Interface studies of ZnO nanowire transistors using low-frequency noise and temperature-dependent I-V measurements

Single ZnO nanowire (NW) transistors fabricated with self-assembled nanodielectric (SAND) and Si O2 gate insulators were characterized by low-frequency noise and variable temperature current-voltage (I-V) measurements. According to the gate dependence of the noise amplitude, the extracted Hooge's constants (αH) are ∼3.3× 10-2 for SAND-based devices and ∼3.5× 10-1 for Si O2 -based devices. Temperature-dependent I-V studies show that the hysteresis of the transfer curves and the threshold voltage shifts of SAND-based devices are significantly smaller than those of Si O2 -based devices. These results demonstrate the improved SAND/ZnO NW interface quality (lower interface-trap states and defects) in comparison to those fabricated with Si O2.