MINA-NEWS #18 - February 2012
The ideal commutation system?
Researchers from IMEP-LAHC and Leti—with the help of a Brown University scientist—recently made an exciting chance discovery: the Z2-FET, a PIN-MOS diode that offers a grid voltage variation of just 1 mV for switching, increasing the current by 8 decades.
The team was working to develop new tunneling SOI transistors when they made the discovery. While exploring new ways to optimize polarization voltage, they stumbled upon the new—and perhaps ideal—commutation system.
On a Z2-FET, negative voltage is applied to the grid and positive voltage is applied to the substrate. This creates two potential barriers. When the voltage applied to the grid is increased, the first barrier lets electrons through; these electrons then cross the second barrier. What is even more impressive is that all of this occurs with a grid voltage variation of just 1 mV. For comparison, MOSFET transistors require 60 mV to increase the current by 1 decade.
The new system will be presented at the IEEE’s VLSI-TSA international symposium in April, and two patent applications have already been filed. Several manufacturers have expressed interest in the system, which is compatible with CMOS-on-SOI technology and can be miniaturized down to just 50 nm in length.
However, what is most exciting is the system’s extremely low power consumption, which will open the door to a host of new opportunities. The researchers are focused primarily on memory applications for the moment, but the Z²-FET could also be used in low-power fast-switching logic circuits.