Patent ID: 7019377

Claim:
An integrated circuit comprising: a high voltage Schottky barrier diode formed in a first region in a semiconductor layer of a first conductivity type comprising: a first field, oxide region defining a cathode region in the semiconductor layer; a first well of a second conductivity type formed in the semiconductor layer underneath an inner edge of the first field oxide region; a polysilicon layer formed partially over the inner edge of the first field oxide region and partially over the first well, the polysilicon layer being separated from the semiconductor layer by a gate oxide layer; and a metal layer formed over the polysilicon layer and the top surface of cathode region of the semiconductor layer, the metal layer forming an anode terminal, wherein the first well forms a guard ring structure surrounding an anode edge of the Schottky barrier diode; and a low voltage device formed in a second region in the semiconductor layer, the low voltage device being formed in a second well of the second conductivity type in the semiconductor layer, wherein the second well is more heavily doped than the first well, the doping level of the first well being selected to provide a breakdown voltage for the Schottky barrier diode that is higher than a breakdown voltage of the low voltage device.