MICRO: 'Round the Circuit

Optical lithography at 157 nm is ready to see the light of day, according to industry experts. International Sematech reports that participants in the recent Third International Symposium on 157-nm Lithography agreed that the industry has overcome all major obstacles to using 157-nm optical lithography at the 65-nm node. Lens designs have been fixed and suppliers are prepared to deliver 157-nm scanners by 2004, according to Tony Yen, the cochairman of the symposium and director of lithography at Sematech.

Held in early September in Leuven, Belgium, the gathering was sponsored by Sematech and IMEC, the university-based research center located in the Belgian city. Selete, the Japanese consortium, also participated. The conference unveiled several breakthroughs, according to Sematech. These include the development of photoresists with more transparency and better imaging characteristics than before, and effective hard fused-silica pellicles.

Significantly, Sematech reports that intrinsic birefringence of CaF₂, which has stymied the use of 157-nm optical lithography, has been solved. Researchers have discovered that by combining lens elements made from <111> and <100> crystals, they are able to minimize the net effects of birefringence.

In two related news items, Sematech and several universities have begun a project to study the mechanism of photochemical darkening. The goal is to develop polymers capable of withstanding 157-nm radiation. In addition, Lambda Physik, a manufacturer of pulsed-UV lasers, plans to invest up to $4.9 million to develop 157-nm laser technology. The German firm shipped prototypes in 1999.

A Massachusetts-based manufacturer of solar cells has received NIST backing to develop a more efficient method of making photovoltaic silicon wafers. NIST's Advanced Technology Program (ATP) has awarded ASE Americas of Billerica, MA, $1.88 million to explore what the company calls "a large technological leap" in the production of the silicon wafers used to make photovoltaic cells. The total cost of the three-year project is $5.6 million. In approving the funding, NIST notes the project could lead to greater use of solar power, less air pollution, and a reduction in dependence on foreign oil.

Typically, the solar wafers are batch-made in large plants where handling, labor, and plant overhead elevate manufacturing costs. ASE Americas proposes to lower those costs by developing continuous production that combines crystal growing and wafer cutting. ASE says it already has created one important element of the process—a method for growing silicon in a hollow octagonal tube. The method minimizes waste by cutting the face of the octagon with a laser, ASE says. The company estimates that the method will cut production costs by 45 to 65%.

IITC solicits 2003 papers

IEEE is asking for technical papers submissions for its International Interconnect Technology Conference (IITC). The fifth annual event will be held June 2–4 in Burlingame, CA. The organizers are requesting papers on all aspects of interconnect technology. Topics include metallization, dielectrics, silicide, CMP, dry processing, and system-on-a-chip processes. Additional topics are process integration, process control, modeling, and reliability.

Papers will be reviewed and accepted for both oral and poster presentations. Accepted submissions will be published in the conference digest and CD-ROM. The submission deadline is January 17, 2003. Instructions are available at www.ieee.org/conference/ iitc or iitc@his.com.

Metrology pioneer honored

Richard Spanier, PhD, of Rudolph Technologies has received the SEMI Lifetime Achievement Award for significant contributions to the technological advancement of semiconductor manufacturing. Spanier, chairman emeritus of the metrology equipment provider, was honored for his role in developing an opaque-film metrology with the potential to hold as key a role in microchip manufacturing as ellipsometry, SEMI says.

The 30-year company veteran created the first fully automated ellipsometer in 1976. In 1990 he invented and subsequently received a patent for simultaneous multiple-angle-of-incidence ellipsometry. Recently, Spanier directed a design team that engineered the MetaPulse metrology system to act like an ellipsometer. The analytical tool measures multilayer films accurately and precisely, SEMI notes.

The team of Karl Olander and Glenn Tom of ATMI received SEMI North America Awards for their contributions to the Safe Delivery Source (SDS) gas storage and delivery system for ion implantation. Stanley Myers, SEMI's president, presented the honors on October 3 at the 29th Annual SEMI Dinner and Awards Ceremony in San Jose.

Minienvironment RP published

The Institute of Environmental Sciences and Technology (IEST) has published a contamination control recommended practice (RP) for minienvironments. IEST-RP-CC028.1, Minienvironments discusses applications, planning, design, and evaluation, and is intended to spark discussion between suppliers and customers in the microelectronics industries of specifications and configurations. The RP does not address microbiological issues or uses. Information: publicationsales@iest.org.