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

Report Date:

1995-09-01

Pagination or Media Count:

24.0

Abstract:

Electron emission has been observed on three types of diamond samples films deposited on both Si100 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 Vmicrometers 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

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