The Band Structure Change of Hf₀.₅Zr₀.₅O₂/Ge System upon Post Deposition Annealing


Hafnium zirconium oxide films have been utilized in negative capacitance (NC) field-effect transistors (FETs). The band alignment of semiconductor and HfZrOₓ film is critical to obtain high device performance. The band alignment of Hf₀.₅Zr₀.₅O₂/SiOₓ/Ge system before and after post deposition annealing at 500 °C is studied via angle resolved X-ray photoelectron spectroscopy, synchrotron radiation photoemission spectroscopy and UV–Visible spectroscopy. The band gap of Hf₀.₅Zr₀.₅O₂ is seen narrowed 0.27 ± 0.05 eV, and the valence band offset between Hf₀.₅Zr₀.₅O₂ and Ge decreases 0.25 eV ± 0.05 eV after PDA at 500 °C. Therefore, the conduction band offset is nearly unchanged. This work gives insights into the interface physics about Hf₀.₅Zr₀.₅O₂/SiOₓ and is valuable for Ge-based NC pFETs. ©2019 Elsevier B.V.


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Germanium, Hafnium zirconium oxide, Energy gap (Physics), Field-effect transistors, Germanium, Hafnium oxides, Molecular orbitals, Photoelectron spectroscopy, Silicon compounds, Synchrotron radiation, X ray photoelectron spectroscopy, Field-effect transistors, Zirconium compounds

National Natural Science Foundation of China (No. 61504070, 61874081, 61534004,61604112, and 61622405), and the Tianjin Natural Science Foundation (No. 15JCYBJC52000)


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