| abstract |
A process for preparing a diamond thin film by an electron assisted chemical vapor deposition (EACVD) is disclosed, in which diamond crystal nucleuses are caused to form and grow to a thin film on a plate substrate (24), maintained at a temperature of in excess of 400°C, under electron bombardments in an atmosphere of a mixed gas of a hydrogen and a hydrocarbon in a reduced pressure. A Boron doped p-type diamond semiconductor is prepared by an addition of a trace amount of diborane in the mixed gas of the hydrogen and the hydrocarbon in said EACVD. |