Termination structure for gallium nitride schottky diode including junction barriar diodes

A method for forming a nitride-based Schottky diode, comprising:

• providing a nitride-based semiconductor body of a first conductivity type;
• forming a nitride-based epitaxial layer of a second conductivity type, opposite the first conductivity type, on a front side of the nitride-based semiconductor body;
• forming a first dielectric layer on the nitride-based epitaxial layer;
• etching the first dielectric layer and the nitride-based epitaxial layer to the nitride-based semiconductor body to define an opening for an anode electrode of the nitride-based Schottky diode and to form an array of islands of the nitride-based epitaxial layer in the opening, the first dielectric layer and the nitride-based epitaxial layer having a slant profile at a side facing the opening for the anode electrode;
• forming a first metal layer on the front side of the nitride-based semiconductor body to form a Schottky junction at the exposed top surface of the semiconductor body, the first metal layer forming the anode electrode of the Schottky diode;
• providing a cathode electrode in electrical contact with the nitride-based semiconductor body;
• and
• forming a plurality of junction barrier diodes at the Schottky junction, anode electrodes of the junction barrier diodes being formed from the array of islands of the nitride-based epitaxial layer of the second conductivity type formed in the opening for the anode electrode and in contact with the nitride-based semiconductor body,
• wherein the nitride-based epitaxial layer forms a guard ring and the first dielectric layer forms a dielectric field plate, the guard ring and the dielectric field plate together forming a termination structure for the Schottky diode, and the termination structure being configured to reduce electric field crowding at the edge of the anode electrode.