Diamond Metal-Semiconductor Field Effect Transistor for High Temperature Applications

Despite the deep dopant level, diamond field effect transistors (FET) are expected to outperform SiC FET on critical aspects such as breakdown voltage, on-resistance, and power loss at elevated temperatures. Among diamond FET devices, hydrogen-terminated diamond FETs based on surface transfer doping has attracted most of the interest due to its high current capability. However, maintaining the stability of the hydrogen termination and the induced 2D hole gas has been challenging. Most hydrogen-terminated diamond FETs are not recommended to operate at temperatures higher than 400 °C even with the surface passivation [1]. In this study, we successfully fabricated a lateral, p-type conducting layer, diamond metal-semiconductor FET and demonstrated its performance at elevated temperatures up to 430 °C despite the fact that the transistors during the measurements were exposed to air with no passivation.