F. Ren

Dept. of Chem Eng., University of Florida, Gainesville

  • 12.19 – kV-Class Vertical p-n Heterojunction Rectifier Based on ITO/Diamond

    H. -H. Wan, University of Florida
    C. -C. Chaing, University of Florida, Gainesville, FL
    J. -S. Li, University of Florida, Gainesville, FL
    F. Ren, Dept. of Chem Eng., University of Florida, Gainesville
    Stephen Pearton, University of Florida

    12.19 Final.2025

    Abstract
    ITO layers were sputter-deposited onto commercially available vertical p/p+ diamond structures consisting of 5 μm thick p-type (1.2 × 1016 cm-3) drift layers deposited by Chemical Vapor Deposition on 250 μm thick heavily B-doped (3 × 1020 cm-3) single crystal substrates. The ITO is found to form a type II band alignment allowing Ohmic contact to the p-type diamond and creating a vertical n-p heterojunction. The maximum reverse breakdown of heterojunction rectifiers was ~1.1 kV, with an on-resistance (RON) of 13 mΩ•cm2, leading to a power figure-of-merit of 99.3 MW/cm2. The on-voltage was 1.4 V, diode ideality factor 1.22, with a reverse recovery time of 9.5 ns for 100 μm diameter rectifiers. The on/off ratios when switching from -5 V forward to 100 V reverse were in the range of 1011 to 1012. This is a simple approach to realizing high performance vertical diamond-based rectifiers for power switching applications.