Synthesis and evaluation of high-quality homoepitaxial diamond made by thecombustion flame method

In the cathodoluminescence (CL) spectra of natural II diamond and high-qual ity chemical vapor-deposited diamond, both a free-exciton recombination rad iation peak originating from high crystallinity (perfection of the crystal structure) and a band A peak originating from low crystallinity (imperfecti on of the crystal structure) are observed. In this study, a homoepitaxial d iamond film is synthesized on a single-crystal diamond (100) substrate by t he combustion flame method, and the film quality is evaluated by CL analysi s. Crystal defects are mechanically introduced into the diamond film to stu dy changes in the CL spectrum and the following results were obtained. (1) High-quality diamond with negligible amounts of nitrogen impurities and cry stal defects can be synthesized at a high rate (100 m/h) using the combusti on flame method. (2) The band A peak corresponding to a crystal defect is b road, with a wavelength of 430 nm. (3) Mechanically introduced cracks (crys tal defects) decrease the intensity of the FETO peak, while the intensity o f the band A peak increases. (C) 2000 Elsevier Science B.V. All rights rese rved.