Improved surface morphology and mobility of AlGaN/GaN HEMT grown on silicon substrate

Abstract

AbstractHigh mobility AlGaN/GaN HEMT was grown on silicon substrates by MOCVD. Smooth and crack‐free wafers were obtained by implementation of an AlN/AlGaN super‐lattice interlayer. We also found that the carrier gases have a great influence on the surface morphology of the AlGaN barrier. With a proper ratio of carrier gases, the AlGaN surface is significantly improved. With other optimized growth conditions, the electron mobility of HEMT can be as high as 1650 cm2/Vs. HEMT devices are also fabricatied and the reverse biased gate leakage current was reduced to 6.5 μA/mm at Vgs = ‐35 V. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)