SYNTHESIS OF PHOSPHORUS-DOPED HOMOEPITAXIAL DIAMOND BY MICROWAVE PLASMA-ASSISTED CHEMICAL-VAPOR-DEPOSITION USING TRIETHYLPHOSPHINE AS THE DOPANT

Triethylphosphine [TEP, P(C2H5)3] was used as a dopant for homoepitaxi al (100) and (111) phosphorus-doped diamond films, which were formed b y microwave plasma-assisted chemical vapor deposition using CH4 as the carbon source. The growth rate of TEP-doped (100) diamond increased w ith increasing atomic ratio of phosphorus to carbon in the gas phase, from 300 nm h(-1) at 0 ppm to 800 nm h(-1) at 10 000 ppm at 850 degree s C. TEP-doped (100) diamond films deposited at temperatures below 850 degrees C were smooth and homoepitaxial, whereas those deposited abov e 950 degrees C as well as the TEP-doped (111) films formed at 750-105 0 degrees C were polycrystalline. Phosphorus was found to be uniformly incorporated into the diamond film, as evidenced by secondary ion mas s spectrometry. The Hall conductivity of the TEP-doped films remained low. (C) 1998 Elsevier Science S.A.