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Nanoscale Vacuums Speed Semiconductors

A new class of low-power, high-speed transistors could be on the horizon, thanks to the vacuum

2 min read
Nanoscale Vacuums Speed Semiconductors

When you want to make the point of how far electronics and computer technology have come in the last sixty years, you likely refer to the old computers that used vacuum tubes for circuitry.

So, it’s a bit counterintuitive to see the latest research that suggests vacuums may be the way forward to help semiconductor electronics keep pace with Moore’s law. Researchers at the University of Pittsburgh have developed a method for generating a vacuum within a semiconductor device to transport electrons more efficiently through it. 

“Physical barriers are blocking scientists from achieving more efficient electronics,” said Hong Koo Kim, principal investigator on the project and Bell of Pennsylvania/Bell Atlantic Professor in the University of Pittsburgh’s Swanson School of Engineering, in a press release. “We worked toward solving that road block by investigating transistors and its predecessor—the vacuum.”

Of course, there already exist vacuum electronic devices, but these require high voltage. The researchers, who published their findings in the journal Nature Nanotechnology, designed an entirely new vacuum electronic device that requires minimal voltage to operate.

The key to the design was the discovery by Kim's team that it was fairly easy to pull electrons out into the air when they are trapped at the interface of an oxide or metal layer inside a semiconductor. These trapped electrons form a two-dimensional electron gas.

The researchers exploited the phenomenon known as Coulombic Repulsion--the repulsive force between two positive or negative charges--to emit the electrons from this electron gas layer. By then applying a small voltage of  1V to the silicon structure, the electrons were extracted into the air, which made it possible for them to travel ballistically in a nanometer-scale vacuum channel without the scattering typically seen in conventional devices.

Kim further noted in the release, “The emission of this electron system into vacuum channels could enable a new class of low-power, high-speed transistors, and it’s also compatible with current silicon electronics, complementing those electronics by adding new functions that are faster and more energy efficient due to the low voltage."

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The First Million-Transistor Chip: the Engineers’ Story

Intel’s i860 RISC chip was a graphics powerhouse

21 min read
Twenty people crowd into a cubicle, the man in the center seated holding a silicon wafer full of chips

Intel's million-transistor chip development team

In San Francisco on Feb. 27, 1989, Intel Corp., Santa Clara, Calif., startled the world of high technology by presenting the first ever 1-million-transistor microprocessor, which was also the company’s first such chip to use a reduced instruction set.

The number of transistors alone marks a huge leap upward: Intel’s previous microprocessor, the 80386, has only 275,000 of them. But this long-deferred move into the booming market in reduced-instruction-set computing (RISC) was more of a shock, in part because it broke with Intel’s tradition of compatibility with earlier processors—and not least because after three well-guarded years in development the chip came as a complete surprise. Now designated the i860, it entered development in 1986 about the same time as the 80486, the yet-to-be-introduced successor to Intel’s highly regarded 80286 and 80386. The two chips have about the same area and use the same 1-micrometer CMOS technology then under development at the company’s systems production and manufacturing plant in Hillsboro, Ore. But with the i860, then code-named the N10, the company planned a revolution.

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