SEMI forum traces road to 300mm

Electronic News, June 30, 1997 by Judy Erkanat

Speakers from Intel, Samsung Electronics and Siemens were joined by others from Motorola, NEC and Texas Instruments.

Motorola's Dan Tull contrasted the cost of building a 300mm fabrication facility to that of a 200mm facility of an equivalent class. "We found a 7 percent increase in cost by going to 300mm," Mr. Tull said. "Three percent of this is attributed to steppers and implanters. We can, however, have the same die output with a 52 percent cut in floor area."

Tim Woolridge from TI said his company was in the race not to be first. "At 300mm, we need everything from scaled-up versions of tools to a completely new tool set," he explained. "New to TI, we see the need for a mini-environment in a front-opening unified pod with an overhead transport system. Extensive intrabay automation is needed in addition to the current interbay automatic delivery."

Mr. Woolridge said TI's first fabs will have no actual production equipment in them, only beta-site units. He puts the installation of TI's first mini-line in January, 1999, to be converted to a working production line by 2000.

"We have a working schedule, but have voiced our concern over the actual availability of 300mm equipment," Mr. Woolridge said. "Our mini-line will have one of each kind of equipment, and can ramp up into a production line by adding new equipment, without being totally dismantled, like many pilot lines."

He felt the personnel mix in the fabrication area would change with 300mm, with an increase in equipment technicians and a decrease in material handling personnel.

TI will put its first 300mm manufacturing site in Italy, if it is a memory facility, or in the U.S., if it is a logic site.

NEC's Seiichiro Takabayashi set the transition point for 300mm wafers in 2004. "Three-hundred millimeter will decrease the cost of a fab due to less lines," he said. "And the move to 300mm is needed to accommodate the increased size of DRAMs."

Mr. Takabayashi expected a 20 percent cost reduction between 200 and 300mm wafers, and put 300mm transition efforts in the second stage, equipment evaluation, out of four. "We have been evaluating equipment since 1Q97," he said. "We expect pilot lines to start 2Q98, with full pilot lines in operation 4Q98. Volume production is expected by first quarter 2000."

Features of 300mm wafer fabrication facilities in NEC's book includes 0.25-micron products like 64-megabit and 256M DRAMs; a production volume of 15,000 wafers per month; and a 1.85 increase in size from eight-inch wafer production, which Mr. Takabayashi said needed to be reduced.

"Features of production include high wafer cost, heavy carrier weight and fine patterns," he said. "Key issues needing to be addressed are the lithography, thermal and wet processes. In all areas we need process uniformity and a reduction in particles and contamination. The key to achievement in this area is high-efficiency equipment and low-cost fab design. NEC's goal for the 300mm transition is the end of 1999."