Identification of boron-related traps via capacitance spectroscopy in diamond Schottky diodes

We present a comprehensive investigation of boron-related trapping phenomena in diamond Schottky diodes based on capacitance-voltage (CV) measurements and isothermal capacitance transient spectroscopy (ICTS). The CV characteristics exhibit a pronounced hysteresis, whose magnitude increases with temperature, thus indicating the presence of temperature-activated charge trapping within the depletion region. ICTS measurements reveal the presence of two distinct trapping processes. The faster process exhibits an activation energy of (0.39 ± 0.02) eV and an unconventional apparent capture cross-section of 1.9 × 10−20 cm2. The extracted activation suggests that the trap is related to substitutional boron. By varying the filling time, we observed an emission process that follows a stretched exponential trend, which is ascribed to a distribution of trap levels. The characterization of the dynamic behavior of boron-related traps with temperature is highly relevant for studying the dynamic properties of diamond-based Schottky-barrier diodes and transistors.