Fundamental structure forming phenomena of polycrystalline films and the structure zone models

Previous structure zone models used for the interpretation of the experimental results were constructed by compiling the various structures found in thick polycrystalline films deposited at different temperatures and parameters. The present paper shows that while the temperature dependence of surface and bulk diffusion can not adequately describe the evolution mechanisms of various polycrystalline thin film structure, the fundamental structure forming phenomena, including the contribution of impurities introduced by the authors make possible the comprehensive description of the structure forming mechanisms. Real structure zone models including also the related textures, are constructed by considering the concentration of impurities (co-deposited additives) in the vapour beam as a new deposition parameter, and the fundamental structure forming phenomena. These are phenomena composed of atomic processes, and can give account for the global effect of the atomic processes and are directly responsible for the structure evolution. Impurities (additives) can promote or inhibit the operation of the structure forming phenomena (promoter or inhibitor resp.). The new structure zone models can be used to tailor polycrystalline film structures of large variety (from large grained through columnar to the micro- or nanocrystalline structures) and to diagnose technologies. (C) 1998 Elsevier Science S.A.