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PATRICK H. SCHNABEL & PATRICIA M. LINDLEY, Charles Evans & Associates, Redwood City, CA, USA
DAVID NEHRKORN & MARIUS KENDALL, Surface Science Laboratories, Mountain View, CA, USA

ABSTRACT

In this study we use TOF-SIMS (Time-of-Flight Secondary Ion Mass Spectrometry), GC/MS (Gas Chromatography/ Mass Spectrometry) and FTIR Spectroscopy (Fourier Transform Infrared) for the identification of different types of airborne molecular contaminants that outgas from cleanroom materials. The materials under investigation include construction materials (e.g., floor tiles, filters and sealants), cleanroom furniture, garments and utensils. The transfer of contaminants onto silicon wafers that are brought into contact with these materials is also investigated. In these experiments, each of the materials produces a fingerprint that can be used to identify potential sources of contamination. The long-term objective of these studies is to generate an extensive database that makes it possible to link contaminants observed on wafers to potential sources within the cleanroom environment.