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Above, IBM employee Mary Westermann inspects one of the fab's 300mm silicon wafers.
The East Fishkill fab turns out the company's 32nm Power7 chips. Such is their complexity, they require 1,200 separate steps to make, and have a yield of around 50-60 percent, according to Arthur. "The size and complexity of the chip generally dictates the yield," he explains. "A smaller chip with less function will yield higher, a more complex chip with more function will generally yield less. Some of our OEM chips have yields that are in the 90s."
Arthur is heading up the project to build the next generation of Power chips, Power8, which are still in the very early stages of design. "The chip designers use mainframes to design these things. We're building chips so we can make the machines so we can design the next generation of chips," he says.
Preventing contamination on the fab floor is paramount, hence the workers' suits. Handling of the wafers is done by cubed robots such as the one above, which move around on tracks attached to the ceiling. They ferry stacks of wafers in batches of 25 from stockers to machines where the circuitry is printed, before transferring them to other parts of the fab for quality testing. With an older chipset such as the Power7, now two years old, only about three wafers of each set of 25 are tested for imperfections, Arthur says. With a newer chip design, a higher number would be examined.
There are around 350 tool operators on the fab floor, though their job is to test and check tools rather than operate them. They are joined by nearly 500 workers employed by IBM's partners, such as Samsung, Global Foundries and ST Micro, who have access to the fab and can work on the tools supplied by their companies.
Alongside IBM Research in nearby Yorktown, much of the fab's work here is focused on developing high-performance chips.
Arthur says the fab is unusual in having production and development share the same facility. "That's rare in the industry. The plus of it is, if you work together, you can save capital equipment, because you're sharing it. The negative is, if you're sharing it, you fight about who gets it," he says, adding that balancing the needs of the two is one of the biggest challenges of his job.
The East Fishkill fab runs three shifts 24/7, and closes down for only three shifts a year: Christmas Eve, Christmas Day and Christmas Night. "We ask for volunteers. We're not at full staff but we actually run those shifts," Arthur says. "The last time this facility closed was four years go. We closed it to do some major preventative maintenance on some of the infrastructure."
During Hurricane Sandy, in October, the fab didn't lose power, but was hit instead by power spikes. "Our equipment has anywhere from seven to 20 PCs that control it," Arthur explains. "So what appears to be the weak link on the tools is the PCs. If you lose power, or if it drops a certain percent for so many cycles, the PC will just lock up. We ended up with 17 power dips here [during Sandy]. We weathered 15. Number 16 took the fab, shut the tools off." It took about eight hours for the tools to restart, he adds.
Power to the fab is fed from three directions, Arthur says, "so we can actually take a hit on one, if the other two stay up... What hurts us is if more than one goes down".