GAN-BASED SCHOTTKY BARRIER DIODE WITH FIELD PLATE

1 . A method for fabricating a gallium nitride (GaN) Schottky diode, the method comprising:

providing an n-type GaN substrate having a first surface and a second surface opposing the first surface;

forming an n-type GaN epitaxial layer coupled to the first surface of the n-type GaN substrate;

removing at least a portion of the n-type GaN epitaxial layer to form a first exposed surface;

forming a dielectric layer coupled to the first exposed surface, the dielectric layer formed using spin coating;

removing at least a portion of the dielectric layer; and

forming a Schottky metal structure coupled to a portion of the n-type GaN epitaxial layer and a remaining portion of the dielectric layer such that:

the remaining portion of the dielectric layer is disposed between the n-type GaN epitaxial layer and the Schottky metal structure; and

the Schottky metal structure forms a Schottky barrier with the portion of the n-type GaN epitaxial layer.

2 . The method of claim 1 wherein removing at least a portion of the n-type GaN epitaxial layer comprises forming a second exposed surface angled with respect to the first exposed surface.

3 . The method of claim 1 wherein removing at least a portion of the dielectric layer comprises forming a first surface of the dielectric layer that is angled with respect to a second surface of the dielectric layer.

4 . The method of claim 3 wherein the first surface has a varying slope with respect to the second surface.

5 . A method for fabricating a III-nitride semiconductor device, the method comprising:

providing a III-nitride substrate having a first surface and a second surface opposing the first surface;

forming a III-nitride epitaxial layer coupled to the first surface of the III-nitride substrate;

removing at least a portion of the III-nitride epitaxial layer to form a first exposed surface;

forming a dielectric layer coupled to the first exposed surface;

removing at least a portion of the dielectric layer; and

forming a metallic layer coupled to a remaining portion of the dielectric layer such that the remaining portion of the dielectric layer is disposed between the III-nitride epitaxial layer and the metallic layer.

6 . The method of claim 5 wherein forming the dielectric layer comprises using a spin-coating technique.

7 . The method of claim 5 wherein removing at least a portion of the III-nitride epitaxial layer comprises forming a second exposed surface angled with respect to the first exposed surface.

8 . The method of claim 7 wherein an angle between the first exposed surface and the second exposed surface is between 45° and 90°.

9 . The method of claim 5 wherein removing at least a portion of the dielectric layer comprises forming a first surface of the dielectric layer that is angled with respect to a second surface of the dielectric layer.

10 . The method of claim 9 wherein an angle between the first surface of the dielectric layer and the second surface of the dielectric layer is less than 45°.

11 . The method of claim 9 wherein the first surface has a varying slope with respect to the second surface.

12 . The method of claim 5 wherein forming the metallic layer further includes forming a Schottky metal structure coupled to a portion of the III-nitride epitaxial layer, the Schottky metal structure forming a Schottky barrier with the portion of the III-nitride epitaxial layer.

13 . The method of claim 5 wherein the dielectric layer includes at least one of benzocyclobutene (BCB) or spin-on glass (SOG).