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The design of vibration-sensitive advanced technology facilities generally involves considerable attention to structural and mechanical aspects. In most cases, the vibration control measures contribute significantly to a facility's cost. The selection of a vibration criterion for use in design is an important step in the design process. Many process equipment manufacturers have provided tool-specific criteria, and the literature contains several forms of "generic" criteria. Unfortunately, there is no standardization in either tool-specific or generic criteria, and considerable confusion can arise, often due to the forms of data representation used. This paper first reviews some of the relevant fundamentals of signal processing, then uses experimental data to develop a tool-specific vibration criterion for an optical microscope. Two dissimilar approaches to generic criteria are discussed, and their signal-processing requirements are examined. They are compared with a manufacturer's published vibration criteria for a projection aligner. Recommendations are given for future development of tool-specific criteria.

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For many areas of acoustics, standards organizations or regulatory bodies have mandated vibration or noise criteria and defined the appropriate processing methods. No such standards exist for vibration-sensitive facilities at this time except as defined by equipment manufacturers, facility owners, and/or vibration consultants. The existing criteria from these groups differ widely in form. This paper reviews the various candidate methods offered by current technology for processing measured vibration data.