Deep UV-assisted capacitance–voltage characterization of post-deposition annealed Al2O3/<b> <i>β</i> </b>-Ga2O3 (001) MOSCAPs

Abstract

In this Letter, the interface state density (Dit) and bulk trap density (nbulk) in post-deposition annealed Al2O3/β-Ga2O3 (001) metal–oxide–semiconductor capacitors (MOSCAPs) are extracted using the deep UV-assisted capacitance–voltage method and an improved physical analytical model. The effects of atomic layer deposition (ALD) temperature and post-deposition annealing (PDA) conditions are also studied. Increasing the deposition temperature and PDA at 500 °C in O2 seems to be an effective way to improve the forward breakdown voltage (BV) and suppress capacitance–voltage hysteresis in Al2O3/β-Ga2O3 (001) MOSCAPs. These results are useful for future high performance Ga2O3-based metal-oxide-semiconductor field effect transistors (MOSFETs) and Fin-FETs.