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V. K. F. CHIA, P. LINDLEY, & M. J. EDGELL, Charles Evans & Associates, Redwood City, CA, USA
S. BISWAS, Evans Europa, London, UK

ABSTRACT

Contamination introduced during semiconductor processing includes transition metals, mobile ions, carbon, and organics. These contaminants can be deposited onto the surface of the wafer or they can be energetically driven into the wafer, to depths of several nanometers. A host of analytical tools are available to measure these contaminants. Amongst these are magnetic sector SIMS (secondary ion mass spectrometry), quadruple SIMS, Surface SIMS (oxygen leak with magnetic sector SIMS), time-of-flight SIMS (TOFSIMS), total reflection x-ray fluorescence (TXRF), vapour phase decomposition TXRF (VPD-TXRF), and VPD-atomic absorption (VPD-AA). In general, no single analytical technique can provide the answer to every contamination problem. Specific requirements of each new situation will often dictate the choice of technique to use. In the analysis of metal contamination the analytical techniques are well established and entrenched in product improvement programs. In the analysis of organic contamination, the choice can be complicated because the effects of different contaminants are only beginning to be understood.