Particle spatial distributions in low-pressure discharges

John E. Daugherty, M. D. Kilgore, David B. Graves

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Scopus citations


Plasma-generated particulates are receiving increased attention as a source of contamination in plasma etching and deposition systems. These particles are suspended electrically in the plasma, and they are subject to electrical, thermophoretic, gravitational, and frictional drag forces from both plasma ions and neutrals. Consequently, they form complex spatial arrangements in the glow. We have investigated these particle arrangements by spatially mapping the particle distribution with a simple HeNe scattering system. We have also employed direct sampling as a way to determine particle size. The systems we have studied include copper and aluminum particles formed in an argon sputtering system, and carbon containing particles grown in a methane discharge. In addition we have modeled a particulate containing discharge in an effort to understand how the particulates act under the influence of electrical forces, ion drag, gravitational forces, and thermophoretic forces. The model is used as an aid in understanding the light scattering results.

Original languageEnglish (US)
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
EditorsCecil J. Davis, Irving P. Herman, Terry R. Turner
PublisherPubl by Int Soc for Optical Engineering
Number of pages6
ISBN (Print)0819407259
StatePublished - 1992
Externally publishedYes
EventProcess Module Metrology, Control and Clustering - San Jose, CA, USA
Duration: Sep 11 1991Sep 13 1991

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


ConferenceProcess Module Metrology, Control and Clustering
CitySan Jose, CA, USA

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


Dive into the research topics of 'Particle spatial distributions in low-pressure discharges'. Together they form a unique fingerprint.

Cite this