Diamond based field-effect transistors with SiNx and ZrO2 double dielectric layers☆

Abstract A diamond-based field-effect transistor (FET) with SiN x and ZrO 2 double dielectric layer has been demonstrated. The SiN x and ZrO 2 gate dielectric are deposited by plasma-enhanced chemical vapor deposition (PECVD) and radio frequency (RF) sputter methods, respectively. SiN x layer is found to have the ability to preserve the conduction channel at the surface of hydrogen-terminated diamond film. The leakage current density (J) of SiN x /ZrO 2 diamond metal-insulator-semiconductor FET (MISFET) keeps lower than 3.88 × 10 − 5  A·cm − 2 when the gate bias was changed from 2 V to − 8 V. The double dielectric layer FET 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 − 28.5 mA·mm − 1 , 2.2 V, 4.53 mS·mm − 1 , 38.9 cm 2 ·V − 1 ·s − 1 , and 2.14 × 10 13  cm − 2 , respectively.