Enhanced in-plane uniformity and breakdown strength of diamond Schottky barrier diodes fabricated on heteroepitaxial substrates
Phongsaphak Sittimart, Shinya Ohmagari, Tsuyoshi Yoshitake
Abstract
Abstract In this study, pseudo-vertical diamond Schottky barrier diodes (SBDs) were fabricated on heteroepitaxial substrates and a metal impurity-incorporated buffer layer to suppress killer defects was inserted. All SBDs exhibited excellent rectifying actions with suppressed leakage current. The in-plane uniformity was improved after the insertion of the buffer layer. Forward characteristics were fitted by thermionic emission theory and Tung’s model in the temperature range from 300 to 480 K. The perfection of the Schottky-diamond interface is discussed. Moreover, the SBDs exhibited a high breakdown voltage with a sudden increase in current at 375 V, which is the highest value reported for heteroepitaxial diamond. These results indicate that heteroepitaxial substrates are a promising alternative for large-area low-cost diamond electronics.