Time not ripe for 450-mm wafers

For a technology that may be at least a decade away from widespread adoption, the 450-mm wafer size has attracted a lot of attention.

Both proponents and opponents have vocally expressed their views, and now it looks like the consensus is that production for 450 mm is about eight to 10 years away. First, many equipment manufacturers say, investments in 300 mm need to be recouped before equipment providers and semiconductor makers will begin to seriously consider 450-mm wafers.

“The best thing right now for the industry is to maximize our investment in 300 mm and extend it further,” says Iddo Hadar, chief technology officer for the foundation technology group at Applied Materials. “For the great majority of semiconductor manufacturers and equipment makers, 450 mm doesn't make any sense.”

research director Dean Freeman says that 2012 may be a more realistic time frame for 450 mm. “Intel and Samsung think they need 450 mm right now to stay on the economic curve, so Intel is driving this, trying to drive the industry forward,” says Freeman. “On the other hand are the device manufacturers and equipment manufacturers finally getting margins on 300 mm saying, 'You must be out of your mind.'”

Another consideration is how much the equipment will cost when the transition happens, Freeman says. “Our estimate is 11 fabs will be able to afford 450-mm equipment, including Intel, the IBM consortia [IBM, Chartered Semiconductor and Samsung], Toshiba, TSMC and possibly STMicroelectronics.

Recognizing that the timing of moving to 450-mm wafers is the $64 million question, Ted Vucurevich, senior vice president and chief technology officer at Cadence Design Systems' advanced research and development group, says, “I don't see it happening before 32 nm and really not likely until the 22-nm process node. The adoption of new process nodes for margin improvement has bifurcated the industry into memory, processor and high-volume SoC providers as 'fast adopters' and 'the rest'.

Challenging adoption of 450-mm wafers is the economic battle that the equipment manufacturers would have to face, since the adoption gap between fast adopters and the rest will mean longer time frames for equipment manufactures to recover development costs of 450-mm tools.

Freeman points out that only Intel and maybe Samsung have the volumes that 450 mm would benefit at this time. “Applied says no, but if Applied starts, the rest of the industry will too,” he notes.

Intel contends that productivity needs improvement, to which Sematech subsidiary ISMI has proposed “300-mm Prime” to improve efficiency by increasing utilization of each piece of equipment in a fab.

On the technology front, Jim Kupec, chief operating officer at e-Silicon and former president of UMC USA, says that a move to 450 mm “is not just incremental pieces plugging in here and there; you have to convert the whole factory chain at the same time.”

“When that's going on,” he explains, “there are groups of things that become barriers and need to be solved all at the same time. For instance, when the industry went from 200 to 300 mm, automation had to be solved because the wafer boxes were so heavy that operators couldn't pick them up anymore without hurting their backs.”

Similarly, these types of issues will come up again in the eventual shift to 450-mm wafers.

Although the barriers seem daunting, there will be a time when it is clearly right to move to a larger wafer size, particularly given Gartner's estimate that it will cost the industry $16 billion in equipment and process development to move to 450 mm. Primarily equipment manufacturers will absorb the bill.