Studies on electron beam evaporated ZrO 2 /AlGaN/GaN metal–oxide–semiconductor high‐electron‐mobility transistors

Metal–oxide–semiconductor high‐electron‐mobility transistors were demonstrated on AlGaN/GaN with electron beam (EB) evaporated ZrO 2 . The composition of the EB deposited ZrO 2 thin films was confirmed using X‐ray photoelectron spectroscopy (XPS). The fabricated ZrO 2 ‐based MOSHEMTs exhibited high positive gate voltage of operation up to +7 V with low gate leakage current. For a comparison, conventional high‐electron‐mobility transistors (HEMTs) were also fabricated with identical device dimensions. The maximum drain current densities of 1168 and 538 mA/mm were observed on MOSHEMTs and HEMTs, respectively. Low gate leakage current density of four orders of magnitude was observed on ZrO 2 ‐based MOSHEMTs when compared with the conventional HEMTs. The observation of high forward on‐voltage with low gate leakage current density and high positive operational voltage reveals the importance of ZrO 2 dielectric films for MOSHEMT devices. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)