Accession Number : ADA308255

Title :   Nucleation Growth and Defect Engineering in Diamond Thin Films.

Descriptive Note : Final rept. 19 Sep 94-18 Sep 95,

Corporate Author : NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF MATERIALS SCIENCE AND ENGINEERING

Personal Author(s) : Narayan, Jagdish

PDF Url : ADA308255

Report Date : FEB 1996

Pagination or Media Count : 5

Abstract : We studied the chemical nature of the substrate and the role of buffer layers on nucleation and growth of diamond during chemical vapor deposition (hot-filament). The transition metals with partially filled d-atomic orbitals are found to stabilize SP2 bonding which leads to enhanced precipitation of SP2 bonded non-diamond carbon phases such as graphite, amorphous and glassy carbon films. We have shown that by alloying these metals with electron donating elements, it is possible to stabilize SP3 bonding and form diamond film directly on the metallic substrates. Similar studies on nucleation and growth of diamond have been performed using AlN buffer layers. The results from these studies are compared with those obtained using buffer layers. By using these concepts, we have minimized the formation of graphitic layers and improved the adhesion of diamond layers on non-carbide forming metallic substrates.

Descriptors :   *GROWTH(GENERAL), *THIN FILMS, *DIAMONDS, *NUCLEATION, *DEFECTS(MATERIALS), *ENGINEERING, BUFFERS, METALS, TRANSITION METALS, LAYERS, ADHESION, FILMS, CHEMICAL VAPOR DEPOSITION, GRAPHITE, SUBSTRATES, AMORPHOUS MATERIALS, CARBON, ALLOYS, ATOMIC ORBITALS, NITRIDES, CHEMICAL BONDS, ELECTRONS, PRECIPITATION, ALUMINUM, ELECTRON DONORS, FILLING, GLASSY CARBON.

Subject Categories : Laminates and Composite Materials
      Inorganic Chemistry
      Physical Chemistry
      Crystallography
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE