A study on electrical properties based on nitrogen distribution in nitrogen-doped hafnium silicate through first-principles

Abstract

Nitrogen doping is a widely used method in the semiconductor industry to reduce leakage current, enhance stability, and increase the dielectric constant of hafnium silicate. This study employs first-principles calculations to analyze the changes in electrical properties resulting from nitrogen distribution in nitrogen-doped hafnium silicate (HfSiON) thin films. Various nitrogen distribution models were established using Density Functional Theory (DFT), and the band gap, density of states (DOS), and dielectric constant of each model were calculated and compared. Preliminary studies confirmed that the distance between nitrogen atoms along the z-axis significantly impacts the band gap, providing guidance for selecting model structures in this experiment. Consequently, we analyzed changes in the band gap, DOS, and dielectric constant at a constant nitrogen concentration based on the spatial positioning of nitrogen atoms. This study highlights the critical role of nitrogen distribution in determining the electrical properties of nitrogen-doped hafnium silicate thin films.