GaN/AlGaN/GaN dispersion-free high electron mobility transistors

US7700973B2 · kind B2 · utility

Assignee

• The Regents of the University of California · US

Inventors

• Likun Shen · Goleta, US
• Sten Heikman · Goleta, US
• Umesh Mishra · Montecito, US

Key dates

• Filing date: Oct 12, 2004
• Grant date: Apr 20, 2010
• Expiry date: Oct 12, 2024

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D62/8503

Abstract

A dispersion-free high electron mobility transistor (HEMT), comprised of a substrate; a semi-insulating buffer layer, comprised of gallium nitride (GaN) or aluminum gallium nitride (AlGaN), deposited on the substrate, an AlGaN barrier layer, with an aluminum (Al) mole fraction larger than that of the semi-insulating buffer layer, deposited on the semi-insulating buffer layer, an n-type doped graded AlGaN layer deposited on the AlGaN barrier layer, wherein an Al mole fraction is decreased from a bottom of the n-type doped graded AlGaN layer to a top of the n-type doped graded AlGaN layer, and a cap layer, comprised of GaN or AlGaN with an Al mole fraction smaller than that of the AlGaN barrier layer, deposited on the n-type doped graded AlGaN layer.