In-situ metalorganic chemical vapor deposition and capacitance-voltage characterizations of Al2O3 on Ga-face GaN metal-oxide-semiconductor capacitors

Abstract

The in-situ metalorganic chemical vapor deposition of Al₂O₃ on Ga-face GaN metal-oxide-semiconductor capacitors (MOSCAPs) is reported. Al₂O₃ is grown using trimethylaluminum and O₂ in the same reactor as GaN without breaking the vacuum. The in-situ MOSCAPs are subjected to a series of capacitance-voltage measurements combined with stress and ultraviolet-assisted techniques, and the results are discussed based on the presence of near-interface states with relatively fast and slow electron emission characteristics. The in-situ MOSCAPs with Al₂O₃ grown at 900 and 1000 °C exhibit very small hystereses and charge trappings as well as average near-interface state densities on the order of 10¹² cm⁻²eV⁻¹.