Computer chip manufacturers are facing a couple of tough challenges: one environmental, the other purely technical. Every year, a typical chip-making plant sucks up about four million gallons of ultrapure water and uses an ocean of toxic chemicals to scrub and prepare microchips for use. At the same time, companies in the highly competitive industry are trying to further shrink transistors and other devices on chips to continue to make computers and other microelectronics cheaper and faster. The solution to both these challenges could come from an unlikely source: carbon dioxide.

Carbon dioxide has long been the nemesis of environmentalists because of its role in global warming, but under just the right conditions-namely, high pressure and the right temperature-it's one of nature's best and most environmentally benign solvents. Decaf-coffee lovers, for instance, benefit from its ability to remove caffeine from coffee beans. During the last few years, carbon dioxide has also made inroads in the dry-cleaning industry, providing a safe cleaning alternative to the chemical perchloroethylene. But it's on the high-tech front that carbon dioxide may make its biggest impact. "There are huge opportunities," says University of North Carolina chemist Joseph DeSimone. "I am confident that carbon dioxide will dominate several of the key steps in microelectronics."