Uniformity Of Algan/Gan Hemts Grown By Ammonia-Mbe On 2-In. Sapphire Substrate

The uniformity of AlGaN/GaN high electron mobility transistor (HEMT) devices has been studied across a 2-in. wafer. The material was grown by ammonia molecular beam epitaxy (MBE) on a sapphire substrate. The devices exhibit uniformity comparable to that obtained by other growth technologies. Parameters measured include peak current density, transconductance, contact and sheet resistances, gate leakage current, f(T) and f(max) current collapse under dc, pulsed, and stressed conditions. The effects of wafer bowing on the quality of the contact lithography were explicitly considered. The results indicate excellent potential of ammonia MBE for the growth of commercially useful materials. (c) 2005 The Electrochemical Society. All rights reserved.