Vacuum
tubes have been retro for decades. They almost completely disappeared
from the electronics scene when consumers exchanged their old cathode
ray tube monitors for flat screen TVs. Their replacement—the
semiconductor—is generally the cheaper, lighter, more efficient, and
easier to manufacture of the two technologies. But vacuum tubes are more
robust in high-radiation environments such as outer space. And since
electrons travel faster in a vacuum than through a semiconductor, vacuum
tubes are an intrinsically better medium for electricity.
An
international team of researchers from NASA’s Ames Research Center in
Moffett Field, Calif., and the National Nanofab Center in Korea have
combined the best traits of both technologies by making a tiny version
of vacuum tubes that could be incorporated into circuits. Their
prototype, a vacuum channel transistor, is just 150 nm long and was made
using conventional semiconductor fabrication methods. Its small size
allows it to operate at fewer than 10 volts, much less than a retro
vacuum tube requires; with further work, the device could be made to use
about 1 volt, which would make it competitive with modern semiconductor
technology.
In a paper accepted to the American Institute of Physics’ (AIP) journal Applied Physics Letters,
the authors write that such a transistor could be useful for
applications in hazardous chemical sensing, noninvasive medical
diagnostics, and high-speed telecommunications, as well as in so-called
“extreme environment” applications for military and space.
“Vacuum nanoelectronics: back to the future? – gate insulated nanoscale vacuum channel transistor,” is accepted to Applied Physics Letters.
