Patent ID: 7521732

Claim:
A vertical heterostructure field effect transistor, comprising: an n-type first metal nitride layer having a first bandgap; an undoped second metal nitride layer disposed on a surface of the n-type first metal nitride layer and having a second bandgap; and a third metal nitride layer disposed on a surface of the undoped second metal nitride layer and having a third bandgap that differs from the first bandgap and the second bandgap, wherein an interface of the third metal nitride layer and the first metal nitride layer forms a 2D electron gas at a first region, and the first region is in electrical communication with a first electrode, and the first electrode is reversibly electrically isolated from a second electrode that is in electrical communication with a second region, and an interface of the third metal nitride layer and the second metal nitride layer defines a third region interposed between the first region and the second region, and in which a 2D electron gas is capable of forming in response to a voltage potential applied to a proximate gate electrode, and the formation of the 2D electron gas in the third region reversibly provides electrical communication of the first region with the second region, wherein the sum total of the first region, the second region, and the third region define an electrically conductive pathway or circuit that extends from the first electrode to the second electrode with the third region being a reversibly electrically-conductive, normally-off switch that blocks a flow of electricity from the first electrode to the second electrode if there is little or no electrical potential applied to the gate electrode, and that permits the flow of electricity from the first electrode to the second electrode if there is a sufficient electrical potential applied to the gate electrode, each of the first, second and third regions being a portion of the conductive pathway or circuit.