Low interfacial trap density and high-temperature thermal stability in atomic layer deposited single crystal Y2O3/n-GaAs(001)

Abstract

A low interfacial trap density (Dit) of 2.2 × 1011 eV−1 cm−2 has been achieved with an atomic layer deposited (ALD) single crystal Y2O3 epitaxially on n-GaAs(001), along with a small frequency dispersion of 10.3% (2.6%/decade) at the accumulation region in the capacitance–voltage (C–V) curves. The Dit and frequency dispersion in the C–V curves in this work are the lowest among all of the reported ALD-oxides on n-type GaAs(001). The Dit was measured using the conductance–voltage (G–V) and quasi-static C–V (QSCV) methods. Moreover, the heterostructure was thermally stable with rapid annealing at 900 °C under various durations in He and N2, which has not been achieved in the heterostructures of ALD-Al2O3 or HfO2 on GaAs.