Epitaxial edge termination for silicon carbide Schottky devices and methods of fabricating silicon carbide devices incorporating same

A method of fabricating a silicon carbide Schottky rectifier, the method comprising the steps of:

• forming a first n-type silicon carbide epitaxial layer on an n-type silicon carbide substrate, wherein the first n-type silicon carbide epitaxial layer has a carrier concentration less than a carrier concentration of the silicon carbide substrate;
• forming a p-type silicon carbide epitaxial layer on the first n-type epitaxial layer;
• forming a patterned passivating oxide on the p-type silicon carbide epitaxial layer to expose a portion of the p-type silicon carbide corresponding to a Schottky contact of the Schottky rectifier;
• thermally oxidizing the exposed portion of the p-type silicon carbide to oxidize the p-type silicon carbide to the first n-type epitaxial layer;
• then
• depositing and annealing an ohmic contact metal on the substrate opposite the first n-type epitaxial layer so as to provide an ohmic contact to the substrate;
• then
• removing the oxidized p-type silicon carbide to expose a portion of the first n-type epitaxial layer corresponding to the Schottky contact;
• and
• forming a Schottky metal on the exposed portion of the first n-type epitaxial layer so as to provide a Schottky contact to the first n-type epitaxial layer.