ENHANCEMENT-MODE HIGH ELECTRON MOBILITY TRANSISTOR STRUCTURE AND METHOD OF MAKING SAME

摘要

An epitaxial structure, such as an enhancement-mode high electron mobility transistor (HEMT) includes a first barrier layer over an aluminum gallium nitride channel layer. The first barrier layer is formed at a first temperature and is overlaid by a second barrier layer formed at a second temperature that is lower than that of the first temperature. The first barrier layer acts as an etch stop when forming a gate recess in the second barrier layer by a wet or dry etching.

主权项

1. An epitaxial structure, comprising:
a) a substrate; b) a buffer layer on the substrate, the buffer layer including gallium nitride; c) a channel layer over the buffer layer, the channel layer consisting essentially of InxGa1-xN, where 0≦x≦1, and wherein the channel layer includes a 2-dimensional electron gas region distal to the buffer layer; d) a first AlN barrier layer over the channel layer formed at a first temperature; and e) a second AlN barrier layer on the first barrier layer, the second barrier being formed at a second temperature, the second temperature being lower than the first temperature, at which the first barrier layer is formed.