Investigation of Insulation Property Degradation in Multilayer Ceramic Capacitor: Oxygen Vacancies Migration by Electrical Field

Abstract

Raman spectroscopy is employed to evaluate a migration behavior of oxygen vacancies in BaTiO3-based multi-layer ceramic capacitor (MLCC) with Ni internal electrode before and after the highly accelerated life test (HALT). The B1 phonon mode of BaTiO3 that is associated to oxygen vibration was harden and broaden near Ni electrodes before HALT. However, harden and broaden of B1 mode were almost observed near the cathodes after HALT. It is considered that the oxygen vacancies that were localized near Ni electrodes before HALT and they were moved toward the cathode because they have positive charge. These results show that oxygen vacancies were migrated and accumulated near cathode under a de bias and caused of insulation resistance degradation of M LCCs. In addition, the Raman spectroscopy is powerful tool for investigation of structural defect distribution including oxygen vacancy with relative high spatial resolution.