Raman and conductivity studies of boron doped microcrystalline diamond, facetted nanocrystalline diamond and cauliflower diamond films

We present data showing how the electrical conductivity and Raman spectra of boron-doped CVD diamond films vary with both B content and crystallite size, for microcrystalline diamond (MCD), facetted nanocrystalline diamond (f-NCD) and ‘cauliflower’ diamond (c-NCD). The position of the Lorentzian contribution to the 500 cm−1 Raman feature was used to estimate the B content. This underestimated the SIMS concentration of B by a factor of ∼5 for the f-NCD and c-NCD films, but remained reasonably accurate for MCD films. One explanation for this is that most of the B incorporates at the grain boundaries and not in substitutional sites.