TAILORING GROWTH AND LOCAL COMPOSITION BY OBLIQUE-INCIDENCE DEPOSITION - A REVIEW AND NEW EXPERIMENTAL-DATA

In this paper features are discussed that are related to the nucleatio n and growth of thin films deposited by physical vapour deposition. Al though the paper is mainly focused on oblique-incidence deposition, a normally-impinging vapour flux will also be described. Two cases of ob lique-incidence deposition will be discussed: one obliquely-impinging flux and two obliquely-impinging fluxes from opposite directions. With respect to the microstructure, both similarities and differences betw een these depositions will be described. Further, a special feature of two obliquely-impinging vapour fluxes is dealt with, which is the loc al composition in the lateral direction (parallel to the substrate). T he oblique and opposing directions can induce an inhomogeneous chemica l composition. This process is referred to as process-induced composit ional separation. In addition to reviewing the literature, the paper s ummarizes experimental data on obliquely co-evaporated Co-Cr, Co-Ag an d Co-Ta films. It will be shown from these experimental data that the two vapour directions can be exploited to tailor compositional inhomog eneities.