Investigation of Silicene Nanoribbon Tunnel FET for Low Power Digital VLSI Circuit Application with Variation of Device Parameters

The unique properties of single layer materials different from their bulk form make them suitable for nanoscale applications. This work presents study of p-i-n based Silicene Nanoribbon (SiNR) Tunnel Field Effect Transistor using NEGF formalism. The Device characteristics, I_ON/I_OFF ratio have been studied by varying high-k dielectric, source and drain doping in SiNR TFET. The obtained I_ON/I_OFF ratios for different gate dielectrics materials are compared with the reported data in literatures and it is observed that the ON current can be increased by using high-k dielectric but for the materials whose dielectric constant exceeds HfO₂, OFF current will also increase. So, it can be inferred that deploying gate material of very high dielectric constant will not be of much benefit rather it will reduce I_ON/I_OFF ratio, which is one of the key FOM in Digital VLSI circuits. HfO₂ can be potential high-k material to be used as gate oxides because of its highest I_ON/I_OFF ratio among all dielectric materials used for constant drain and source doping. OFF current is not much influenced by source doping however ON current increases due to wide tunneling window set up by gate potential for low source doping. OFF current and ambipolar conduction is increased by increasing drain doping concentration of SiNR TFET.