High-electron-mobility AlGaN∕GaN heterostructures grown on Si(001) by molecular-beam epitaxy

Abstract

The growth of AlGaN∕GaN heterostructure on Si (001) substrates by molecular-beam epitaxy using ammonia as nitrogen precursor is reported. The structural, optical, and electrical properties of such heterostructures are assessed. It is shown that a two-dimensional electron gas is formed at the Al0.23Ga0.77N∕GaN interface. This type of heterostructure exhibits a sheet carrier density of 4.2×1012cm−2 with a mobility of 730cm2∕Vs at room temperature. Preliminary results concerning high-electron-mobility-transistor static characteristics are presented.