There’s a lot of silicon in the world. It’s the second most-abundant element on Earth. But pure silicon — the kind you can use in microchips and solar cells — is hard to come by.
Back in July of last year, we reported that silicon purification startup 6N Silicon had closed a C$6 million ($5.9 million) venture round to commercialize its process for purifying silicon. “6N’s process will take significantly less time to build a facility and the production costs will be a fraction of the ‘Siemens process,’” 6N founder Scott Nichol told us at the time. We recently checked in with David Dunnison, 6N’s VP of business development, to see if the company kept its promises.
Last May, all the company had was a building. But by September, the company’s pilot line was up and running, and now it’s producing mixable-grade silicon at a rate of 70 tons per year running at a single shift. Well, that sounds promising.
6N makes silicon that can be combined with scrap from the chip manufacturing industry to make crystalline silicon, which is used in solar panels. Unlike chip-grade silicon — which is measured in parts-per-trillion for purity — solar cells can use parts-per-million purity (hence the “six nines” implied in the company’s name.)
Until 2005, there was no need to stretch the supply of pure silicon by mixing it — there was enough scrap material to go round. But then demand outstripped supply, and the startups weren’t far behind: “Last year in March, there were 82 companies in this space,” said Dunnison. “In January 2008 there were 163. That’s two new companies a week.”
The company’s founders have been able to use their background in Canada’s mining industry to address the silicon purification problem head on. 6N’s technology can make 1,000 metric tons of mixable silicon a year in a 12,000-square-foot facility. Compare that to the traditional chip-grade silicon industry, which requires a large chemical plant that occupies several hectares, distills rock, processes hot gas and consumes a whole lot of power.
While the company’s output is still in the “mixable range,” Dunnison said the company is seeing lower-than-expected levels of impurities in its process and is very optimistic. In fact, 6N wants to make solar-grade silicon without mixing it at all. “We’re confident we can get to a pure grade in the next year or so.”