IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Thin Films Tuesday Sessions
       Session TF-TuA

Invited Paper TF-TuA1
Mechanical Properties and Stresses in Ion-Assisted Thin Films

Tuesday, October 30, 2001, 2:00 pm, Room 123

Session: Growth and Properties of Thin Films
Presenter: G.S. Was, University of Michigan
Correspondent: Click to Email
Understanding the origin of stresses in thin films is critical to the control of film properties. Experiments were conducted to determine the origin of residual stresses in amorphous Al@sub2@O@sub3@ and crystalline Al and Nb films, and to control the stre sses in multilayer structures using ion-assisted deposition. Monolithic films were deposited during bombardment by Ne, Ar or Kr ions over a narrow range of energies, E, and a wide range of ion-to-atom arrival rate ratio, R. Films were characterized in terms of composition, thickness, density, crystallinity, microstructure, hardness and residual stress. Stress varied strongly with ion beam parameters, and with the resulting gas content. Residual stress and gas content saturated at a normalized energy of ~20 eV/atom or an R of ~0.05. Where residual stress varied linearly with RE@super1/2@, results are consistent with an atom peening model, but saturation at high R or RE@super1/2@ is inconsistent with such a model. The various mechanisms for residual stress control in monolithic amorphous and crystalline solids and the application of residual stress control to multilayered structures will be discussed. In Nb and Al films, the mechanisms for controlling crystallographic texture and the application of texture control for improved film properties are also presented. In both systems, texture developed slowly, but produced remarkable effects on plastic flow in the film. Specifically, examples will focus on crystallographic texture control in order to control the strength of the film/substrate interface and susceptibility to plastic flow in the film.