Currently, the aim of research in diamond film synthesis on silicon substrates is to gain an understanding of the mechanisms responsible for the development of highly oriented film and for the formation of epitaxial nuclei. With this as our goal we have applied plan-view transmission electron microscopy (TEM) for analysis of a diamond film grown on Si at various stages of film growth.

An ASTeX™ MPCVD system was used to deposit diamond on a single-crystal (100) Si substrate under the following conditions: 970°C, 700W microwave power, 2% CH4 in H2, 90 torr., and 4 hours. The growth step was preceded by a BEN stage in which a negative potential of 200V was applied to the substrate for 25 minutes at 600°C, 700W, 4% CH4 in H2, and 20 torr.. Three different types of plan-view TEM samples were prepared. For one the common procedure of backthinning, dimpling, and ion milling was applied to produce a specimen which reveals microstructures at the film surface.