Author: A. Tijjani, A. Abubakar, S.M. Gana and S.M. Faiza

Abstract:

Carbon Nanotube Field Effect Transistors (CNTFETs) are promising nano-scaled devices for implementing high performance and low power circuits. As the conventional silicon metal-oxide semiconductor field effect transistor (MOSFET) approaches its scaling limits, many novel device structures are extensively explored. The CNTs give a great opportunity of scaling the circuit design to the nano regime. The aim of this project is to study the diameter variation effect in carbon nanotube FET based on simulation study. A nano devise simulator called FET toy is used to study the diameter variation with CNTFETs as channel material, SiO2 as di-electric material and gate control parameter of 0.88. The scope of this project covers the diameter range of (0.5 nm -5 nm) with other parameters such as; temperature, drain control and. The various output parameters that were studied are drain current versus gate voltage, quantum capacitance versus gate voltage, ratio of transconductance versus gate voltage and sub-threshold parameters like; ON current (Ion)), OFF current (Ioff), threshold swing (s), Drain Induced Barrier Lowering (DIBL), transconductance (gm), output conductance (gd), voltage gain (AV), carrier injection velocity (vinj) and Ion/Ioff ratio. From the result obtained, carbon nanotube as channel material with SiO2, gate control 0.88 at room temperature (300 K) can be used to suppress the subthreshold with drain current around 68 micro amps, the quantum capacitance at higher voltage is 1.62 V and ratio of transconductance at higher voltage is 1.64.