Patent ID: 8803236
Filing Date: 2014-08-12
Classification: H01L

Abstract:
1. A lateral double diffused metal-oxide-semiconductor (LDMOS) device, comprising: a semiconductor substrate, having a first conductivity type; an epitaxial semiconductor layer formed over the semiconductor substrate, having the first conductivity type; a gate structure disposed over a portion of the epitaxial semiconductor layer; a first doped region disposed in a portion of the epitaxial semiconductor layer adjacent to a first side of the gate structure, having the first conductivity type; a second doped region disposed in a portion of the epitaxial semiconductor layer adjacent to a second side of the gate structure opposite to the first side, having a second conductivity type opposite to the first conductivity type; a third doped region disposed in a portion of the first doped region, having the second conductivity type; a fourth doped region disposed in a portion of the second doped region, having the second conductivity type; a trench formed in a portion of the third doped region, the first doped region and the epitaxial semiconductor layer under in the first doped region; an insulating layer covering the third doped region, the gate structure, and a portion of the fourth doped region; a conductive layer conformably formed over a bottom surface and a plurality of sidewalls of the trench, covering the insulating layer; a dielectric layer disposed in the trench and over the conductive layer; and a diffused region disposed in a portion of the epitaxial semiconductor layer under the first doped region, having the first conductivity type, and the diffused region physically contacts the semiconductor substrate and surrounds portions of the sidewalls and the bottom surface of the trench, and the diffused region does not physically contact the first doped region.