In situ atomic layer deposition study of HfO2 growth on NH4OH and atomic hydrogen treated Al0.25Ga0.75N

The atomic layer deposition (ALD) of HfO2 on the native oxide, NH4OH, and atomic hydrogen treated Al0.25Ga0.75N surface was studied using in situ X-ray photoelectron spectroscopy (XPS), after each individual half cycle of the ALD process. During the deposition process, minimal change in the chemical states of Ga and Al is detected, with no evidence of interfacial oxide generation. The initial HfO2 growth rate on the native oxide Al0.25Ga0.75N surface is very low, however, exposure of the Al0.25Ga0.75N surface to atomic hydrogen decreases the concentration of carbon and oxygen and enhances the HfO2 growth rate. (C) 2013 AIP Publishing LLC.