STUDY OF ANTIPHASE BOUNDARIES AND LOCAL 3X1 CONFIGURATION ON THE (001) SURFACE OF HOMOEPITAXIAL DIAMOND FILMS BY SCANNING-TUNNELING-MICROSCOPY

Homoepitaxial diamond films have been studied using scanning tunneling microscopy. Boron-doped films were grown on diamond (001) substrates by microwave plasma-assisted chemical vapor deposition. Atomic resolut ion scanning tunneling microscopy (STM) images showed a dimer-type 2 x 1 reconstructed surface structure and features such as steps, kinks a nd terraces. Single steps where dimer rows on the upper terrace are no rmal to the step edge are ragged and the steps where dimer rows are pa rallel to the step edge are straight, indicating that the steps have d ifferent formation energies. The double-domain surface structure obser ved with STM was in agreement with low-energy electron diffraction pat tern. Atomic images revealed two different types of antiphase boundary on the diamond (001) surface. These antiphase boundaries run parallel to or perpendicular to the dimer rows where dimer rows shift by only one lattice constant of the diamond (001) surface. We found that singl e dimer rows preferentially extended along an antiphase boundary. Loca l 3 x 1 configurations have been observed on homoepitaxially grown dia mond (001) surface.