September 1999

Computing After Silicon

How will computers be built after 2015? Hewlett-Packard's Stan Williams thinks he has a good recipe. It's not perfect-but that's the beauty of it.

By Technology Review

Four years ago, UCLA chemistry professor R. Stanley Williams and computer giant Hewlett-Packard (HP) made mid-career changes at the same time. The company had grown into one of the world's leading computer and microprocessor makers, but it still didn't have a fundamental research group. Williams had spent the previous fifteen years in academia and feared he was losing contact with the realities of the business (earlier in his career he had worked for several years at Bell Laboratories.) The solution: a basic research lab at HP directed by Williams.

As head of the lab, Williams' chief concern is the future of computing. The progressive miniaturization of silicon-based integrated circuits has led to smaller, cheaper, more powerful machines. State-of-the-art chips now have features as small as several hundred nanometers across (a nanometer is a billionth of a meter). That's small. But according to Williams' calculations, the ability to continue to shrink silicon-based devices is likely to grind to a halt somewhere around 2010. Such predictions are hardly shocking-other Silicon Valley experts have reached similar conclusions. What is surprising is that Williams believes he and his collaborators at HP and UCLA have hit on a solution: a viable heir to silicon.

If Williams is right, computing will one day rely on nanometer-scaled components cheaply and easily assembled using simple chemistry. Instead of today's technique of precisely carving features onto silicon chips to create complex and near-perfect patterns, technicians will dip substrates into vats of chemicals. And if the mix is right, wires and switches will chemically assemble themselves from these materials. It would make possible tiny, inexpensive and immensely powerful computers. This is a fascinating vision. Yet, after all, Silicon Valley (and the popular press) are full of fascinating visions of the future of computing. What makes the concoctions Williams is cooking up at HP more compelling is that they're not just ideas. Last year Williams and his co-workers published a report in Science describing a computer architecture that could make chemically assembled circuits feasible; and this July the group published a second Science paper, this time describing the synthesis of a first potential component of their computer-molecular electronic switches. The results made headlines in newspapers around the country.

In the weeks before the media frenzy, TR Senior Editor David Rotman chatted with Williams about computing after silicon, basic research in high-tech corporations, and his own personal transition from the university to the private sector.

TR: You came to HP in 1995 to establish a basic research lab after being a professor at UCLA. What was your mission?
WILLIAMS: Hewlett-Packard never really had a basic research group. In the past, there had been discussions within HP in which people said, we really ought to be doing more basic research, we really ought to be somehow returning knowledge to the well-those kind of philosophical discussions. And there were always a few people doing some fundamental work. But HP realized that it had to create a separate group that was more isolated from the daily demands of product research to have a sustained effort. I was contacted and asked if I would be interested in trying to bootstrap up a basic research group. I firmly believed, and in fact I believe even more strongly now, that fundamental research has real value for a corporation.