Material Limitations for the Development of High Performance SiC NWFETs

Back-gated field effect transistors (FETs) based on 3C-SiC nanowire (NW) were fabricated and the electrical characterization revealed devices with either ohmic or rectifying contacts leading to two different operation modes. The transistors with ohmic-like contacts manifest very weak gating effect and the device switching off is not achievable even for high negative gate voltages due to the high electron concentration along the nanowires. In contrast, the devices with Schottky contact barrier at Source / Drain regions demonstrate a well determined switching off and in general better performance thanks to the modulation of the drain current through the control of Schottky barriers transparency at the source and drain regions. Nevertheless, ohmic contact devices are expected to demonstrate even better performance if the NW material quality as well as the quality of the interface with the gate oxide is substantially improved.