Chemical Structure of HfO₂/Si Interface with Angle-Resolved Synchrotron Radiation Photoemission Spectroscopy

Interfacial chemical structure of HfO₂/Si (100) is investigated using angle-resolved synchrotron radiation photoemission spectroscopy (ARPES). The chemical states of Hf show that the Hf 4f binding energy changes with the probing depth and confirms the existence of Hf--Si--O and Hf--Si bonds. The Si 2p spectra are taken to make sure that the interfacial structure includes the Hf silicates, Hf silicides and SiO_x. The metallic characteristic of the Hf--Si bonds is confirmed by the valence band spectra. The depth distribution model of this interface is established.