Accession Number : ADA289092

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

Descriptive Note : Semiannual Technical rept. 1 Jul-31 Dec 94,

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

Personal Author(s) : Davis, Robert F. ; Bedair, S. ; El-Masry, N. A. ; Glass, J. T. ; King, S.

PDF Url : ADA289092

Report Date : DEC 1994

Pagination or Media Count : 54

Abstract : Residual surface contaminants were removed from vicinal 6H-SiC(0001) surfaces in UHV via high temperature annealing in SiH4. Characterization via AES, EELS, LEED, XPS, and UPS was conducted. At T>850 deg C, the surface oxide was rapidly removed. Exposure to approx. 400 Langmuir (10(exp-6) Torr(dot)liter/s) of SiH4 resulted in complete surface oxide removal and a nearly stoichiometric (l x l) 6H-SiC surface suitable for ALE of SiC. Further exposure resulted in a (3 x 3)R30 deg Si-rich reconstructed surface. Subsequent annealing in UHV resulted in a (square root of 3 x square root of 3)R30 deg Si deficient/graphitic reconstructed surface. The first set of wafers containing HBT device structures were fabricated on SiC films grown via ALE. No transistor activity was detected. Electrical characterization and SEM showed the most likely fault to be inaccurate etching of the SiC emitter. Nucleation and growth of oriented diamond particles on seeded, <0001> oriented single crystal Co substrates was achieved via multi-step, hot-filament CVD process involving seeding, annealing, nucleation and growth. Diamond particles oriented <111> were obtained. Micro-Raman showed a FWHM of 4.3/cm. A very weak graphitic peak was observed on regions of the substrate not covered by the diamond particles. A nucleation model has been proposed. Initial results showed that CeO2 film grows epitaxially on (111) Si substrates. The CeO2 films had density of interfacial traps and fixed oxide charge values comparable to that of amorphous SiO2/Si.

Descriptors :   *COMPOSITE MATERIALS, *THIN FILMS, *EPITAXIAL GROWTH, *SURFACES, *GROUP IV COMPOUNDS, DENSITY, PEAK VALUES, ANNEALING, REMOVAL, MODELS, INTERFACES, SILICON DIOXIDE, HIGH TEMPERATURE, DIAMONDS, CHEMICAL VAPOR DEPOSITION, GRAPHITE, SUBSTRATES, AMORPHOUS MATERIALS, NUCLEATION, BACKSCATTERING, ETCHING, REGIONS, PARTICLES, OXIDES, X RAY PHOTOELECTRON SPECTROSCOPY, RESIDUALS, CONTAMINANTS, WAFERS, AUGER ELECTRON SPECTROSCOPY, LOW STRENGTH, BIPOLAR TRANSISTORS, TRAPS, COBALT.

Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Laminates and Composite Materials
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE