While RF CMOS and silicon germanium (SiGe)-based biCMOS technologies continue to make progress and advance on the traditional gallium arsenide (GaAs) turf, with RF LDMOS power transistors improving in frequency, performance and cost to strengthen their position in the wireless infrastructure space, GaAs-based ICs and power transistors are not taking a back seat. Ongoing improvements in performance, efficiency and cost structure of pseudomorphic high-electron mobility transistors (pHEMTs) and heterojunction bipolar transistors (HBTs), with lower power dissipation, have enabled GaAs devices to maintain the growth path. In niche applications where high voltage and high linearity are requried, MESFETS continue to serve. Coupled with the overall market growth driven by wireless and mobile products and services in the consumer and communications space, consumption of leading-edge GaAs devices keep increasing. Consequently, in a five-year outlook prepared by Strategy Analytics, the market research firm predicts that GaAs revenues will grow by 36% over 2005 to 2010, breaking the $3 billion barrier this year.

By comparison to overall semiconductor revenues, the GaAs numbers seem like a drop in the bucket. Worldwide semiconductor revenue will grow to $254.7 billion in 2006, up 7.4% from $237.1 billion in 2005, as predicted by iSuppli. According to iSupply, the five-year average growth rate for semi-conductor revenues is expected to be around 8.2%.

Mobile and cellular handsets are expected to be the primary drivers for GaAs growth, characterized by multimode and multiband operational requirements. The added complexity of multimode and multiband hand-sets will increase GaAs device penetration in 3G handsets, according to Strategy Analytics. “2006 and beyond will see the market shift toward EDGE/GPRS-based and WCDMA/EDGE multimode, multiband architectures. This will actually increase the number of HBT and pHEMT dies going into increasingly complex RF front-end module solutions, stated Asif Anwar, director of the Strategy Analytics GaAs and Compound Semiconductor Technologies service.”

Demand from other applications will also augment GaAs device revenues. Furthermore, the analyst foresees increased demand from a whole host of other markets based on emerging standards, such as the IEEE 802.11n and WiMAXs, in which GaAs is the enabling technology.

Hence, major GaAs suppliers have begun to expand product portfolio and manufacturing capacity. For instance, recently RFICs and power amplifier (PA) supplier RF Micro Devices unveiled plans to expand its wafer fabrication facility in Greensboro, North Carolina. Estimated to cost around $80 million, the company, in fact, has begun expanding its wafer fabrication equipment base in existing clean room facilities. Volume production is anticipated later this year. The planned expansion at Greensboro campus is expected to increase RFMD's six-inch wafer manufacturing capacity by approximately 40% from current levels when fully operational. As per RFMD, its expansion is driven by demand for its PAs and front-end modules for growing cellular handsets and WLAN markets. As a result, both GaAs HBT and pHEMT process technologies will see increased capacity with the new expansion plan in 2007.

Likewise, other major proponents like Anadigics, Freescale, Hittite Microwave, M/A-COM, Mimix Broadband, Renesas, Skyworks, Toshiba, TriQuint Semiconductor, and others continue to regularly revamp and expand their microwave and millimeter-wave product portfolios with new devices and higher performance bars. Last year, Anadigics pushed the integration envelope for GaAs ICs by merging HBT and pHEMT transistors on the same die to merge PAs and RF switches on a single RF chip. Earlier, such functions were built on separate dies. Similarly, Freescale has achieved new high-voltage GaAs devices that operate up to 6 GHz. With an operating voltage above 20 V, these GaAs devices will achieve output powers as high as 100 W while still meeting the stringent demands of digitally modulated systems.

Despite the tougher competition from CMOS and other emerging materials, GaAs will continue to play a prominent role in the wireless and microwave/millimeter-wave communications systems.