Accession Number : ADA313765

Title :   Diagnostics of Diamond Film Deposition Plasmas.

Descriptive Note : Final rept. 1 Mar 93-28 Feb 96,

Corporate Author : SRI INTERNATIONAL MENLO PARK CA MOLECULAR PHYSICS LAB

Personal Author(s) : Stalder, Kenneth R. ; Jeffries, Jay B.

PDF Url : ADA313765

Report Date : AUG 1996

Pagination or Media Count : 100

Abstract : Diagnostic measurements of diamond-depositing dc arcjet plasmas are described. Polycrystalline diamond films with high-quality Raman spectra are grown using both low-pressure (5 to 40 Torr) and high-pressure (200 Torr) plasma arcjets. A number of different techniques, including laser-induced fluorescence (LIF), optical emission spectroscopy, mass spectroscopy, and Langmuir probe methods were developed and applied to measure properties of the plasma's physical and chemical environment as it deposits diamond on a surface. Low pressure arcjets are usually well out of thermal equilibrium even as they strike the substrate surface. LIF measurements show the gas temperature actually increases downstream of the arc, from 1800 to 2400 K, as a result of hydrogen atom recombination, whereas, Langmuir probe measurements show the electron temperature is roughly constant at 1 to 2 eV (12,000 to 24,000 K). Many species important for characterizing the physical environment have been detected with the optical methods (C2, CH, C3), and the mass spectroscopic measurements have focused on the species thought to be important for diamond growth (CH3 and C2H2).

Descriptors :   *DIAMONDS, *DIELECTRIC FILMS, OPTICAL PROPERTIES, LASER INDUCED FLUORESCENCE, PLASMAS(PHYSICS), THERMAL STABILITY, MASS SPECTROSCOPY, SURFACES, DEPOSITION, ELECTRON ENERGY, EMISSION SPECTROSCOPY, LANGMUIR PROBES, PLASMA DIAGNOSTICS, POLYCRYSTALLINE.

Subject Categories : Ceramics, Refractories and Glass

Distribution Statement : APPROVED FOR PUBLIC RELEASE