A tunneling field-effect transistor incorporating 2D and 3D materials which offers both high current density and robust on/off switching, for use in low-power electronics.

Transistors are the most widely-produced electronic devices in the world, with over 13 sextillion devices ever manufactured. Modern transistors use a metal-oxide-semiconductor field effect (MOSFET) architecture. These MOSFETs have a limited 60 mV/decade subthreshold swing, meaning they cannot switch between ON and OFF beyond a certain speed. Current tunneling field effect transistors (TFETs) can achieve better subthreshold swings, but suffer from low ON current density and relatively high OFF leakage current.

This technology incorporates a two dimensional material into a TFET design. The device uses highly efficient band tuning and quantum tunneling to provide reliable ultra-low power performance. This offers a superior subthreshold swing, ON current density, and ON/OFF current ratio compared to other transistors.

The TFET design uses few-layer InSe as a bridge between a p-type Si source and metal drains. A Ti/Au gate with an AlOx dielectric tunes the bandstructure of InSe to switch between ON and OFF states. The researchers manufactured the device using mechanical stamping, electron beam lithography, and metal deposition and lift-off processes.

• ON current density of 0.3 µA/µm at drain bias of -1 V
• ON/OFF current ratio of 106 mV/dec at <60 mV/dec operating conditions
• Subthreshold swing minimum of 6.4 mV/dec and average of 30 mV/dec over 4 decades, well under the MOSFET minimum 60 mV/dec
• A small gate voltage change of 180 mV modulates output current by more than 5 orders of magnitude