Before entering the cleanroom in D1D, as Intel calls its 17 million-cubic-foot microprocessor factory in Hillsboro, Oregon, it’s a good idea to carefully wash your hands and face. You should probably also empty your bladder. There are no bathrooms in the cleanroom. Makeup, perfume, and cosmetics are forbidden. Writing instruments are allowed, as long as they’re special sterile pens; paper, which sheds microscopic particles, is absolutely banned. If you want to write on something, you’ll have to use what is known in the industry as “high-performance documentation material,” a paperlike product that doesn’t release fibers.
After you put on a hairnet, your next stop is the gowning station, inside a pressurized room that sits between the outside world and the cleanroom itself. A hard breeze, sent by a cleaning system that takes up the equivalent of four and a half football fields, hits you as you walk in, removing stray matter—dust, lint, dog hairs, bacteria. You put on pre-gown gloves, then a white bodysuit with a hood and surgical-style mouth cover, followed by a second pair of gloves, a second pair of shoe covers, and safety glasses. None of these measures are for your safety; they protect the chips from you.
The air in the cleanroom is the purest you’ve ever breathed. It’s class 10 purity, meaning that for every cubic foot of air there can be no more than 10 particles larger than half a micron, which is about the size of a small bacteria. In an exceptionally clean hospital OR, there can be as many as 10,000 bacteria-size particles without creating any special risk of infection. In the outside world, there are about 3 million.
The cleanroom is nearly silent except for the low hum of the “tools,” as Intel calls them, which look like giant copy machines and cost as much as $50 million each. They sit on steel pedestals that are attached to the building’s frame, so that no vibrations—from other tools, for instance, or from your footfalls—will affect the chips. You step softly even so. Some of these tools are so precise they can be controlled to within half a nanometer, the width of two silicon atoms.
It’s surprisingly dark, too. For decades, Intel’s cleanrooms have been lit like darkrooms, bathed in a deep, low yellow. “That’s an anachronism,” says Mark Bohr, a small, serious man who has spent his entire 38-year career making chips, and who’s now Intel’s top manufacturing scientist. “Nobody’s had the courage to change it.”
Chips are made by creating tiny patterns on a polished 12-inch silicon disk, in part by using a process called photolithography and depositing superthin layers of materials on top. These wafers are kept in sealed, microwave oven-size pods called “foups” that are carried around by robots—hundreds of robots, actually—running on tracks overhead, taking the wafers to various tools. The air inside a foup is class 1, meaning it probably contains no particles at all. Periodically, the wafer is washed using a form of water so pure it isn’t found in nature. It’s so pure it’s lethal. If you drank enough of it, it would pull essential minerals out of your cells and kill you.
Over the next three months—three times the amount of time it takes Boeing to manufacture a single Dreamliner—these wafers will be transformed into microprocessors. They’ll make their way through more than 2,000 steps of lithography, etching, material application, and more etching. Each will then be chopped up into a hundred or so thumbnail-size “dies,” each of which will be packaged in a ceramic enclosure. If everything functions properly, none of the 100,000 or so people who work at Intel will ever touch them. The endpoint of this mechanized miracle: the Intel Xeon E5 v4, the company’s latest server chip and the engine of the internet...