GigaOM » Integrated circuits

Step aside, transistor; It’s the vacuum tube’s turn to shine again

Kevin Fitchard — Wed, 11 Jul 2012 18:44:54 +0000

When a trio of engineers led by Bill Shockley built the first solid-state transistor at Bell Labs in 1947, they thought they had consigned the vacuum tube to oblivion. Bell Labs’ owner at the time AT&T wanted a replacement for the fragile and bulky glass tubes that powered Ma Bell’s innumerable switches. What Shockley and company created, however, was the foundation of all modern electronics.

Today you’ll only find a vacuum tube in a guitar amp or by rooting around in your grandfather’s old Hi-Fi. But vacuum tubes – or at least their underlying principles – may be set to make a resurgence. A team of researchers at the University of Pittsburgh are investigating the possibility of replacing silicon with vacuums as the medium for electron transport in an effort to build faster and more efficient electronic machines.

As Moore’s Law shrinks down the transistor to nanometer size on today’s integrated circuits, the electrons are running out of space to move around, explained principle investigator Hong Koo Kim in a Pitt news release:

The ultimate limit of transistor speed, says Kim, is determined by the “electron transit time,” or the time it takes an electron to travel from one device to the other. Electrons traveling inside a semiconductor device frequently experience collisions or scattering in the solid-state medium. Kim likens this to driving a vehicle on a bumpy road—cars cannot speed up very much. Likewise, the electron energy needed to produce faster electronics is hindered.

The best way to avoid that kind of scattering is to use no medium at all, either a “vacuum or the air in a nanometer scale space.” Kim said. “Think of it as an airplane in the sky creating an unobstructed journey to its destination,” he said.

Kim isn’t advocating a return to the old red-hot vacuum tube, rather he and his team are building on today’s silicon foundations. They’re developing a method in which electrons can be extracted from semiconductors into the air and then directed via vacuum channels over the surface of the circuit.

If the Pitt researchers can develop a commercially viable vacuum channel technology, it could mean another revolution in microelectronics, creating a new class of high-speed and low-power transistors. That would allow chipmakers to keep riding Moore’s Law and device makers to build more powerful computers, smartphones and tablets that drain less energy.

Kim’s team published their conclusions this month in the journal Nature Nanotechnology. But for a more concise – and entertaining – explanation of their efforts check out the Nation Science Foundation’s podcast on the top: Vac to the Future.

Photo courtesy of Shutterstock user SPbPhoto

Related research and analysis from GigaOM Pro:
Subscriber content. Sign up for a free trial.

SuVolta gets $17.6M to make power-sipping chips

Stacey Higginbotham — Thu, 05 Jan 2012 15:21:37 +0000

Apparently, I’m not the only one who thought SuVolta is a great example of the future of chip tech. Bright Capital, Kleiner Perkins Caufield & Byers, August Capital, New Enterprise Associates, Northgate Capital and DAG Ventures all have contributed to a $17.6 million funding round in the company, which doesn’t exactly design chips but has come up with a novel way to design transistors in a way that makes them use less power.

Chips made using its technique have recently run at full speed but consumed half the power of their counterparts that use traditional transistors. This isn’t just a concern of a crazy startup; Intel recently unveiled a new process technology using 3-D transistors that is designed to save on power by helping chips continue to get smaller.

However, SuVolta’s process is pretty sweet because it uses the existing manufacturing tools already in place at the multi-billion semiconductor manufacturing plants, and because it should continue to work as designers shrink their chips. SuVolta also licenses some IP that gives designers a way to tweak their circuits to optimize the efficacy of the power-saving transistors.

It’s also designed to work best for systems on a chip, which are clusters of different processors integrated on one piece of silicon. In PCs and servers, a single or multi-core CPU was the ideal design choice, but for mobile devices and consumer products, integrating a bunch of different types of cores on a single chip has won out because it saves on space and power. This is why I listed SuVolta one of the three startups that showcase the future of chips.

And saving on space and power is the name of the game as devices go mobile and energy becomes a huge issue, either because of battery life or because power generation has become such a limiting factor in the data center. In fact, many of the chip companies that have managed to raise money in the last two or three years are working to reduce power either through some new process or through using new architectures to perform work more efficiently. Companies such as Adapteva, which is using a different architecture to deliver performance with less power in supercomputers and phones; Calxeda, which is trying to use ARM-based chips for low-power servers; and Lyric Semiconductor, which is focused on a new type of computing, all have raised money in the last few years.

But to show how rare such capital-intensive chip deals are, SuVolta pulled together this infographic to drive it home. As a chip reporter who once covered the bubble years when chip startups were a dime a dozen, I live this shrinkage, because there are fewer pitches and fun stories to write, but this makes it easy for everyone to see what’s going on.

Related research and analysis from GigaOM Pro:
Subscriber content. Sign up for a free trial.