Thermal stability and energy-band alignment of nitrogen-incorporated ZrO2 films on Si(100)

Thermal stability and energy-band alignment of ZrOxNy films on Si are investigated using x-ray photoelectron spectroscopy and spectroscopy elliposometry (SE). The results show that the Zr–N bonds in as-oxidized ZrOxNy films are thermally unstable, while the N–O bonds in ZrOxNy matrix are stable even at high annealing temperature of 900°C. Optical properties are also analyzed based on the SE fitting results. The slight blueshift in the absorption edge indicates the increased band gap from 3.9to5.1eV after the additional annealing. Based on the valence-band spectrum results, zero-field energy-band alignments for ZrOxNy∕Si and ZrOxNy∕SiO2∕Si stacks are extracted.