Effects of filament and reactor wall materials in low-pressure chemical vapor deposition synthesis of diamond

Abstract

Well-faceted diamond crystals and polycrystalline films have been produced by low-pressure, hot-filament-activated, chemical vapor deposition with the use of methane/ hydrogen gas. The effects on growth and morphology of varying filament and reactor tube materials as well as tube diameter are reported. Tungsten and tantalum filaments, operated under similar conditions, produced diamonds at essentially the same growth rates (typically ∼2 μm/h) and with similar crystallographic properties. Platinum filaments produced only graphitic deposits. Diamond growth and morphology appeared not to be influenced by changing the reactor wall material from fused quartz to Al2O3 or Pyrex or by varying the tube diameter.