PUB - Publikationen an der Universität Bielefeld

The influence of nitrogen-containing species on the growth of diamond films is well-established in microwave and hot filament chemical vapour deposition (CVD) systems. Here, diamond CVD was investigated in atmospheric acetylene-oxygen flames doped with N-containing species [N-2, N2O, NH3, N(CH3)(3)]. Small amounts of these additives increase the growth rate, while higher concentrations lead to preferential sp(2) carbon deposition. The growth-effective amount of N-additive decreases by more than an order of magnitude in the sequence N-2 > N(CH3)(3) congruent to N2O > NH3. Simulation of the gas phase chemistry in a stagnation-flow geometry shows that the transformation of the additives towards HCN, NO and N is strongly correlated with growth enhancement and film quality decrease.