Improving reliability of beveled power semiconductor devices passivated by SIPOS

Semi-insulating polycrystalline silicon films were prepared by direct current glow discharge on bevelled power semiconductor devices. Devices passivated by polyimide were also fabricated for comparison studies. The reverse current-voltage characteristic was studied at room temperature and high junction temperature. The differences arose from the remnant unbalance charges in the passivants as well as the varying dielectric strengths. Passivation materials applied to the beveled devices played a key role in achieving the targeted voltage. Results obtained indicated that the performance of power semiconductor devices passivated by SIPOS were superior to those passivated by polyimide, and SIPOS based process was effective and expected to enhance the reliability and yield.