A dark and potentially stormy day threatened the opening ceremonies for Soitec's Bernin II facility in late September. The lush cornfields surrounding much of the site might have welcomed a little moisture, while an early dappling of snow high in the mountains lent a winter-wonderland flavor to the already gorgeous natural setting. But a chilly, soggy ribbon-cutting and hundreds of jostling umbrellas were not the kind of mise en scène the French hosts had in mind.

Fortunately, the silicon-on-insulator manufacturer's luck held, the rain stayed away, and the event went off nearly hitchless. Non-Francophones listened to English translations of the speechifying on wireless headsets while those unable to fit into the main reception area watched on a series of flat-screen monitors. Company president and cofounder André Auberton-Hervé welcomed the guests and other attendees, remarking on "the confidence in our growth and the products that we offer," which had been shown by regional authorities. When a parade of dignitaries took their turns at the podium, the rapt attention paid to Auberton-Hervé's words was replaced by the increasing buzz of conversation, making it difficult to hear the speakers. Seems the French have as much respect for politicians and bureaucrats as their counterparts in the rest of Europe and across the Atlantic.

With much of the chipmaking realm in economic retreat, SOI is one of the few industry sectors advancing financially and technologically. Most major semiconductor players have championed the integration of the enhanced wafers into their fabs, citing them as part and parcel of many current and next-generation high-performance devices. As the leading stand-alone SOI manufacturer, Soitec has experienced vertiginous growth, increasing revenues 147% in 2001 to grab 70% of the world market, according to figures from VLSI Research. The company says its new facility will boost its annual capacity to more than 2 million wafers, with much of that dedicated to 300-mm substrates.

Soitec has come a long way since the spring of 1997, when I first visited the company's meager pilot line housed in the LETI research fab in nearby Grenoble. Then a spinoff company waiting to leave the governmental mother-incubator lab and strike out on its own, Soitec battled widespread skepticism about SOI's potential. What a difference sound management and an accelerated industry roadmap can make in a few years. Technological acceptance and orders by major customers don't hurt either.

During a panel discussion held on Soitec's opening day, Honeywell's Gary Kirchner explained that his company was one of the first to bring out SOI-based products. He said that the defense and aerospace firm was "basing all of [its] product technology on SOI," including radiation-hardened CMOS devices, microwave-on-insulator chips, and MEMS-based sensors. "SOI is outstanding for mixed-signal and analog applications," he added, citing "first-pass successes" on analog SOI-based wireless devices, which could "replace or enhance the existing GaAs" technologies.

IBM's Ghavam Shahidi said that his company's 64-bit Power 4 microprocessors are based on SOI at 180 nm and that Big Blue was starting to ship 130-nm product made on the bonded wafers. He sees a material transition taking place, with SOI well positioned as a key enabling technology. Since gate-oxide scaling and higher doping levels are both hitting their limits in conventional bulk material, the IBMer believes that performance-enhancing materials such as SOI and strained silicon must be integrated for the 65-nm node to succeed.

Fellow panelist René Zingg of Philips Semiconductor underscored Shahidi's comments, saying his company has seen a "fundamental advantage" with SOI compared with bulk silicon on the firm's high-voltage, high-power applications. "We have better control over impurities in SOI, so we can stuff more dopant in it," he noted. SOI's marketplace maturation still faces many significant challenges. Process control and metrology issues loom large, since the failure to detect a defective SOI wafer in real time can threaten the yields of hundreds of expensive wafers following in the production queue. Economics questions also remain, such as whether Soitec and other SOI manufacturers can be profitable while delivering quality wafers at a reduced price.

But none of these challenges seems insurmountable. While the weather continues to be dismal over most of Semiconductorville, for le quartier de SOI the forecast is sunny and bright.

Tom Cheyney
Editor
tom.cheyney@cancom.com