Dramatic switching behavior in suspended MoS₂ field-effect transistors

When integrating MoS₂ flakes into scaling-down transistors, the short-channel effect, which is severe in silicon technology below 5-nanometer, can be avoided effectively. MoS₂ transistors not only exhibit a high on/off ratio but also demonstrate a rapid switching speed. According to the theoretical calculation, the thermionic limit subthreshold slope (SS) of the ideal device could reach 60 mV/dec. However, due to the confinement of defects from substrates or contamination during the process, the SS deteriorates to more than 300 mV/dec, causing serious power consumption. In this work, we optimize the SS through structure design of MoS₂ transistors. The suspended transistors exhibit a high on/off ratio of 10⁷ and a minimum SS of 63 mV/dec with an ultralow standby power at room temperature. This study demonstrates the promising potential of structure design for electronic devices with ultralow-power switching behaviors. (paper)