Oxygen vacancy formation and annihilation in lanthanum cerium oxide as a metal reactive oxide on 4H-silicon carbide

Abstract

A mechanism regarding the redox reaction in lanthanum cerium oxide (La_xCe_yO_z) post-deposition annealed in reducing and oxidizing atmosphere was schematized and discussed in association with the presence of lanthanum as a substitutional cation. Analyses have been performed using X-ray diffraction, energy-filtered transmission electron microscopy, scanning transmission electron microscope-energy dispersive spectroscopy line scan, and capacitance–voltage measurements. The results showed the presence of an oxygen vacancy when La³⁺ was in its substitution site, while annihilation of oxygen vacancy was accompanied by a displacement of La³⁺ from the substitutional site to the interstitial site via a kick-out mechanism prior to its disappearance from the CeO₂.