MICRO: Cox (March 2001)

James Cox and Sig Koenigseder, The testing of a catalytic-based point-of-use abatement system found that it is capable of destroying >99% of PFC gases from the exhaust of a 300-mm dielectric etch process tool. Perfluorocompounds (PFCs) are used extensively by the semiconductor industry in etch processes and chemical vapor deposition (CVD) chamber cleans. Common PFCs used in these processes include perfluoromethane (CF ). These compounds were originally adopted for use in IC production because they are relatively stable, nontoxic, noncorrosive, easy to handle, and low in cost. However, because their stability and strong infrared absorption make them potentially significant contributors to global warming, the industry is now striving to achieve reductions in fabrication facilities' PFC emissions. At 80%, carbon dioxide (CO ) accounts for the largest share of global-warming gases in the earth's atmosphere, while PFCs make up only 2% of the global total of such gases. However, when rated against CO , which has been given an arbitrary global-warming-potential val-ue of one, PFCs have po- tential values that are from thousands to tens of thousands of times higher. The semiconductor industry is responsible for approximately 5% of the PFC emissions in the United States, equivalent to 0.1% of the global-warming gases in the earth's atmosphere. Although this percentage may seem trivial, the industry's PFC emissions have nearly tripled since 1990, and a steady increase is expected to continue as the industry continues to expand. To combat this trend, government and industry experts have worked cooperatively to create a voluntary PFC emissions reduction plan. Under the resulting agreement, known as the memorandum of understanding, the U.S. semiconductor industry will unilaterally reduce PFC emissions over the next decade. In addition, by 2010 the Semiconductor Industry Association (SIA) seeks to reduce PFC emissions to 10% below the output levels of 1995 for its