SpeedFam builds cleanroom with a view
New R&D center features unique glassed corridor design
By Judy Keller
Visitors to SpeedFam International`s new $18 million, 87,000-square-foot research and development technology center will be able to walk straight into the heart of its 21,000-square-foot Class 1 to Class 10,000 cleanroom without concern for contamination. In fact, says Russ Douglass, SpeedFam senior vice president, “we`ll be able to take our customers to see our operation in their street clothes.”
The supplier of high-throughput chemical mechanical planarization (CMP) systems for the semiconductor thin-film memory disk media and silicon wafer industries broke ground in January on the new center, which features a unique cleanroom design incorporating a glassed viewing corridor along an entire wall of the cleanroom area and another nearly circular (340 degree) viewing bay in the center of the space.
The new facility was designed and built by architectural firm Balmer and Associates in collaboration with general contractor Hardison and Downey, both of Phoenix, AZ, with cleanroom outfitting and implementation by Clean Rooms West (Tustin, CA).
The new technology center will be co-located with SpeedFam`s manufacturing facility at the company`s 13.5-acre site in Chandler, AZ. The expansion comes just a year after the company built the initial facility which houses its own 200 square feet of Class 10 cleanroom space and 300 square feet of Class 1,000 space. According to Douglas, the company needed additional space to support its process research and development work.
The new R&D center will simulate a complete semiconductor fab environment, accommodating some 250 engineers and scientists as well as software development specialists. Its cleanrooms will accommodate 15 CMP tools as well as metrology equipment. Most of the CMP, silicon wafer and thin-film media disk laboratory space will incorporate raised flooring allowing for more than a 50- percent future expansion of the Class 1 space.
Four laboratory stations dedicated to multiple research applications will be included in the new center, specifically for 300 mm and copper process development. The stations will have increased waste treatment and air handling capabilities for the copper and HF process applications.
The new facility is expected to take roughly 12 months to complete with walls scheduled for tiltup sometime in May of this year and move-in by January 1999.
Sitting pretty
According to Wes Balmer, president of Balmer and Associates, the biggest challenge was designing a facility that would be both aesthetically pleasing as well as functional. “Cleanrooms are usually designed by engineers for the equipment inside them, but we wanted to also design for the people who work in them.” Balmer points out that while in the past, “most cleanrooms were built with small viewing windows, in some cases mere portholes, the trend today is more toward open space.”
The glass used in the SpeedFam cleanroom is 34-inch thick, which Balmer describes as “laminated in some places, and tempered in others, depending on what kind of equipment will be located near it.” Balmer points out that the use of a glass wall in the cleanroom was feasible because the CMP work being conducted is not a moisture-intensive process and therefore condensation was not a major factor.
The clean space is designed in a multiple ring configuration fanning out from the center of Class 1 to Class 10 space to the separate 12,000 square feet of Class 1,000 space. A gownroom sandwiched between the Class 10 and Class 1,000 areas serves multiple cleanroom classification levels with six air showers servicing the higher class-level space, and all accessible to both areas of cleanspace.
According to Balmer, since building code restrictions prohibit a corridor from being considered a rated wall for the cleanroom, it was necessary to design a work-around solution. “We kept the viewing area distinct from the cleanroom exit which is built to meet the code for buildings containing hazardous materials and to keep the cleanroom environment intact,” Balmer says.
Clean Rooms West will be responsible for pressurizing the inside perimeter of the cleanroom space. Here the challenge is to provide adequate airflow for such a large cleanroom space without placing air ducts, fans or vents in the glass wall.
The entire array is serviced by one continuous ceiling grid of proprietary, heavy-duty galvanized material and standard aluminum honeycombed walls. The ceiling grid holds all of the air ductwork with extra ceiling vents and floor returns added to make up for the lack of vents in the glass wall. All the air ducts are in the dual plenum above the ceiling grid with all of the returns in the facility`s basement. According to Clean Rooms West President Steve Alley, the main curve of the windows in the viewing area was specifically designed to be the back-end of the equipment, or the “dirty area” of the cleanroom. “As far as air flow and the glass wall, there won`t be any stagnant areas,” asserts Alley, and “because they will be visible from the viewing area, all of the pass-throughs and vents will be finished and aligned.”
To deal with rapidly changing technology needs, the cleanroom`s modular walls can be easily reconfigured to adjust the relative percentages of class-level space. Initially 30 percent of the building will be Class 10, but with more fans and filter units, the area can be adjusted as needed. Alley says the Class 1,000 area could be changed to Class 100 in about a week through the addition of ULPA filters and a readjustment of the equipment.
The ULPA-filtered system will move 500,000 CFMs of recirclulated air with an additional 500,000 CFMs possible through the use of a redundant make-up air unit. Because of the strength of the double T-bridge-deck design, there was no need to re-engineer the roof for the 65-ton HVAC cooling towers or to provide bracing.
Fixtures and features
The plant includes an 18-megahohm, 300-GPM ultrapure water system incorporating waste treatment for slurries and metal removal for copper and nickel processes. About 60 percent of the water used in the facility is recycled through two redundant 150-GPM reverse osmosis and deionized water systems. All of the estimated 25 miles of chilled water, process piping and utilities and waste treatment lines for slurries and metal removals are in the facilities 912-foot basement allowing the cleanroom space to be largely reconfigured from below, and avoiding the need to frequently move heavy CMP equipment where it can become stuck on trenches or caught on pedestals.
Another special consideration is humidity control. The center will house various kinds of equipment, and it is now not possible to accurately predict what the requirements will be for developing new products or for testing new manufacturing processes. As a result, planning for both high and low humidity was a real dilemma.
Although the temperature range of semiconductor cleanrooms is usually fairly stable (62-68 degrees Fahrenheit), humidity requirements can range as low as 30 percent to as high as 50 percent, depending on the process. To regulate humidity levels, most cleanrooms incorporate both a liquid desiccant dehumidifier and a separate humidifier. SpeedFam`s cleanroom, however, will use a single multi-purpose system from Kathabar Inc. (New Brunswick, NJ). According to Alley, the combined humidifier/dehumidifier will reduce costs by some 30 percent.
At present, SpeedFam International expects the new facility to be finished on time and within budget.
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Speedfam`s new R&D center will simulate a complete semiconductor fab environment, housing some 250 engineers, scientists and software development specialists and a 21,000-square-foot class 1 to Class 10,000 cleanroom.