First-principles study of the electronic structures and dielectric properties of the Si/SiO2 interface

摘要

A first-principles study of the electronic structures and dielectric properties of Si/SiO2 interfaces is implemented. Comparing the interfaces with and without defects, we explore the relationship between the defects and the dielectric properties, and also discuss the effect of the defects on the leakage current between the gate electrode and silicon substrate. We found that the electrons around the Fermi level percolate into the SiO2 layers, which reduces the effective oxide thickness and is expected to enhance the leakage current. The dangling bonds largely affect the dielectric properties of the interface and the termination of dangling bonds by hydrogen atoms is successful in suppressing the increase of the dielectric constant.