ELECTRONICS INDUSTRY WASTE STREAM REDUCTION: APPLICATION OF ENVIRONMENTALLY FRIENDLY, POLYMER RESIST/MASK FOR MICROCIRCUIT LITHOGRAPHY

No one questions the philosophy that it is better to avoid industrial pollutionrather than to attempt the clean up of an environmentally abused site.Unfortunately, we are slow to learn this lesson and hazardous wastes become moreexotic and continue to increase. Causing 21 of the 28 EPA superfund sites in theSilicon Valley (Witkowski and Menon 1991), the semiconductor industry was, andcontinues to be, a major produce of hazardous waste.In the fabrication of chrome-plated masks, several chemicals and a significantfraction of the chromium are washed down the drain. Lynntech, Inc. proposes theapplication of a conducting polymer as a replacement for the resist and mask,eliminating many of the chrome-plate preparation steps and wastes. In contractsto traditional lithography (where the molecular weight of the resist is alteredduring exposure), substrates are spin-coated with a monomer and the desiredpattern is exposed. The exposed regions polymerize, permanently adhering to theplate and replacing the chrome. The unexposed monomer may be rinsed away withwater and is easily removed from the waste stream. The polymer itself isenvironmental friendly, and the simplification of mask preparation lowers thenumber and amount of hazardous chemicals which are presently necessary.