Characterization of Particles in High-Purity Gases

  • W. R. GerristeadJr.
  • E. F. Ezell
  • R. Sherman


Sub-micron particle analysis methods for VLSI gas distribution systems include laser particle counting and SEM/microprobe evaluation of particles collected on membrane filters. In this paper, the performance of automated SEM/microprobe methods is compared to the performance of laser particle counters in counting and sizing submicron particles. This comparison of particle counting methods involves analyses of membrane filters exposed to gas streams that were simultaneously sampled by laser particle counters. Experimental results demonstrate the ability of the SEM/microprobe technique to count, size, and compositionally identify submicron particles that are typically found in high purity gas streams. The advantages and disadvantages of SEM/microprobe analysis and laser particle counter analysis are also discussed.


Relative Efficiency Submicron Particle Filter Surface Error Treatment Backscatter Intensity 
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Copyright information

© Springer Science+Business Media New York 1990

Authors and Affiliations

  • W. R. GerristeadJr.
    • 1
  • E. F. Ezell
    • 1
  • R. Sherman
    • 1
  1. 1.Technical CenterThe BOC Group Inc.Murray HillUSA

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