Lawrence Berkeley National Laboratory
Soft X-ray photoemission studies of Hf oxidation
- Author(s): Hamdan, N.M.
- et al.
Soft X-Ray Photoemission Spectroscopy using surface sensitive Synchrotron Radiation has been applied to accurately determine the binding energy shifts and the valance band offset of the HfO2 grown on Hf metal. Charging of oxide films under x-rays (or other irradiation) is circumvented by controlled and sequential in-situ oxidation. Photoemission results show the presence of metallic Hf (from the substrate) with the 4f7/2 binding energy of 14.22 eV, fully oxidized Hf (from HfO2) with the 4f7/2 binding energy of 18.16 eV, and at least one clear suboxide peak. The position of the valence band of HfO2 with respect to the Hf(m) Fermi level is determined as 4.05 eV.