Patent ID: 8304312
Filing Date: 2012-11-06
Classification: H01L

Abstract:
1. A method for forming a semiconductor power device on a semiconductor substrate comprising: providing a semiconductor substrate; opening a plurality of deep, trenches in the semiconductor substrate and growing an epitaxial layer that fills said deep trenches and covers a top surface of said semiconductor substrate with a top epitaxial layer, wherein the portions of the epitaxial layer in the epitaxial deep trench and said top epitaxial layer are simultaneously grown as a single layer and wherein the epitaxial layer is of an opposite conductivity type as the semiconductor substrate; and forming a plurality of trench MOSFET cells in said top epitaxial layer by opening a plurality of trench gates and implanting a plurality of gate-shielding dopant regions below said gate trenches for shielding trench gates of said transistor cells during a voltage breakdown of said semiconductor power device with the top epitaxial layer acting as the body region and the semiconductor substrate acting as the drain region, wherein a super junction effect is achieved through charge balance between the portions of the epitaxial layer in the deep trenches and the portions of the semiconductor substrate lateral to the deep trenches.