3326-V Modulation-Doped Diamond MOSFETs

This letter reports the fabrication and characterization of 3.3-kV modulation-doped diamond metal–oxide–semiconductor field-effect transistors (MOSFETs). The modulation doping was performed via NO2delta doping in the Al2O3gate layer. The modulation-doped diamond MOSFET with a gate length of2.8~μ mshowed a maximum drain current density of 0.42 A/mm, with an estimated specific ON-resistance of13.48~mΩ · cm^2. Therefore, the Baliga’s figure-of-merit (BFOM) was determined to be 820.6 MW/cm2. A subthreshold swing of 109.89 mV/dec, indicative of a high-quality Al2O3/diamond interface with an interfacial state density of1.49 × 10^12cm−2eV−1, was obtained. The maximum effective mobility was estimated to be 496 cm2/Vs near the threshold, and a maximum output power density of 46.5 W/mm was projected.