adams@swbatl.UUCP (4237) (12/02/89)
Title: Silicon Needle May Signal New Age in Microelectronics
Author: Cathryn Conroy
Source: Online Today Daily Edition on CompuServe,
November 25, 1989
Bellcore scientists have developed what they believe is the
sharpest silicon needle ever created, measuring just a few atoms
wide at the tip.
At 50,000 times smaller than the diameter of a human hair, the
needle could play a key role in the resurgence of vacuum tubes. It
would serve as an electronic emitter, which is the heart of a vacuum
tube.
These new miniature vacuum tubes could lead to ultra-fast
communications equipment and computers, as well as flat display
panels that could be used as high-definition television screens.
Newly developed vacuum tubes are unlike those formerly associated
with radios and televisions, in that they're so small they can be
seen only through a microscope. In addition, electrons are produced
in the new tubes by applying voltage to a very sharp tip. In the
old-fashioned tubes, a hot filament was used to create electrons.
The challenge facing researchers has been to create an emitter tip
that's sharp enough to produce many electronics at low voltage.
Until now, the sharpest tips used as electron emitters were between
20 to 40 nanometers wide. (As a point of reference, a human hair is
about 50,000 nanometers wide.)
Bellcore has applied an oxidation treatment process to tiny
silicon cones that has resulted in tips less than one nanometer
wide. The diameter of an atom is about three-tenths of a nanometer.
These silicon tips can produce substantially more electrons than
previous emitters while using less voltage, according to Bob Marcus,
Bellcore's district manager for materials and device analysis.
He said that research is now focusing on measuring the actual
electron emission from the tips, as well as studying device
applications and additional features of the oxidation process.
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# ---Tom Adams--- | uunet!swbatl!adams or adams@swbatl.swbt.com
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