Basic phenomena in low pressure plasma processing discharges

Summary form only given. Reactive plasma processes have been and are being developed in many labs worldwide for a wide range of industrial applications. Although the design of these processes is guided by some knowledge of the chemistry involved, process development has been largely empirical due to uncertainties associated with the nonequilibrium nature of low pressure discharges. As the use of plasma processing becomes more and more entrenched in manufacturing there is a strong incentive to elevate the state of understanding of fundamental phenomena that govern these processes, through the development and use of appropriate diagnostic and modeling tools. Because of the collaborative contributions of researchers from a wide range of backgrounds and its extensive infrastructure, the Engineering Research Center (ERC) for Plasma-Aided Manufacturing at UW-Madison is particularly well-suited to address questions about fundamental phenomena in processing plasmas, as well as sensor development. For example, we have successfully combined optical spectroscopy, mass spectrometry, Langmuir probes and modeling to make several important discoveries about process chemistry in low pressure, "high density" fluorocarbon discharges used in the selective etching of silicon dioxide over silicon. These studies have demonstrated both the importance of reactions on chamber walls to the gas phase chemistry and the chemical role of ions in substrate surface reactions responsible for selectivity. An overview of ERC activities in etching and deposition will be presented, with an emphasis on studies of basic processes.