A new method of recycling gallium arsenide wafers promises a higher rate of recovered wafers and faster throughput than existing technology, claims the head of the company that developed the technique. Norman Rathie of Met-Tech says his company's method successfully recycles more than 98% of GaAs crystal scrap while remaining environmentally safe. Met-Tech's oxidative leach uses organic and hydrogen peroxide to leach the gallium. The combined solvent extraction–electro purification method operates at a low temperature of 45°C, notes Rathie, president and CEO of the start-up.

The other common separation methods for recovering gallium operate at an efficiency of 92%, Rathie points out. Both technologies, however, present environmental problems, according to the executive. Furnace-based technology releases arsenic fumes and produces an arsenic oxide. Current hydrometallurgical technology uses a nitric acid leach that produces nitric oxide fumes and sodium nitrate solution.

Met-Tech's purification technique has several advantages, Rathie says. Organics are recycled while hydrogen peroxide is catalyzed. The purity of the starting material is not critical, and the technique offers a significant opportunity for automation.

With growth in demand for other compound semiconductor materials, Rathie believes the technology has the potential for use with materials such as indium phosphide. He says the historical cost of recovering gallium from ground is significantly higher than the cost of recycling it. Wafer manufacturers need to maximize the amount of gallium recovered from scrap because of wide fluctuations in price, he adds. The global market for the element is approximately 200 metric tons; 140 from recycled gallium, 60 from primary sources, according to Rathie. Based in Burlington, ON, Canada, Met-Tech spun off from technology developed at Monsanto.

A market research firm predicts the worldwide market for gallium arsenide microchips will grow 17% in 2002. The Information Network of New Tripoli, PA, forecasts revenues of $2 billion this year, propelled by sales of cellular phones. A decrease in the cost of epitaxial GaAs pHEMT and HBT technology will boost the market share of handset power amplifiers as the technology overtakes silicon, according to the firm. Microwave communications equipment and gigabit Ethernet are also fueling greater use of GaAs devices.

RF Micro Devices of Greensboro, NC, leads the worldwide market for GaAs ICs with 14.5%, the research firm reports. The producer will keep its spot in 2002 over both Vitesse Semiconductor of Camarillo, CA, and TriQuint of Hillsboro, OR, even though the latter manufacturer purchased the gallium arsenide IC business of Infineon. RF Micro manufactures a wide range of standard and custom radio-frequency devices, the Information Network notes, adding that approximately 44% of its products in 2001 were power amplifiers.

Increasing penetration of optical communications and wireless handsets will drive the markets for silicon-germanium ICs to the $2.1 billion mark by 2005, according to the market research firm. SiGe chips will compete with GaAs devices in the receiver portion of a wireless handset. GaAs devices will prevail in the RF front-end transmitter portion.

The organizers of the ASMC 2003 technical event have issued a call for papers covering a range of manufacturing issues. Yield enhancement, advanced metrology, processes, contamination-free manufacturing, MEMS technology, and 300-mm manufacturing are among the categories covered. Additional topics are cost reduction, equipment reliability, factory automation, and photolithography challenges. The 14th Annual IEEE/SEMI Advanced Semiconductor Manufacturing Conference and Workshop is scheduled for March 31–
April 1, 2003, in Munich.

Presentations must be original, noncommercial, and unpublished. Organizers encourage submission of papers coauthored by a user and a supplier that offer practical solutions to actual manufacturing problems.

The deadline for abstracts of one to two pages is September 3, 2002. Authors will be notified of their selection in October. All abstracts will be peer reviewed and will be chosen for the clarity of their presentation of problem, analysis, solution, and conclusion. Only abstracts sent electronically as an Adobe Acrobat (.pdf) or MS Word file will be accepted.

Camera-ready final manuscripts and copyright forms must be sent electronically by January 31, 2003, to make the publication date for the ASMC 2003 proceedings. SEMI and IEEE are also organizing a workshop to run concurrently. Possible topics include 193-nm photolithography integration, customer requirements and supplier capabilities, and workforce issues. Other ideas are sought.

Abstracts and workshop proposals may be sent to SEMI Europe, Ave. des Beaux Arts 1040, Brussels, Belgium, attn: Johanna Turpeinen; or, SEMI, Washington, DC, 1401 K St., NW, Ste. 601, Washington, DC 20005; e-mail, mkindling@semi.org.