Accession Number : ADA260551


Title :   Diamond Homoepitaxy by Chemical Vapor Deposition


Descriptive Note : Annual rept. 1 Jan-31 Dec 1992


Corporate Author : PENNSYLVANIA STATE UNIV UNIVERSITY PARK MATERIALS RESEARCH LAB


Personal Author(s) : Badzian, Andrzej ; Badzian, Teresa


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a260551.pdf


Report Date : Feb 1993


Pagination or Media Count : 12


Abstract : Gem-quality single crystals of diamond were grown by homoepitaxy using microwave plasma assisted chemical vapor deposition. Raman spectra of the (001) film show very low background and the narrowest width at half maximum of the 1332 /cm peak was 1.7 /cm. A prism crystal 1.2 mm high was grown in the 110 direction at 1200 deg C and 1% CH4 in H2. Its Raman peak has a width of 2.7 /cm. Homoepitaxy is a tool used to study growth processes by analyzing the geometrical details of surfaces morphologies. Growth steps on the (001) surface develop in the 110 directions while triangular plates appear on the (111) surface. The (110) atomic plane does not appear in the 110 growth direction with microfaceted (111) and (111) planes present instead. Crystal structure of diamond grown in the (001), (111), (110) substrates, as well as growth sectors developed in conjunction with this epitaxy, were studied by X-ray diffraction techniques: Laue, oscillation and rotation methods. Atomic force microscopy reached atomic resolution on the (001) surface. The presence of a 2.12 A reflection demonstrated distortion of cubic symmetry and deformation of carbon tetrahedra in the case of (111) epitaxy. In the (110) growth sector a polytype/ superstructure network with periodicity three times larger than that of the cubic form was determined. In general it is possible to form tetrahedral carbons with the sequence of tetrahedra different from that of cubic and hexagonal diamonds.... Diamond, Chemical vapor deposition, Homoepitaxy, Stacking faults.


Descriptors :   *CRYSTAL STRUCTURE , *CHEMICALS , *DIAMONDS , *EPITAXIAL GROWTH , *VAPOR DEPOSITION , REPRINTS , RESOLUTION , MICROWAVES , CARBON , SYMMETRY , PLATES , DIFFRACTION , SPECTRA , DEPOSITION , SURFACES , HYDROGEN , SEQUENCES , REFLECTION , SUPERSTRUCTURES , PERIODIC VARIATIONS , ATOMIC STRUCTURE , FAULTS , RAMAN SPECTRA , STACKING , DISTORTION , PLASMA DEVICES , ROTATION , OSCILLATION , METHANE , WIDTH , GEOMETRY , SUBSTRATES , X RAY DIFFRACTION , SINGLE CRYSTALS , FILMS , STRUCTURES , DEFORMATION , TOOLS


Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Geology, Geochemistry and Mineralogy
      Crystallography


Distribution Statement : APPROVED FOR PUBLIC RELEASE