Low-temperature properties of ZnO on Insulator MOSFETs

ZnO on Insulator is an emerging technology with numerous possible applications. We investigate for the first time ZnO MOS transistors in a wide range of temperature in order to clarify the transport mechanisms in thin ZnO films. Since these devices are controlled with a bottom gate, their characteristics reveal the properties of the back channel located at the ZnO-SiO₂ interface. ZnO FETs feature relatively high mobility, low subthreshold swing and good interface quality. The variations of the threshold voltage and swing with temperature are comparable with the results reported in SOI MOSFETs. However, the carrier mobility behavior is very particular due to the incomplete crystallization of the ZnO film.