Patent ID: 9054129
Filing Date: 2015-06-09
Classification: H01L

Abstract:
1. A semiconductor device, comprising: a semiconductor substrate having a first conductivity type; an epitaxial structure of the first conductivity type disposed over the semiconductor substrate; a well region of a second conductivity type formed in the epitaxial structure and the semiconductor substrate, wherein the second conductivity type is opposite to the first conductivity type; a drain region and a source region respectively formed in the epitaxial structure inside and outside of the well region; at least one set of first, second and third heavily doped regions formed in the well region between source and drain regions, wherein the first, second and third heavily doped regions are adjoined sequentially from bottom to top and the second heavily doped region has a doping concentration greater than that of the well region, and the first and third heavily doped regions have a doping concentration similar to that of the well region, wherein the second heavily doped region has the first conductivity type, while the first and third heavily doped regions have the second conductivity type; and a gate structure disposed over the epitaxial structure.