We fabricated dual-gate ZnO nanorod metal-oxide semiconductor field-effect transistors (MOSFETs) where a Si substrate with a 200nm thick SiO2 layer was used as a bottom-gate and a Au electrode with a 100nm thick SiO 2 layer was used as a top-gate. From current-voltage characteristic curves of the nanorod MOSFETs, the top-gate mode operation exhibited significantly enhanced device characteristics compared with the bottom-gate case. A switch current ON/OFF ratio of the top-gate mode (105-10 7) was at least one order of magnitude larger than that of the bottom-gate mode (104-106). Normalized transconductance, one of the key transistor parameters, was also drastically increased from 0.34νSνm-1 for the bottom-gate to 2.4νSνm-1 for the top-gate mode. The enhanced device performance can be explained in terms of geometric field enhancement and the resulting efficient gating effect for the top-gate mode geometry.
ASJC Scopus subject areas
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering
- Electrical and Electronic Engineering