AUSTIN, Tex. -- International Sematech today announced it has completed the first phase of evaluations of low-k dielectric films for copper interconnect structures in 0.18-micron ICs. Some of these materials are believed to be strong candidates for the replacement of conventional silicon-dioxide insulators in high-speed integrated circuits.

The Austin-based consortium said results from its copper-damascene tests are being made available only to its member companies--13 companies, including some of the largest chip makers worldwide (Intel, IBM, Motorola, Texas Instruments, STMicroelectronics, Infineon, Hyundai, and Taiwan Semiconductor Manufacturing Co.). No information was released to the public about the performance of these materials.

In phase-one evaluation tests, one layer of copper metal was processed on a silicon substrate using films of materials with dielectric constants of 3.0 to 2.1. Conventional silicon dioxide has a dielectric constant of about 4.1.

While many major IC makers are making the transition from aluminum to copper interconnects, the industry continues to search for new dielectrics to replace silicon dioxide as insulators between metal lines. The hope is to find a new material that not only reduces capacitance in interconnects but integrates well into dual-damascene process steps. The thermal and mechanical properties of dielectric films are crucial.

"Our program focuses on a number of critical issues, including extensive material characterization, process integration, and electrical performance," said Paul Winebarger, director of interconnect at Sematech, which hopes its evaluations will help accelerate the use of low-k materials in copper interconnect structure early this decade."

"This work is a learning and data gathering process," he said. "Representative materials from those that have been tested at one-metal level will now be used to attempt fabrication of via chain structures with two levels of copper metal in low-k dielectric."

While Sematech is not planning to publicly release results from the low-k dielectrics tests, material and tool suppliers participating in phase-one evaluations are expected to promote their involvement in the consortium's interconnect program. For example, Applied Materials Inc. announced last Friday that its low-k material, called Black Diamond, had been "validated" by Sematech's tests (see March 3 story).

Today, Sematech did released a list of suppliers providing materials for testing of one-level metal devices. The vendors and materials were: Applied Materials (Black Diamond); Asahi Chemical (ALCAP-S); Dow Chemical (SILK, BCB); Dow Corning (XLK, 3MS); Hitachi Chemical (HSG RZ25); Honeywell Electronic Materials (HOSP, FLARE, Nanoglass); JSR (LKD); Novellus (CORAL, AF4); Battelle PNNL (Mesoporous silica); and Schumacher (PAE-2).

Tools and suppliers used to fabricate the test devices included: low-k spin tools from Tokyo Electron Ltd. (TEL); curing furnace from TEL; low-k etch and strip systems from Lam Research, Applied Materials, Eaton Semiconductor Equipment, and TEL; copper electroplating tools from Novellus and Semitool; CVD dielectric deposition equipment from Novellus and Applied Materials; and CMP systems from Applied Materials and IPEC/Westech.