RELAXATION OF RESIDUAL-STRESSES IN HIGHLY STRESSED MULTILAYERS INITIATED BY ION IRRADIATION

In situ deformation measurements (static and dynamic) of W/Cu multilay er films were made by employing laser interferometric and piezoelectri c transducer techniques to register mechanical waves generated during ion irradiation of multilayers. It is found that the kinetics of relax ation of tensile and compressive stresses initiated by ion irradiation in initially highly stressed microstructures is different. The proces s of relaxation of compressive stress has a threshold character and ta kes place when the energy retained in the film is approximately equal to the energy required to produce 10(-2)-10(-1) displacements per targ et atom.