AFM STUDY ON THE NONMONOTONIC TEXTURE EVOLUTION OF HETEROEPITAXIALLY NUCLEATED DIAMOND FILMS

After the heteroepitaxial nucleation of diamond on Si(001) the texture of the film depends strongly on the subsequent growth process. Accord ing to the van der Drift mechanism of evolutionary selection, a growth parameter or slightly below 3 should result in a splitting of the cen tral pole density maximum at chi = 0 degrees in the {400} pole figure into four maxima for high film thicknesses. In contrast, a strong narr owing of this maximum for the studied films was observed experimentall y. Based on simple geometric considerations a two-dimensional simulati on is presented which shows that in the growth competition between two selected grains for alpha < 3 the preferred crystallite which will fi nally survive may occupy considerably less volume and surface area in an intermediate stage of film growth. Atomic force microscopy (AFM) ha s been used in order to test whether this non-monotonic behaviour has an influence on the macroscopic film texture resulting in a transient narrowing of the pole figure. The measured correlation between the til t angles and the mean areas of the top {001} facets supports the assum ption that the effect described by the simulation contributes to the o bserved texture evolution.