Enhanced Electrical Conductance of ZnO Nanowire FET by Nondestructive Surface Cleaning

Electrical characteristics of zinc oxide nanowire (ZNW) FETs are investigated by nondestructive surface cleaning, ultraviolet irradiation treatment at high temperature and vacuum. UV-light-stimulated oxygen desorption from the active channel improves the device performance of ZNW-FETs. Results show that charge transport in single ZNW strongly depends on its surface environmental conditions and can be explained by formation of depletion layer at the surface by various surface states present on it. The nondestructive surface cleaning removes these absorbed surface states from the nanowire and the current values increase upto ~ 7 muA from ~ 0.4 muA at a bias voltage of 3 V. ZNW-FETs fabricated in this study exhibit mobility of ~ 28 cm²/Vmiddots and a high I _ON ne I _OFF ratio of ~ 10⁶.