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

Sanghyun Ju, Purdue University
Sunkook Kim, Purdue University - Main Campus
Saeed Mohammadi, School of Electrical and Computer Engineering, Purdue University
David B. Janes, Purdue University

Abstract

Single ZnO nanowire (NW) transistors fabricated with self-assembled nanodielectric (SAND) and SiO2 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 (alpha(H)) are similar to 3.3x10(-2) for SAND-based devices and similar to 3.5x10(-1) for SiO2-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 SiO2-based devices. These results demonstrate the improved SAND/ZnO NW interface quality (lower interface-trap states and defects) in comparison to those fabricated with SiO2.