| Nickel-titanium shape memory alloys are potential thin film candidates for microelectromechanical systems. NiTi thin films can be ion sputter deposited onto a silicon substrate and can be activated by Joule heating. However, in order to develop NiTi microelectromechanical devices, fundamental characteristics of the film/substrate system, such as residual stress and adhesion must be understood. Residual film stress is an important parameter since thermoelastic transformation temperatures in NiTi are strongly affected by applied stress. Good adhesion between the film and substrate is also necessary for a robust microelectromechanical system. In the present work, NiTi films were grown on (100) Si by ion sputtering and by ion beam assisted deposition (IBAD). The as-deposited films were amorphous and were annealed after deposition at 600... |
