MICROSTRUCTURAL EVOLUTION OF DIAMOND SI(100) INTERFACES WITH PRETREATMENTS IN CHEMICAL-VAPOR-DEPOSITION

Diamond was deposited on Si(100) substrates by the microwave plasma-as sisted chemical vapor deposition method in three steps: carburization, biasing, and growth. High-resolution transmission electron microscopy in cross-sectional view has been used to observe the evolution of mic rostructures around the interfacial region between diamond and Si in e ach processing step. The chemistry near the interface was characterize d with elemental mapping using an energy-filtered imaging technique wi th electron energy loss spectroscopy. An amorphous carbon layer, beta- SiC and diamond particles, and graphite plates have been observed in t he carburization stage. beta-SiC can form in epitaxial orientation wit h Si in the following stage of biasing. Graphite and amorphous carbon were not observed after the bias was applied. Diamond grains were alig ned in a strongly textured condition in the growth stage. It has been found that diamond, SiC, and Si all have (111) planes in parallel. The relation of the evolution of microstructure with the processing condi tions is also discussed.