Hydrogen-terminated diamond field-effect transistor with AlOx dielectric layer formed by autoxidation.

ABSTRACT

Fabrication of hydrogen-terminated diamond (H-diamond) field-effect transistor (FET) with AlOx dielectric layer has been successfully carried out. The AlOx layer was formed by auto-oxidizing 6 nm Al film in the air at room temperature, and a FET without AlOx dielectric layer has also been fabricated for comparison. For both FETs, 100 nm Al layers were deposited as the gate electrodes, respectively. The leakage current density in FET with AlOx dielectric layer was four magnitude orders lower than that without AlOx dielectric layer at VGS = -5 V, indicating that AlOx dielectric layer could effectively reduce leakage current and prevent reverse ID in ID - VDS caused by defects on diamond surface. Distinct pinch-off characteristic with p-type channel was observed in ID - VDS measurement. The threshold voltage was -0.4 V at VDS = -15 V.