Crystallographic evolution of microstructure in thin film processing: Part I. grain size distribution
Processing parameters and the resulting properties of a material are linked by the relationship between processing and microstructure. Characterizing the effect of processing variations on microstructure and determining its origin are essential to advanced material development. In this and a companion article, some readily applied techniques for producing quantitative data on grain size and shape, as well as grain and boundary crystallography, are described. The method described in Part I utilizes transmission electron microscopy and image analysis to measure grain size in large quantities (2000 to 3000 grains per sample), differentiated into orientation class subpopulation distributions. On application to Ni thin films produced by ion assisted deposition, the results have identified an orientation subpopulation that is predominantly responsible for the larger grain sizes observed in films grown under high ion flux. Larger grain size and the development of a preferred orientation have both been associated with increasing ion flux during growth, however, these results give the first experimental evidence connecting grain size and texture in these films.