Design of Ambipolar CNTFET based Universal Logic Gates

Many emerging technologies have reported ambipolar devices. It is popularly used because of it’s controllable nature. This controllable nature allows the device to work either as n-type or p-type device. In this work, MOS based universal gates (i.e NOR and NAND gate) and ambipolar CNTFET based universal gates have been designed in a novel way. The circuits based on ambipolar CNTFET have been designed using transmission gate method. The circuit designing of MOS based universal gates require four transistors whereas ambipolar CNTFET based transistors require two transistors. The working of both the devices is verified by carrying out the simulation for both of them. The simulation results show that both waveforms are similar to each other. Thus, more number of functions can be performed by using CNTFET based logic gates thereby increasing overall system performance. All the circuit designing and simulation is carried out on HSPICE. Proposed ambipolar CNTFET based devices are simulated using Stanford CNFET model. Parameters are VDD = 1 V, Width of Channels = 381.5 nm, Pitch (S) = 20 nm, Number of CNTs (N) = 20, Diameter of CNT (DCNT) =1.5 nm. Design and simulation of universal logic gates is done at 45nm technology node.