Not sure why the link didn't work, but it apparantly is timed, so wouldn't work forever, either (such is the state of news...). Anyway, hope quoting it here won't create problems. I had the orientation wrong, but the end results are the same....in today's crystals, they have to cut them like planks from a log, rather than disks from the cylinder, which means various sized wafers, and a lot more waste. If this gets to mass production, it will change the cost structure radically.
Copyright 2009 Nashua Telegraph
Nashua startup has plan to grow sapphires sideways for use in LEDs
Here's an idea for a new company you probably hadn't thought of: Grow a bunch of big sapphires but do it sideways.
That is one way (a really superficial way, I admit) to think about the core business of Nashua's ARC Energy, a company co-founded two years ago by Kedar Gupta, who is best-known for helping to create GT Solar in Merrimack.
Located in a faceless business condo behind a Market Basket on Route 101A, ARC Energy is pretty stealthy - it doesn't even have a Web site, for crying out loud. Yet, it is exactly the sort of startup that makes New Hampshire officials ecstatic.
ARC Energy is a small (seven employees, no sales yet) company started by a seasoned tech-industry professional that is developing new technologies with the help of the state university in order to enter the ground floor of a large, growing and "green" industry.
From the point of view of New Hampshire, you could hardly design a better storyline. Any day now, I expect to see them featured in a "We're Geeky in The Granite State" YouTube promotional video.
At ARC Energy, however, they're not worrying how to get the best camera angle but how to get the best angle on their crystal growth.
Here's some background, courtesy of Gupta and Rick Schwerdtfeger, vice president of engineering.
Most of the world's LEDs are built atop sapphires, which have to be grown inside huge, hot (3,700 degree Fahrenheit) furnaces. This is a slow and expensive process, which is why LEDs cost too much to be used as household bulbs.
ARC Energy would like to change this fact, which would create a whole new type of ultra-efficient lighting. "The question is, how do we produce sapphires, or provide a machine that produces sapphire, that are much less expensive? We believe we have done that," Schwerdtfeger said.
"Our machine is unique. It is the only one," said Gupta, who left GT Solar at the end of 2006 and has funded ARC Energy entirely by himself.
ARC Energy's heart is a half-million-dollar furnace - three of which are under testing and development at semiconductor firms in Taiwan - that grows sapphire crystals.
They melt "seed stock" of sapphire and other ingredients, including grains of aluminum oxide exactly like the ones that make sandpaper scratchy, using temperatures hot enough to melt aluminum, then cool them just the right amount for crystallization to occur.
The result, called a "boule," looks like a 6-inch-diameter column of glass, but if properly made, can be worth tens of thousands of dollars. (Sapphire jewelry has colors because of impurities in the crystal, but commercial sapphire is usually clear.)
LED firms cut or drill those columns to create sapphire wafers, usually 2 inches in diameter, and then use each wafer to create hundreds of tiny LEDs used in everything from stoplights to laptops, with a future market developing for ultra-thin LED television sets.
Lots of firms grow sapphire boules. What's different about ARC Energy's product is the orientation of the crystal.
Crystals are made up of repeating patterns of atoms - that's pretty much the definition of a crystal. Any crystal has different properties depending on how the pattern is oriented, just as wood has different properties depending on whether you are working with the grain or against it.
Staff photo by Don Himsel
A “boule†of sapphire created by the ARC Energy furnace holds a half-dozen wafers that can be used to make LEDs.
Sapphire wafers for LEDs need to have what is known as the C-axis pointing up, but traditional sapphire boules have the C-axis pointing sideways.
This doesn't sound like much of a problem, but Schwerdtfeger said this 90-degree difference greatly complicates the process of getting wafers out of boules, resulting in huge amounts of wasted sapphire.
ARC Energy thinks it has the "recipe" - their term, not mine - to grow boules with the C-axis pointing up; in other words, to grow them sideways.
Their furnace does this by using four different methods to precisely manipulate temperatures during the 14-day process of creating a boule.
"Removing heat is what crystal growth is all about," Schwerdtfeger said. "How and when you remove the heat determines how well it grows, how fast, and how uniformly it grows."
The C-axis in ARC Energy's boules is pointing in the right direction within a degree or two. Alas for the company, commercial production needs precision within a couple of tenths of a degree.
The company is tweaking its recipe to improve this orientation. It is also working with UNH mechanical engineering Professor James Krzanowski to develop machinery to keep precise orientation even when the boule is being sliced and diced.
"You can't just slap it into a vice and cut it with a hacksaw," Schwerdtfeger said, joking.
Krzanowski and ARC Energy together received one of several Granite State Technology Innovation Grants from the New Hampshire Innovation Research Center, which supports research partnerships between New Hampshire companies and college laboratories.
The process is so computerized that ARC Energy officials can control much of it through their Blackberries while sitting on the beach, if they so desire, but they still hope to automate more of it.
That is the sort of process optimization issues that any startup faces in order to move from research and development to commercialization.
Still, when one of your co-founders helped build a startup into the state's shining example of a green-energy company, there's hope.
"Our philosophy is to be No. 1," Gupta said firmly. "That is what we will do."
Granite Geek appears Wednesdays in the Telegraph, and in a blog online at granitegeek.org. David Brooks can be reached at 594-5831 or dbrooks@nashuatelegraph.com.
Granite Geek appears Wednesdays in the Telegraph, and in a blog online at granitegeek.org. David Brooks can be reached at 594-5831 or dbrooks@nashuatelegraph.com.