Performance of hydrogen-terminated diamond MOSFET with LaB6/Al2O3 bilayer dielectric

Abstract A diamond-based field effect transistor with LaB6/Al2O3 bilayer has been fabricated. Al2O3 and LaB6 layer were deposited by atomic-layer-deposition and electron beam evaporation system, respectively. The LaB6/Al2O3 bilayer shows a high dielectric constant (29.8). The leakage current density of LaB6/Al2O3 diamond metal-insulator-semiconductor field effect transistor keeps lower than 1 × 10−6 A cm−2 when the gate bias changed from 5 V to −5 V. This device operates in a p-type depletion mode, whose maximum drain-source current, threshold voltage, maximum transconductance, effective mobility and sheet hole density are determined to be −73.8 mA·mm−1, 2.2 V, 10.4 mS·mm−1,128 cm2·V−1·s−1, and 3.2 × 1013 cm−2, respectively.