IEEE Electron Device Letters | 2021
345-MW/cm² 2608-V NO₂ p-Type Doped Diamond MOSFETs With an Al₂O₃ Passivation Overlayer on Heteroepitaxial Diamond
Abstract
Diamond metal oxide semiconductor field effect transistors (MOSFETs) on high-quality heteroepitaxial diamond (Kenzan diamond<sup>®</sup>) with NO<sub>2</sub> p-type doping and an Al<sub>2</sub>O<sub>3</sub> passivation overlayer exhibited a high off-state breakdown voltage of −2608 V. The 100-nm-thick Al<sub>2</sub>O<sub>3</sub> passivation overlayer on the hole channel increased the high-voltage-handling capability of the MOSFETs by substantially suppressing the off-state drain leakage currents. The MOSFET showed a specific on-resistance of 19.74 <inline-formula> <tex-math notation= LaTeX >$\\text{m}\\Omega \\cdot $ </tex-math></inline-formula>cm<sup>2</sup> and a maximum drain current density of −288 mA/mm, with an extremely low gate leakage current <inline-formula> <tex-math notation= LaTeX >$ < 10^{-{6}}$ </tex-math></inline-formula> mA/mm. The Baliga’s Figure-Of-Merits was experimentally determined to be 344.6 MW/cm<sup>2</sup>, and the maximum DC power density was observed to be 21.0 W/mm.