Short channel carbon nanotube thin film transistors with high on/off ratio fabricated by two-step fringing field dielectrophoresis

Abstract

A two-step fringing field dielectrophoretic assembly method for carbon nanotube thin film transistors (CNT-TFTs) fabrication was demonstrated. Densely aligned CNT arrays were assembled at the source and drain electrodes sequentially which form a cascade structure of the aligned CNT arrays. The cascade structure reduces the possibility of percolating metallic pathways in the channel, which is beneficial to device performance. In this way, both high on/off current ratio Ion/Ioff (up to 107) and high out-put current density (8.5μA/μm) were obtained in short channel length (1–2.5μm) CNT-TFTs. The reported CNT assembling strategy is site selective and highly efficient, which can be scaled up to large size substrates and leads to high throughput of CNT-TFTs fabrication.