Tunnel field-effect transistor

The tunnel field-effect transistor (TFET) is a new type of transistor. Even though its structure is very similar to a metal-oxide-semiconductor field-effect (MOSFET), the fundamental switching mechanism differs, making this device a promising candidate for low energy electronics. TFETs switch by modulating quantum tunneling through a barrier instead of modulating thermionic emission over a barrier as in traditional MOSFETs. Because of this, TFETs are not limited by the thermal Maxwell–Boltzmann tail of carriers, which limits the subthreshold swing of MOSFETs to 60 mV/dec at room temperature (exactly 63mV/dec. at 300K). Joerg Appenzeller and his colleagues at IBM were the first to demonstrate that current swings below the MOSFET’s 60-mV-per-decade limit were possible. In 2004, they reported they had created a tunnel transistor with a carbon nanotube channel and a subthreshold swing of just 40 mV per decade.