Tunneling Field Effect Transistors

Tunneling field effect transistors (TFETs) offer interesting opportunities to address two major challenges faced by aggressively scaled conventional complementary metal-oxide-semiconductor technology: Scaling the supply voltage and minimizing the leakage currents that degrade the I_ON/I_OFF switching ratio. This chapter presents a hetero-structure Si/InAs p-channel TFET device concept that combines the advantages of a low band-gap InAs source injector and inherent high drive current advantage in nanotube TFET. In designing a TFET based on Band-To-Band-Tunneling (BTBT), there are two different tunneling modes that can be employed depending on the device structure. The first is lateral tunneling, also known as point tunneling, in which the electrons are injected from the source to the channel region in a direction parallel to the semiconductor/gate-dielectric interface. The other type of BTBT is vertical tunneling in which the electrons tunnel within the source region in the direction perpendicular to the semiconductor/gate-dielectric interface.