Automated marriage

An automated material-handling system (AMHS) recently qualified at International Sematech combines overhead transport and conveyor systems from two different vendors for the first time in a 300-mm manufacturing facility. The hybrid AMHS became fully operational in late June in a 2800-sq-ft portion of the consortium's advanced technology development fab in Austin, TX.

PHOTO COURTESY OF INTERNATIONAL SEMATECH

Integrating SK Daifuku's CLW-7 overhead monorail unit with Middlesex's Clean Drive conveyor, the unified system "provides better throughput, more flexibility, and greater tool utilization" than conventional transport systems, says Marlin Shopbell, an AMD assignee who manages Sematech's AMH project. "Both companies implemented hardware and software capabilities that they had not previously offered to customers, in order to gain the full benefits of the systems integration, such as bidirectional vehicles from Daifuku, SEMI E-84 controlled transfer between conveyor and [overhead transport] vehicles, and software integration of the two systems."

The so-called fourth-generation system bypasses the stocker by putting a FOUP in a buffer right in front of the tool if that tool's loadports are occupied, explains Shopbell. "The FOUP stays close to where it's needed, instead of in a stocker that might be 30 to 40 meters away." The AMHS processes wafers through seven tools on the ISMT fab's copper line: two furnaces and deposition tools, and single CMP, plating, and wafer-sorter platforms. The system shows interoperability with other automation components as well, using FOUPs from three suppliers on five different types of loadports within the same cell. "The response from member companies has been very positive," notes Shopbell. "The marriage of cleanroom conveyor technology with existing OHT technology will help the industry move toward fully automated, direct tool-to-tool wafer delivery."