>Vitesse will be fine, however they will increasingly come under attack from CMOS and SiGe (and even other technologies I've read about recently). I believe they will continue to be one of the finest Comm IC companies on the planet, but they may have to continue fighting the GaAs sceptics along the way.<
an update on Si 'vs.' GaAs follows. culled off the RFMD board with a tip o' the clean room head-cloak to George Gilder (for you Wired readers).
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GaAs vendors speak the unspeakable: silicon
By Robert Ristelhueber
EE Times
(10/15/99, 4:23 p.m. EDT)
SAN MATEO, Calif. ? The announcement this week that RF Micro Devices Inc. will be using IBM's silicon germanium process technology to fabricate radio-frequency ICs was only the latest evidence of a stampede by gallium arsenide (GaAs) chip makers to silicon-based solutions.
In addition to the move by RF Micro Devices, Vitesse Semiconductor Corp. has acquired three companies in the past year, all of them firmly based in silicon; Anadigics Inc. has shipped its first silicon IC, a dual-frequency synthesizer; and TriQuint Semiconductor Inc. has begun internal development using silicon.
The activity is ironic, given that the long-touted "technology of the future" has seemingly come of age. GaAs chip makers are enjoying strong, even record, demand because of the boom in portable wireless gear. But rapid progress being made elsewhere in silicon, particularly SiGe, has forced GaAs advocates to hedge their bets.
Vitesse (Camarillo, Calif.) is a company name synonymous with GaAs, yet 60 percent of its designers today are working on CMOS products. "We're not going to fight the market," said Lou Tomassetta, the president and chief executive officer. "Our strategy is to be a communications chip supplier using whatever technology is the right answer."
The company's recent acquisitions have pushed it deep into silicon. Beginning last fall, Vitesse picked up Vermont Scientific Technologies, a design house for Sonet, asynchronous transfer mode, frame relay and other communications circuits; Serrano Systems Corp., a designer of Fibre Channel and SCSI solutions; and Xaqti Corp., a network processor company.
While GaAs will probably always have a performance advantage over silicon at the high end, "for very large processor chips with big blocks of RAM, GaAs will be way too much power," Tomassetta said. He expects that 20 to 25 percent of Vitesse's revenue will come from silicon products in a couple of years, but that figure could surge to more than 50 percent.
Vitesse and the other GaAs suppliers can hear the footsteps of silicon-based vendors, said Robert McCormack, an analyst with Integral Capital Partners (Menlo Park, Calif.). "Innovative companies like NewPort Communications are working entirely in CMOS," he said. "[It] offers lower cost and better ability to integrate." Since the chip industry overwhelmingly uses silicon, getting on the CMOS process road map will be a major advantage over the long term.
RF Micro Devices has working parts based on SiGe and will start shipping them to customers before the end of the year, said Jerry Neal, cofounder and vice president of sales and marketing for the Greensboro, N.C., company. While Neal expects GaAs will remain the dominant technology at his company, there is room for other approaches.
"If you need a highly integrated high-frequency RF part, SiGe with BiCMOS can do the control function with much lower power than with GaAs HBT [heterostructure bipolar transistors]," he said.
Natural strengths
"I think that every new technology has its own application area where it's strong," Neal said. GaAs has lower parasitics than either silicon or SiGe, and remains the choice in higher-voltage applications. SiGe is nearly as good as GaAs HBT in the top frequency response, but at a sacrifice of voltage breakdown, he said. "You use the given technology where it has natural strengths."
Anadigics (Warren, N.J.) has recently been active in moving beyond its traditional GaAs base. This past summer, it introduced a silicon dual-frequency synthesizer for low-cost tuner applications, and then signed a joint-development agreement for RF ICs based on SiGe with Temic Semiconductors, a subsidiary of Atmel Corp.
Shortly after being named president and chief executive officer of Anadigics a year ago, Bami Bastani said in an interview that "Emerging technologies have to get into volume to be real, but you can't turn a blind eye to them."
Anadigics is in a quiet period because of a pending public offering, so no spokesman was willing to comment on the new direction. But in its recent filing with the Securities and Exchange Commission, the company said, "In the next few years, we believe there are opportunities to develop integrated circuits in silicon or silicon germanium which would enhance our GaAs integrated circuits in modules." The company's recently established RF Standard Products Group will explore the use of these technologies in wireless applications.
TriQuint Semiconductor (Hillsboro, Ore.) is also engaged in silicon development, said chief executive officer Steve Sharp. "We're always looking at new technologies. Even within GaAs, there's no one best technology for all applications," Sharp said.
But TriQuint isn't about to abandon GaAs. While silicon or SiGe can provide lower cost, particularly with large die, it can't match the electron mobility or resistance of GaAs. "In communications, there's such a hunger for higher bandwidth and lower jitter and noise. Cost is not the primary objective in most applications," Sharp said.
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