Tuning thermal stability and electronic properties of germanium oxide on Ge(001) surface with the incorporation of nitrogen

The application of germanium as a channel material of transistors in near future requires an improved understanding of the interface between germanium and its potential passivation layer. In this study, we study effects of nitrogen incorporation on the thermal stability and electronic properties of GeO_xN_y/Ge interface by using high‐resolution X‐ray photoemission spectroscopy. We find that with the increasing nitrogen concentration in the GeO_xN_y films, the thermal stability can be increased, while the valence band offset with the Ge(001)substrate is decreased. First‐principles calculations further suggest that the unpaired p orbitals of nitrogen atoms induce electronic states near valence band edge, contributing to the reduction of the valence band offset. Our results provide a possibility to tune electronic and thermal properties of GeO_xN_y/Ge interface by controlling nitrogen concentrations during the growth.