Impact of Varying the Carbon Nanotube (CNT) Diameters on the Performance of Carbon Nanotube Field Effect Transistor (CNTFET)

Silicon-based technology has experienced phenomenal growth in the last few decades. Si MOSFET gives us higher performance when we reduced its dimensions but when it reaches its limiting size, various shortchannel effects appear to affect its performance. In that case the semiconductor industry is looking for different materials and devices to integrate with the current silicon-based technology and in the long run, possibly replace it. Among all the alternatives investigated, Carbon Nanotube Field Effect Transistor (CNTFET) has been found to be the most promising one due to its superior electrical properties. In this paper we have investigated the current-voltage characteristics of cylindrical CNTFET by varying carbon nanotube (CNT) diameters. We have also studied the key parameters of CNTFET such as drive current (I_on), average electron velocity, I_on/I_off ratio, transconductance (g_m), output conductance (g_d) and subthreshold swing.