Accession Number:

ADA252648

Title:

Growth, Characterization and Device Development in Monocrystalline Diamond Films

Descriptive Note:

Quarterly letter rept. 1 Apr-30 Jun 1992,

Corporate Author:

NORTH CAROLINA STATE UNIV AT RALEIGH

Personal Author(s):

Report Date:

1992-06-01

Pagination or Media Count:

15.0

Abstract:

Initial bias-enhanced heteroepitaxial nucleation on single crystal SiC has proven to be successful. Transmission electron microscopy TEM showed that approximately half of the diamond nuclei were in epitaxial alignment with the SiC substrate. Further TEM both confirmed this epitaxy and also clearly indicated that the nuclei were tilted by several degrees. This tilting was determined to be a result of the high density of inefficient misfit dislocations at the interface. It was found that the tilt component of the misfit dislocations could account for the misorientation in the crystals. It was also suggested that by attempting to grow diamond 114 on SiC221 the interfacial strain energy and resulting misorientation could be significantly reduced. Photoemission spectroscopy was used to compare the effect of plasma cleaning procedures, and high temperature annealing procedures, on natural type 2B diamond 111 surface. The hydrogen on the diamond surface was desorbed by annealing the diamond to approximately 950 deg C, and the sharp peak in the photoemission spectra, observed prior to annealing and indicative of a negative electron affinity surface, disappeared. The peak could be recovered by exposing the surface to either plasma generated or hot filament excited mono-atomic hydrogen.

Subject Categories:

  • Crystallography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE