Phosphorus incorporation in plasma deposited diamond films

Phosphorus-doped polycrystalline and homoepitaxial diamond films were grown using both microwave and dc plasma assisted chemical vapor deposition. P incorporation was quantified using secondary ion mass spectrometry, and was approximately ten times greater for polycrystalline films deposited using dc plasmas compared to microwave plasmas. For microwave-assisted growth, P incorporation was approximately ten times greater in polycrystalline than homoepitaxial films. These effects appear to be due to preferential incorporation at grain boundaries, since higher levels of P are measured in samples with smaller grains. The films were highly electrically resistive, with conductivities of 10−10–10−9/Ω cm at room temperature.