Accession Number:

ADA252872

Title:

Atomic Force Microscopy of (100), (110), and (111) Homoepitaxial Diamond Films

Descriptive Note:

Technical rept.,

Corporate Author:

RICE UNIV HOUSTON TX DEPT OF CHEMISTRY

Report Date:

1992-05-29

Pagination or Media Count:

33.0

Abstract:

We present atomic force microscopy images of diamond films grown by chemical vapor deposition epitaxially on diamond 100, 110, and 111 substrates. The films were grown from 0.2-1.6 mixtures of CH4 and C2H2 and H2 in a hot-filament reactor at a total pressure of 25 Torr. The substrate and filament temperatures were held at 810-1000 deg C and 2000-2150 deg C, respectively. A 100-oriented diamond film grown with 0.3 CH4 at a substrate temperature of 810 deg C was rough on the micron scale, exhibiting pyramidal features, terraces, and penetration twins, while films grown at higher substrate temperatures and hydrocarbon flow rates were smooth on the nm scale and showed evidence of a 2x1 reconstruction. A 110-oriented film was very rough on the micron scale but nearly atomically smooth on the 0.5-5nm scale and exhibited local slopes higher than 40 deg with no evidence of faceting. A film grown on a diamond 111 substrate underwent spontaneous fracture due to tensile stress and exhibited a roughness of 10-50 nm on the 100 nm lateral scale in regions far away from any cracks. The implications of the morphological features for diamond growth mechanisms are discussed.

Subject Categories:

  • Physical Chemistry
  • Crystallography
  • Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE