High electron mobility transistor with deep charge carrier gas contact structure

Abstract

A method of forming a semiconductor device includes providing a heterojunction semiconductor body. The heterojunction semiconductor body includes a type III-V semiconductor back-barrier region, a type III-V semiconductor channel layer formed on the back-barrier region, and a type III-V semiconductor barrier layer formed on the back-barrier region. A first two-dimensional charge carrier gas is at an interface between the channel and barrier layers. A second two-dimensional charge carrier gas is disposed below the first two-dimensional charge carrier gas. A deep contact structure in the heterojunction semiconductor body that extends through the channel layer and forms an interface with the second two-dimensional charge carrier gas is formed. The first semiconductor region includes a first contact material that provides a conductive path for majority carriers of the second two-dimensional charge carrier gas at the interface with the second two-dimensional charge carrier gas.