Almost perfectly oriented heteroepitaxial diamond film was deposited on the (100)Si substrate by the carburization, bias-enhanced nucleation, and growth process in a dense plasma using a bell-jar-type microwave-plasma chemical vapor deposition (CVD) system with an ASTeX 1.5 kW magnetron plasma source. This dense plasma was a prerequisite for the perfect orientation and was not obtained simply by increasing microwave power, but was obtained by introducing a graphite block between the substrate and the substrate holder. The plasma was concentrated over the substrate especially at the four corners with a thickness of several millimeters. (C) 1996 American Institute of Physics.