Enhanced reliability of ultra-thin multilayer ceramic capacitors (MLCCs) based on re-oxidation process

Ultra-thin base metal electrodes-multilayered ceramic capacitors (BME-MLCCs) with high volume capacitance are considered to be a charming device for a diverse range of electric applications. Here, we fabricated the MLCCs with ultra-thin layer of ~ 1.2 μm and a high capacitance of ~ 47 μF via high oxygen re-oxidation process. Defect chemistry analysis of the re-oxidation process reveals that about 1 nm thick for inter-diffusion layer between Ni and BaTiO 3 appeared in higher oxygen re-oxidation process compared with lower oxygen re-oxidation process dominated by 3 nm thick for inter-diffusion layer. The results show that oxygen vacancy concentration is decreased when oxygen partial pressures of re-oxidation rise from 10 –6 to 10 –4 atm. In addition, the Schottky barrier at the BaTiO 3 (BT)–Ni interface increased from 1.30 to 1.82 eV, and the amount of oxygen ( x ) in BaTiO x at the interface decreased from 3 to 2.75, with a smaller decrease, which is conducive to the improvement of the overall reliability of MLCCs. The final results show that the MLCCs with high oxygen re-oxidation process demonstrated a high breakdown voltage of 52.74 V/μm and superior reliability at 2.5 V and 105 °C. This work demonstrates a strategy of effectively improving the reliability of BME-MLCCs with high capacitances.