GaN HEMTs AND GaN DIODES

摘要

A GaN hetereojunction structure has a three-layer dielectric structure. The lowermost and middle portions of the gate electrode together define the gate foot, and this is associated with two dielectric layers. A thinner first dielectric layer is adjacent the gate edge at the bottom of the gate electrode. The second dielectric layer corresponds to the layer in the conventional structure, and it is level with the main portion of the gate foot.

主权项

1. A GaN hetereojunction semiconductor device comprising:
a substrate; a layer structure having a first layer having a first bandgap and a second layer having a second bandgap, wherein the first layer is located between the substrate and the second layer; and a Schottky gate electrode and a first further electrode each conductively coupled to a different area of the heterojunction, said Schottky gate electrode comprising a central region and an edge region, wherein the Schottky gate electrode comprises: a lowermost portion which is co-planar with a first dielectric layer portion over the second layer; a middle portion which is co-planar with a second dielectric layer, the middle portion overlapping the lowermost portion; and an upper portion which is co-planar with a third dielectric layer, the upper portion overlapping the middle portion.