Comparison Between the Electrical Properties of ZnO Nanowires Based Field Effect Transistors Fabricated by Back- and Top-Gate Approaches

Abstract

Large-quality, well-crystallized growth of ZnO nanowires was done via non-catalytic thermal evaporation process on silicon substrate only by using metallic zinc powder and oxygen as source materials for zinc and oxygen, respectively. The electrical properties of the as-grown ZnO nanowires were examined by fabricating a single nanowire based FETs which were fabricated via two approaches, i.e., back- and top-gate approaches by using electron beam lithography (EBL) and photolithography processes. ZnO FETs electrical properties were characterized by IDS–VDS and IDS–VGS measurement. The fabricated single ZnO nanowire based FETs by back- and top-gate approaches exhibited field effect mobilities of ∼4.25 and ∼12.76 cm2/Vs, respectively. Moreover, the carrier concentrations for the fabricated back- and top-gate FETs were ∼1.6 × 1017 and ∼1.37 × 1018 cm−3, respectively. From our studies it was observed that the fabricated top-gate FETs exhibited higher and good electrical properties as compared to ZnO nanowire FETs fabricated using back-gate approaches.