Tunnel field-effect transistor

Even though its structure is very similar to a metal–oxide–semiconductor field-effect transistor (MOSFET), the fundamental switching mechanism differs, making this device a promising candidate for low power electronics.

[3] Theoretical work has indicated that significant power savings can be obtained by using low-voltage TFETs in place of MOSFETs in logic circuits.

The advent of a mass-producible TFET device with a slope far below 60 mV/decade will enable the industry to continue the scaling trends from the 1990s, where processor frequency doubled each 3 years.

The device is operated by applying gate bias so that electron accumulation occurs in the intrinsic region for an n-type TFET.

[6] By 2010, many TFETs have been fabricated in different material systems,[4] but none has yet been able to demonstrate steep subthreshold slope at drive currents required for mainstream applications.

In IEDM' 2016, a group from Lund University demonstrated a vertical nanowire InAs/GaAsSb/GaSb TFET,[7] which exhibits a subthreshold swing of 48 mV/decade, a on-current of 10.6 μA/μm for off-current of 1 nA/μm at a supply voltage of 0.3 V, showing the potential of outperforming Si MOSFETs at a supply voltage lower than 0.3 V. Double-gate thin-body quantum well-to-quantum well TFET structures have been proposed to overcome some challenges associated with the lateral TFET structure, such as its requirement for ultra sharp doping profiles; however, such devices may be plagued by gate leakage due to large vertical fields in the device structure.

Drain current vs. gate voltage for hypothetical TFET and MOSFET devices. The TFET may be able to achieve higher drain current for small voltages.
Basic lateral TFET structure.
Energy band diagram for a basic lateral TFET structure. The device turns "on" when sufficient gate voltage is applied such that electrons can tunnel from the source valence band to the channel conduction band.