Temperature Dependence of Species Concentrations Near the Substrate during CVD Diamond Growth

Abstract

Measurements have been made of the temperature dependence of CH3, CH4, and C2H2 very near the substrate during filament-assisted diamond growth. CH3 was detected using (2+1) resonance-enhanced multiphoton ionization (REMPI), and CH4 and C2H2 concentrations were measured using sampling mass spectrometry. A strong dependence of the CH3 REMPI signal on substrate temperature was observed, which at low temperatures may be characterized as having an activation energy of approximately 4 +/- 1 kcal/mole. Methane and acetylene, on the other hand, are relatively independent of substrate temperature. These results are most likely due to recombination of methyl to methane in the cool gas layer near the substrate or on the surface at low substrate temperatures.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1992
Accession Number
ADA256762

Entities

People

  • D. G. Goodwin
  • E. J. Corat

Organizations

  • California Institute of Technology

Tags

Communities of Interest

  • Energy and Power Technologies
  • Weapons Technologies

DTIC Thesaurus Topics

  • Acetylenes
  • Alkynes
  • Chemical Vapor Deposition
  • Chemistry
  • Conversion
  • Energy
  • Engineering
  • Heat Of Activation
  • Jet Propulsion
  • Low Temperature
  • Mass Spectrometry
  • Materials
  • Materials Science
  • Measurement
  • Optical Materials
  • Spectrometry
  • Substrates

Fields of Study

  • Physics

Readers

  • Molecular Photonics/Laser Physics
  • Surface Engineering/Surface Coating Technology.