Interface spacing, stability, band offsets, and electronic properties on a (001) SrHfO3/GaAs interface: First-principles calculations

Abstract

SrHfO 3 is a potential dielectric material for metal-oxide-semiconductor (MOS) devices. SrHfO 3 /GaAs interface has attracted attention due to its unique properties. In this paper, the interface properties of (001) SrHfO 3 /GaAs are investigated by first principles calculations based on density functional theory (DFT). First of all, the adsorption behavior of Sr, Hf and O on GaAs surface is investigated. O has lower adsorption energy on Ga surface than on As surface. Then, some possible (0 0 1) SrHfO 3 /GaAs configurations are considered to analyze the interface spacing, stability, band offsets and charge transfer. HfO 2 /Ga(2) and SrO/Ga(1) configurations in binding energy are lower than other interface configurations, indicating that they are more stable. At last, we study the electronic properties of HfO 2 /Ga(2) and SrO/Ga(1) configurations. The electronic density of states suggests that the systems exhibit metallic behavior. The band offset and charge transfer are related to the interface spacing. The valence band offset (VBO) and charge transfer will decrease with increasing interface spacing.