Patent ID: 8679954

Claim:
A method for making a schottky diode, the method comprising: preparing an SiC substrate including a first surface and a second surface opposite to the first surface; forming a semiconductor layer on the first surface of the SiC substrate; forming a guard ring in the semiconductor layer by ion injection; forming an insulation layer on the semiconductor layer, the insulation layer covering the guard ring; forming an ohmic electrode on the second surface of the SiC substrate, thereby providing a first laminated body made up of the SiC substrate, the semiconductor layer, the guard ring, the insulation layer and the ohmic electrode; subjecting the first laminated body to a first heat treatment; forming an opening in the insulation layer after the first heat treatment, thereby exposing a part of the semiconductor layer and a part of the guard ring through the opening; forming a schottky electrode and a metal layer covering the schottky electrode, thereby providing a second laminated body made up of the first laminated body, the schottky electrode and the metal layer, the schottky electrode being configured to cover the exposed pan of the semiconductor layer and the exposed part of the guard ring; and subjecting the second laminated body to a second heat treatment.