In conventional silicon transistors, a certain finite voltage swing on the order of 150-200 mV (for high performance devices) is needed to switch a device between the on and off states. Reducing that number would enable drastic improvements in power consumption, because modern chips have many millions of transistors – but the fundamental physics of thermionic emission over an energy barrier is in the way.
International Business Machines (IBM) Corporation of NY recently received a contract option for $6.4 million under a DARPA program known as “Steep-subthreshold-slope Transistors for Electronics with Extremely-low Power (STEEP). The goal is to develop novel transistor technologies based on non-thermionic switching, allowing manufacturers to build high-performance logic circuits with very low power consumption. At this time $4.5 million has been obligated by Det 1 AFRL/PKDA at Wright-Patterson Air Force Base, OH (FA8650-08-C-7806).
IBM’s new devices under this DARPA-funded research program will utilize a fundamentally different mechanism of operation based upon quantum mechanical tunneling, which allows them be switched on and off over a much smaller voltage range. Such devices have previously been demonstrated, but only at extremely low performance levels. The goal of this program is to build a device that meets the performance criteria for much higher-performance computing.