Accession Number : ADA259247


Title :   Low Temperature Deposition and Characterization of N- and P-Type Silicon Carbide Thin Films and Associated Ohmic and Schottky Contacts.


Descriptive Note : Annual rept.


Corporate Author : NORTH CAROLINA STATE UNIV AT RALEIGH


Personal Author(s) : Davis, R F ; Nemanich, R J ; Kern, R S ; Patterson, R ; Rowland, L B ; Spellman-Porter, L ; Tanaka, S


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a259247.pdf


Report Date : Jan 1992


Pagination or Media Count : 65


Abstract : Single-crystal epitaxial films of cubic Beta(3C)-SiC(111) and AlN(0001) have been deposited on alpha(6H)-SiC(OOO1) substrates oriented 3-4 deg towards 1120 at 1050 deg C via gas-source molecular beam epitaxy using disilane (Si2H6), ethylene (C2H4), thermal evaporation of Al and activated N species derived from an ECR plasma. High resolution transmission electron microscopy revealed that the nucleation and growth of the Beta(3C)-SiC regions occurred primarily on terraces between closely spaced steps. Pseudomorphic bilayer structures containing Beta(3C)-SiC and 2H-AlN have been grown under the same conditions for the first time. HREED and cross-sectional HRTEM showed all layers to be monocrystalline. Initial high temperature chemical interdiffusion studies between SiC and AIN show that all components diffuse very slowly across the interface. AHRTEM and SAS are being used to determine the concentration profiles. Thin film solid solutions of AIN and SiC have been deposited using similar techniques and conditions as the individual compounds. Metal contacts of Ti, Pt and Hf deposited at RT on n-type alpha(6H)-SiC(OOO1) exhibit rectifying behavior with ideality factors between 1.01 and 1.09. The Pt and Hf contacts had leakage currents of 5xl0-8 A/cm2 at -10V. Values of barrier heights for all contacts were within a few tenths of 1.0eV which is indicative that the Fermi level is pinned at the SiC surface.


Descriptors :   *LOW TEMPERATURE , *THIN FILMS , *DEPOSITION , METALS , SOURCES , CHEMICALS , LAYERS , RESOLUTION , SINGLE CRYSTALS , SUBSTRATES , MICROSCOPY , GASES , NITRIDES , MOLECULAR BEAMS , REGIONS , HIGH RESOLUTION , SOLIDS , NUCLEATION , CRYSTALS , CURRENTS , SILICON CARBIDES , SOLID SOLUTIONS , EVAPORATION , VALUE , N TYPE SEMICONDUCTORS , BEHAVIOR , DIFFUSION , TITANIUM , METAL CONTACTS , PLATINUM , BARRIERS , PROFILES , ELECTRONS , ETHYLENE , SURFACES , ELECTRON MICROSCOPY , TIME , EPITAXIAL GROWTH , FILMS , STRUCTURES , HIGH TEMPERATURE , INTERFACES , HAFNIUM , TEMPERATURE


Subject Categories : Organic Chemistry
      Physical Chemistry
      Electrical and Electronic Equipment
      Crystallography


Distribution Statement : APPROVED FOR PUBLIC RELEASE