Dependence of energy band offsets at Ge2Sb2Te5/SiO2 interface on nitrogen concentration

Abstract

The electronic property for a series of nitrogen-doped Ge2Sb2Te5 phase change material was characterized using high-resolution x-ray photoelectron spectroscopy. The Te 3d5/2 and Si 2p core-level spectra as well as valence band spectra were used in the analysis. As the nitrogen content increases, the valence band offset also decreases, while that of the conduction band increases. Our results show that the valence band and conduction band offsets of nitrogen-doped Ge2Sb2Te5 on silicon oxide exhibit a linear dependence on nitrogen content in the film, for nitrogen content of up to 8.4 at. %.