Accession Number : ADA303115

Title :   Growth, Characterization and Device Development in Monocrystalline Diamond Films.

Descriptive Note : Quarterly technical rept. 1 Jul-30 Sep 95,

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

Personal Author(s) : Davis, R. F. ; Glass, J. T. ; Nemanich, R. J. ; Sitar, Z. ; Baumann, P. K.

PDF Url : ADA303115

Report Date : SEP 1995

Pagination or Media Count : 24

Abstract : Electron emission has been observed on three types of diamond samples: films deposited on both Si(100) wafers and on individual Mo tips via plasma chemical vapor deposition (CVD) and also on the Mo tips via dielectrophoresis of diamond powder. In the first sample type, ultraviolet photoemission spectroscopy showed that the samples exhibited a negative electron affinity after exposure to a hydrogen plasma. Secondary electron emission yields varied from 2.2 to 9.2. Field emission current-voltage measurements showed threshold voltages ranging from 28 to 84 V/micrometers and effective emission barrier heights from 0.15 to 0.33 eV. The film with the highest secondary yield also exhibits the lowest emission threshold. In the last two sample types, transmission and scanning electron microscopies revealed a significant amount of diamond on the tips of the Mo emitters. The field emission characteristics were investigated before and after diamond deposition. The CVD diamond coated emitters exhibited a significant increase in emission current. A possible mechanism to explain the current enhancement by diamond powder coated Mo emitters has been presented. jg p2

Descriptors :   *FILMS, *DIAMONDS, *SINGLE CRYSTALS, *EPITAXIAL GROWTH, SCANNING, OPTIMIZATION, POWDERS, PLASMAS(PHYSICS), THRESHOLD EFFECTS, ELECTRONIC SCANNERS, VOLTAGE, CHEMICAL VAPOR DEPOSITION, MOLYBDENUM, HYDROGEN, ELECTRON MICROSCOPY, COATINGS, FIELD EMISSION, ELECTRON EMISSION, PHOTOELECTRIC EMISSION, ULTRAVIOLET SPECTROSCOPY, SILICON, SAMPLING, SECONDARY EMISSION, ELECTRIC CURRENT, EMITTERS, ELECTRICAL MEASUREMENT, ELECTROPHORESIS.

Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Electrical and Electronic Equipment
      Coatings, Colorants and Finishes
      Atomic and Molecular Physics and Spectroscopy
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE