ABSTRACT
Field Effect Transistor (FET) finds a major role in digital circuits because of its better current-carrying capacity compared with bipolar transistors. The FET operation depends on the voltage applied to the device to regulate the majority of carriers (n-type electrons and p-type holes) in the channel. the chapter starts with the types of FETs, and the advantages of mosfet were discussed. the most commonly used FETS are MOSFETS. we move into the short channel effects (SCEs) due to MOSFET scaling. in a continuous effort to overcome the problems posed by SCEs, a classical, planar, single-gate MOSFET device has evolved into three-dimensional devices with structural modifications. increasing the effective number of gates around the channel will enhance the electrostatic control of the channel by the gate and thus reduce the short channel effects. high-k materials are introduced with multi-gate MOSFETs to further improve the device performance and reduce the gate leakage current. in recent times, scaling of MOSFETs has reached the physical limitation of its size (5 nm), and this has raised the need for novel device architectures to replace the MOSFET technology for semiconductor industries. the current research is mostly focused on tunnel field effect transistors, junctionless transistors, silicon nanowire transistors, and carbon nanotube transistors. A brief introduction to all these novel device architectures is presented.
