Accession Number : ADA311027

Title :   Atomic Layer Epitaxy of Group IV Materials: Surface Processes, Thin Films, Devices and Their Characterization.

Descriptive Note : Semiannual technical rept. 1 Jan-30 Jun 96,

Corporate Author : NORTH CAROLINA STATE UNIV AT RALEIGH

Personal Author(s) : Davis, Robert F. ; Bedair, S. ; El-Masry, N. A. ; Sitar, Z. ; Han, S. K.

PDF Url : ADA311027

Report Date : JUN 1996

Pagination or Media Count : 25

Abstract : The growth parameter, alpha, the ratio of the growth rates on (100) and (111) facets for diamond films deposited on Si and Ti by microwave plasma CVD has been studied using SEM micrographs. Different morphologies were generated on Si under different deposition conditions. The value of alpha increased with increasing temperature and increasing methane concentration, as expected. A value of alpha for Ti was not obtained due to the heavily twinned particles. Violet/blue photoluminescence from epitaxial cerium dioxide films on Si substrates was observed for the first time. The films were deposited on Si(111) substrates under UHV conditions using pulsed laser ablation of a cerium oxide target. They were rapid thermally annealed in argon, and excited by a He-Cd ultraviolet laser of 325 nm wavelength. The emission might be due to charge transfer transitions from the 4f band to the valence band of CeO2. Growth of Si on nearly lattice matched CeO2/Si(111) substrates for silicon-on-insulator (SOI) applications is reported. A low pressure chemical vapor deposition (LPCVD) growth technique was employed using 1% disilane in N2 to deposit silicon at 700 and 750 deg C on single crystal CeO2 films deposited under UHV conditions in the same growth apparatus. The RHEED patterns obtained and the surface morphology of the grown films indicated a three-dimensional mode of crystal growth.

Descriptors :   *COMPOSITE MATERIALS, *THIN FILMS, *SURFACE PROPERTIES, *GROUP IV COMPOUNDS, *ATOMIC LAYER EPITAXY, ABLATION, PARAMETERS, PLASMAS(PHYSICS), PHOTOLUMINESCENCE, MORPHOLOGY, FILMS, DIAMONDS, LOW PRESSURE, CHEMICAL VAPOR DEPOSITION, EPITAXIAL GROWTH, MICROWAVES, SUBSTRATES, PULSED LASERS, REFLECTION, TARGETS, LASERS, HIGH ENERGY, DEPOSITS, OXIDES, VALENCE BANDS, SILANES, CHARGE TRANSFER, TITANIUM, TRANSITIONS, METHANE, BLUE(COLOR), ARGON, ELECTRON DIFFRACTION, CRYSTAL GROWTH, ULTRAHIGH VACUUM, ULTRAVIOLET LASERS, CERIUM COMPOUNDS, DIOXIDES, HELIUM CADMIUM LASERS, SILICON ON INSULATOR.

Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Lasers and Masers
      Laminates and Composite Materials
      Crystallography
      Atomic and Molecular Physics and Spectroscopy
      Plasma Physics and Magnetohydrodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE