A ZnO-based MOSFET with a photo-CVD SiO₂ gate oxide

We demonstrate that a high quality SiO₂ was successfully deposited onto ZnO by photochemical vapor deposition (photo-CVD). ZnO-based metal-oxide-semiconductor field effect transistors (MOSFETs) were also fabricated with such a photo-CVD oxide as the insulating layer. As compared with similar structure of ZnO-based metal-semiconductor FETs (MESFETs), it can be found that the gate leakage current was decreased to more than three orders of magnitude by inserting the photo-CVD oxide layer between ZnO and gate metal. With the 2 νm gate length, we also found that the saturated I_ds and maximum G_m of the fabricated ZnO-based MOSFET were 61.1 mA mm^-1 and 10.2 mS mm^-1, respectively.