Provides advanced treatment and in-depth coverage of the origins, procedures, and disposal of contaminants in the manufacturing of semiconductors and other precision products. Offers solutions to inadequate areas of measurement capability and control technology, clarifying problems in the industry.
Semiconductor chip manufacturing, now a $200 billion per year industry, is carried out in the cleanest manufacturing areas on earth. As measured by the metric of aerosol particle concentration, chips are manufactured in rooms far cleaner than surgical operating rooms, because trace contamination can ruin products and thus can also ruin companies.
In the 1970s and early 1980s, product yield—the number of salable chips produced divided by the number of chips started through the production line— among U.S. manufacturers was on the order of 10–15%, while Japanese competitors achieved yields on the order of 60–90% and even higher. One factor thought to be significant in accounting for this striking difference was the greater awareness of the importance of contamination control characterizing Japanese manufacturers. The Japanese model, as detailed in the many Ohmi publications [1, 2], emphasized the complete elimination of all identifiable contaminants in the chip manufacturing environment regardless of cost or the absence of a clear, demonstrated link between these contaminants and yield. The axiom accepted without proof was that contamination was bad for—and potentially fatal to—products and had to be eliminated at all costs. The U.S. approach, on the other hand, often was “show me” before taking corrective action, and, since the link between contamination and yield is complex and dependent on many variables, making it difficult to establish clear proof of cause and effect, corrective action was slower in coming.