Al2O3/InAs metal-oxide-semiconductor capacitors on (100) and (111)B substrates

Abstract

The influence of InAs orientations and high-k oxide deposition conditions on the electrical and structural quality of Au/W/Al2O3/InAs metal-oxide-semiconductor capacitors was investigated using capacitance-voltage (C-V) and x-ray photoemission spectroscopy techniques. The results suggest that the interface traps around the conduction band edge are correlated to the As-oxide amount, while less to those of As-As bonds and In-oxides. The quality of the deposited Al oxide determines the border trap density, hence the capacitance frequency dispersion. The comparison of different processing conditions is discussed, favoring a 350 °C high-k oxide deposition on (111)B substrates followed by an annealing procedure at 400 °C.