Patent ID: 7220661

Claim:
A method of fabricating a rectifier comprising: epitaxial depositing a semiconductor layer, having a first concentration of a first type of dopant, upon a substrate having a second concentration of said first type of dopant; etching a plurality of trenches into said epitaxial deposited semiconductor layer; implanting said epitaxial deposited semiconductor layer proximate a bottom of said plurality of trenches at a third concentration of a second type of dopant, wherein a portion of said epitaxial deposited semiconductor layer proximate walls of said plurality of trenches is not implanted with said second type of dopant, and said implanting forms a plurality of substantially concentric rings of semiconductor material doped with the second type of dopant: depositing a dielectric in said plurality of trenches; and depositing a first metal layer upon said epitaxial deposited semiconductor layer, wherein said first metal layer is separated from said epitaxial deposited semiconductor layer implanted with said second type of dopant by said dielectric.