COMBUSTION FLAME GROWN DIAMOND FILMS

For many applications, including those in the biomedical field, diamond and diamond-like coatings are required to be of uniform thickness and uniform surface morphology. Film deposition processes are required which exhibit a high density of nucleation sites. The range of techniques reported in the literature used to grow diamond or hard carbon films is ever widening, however, there is still much to be learned on how the process variables influence nucleation and subsequent film formation/growth. In order to obtain preliminary systematic information on the factors which influence nucleation and growth, the combustion flame process has been employed. Although this technique is not directly applicable to biomedical applications, it can nevertheless be used to indicate trends which will have some relevance to the more promising processes. In particular, a series of experiments has been carried out to investigate how the nucleation density and morphology of diamond/diamond-like carbon films are influenced by substrate surface finish and substrate temperature. Nucleation density is shown to increase approximately linearly with temperature up to 1300 K, and with decreasing surface roughness down to surface roughness values of 0.07 μm. © 1992.