H01L

Abstract:
A fabrication method for high voltage devices with at least one deep edge ring, the method comprising the steps of:(a) growing a lightly doped N-type epitaxial layer on a heavily doped N-type substrate;(b) growing an oxide on an upper portion of the epitaxial layer;(c) forming at least one opening in the oxide and implanting boron ions into the at least one opening to form at least one body region in the epitaxial layer;(d) etching the oxide adjacent the at least one body region to expose regions for aluminum ion implantation;(e) forming a layer of preimplantation oxide in the exposed regions;(f) masking the at least one body region with a layer of photosensitive material and implanting aluminum ions into substantially only the exposed regions; and(g) a single thermal diffusion process forming a layer of thermal oxide on the epitaxial layer and simultaneously forming the at least one body region and at least one deep aluminum edge ring that is adjacent the at least one body region and formed more deeply in the epitaxial layer than the at least one body region.