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

本文发展了一种使用两步边缘场电泳制备碳纳米管薄膜晶体管的方法.利用该方法可以在晶体管的源电极和漏电极处分别得到高密度且有取向排列的碳纳米管阵列.通过控制源漏电极间距可以使这两个碳纳米管阵列在晶体管的沟道中交汇,形成级联结构的导电通路.这种级联结构不仅能有效地降低晶体管沟道中金属性碳纳米管形成导电通路的概率,而且大大减少了每条导电通路中的碳纳米管交叉结的数量,有利于提高器件的性能.利用该方案制备的短沟道(1~2.5μm)碳纳米管薄膜晶体管的电流开关比高达107,输出电流密度达8.5μA/μm.该碳纳米管薄膜的组装方法位置可控、制备效率及成品率高,且可以扩展到大尺寸的基片上,能够极大地提高碳管薄膜...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 I-on/I-off (up to 10(7)) and high out-put current density (8.5 mu A/mu m) were obtained in short channel length (1-2.5 mu m) 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.supported by the National Natural Science Foundation of China,Beijing Municipal Science & Technology CommissionSCI(E)EI中国科学引文数据库(CSCD)liangxl@pku.edu.cn10794-800+7446