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April 4, 2002...The good news is that the Japanese government has awarded one of its most prestigious compound semi industry researchers, Shuji Nakamura, a whopping $16 million to develop GaN bulk material... despite the fact that Professor Nakamura no longer resides in Japan. He is now a professor at the University of California Santa Barbara (UCSB) and director of UCSB's wide bandgap (WBG) compound semiconductor-based Center for Solid State Lighting and Displays. The cash infusion to such a noteworthy researcher is expected to lend a considerable boost to popularizing bulk GaN efforts. The bad news is that some of those reporting this story still mistakenly call Shuji the "inventor of the blue laser diode." Credit for that feat, as he himself acknowledges on our classic Nitride 101 video (which featured Shuji Nakamura just before he left Nichia) goes to a litany of researchers who actually discovered the lasing effects of Nitride material many years ago. What Shuji Nakamura did, while at Nichia, was to lead the team that made blue lasers lase long enough and efficiently enough to deem them commercially viable. That was no small feat, of course, and one that will lead to applications few outside the compounds can even fathom. Those who read our articles and commentaries routinely here at CompoundSemi News know that blue spectrum laser diodes are being queued up as viable replacements for DVDs and as those who've learned from our Nitride 101 and GaN 101 tutorials will testify, applications go well beyond DVDs and the environmental aspects that accompany nitride development are equally exciting and ultimately, probably even more important.
Are others already working on bulk GaN? That's the other thing disturbing about this announcement and the initial coverage. The statement: "So far, GaN has been made only in the form of thin films, but the bulk crystal form is the key to widespread commercial use of gallium nitride in such devices as lasers and transistors" isn't quite right either. Technologies and Devices International (TDI) is already well along in their commercialization efforts of what they call True Bulk GaN to the point where they're already expanding their production facilities and ramping for shipments. Samples of their 2 inch diameter sliced and polished material from the boules have been out and around for almost a year now. I'll admit I haven't kept up with all the specifics, but I believe ATMI made excellent strides in bulk GaN sometime back, and if I remember my history correctly, researchers in Poland at Unipress have long been at it, as have the team of Les Eastman and Mike Spencer at Cornell. Then there are TDI's peers at Kyma who know a great deal about the subject as well. Feel free to add to this knowledge base by contacting me and we'll cover the latest progress (or review the history lessons) in subsequent columns. But suffice to say, yet again as a word of caution... when you hear "first" and "invented" and "so far nobody else..." type statements, its best to raise an eyebrow, or just ignore them. That's what the most seasoned and jaded technology editors have painfully learned how to do. |
