Particle Elimination by Design Intervention

Abstract

Reduction and control of particulates in plasma processing is a key goal and requirement for tool and process engineers alike. Yet, plasma tools are amongst the "dirtiest" of dry processing tools in a fab line, having contamination levels orders of magnitude higher than the clean room in which they are operated. This raises an important question: why is it that great strides have been made in reducing contamination levels in many other process tools, yet plasma tools have shown much less improvement? The answer is striking and profound: because particles in plasma processes behave differently than particles in any other ambient. Our understanding of particle behavior - and our methods for control of particles is based upon neutral, rather than ionized ambient. These approaches are less effective in a plasma environment. Controlling contamination in plasma processes is intuitive and scientific, once a proper understanding of particle behavior is obtained for ionized environments. from this applied science, new technologies have been developed for plasma processes. Using these new technologies, electrode designs for active particle reduction have been tested and implemented. Some results will be graphically demonstrated in a short video tape. From the manufacturing results, other discoveries result, such as relation between process uniformity and particle contamination. The improvement process continues, not depending on luck or divine intervention to improve tool performance, but upon close interaction between researcher, process engineer and tool designers.