In Search of a Drought-Proof Source - The Ripple Effect: The Fate of Freshwater in the Twenty-First Century - page 293

Fab 32 is a behemoth in the desert: a long, low, wide building clad in gray metallic
tiles. Big enough to fit seventeen football fields inside, the 1-million-square-foot factory
employs over a thousand people, some of whom spend their days clad in full-body
white suits, like Woody Allen in Sleeper,padding up and down white hallways and etch-
ing computer chips in 184,000 square feet of clean rooms. Fab 32 was Intel's first high-
volume producer of its forty-five-nanometer (45 billionths of a meter) transistors, which
are so small that more than 2 million of them can fit on the period at the end of this
sentence . Millions of these transistors are used in processors for computers and servers.
They are produced on three-hundred-millimeter silicon wafers, which cost less, and use
40 percent less water, than the older two-hundred-millimeter wafers. Fab 32 produces
some of the most advanced computer chips in the world. (Though, in a demonstration
of Moore's law, Intel was producing twenty-two-nanometer transistors at other plants
by late 2010. To keep pace, Intel plans a $7 billion upgrade to its Arizona fabs to manu-
facture its latest chips there.)
To many observers, Chandler seemed an eccentric place for Intel to build such a
large, costly, high-tech fab. For one thing, the city was not much to look at. Chandler
began as a ranch, grew into a small town, and eventually expanded into a pleasant, bland
satellite of Phoenix. Forbesranked Chandler as “ one of the most boring cities in Amer-
ica , ” based on how rarely it was mentioned in the press (it is best known for its Peacock
Day parade); it hardly seemed like a natural it for a sophisticated, global, bleeding-edge
technology firm such as Intel. More important, Chandler sits adjacent to the hottest city
in the nation, in the shimmering Valley of the Sun, in the blazing Sonoran Desert, where
water and the ecosystem are constant worries.
Computer-chip fabrication is water intensive. In Silicon Valley , California, the center
of US microchip production, fabs from several companies account for a quarter of the
water consumed and have faced complains about air and groundwater pollution. Of
the twenty-nine Superfund sites in Silicon Valley (the most concentrated number in the
United States), nineteen were contaminated by TCE, PCBs, and Freon from computer-
chip manufacturers. Fabs are thirsty because as each of several dozen semiconductor
layers is applied and etched to a silicon wafer, it must be rinsed by an atomized spray
of water to keep it clean. Water has unique properties that remove molecular contamin-
ants. Microprocessors are so sensitive that even minute particles in the water—traces of
perfume or cologne, lotion, mold spores, or even smoke particles—can destroy a wafer.
Computer-chip fabrication requires “ ultrapure water ,” which acts as a sponge for mi-
crocontaminants, such as colloidal solids, particles, total organic carbon, bacteria, pyro-
gens (fragments of bacteria), metal ions, and the like.
A few years ago, the three Intel fabs at the Ocotillo campus in Chandler would have
required at least 7 million gallons of water per day to produce their transistors. But in