Demonstration and analysis of reduced reverse-bias leakage current via design of nitride semiconductor heterostructures grown by molecular-beam epitaxy

An approach for reducing reverse-bias leakage currents in Schottky contacts formed to nitride semiconductor heterostructures grown by molecular-beam epitaxy is described, demonstrated and analysed. By incorporation of a GaN cap layer atop a conventional Al(sub x)Ga(sub 1-x)N/GaN heterostructure field-effect transistor epitaxial layer structure, the direction of the electric field at the metal-semiconductor interface of a Schottky contact is reversed, resulting in a suppression of electron flow into conductive screw dislocations.