Patent ID: 8685849

Claim:
A method comprising: forming a second semiconductor layer on a first semiconductor layer, wherein the first semiconductor layer has a first concentration of a first dopant type; forming a third semiconductor layer on the second semiconductor layer, wherein the third semiconductor layer has a second concentration of the first dopant type that is less than the first concentration and wherein the second semiconductor layer has a graded concentration of the first dopant type that is substantially equal to the second concentration proximate the third semiconductor layer and greater than the second concentration proximate the first semiconductor layer, wherein the width of second semiconductor layer is between ten and forty five percent of the width of the third semiconductor layer, wherein the doping profile of the second semiconductor layer has a concentration approximately equal to the doping concentration in the third semiconductor layer proximate the third semiconductor layer, and wherein the doping concentration of the second semiconductor layer is between five and twenty times greater than the doping concentration of the third semiconductor layer proximate the first semiconductor layer; forming a guard region in the third semiconductor layer opposite the second semiconductor layer, wherein the guard region has a first concentration of a second dopant type such that the width and smooth graded doping profile of the second semiconductor layer reduces an electric field proximate the guard region; and depositing a metal layer on the third semiconductor opposite the second semiconductor layer and a portion of the guard region, wherein the metal layer forms a Schottky junction with the third semiconductor layer.