Al2O3/InGaAs interface passivation by fluorine-containing anodic layers

Abstract

The morphology, chemical composition, and electronic properties of Al2O3/InGaAs interfaces with and without anodic oxide layers, formed in DC plasma (O2, Ar) with different contents of the fluorinating component (CF4), were studied. It is shown that thin fluorinated anodic oxide layers, in combination with annealing at 300 °C, reduce the density of interface states by a factor of 3–4 over the entire bandgap. The minimum state density values near the midgap determined by the Terman method are about 2 × 1012 eV−1 cm−2. However, it is demonstrated that, in contrast to the Al2O3/InGaAs interface, the interface with a fluorinated oxide is not stable and degrades when heated above 300 °C.