Effect of atomic layer deposition growth temperature on the interfacial characteristics of HfO2/p-GaAs metal-oxide-semiconductor capacitors

The effect of atomic layer deposition (ALD) growth temperature on the interfacial characteristics of p-GaAs MOS capacitors with ALD HfO2 high-k dielectric using tetrakis(ethylmethyl) amino halfnium precursor is investigated in this study. Using the combination of capacitance-voltage (C-V) and X-ray photoelectron spectroscopy (XPS) measurements, ALD growth temperature is found to play a large role in controlling the reaction between interfacial oxides and precursor and ultimately determining the interface properties. The reduction of surface oxides is observed to be insignificant for ALD at 200 degrees C, while markedly pronounced for growth at 300 degrees C. The corresponding C-V characteristics are also shown to be ALD temperature dependent and match well with the XPS results. Thus, proper ALD process is crucial in optimizing the interface quality. (C) 2014 AIP Publishing LLC.