Fabrication and Electrical Characterization of Single Walled Carbon Nanotube based Thin Film Transistors

Abstract

i newlineAbstract newlineThe main goal in the area of flexible electronics applications such as large area flexible newlinedisplays is to develop a scalable process of fabrication for devices like thin film newlinetransistors (TFTs) on flexible substrates. The possibility of the TFTs used in bent newlineconditions of substrates, their working in environments at temperatures higher than room newlinetemperature and stability of TFTs exposed to air after fabrication are to be investigated. newlineThis work demonstrates the wafer-scale fabrication of carbon nanotube thin film newlinetransistors (CNTTFTs) on the flexible surface with variable dimensions. The thin film of newlinesingle-walled carbon nanotubes is used as channel in CNTTFTs. The polyimide is used as newlinea flexible substrate for the fabrication of CNTTFTs. Different types of CNTTFTs are newlinefabricated with a single-gate (at bottom and top of the channel) and dual-gate (on either newlineside of the channel). newlineIn the fabrication of CNTTFTs, two gate dielectrics silicon dioxide (SiO2) and hafnium newlinedioxide (HfO2) are used. SWCNTs with semiconducting purity 99.99% and 95% are used newlinefor developing thin film channels. These thin films are deposited using a dip coating newlineprocess and obtained a maximum density of SWCNTs of 110 SWCNTs/and#956;m2. Source, newlinedrain, and gate, terminals of the CNTTFTs are realized using a photolithographic process newlinewith 6 different masks. To analyze the performance of CNTTFTs on a flexible substrate newlinean array of devices with channel length varying from 3 to 100 and#956;m and width 3 to 50 and#956;m is newlinefabricated. newlineFabricated CNTTFTs are analyzed for their electrical characteristics for different bending newlineconditions, temperature variations, and aging. The electrical performances of CNTTFTs newlineare obtained by performing I-V characteristics such as output and transfer characteristics. newlineElectrical performance parameters of CNTTFTs such as threshold voltage, on-current, onoff newlinecurrent ratio, subthreshold swing, transconductance, and mobility are extracted from newlineelectrical characteristics of various devices under different conditions. newlineThe CNTTFTs with a