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

摘要

SrHfO3 is a potential dielectric material for metal-oxide-semiconductor (MOS)devices. SrHfO3/GaAs interface has attracted attention due to its uniqueproperties. In this paper, the interface properties of (001) SrHfO3/GaAs areinvestigated by frst principles calculations based on density functional theory(DFT). Firstof all, the adsorption behavior of Sr, Hf and O on GaAs surface isinvestigated. O has lower adsorption energy on Ga surface than on As surface.Then, some possible (0 0 1) SrHfO3/GaAs confgurations are considered to analyzethe interface spacing, stability, band offsets and charge transfer. HfO2/Ga(2)and SrO/Ga(1) configurations in binding energy are lower than other interfaceconfigurations, indicating that they are more stable. At last, we study theelectronic properties of HfO2/Ga(2) and SrO/Ga(1) configurations. Theelectronic density of states suggests that the systems exhibit metallicbehavior. The band offset and charge transfer are related to the interfacespacing. The valence band offset (VBO) and charge transfer will decrease withincreasing interface spacing.