MIT Technology Review

Thursday, November 29, 2012

A Revolutionary Idea in Semiconductor Manufacturing

Big claims from Swedish researchers. Could the process be streamlined a thousandfold?

Flipping through journal headlines, your heart may not skip a beat when you read a title like “Continuous gas-phase synthesis of nanowires with tuneable properties.” But that article, published in the latest issue of Nature, actually points to something very exciting indeed: a novel method that could revolutionize the manufacture of semiconductors. 

Semiconductors, of course, are those materials whose in-between properties--they don’t conduct electricity as well as metal; they don’t stop a current as well as an insulator--allow us to control their conductive capacity, making them useful ingredients in everyday products like transistors, solar cells, and LEDs. There already exists a highly intuitive manufacturing process for semiconductors, usually beginning with a silicon wafer or other substrate. But a researcher at Lund University in Sweden named Lars Samuelson got an idea: What if a substrate wasn’t needed at all?

“When I first suggested the idea of getting rid of the substrate, people around me said ‘you’re out of your mind, Lars; that would never work,’” he said in a press release. Well guess what, people around Lars? You were wrong!

Samuelson et al. developed a process wherein semiconductors grow from freely suspended nanoparticles of gold in a flowing gas. They call the process “aerotaxy.” Said Samuelson: “The basic idea was to let nanoparticles of gold serve as a substrate from which the semiconductors grow. This means that the accepted concepts really were turned upside down!” Whereas the currently accepted process must be run in batches, making the whole process more time-consuming, the new process would be quick and continuous, he added. And since the process does away with the substrate, manufacturers can save substantial sums on those semiconductor wafers, no longer needed.

What sort of numbers are we talking about here? Lund University says the process of manufacturing semiconductors could become a thousand times quicker. Sounds like there’s real money involved here, and it’s no surprise that while the bulk of the authors on the Nature paper are employees of Lund University, one of the co-authors is Martin Magnusson, of the start-up company Sol Voltaics AB. Samuelson says he hopes the product can be commercialized in two to four years.

For more details on “aerotaxy,” and how it spun out of an innovative method in the manufacture of nanowires called “epitaxy,” check out Lund’s press release or the Nature article. And for a skeptical take on how useful or revolutionary this development is, there are plenty of commenters on Slashdot who doubt this advance will make a dramatic difference. “This article wins today's coveted ‘Most Hyperbolic Headline’ award,” grumbles one--though even that observer concedes that the development seems useful in the realm of optics.