Current voltage characteristics of Carbon Nano Tube Field Effect Transistor

Carbon Nanotube Field Effect Transistors (CNTFET) are promising nano-scaled devices for implementing high performance, very dense and low power circuits. The core of a CNTFET is a carbon nanotube. Its conductance property is determined by the so-called chirality of the tube; chirality is difficult to control during manufacturing. This results in conducting (metallic) nanotubes and defective CNTFETs similar to stuck-on (SON or source-drain short) faults, as encountered in classical MOS devices. This paper studies this phenomenon by using layout information and presents modeling. For CNTFET-based circuits (e.g. intramolecular), these defects are analyzed using a traditional stuck-at fault model. This analysis is applicable to primitive and complex gates. In this paper, we have also developed a simple analytical model for ballistic nano transistors that operate by modulating the charge in the device (as opposed to modulating the current at the contact). This analytical model captures the essential physics of MOSFET-like ballistic nanotransistors and provides a convenient way to assess and compare transistors at the ballistic limit. The circuit simulation was carried out using SPICE model and the current voltage characteristics were obtained.