New transistor overcomes power challenges

Professor Banerjee (right) and his UC Santa Barbara teamEngineers at the University of California
Santa Barbara have shown off a new transistor that switches at 0.1 volts and reduces power dissipation by over 90 percent, compared to the latest silicon transistors (MOSFETs).

Continuing miniaturisation of MOSFETs poses a power dissipation challenge because of their fundamental turn on characteristics.

The engineers at UC Santa Barbara have used the quantum mechanical phenomenon of “band to band” tunneling to make a tunnel field effect transistor.

Professor Kaustav Banerjee at UC Santa Barbara, said: “We restructured the transistor’s source to channel junction to filter out high energy electrons that can diffuse over the source/channel barrier even in the off state, thereby making the off state current negligibly small.”

The engineers said that the global electronics industry loses billions of dollars a year because of the power dissipation effect.

He said: “This transates into lower battery lifetime in personal devices like cell phones and laptops and massive power consumption of servers in large data centres.”

The transistor the engineers have designed used a layered two dimensional material called molybdenum disulphide, with the current carrying channel played over a highly doped germanium as the source electrode.

“We have engineered what is, at present, the thinnest channel subthermionic transistor ever made,” said Banerjee.