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

Abstract

A diamond-based field-effect transistor (FET) with SiNx and ZrO2 double dielectric layer has been demonstrated. The SiNx and ZrO2 gate dielectric are deposited by plasma-enhanced chemical vapor deposition (PECVD) and radio frequency (RF) sputter methods, respectively. SiNx 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 SiNx/ZrO2 diamond metal-insulator-semiconductor FET (MISFET) keeps lower than 3.88×10−5A·cm−2 when the gate bias was changed from 2V to −8V. 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 −28.5mA·mm−1, 2.2V, 4.53mS·mm−1, 38.9cm2·V−1·s−1, and 2.14×1013cm−2, respectively.