Patent ID: 8969952
Filing Date: 2015-03-03
Classification: H01L

Abstract:
1. A power semiconductor device, comprising: a semiconductor substrate having a first conductivity type; an epitaxial layer on the semiconductor substrate; an ion well having a second conductivity type in the epitaxial layer, wherein the ion well has a junction depth; a gate trench in the epitaxial layer, wherein a depth of the gate trench is greater than the junction depth of the ion well; a gate oxide layer on interior surface of the gate trench; a gate within the gate trench; and at least a pocket doping region having the second conductivity type within the epitaxial layer and being situated directly under a bottom surface of the gate trench, wherein the pocket doping region extends to cover a lower sidewall of the gate trench and wherein the pocket doping region does not completely cover the bottom surface of the gate trench.