Qin, XiaoyeDong, HongKim, JiyoungWallace, Robert M.2014-12-182014-12-182014-10-09Qin, X., H. Dong, J. Kim, and R. M. Wallace. 2014. "A crystalline oxide passivation for Al₂O₃/AlGaN/GaN." Applied Physics Letters 105(14): 141604-1 to 5.0003-6951http://hdl.handle.net/10735.1/4235In situ X-ray photoelectron spectroscopy and low energy electron diffraction are performed to study the formation of a crystalline oxide on the AlGaN surface. The oxidation of the AlGaN surface is prepared by annealing and remote N₂+O₂ plasma pretreatments resulting in a stable crystalline oxide. The impact of the oxide on the interface state density is studied by capacitance voltage (C-V) measurements. It is found that a remote plasma exposure at 550⁰ C shows the smallest frequency dispersion. Crystalline oxide formation may provide a novel passivation method for high quality AlGaN/GaN devices.en©2014 AIP Publishing LLCAluminum oxideAluminium gallium nitrideGallium nitrideCrystalline oxidearticle10514