In-Depth Profile of Hf-Based Gate Insulator Films on Si Substrates Studied by Angle-Resolved Photoelectron Spectroscopy Using Synchrotron Radiation

抄録

  We have investigated chemical-state-resolved in-depth profiles of HfO₂/SiO_x and HfSiO/SiO_xN_y films using angular-dependent photoemission spectroscopy and Maximum-entropy method. Maximum-entropy method enables to reproduce the stack structure from angular-dependence of core-level spectra and it is utilized to determine atomic concentration of the interfacial layer. For the HfO₂/SiO_x film, it is elucidated that the Si⁺ and Si²⁺ sub-oxide components are located in the vicinity of Si substrate and Si³⁺ is distributed around the interfacial layer. In addition, annealing-temperature dependence of in-depth profile for the HfSiO₂/SiO_xN_y film have been demonstrated, which reveals that Si oxide components diffuse from the interfacial SiO_xN_y layer into the HfSiO layer during annealing.