Homoepitaxial growth of CVD diamond: effect of nitrogen contaminations on growth rates

Homoepitaxial diamond films were deposited on {100} and {111} oriented substrates using microwave plasma assisted CVD. The growth rate was measured in situ using laser interferometry. Various amounts of (exp 15)N(ind 2) were admixed to the process gas (0-50 ppm). The growth rate on {100} faces was found to increase significantly (by a factor 1.8) with increasing (exp 15)N(ind 2) content. In contrast, on {111} faces only a minor increase of the growth rate upon nitrogen admixture was observed. These findings are in perfect agreement with the observed influence of nitrogen contaminations on the alpha-parameter, as derived by the X-ray texture analysis of polycrystalline diamond films.