Low temperature AIN growth by MBE and its application in HEMTs

Low temperature growth of AIN from 470 degrees C clown to room temperature has been studied by RE-plasma assisted molecular beam epitaxy (PAMBE). Partially amorphous AIN was achieved at growth temperatures below 250 degrees C. We demonstrate the application of the low temperature (LT-) AIN as an in-situ surface passivation technique for Ill-nitride based high electron mobility transistors (HEMTs). High 2DEG densities 2 x 10(13) cm(-2) and sheet resistance < 250 Omega/square at room temperature were first obtained for MBE grown AlN/GaN HEMT structures with thin high temperature AIN barrier, then capped with LT-AlN ( <4 nm). Using this novel technique, low DC-RF dispersion with gate lag and drain lag below 2% is demonstrated for an AlN/GaN HEMT. (C) 2015 Elsevier B.V.. All rights reserved.