Heteroepitaxial MgO films have been grown on SiC-buffered Si(0 0 1) substrates by chemical vapor deposition using a single source in an ultrahigh vacuum chamber. The crystallinity of the MgO films deposited in the temperature range 600-850degreesC has been investigated by reflection high-energy electron diffraction (RHEED) and X-ray diffraction (XRD). RHEED patterns showed ordered spot structures with twin spots for the films grown in the temperature range 700-850degreesC, and ring structures for the films grown below 600degreesC. XRD patterns, rocking curve measurements, and pole figure analysis have also indicated that the films are grown partly epitaxially in the [1 0 0] direction at growth temperatures between 700degreesC and 850degreesC. (C) 2002 Published by Elsevier Science B.V.