Patent ID: 8237239

Claim:
A Schottky diode device, comprising: a p-type semiconductor structure; a n drift region disposed over the p-type semiconductor structure, wherein the n drift region comprises first and second n-type doping regions having different n-type doping concentrations, and the second n-type doping region surrounds sidewalls of the first n-type doping region and is formed with a dopant concentration greater than that in the first n-type doping region, and a bottom surface of the first n-type doping region physically contacts the p-type semiconductor structure; a plurality of isolation structures disposed in the second n-type doping region of the n drift region, defining an anode region and a cathode region, wherein the anode region exposes a top surface of the first n-type doping region and the cathode region partially exposes a top surface of the second n-type doping region; a third n-type doping region disposed in the second n-type doping region exposed by the cathode region, wherein the third n-type doping region is formed with a dopant concentration greater than that in the second n-type doping region; an anode electrode disposed over the first n-type doping region in the anode region; and a cathode electrode disposed over the third n-type doping region in the cathode region.