Calculation of the SAW-induced stress distributions in an electrode of a SAW-device on LiTaO3

Acoustomigration is a well-known phenomenon, which may occur in surface acoustic wave (SAW)-devices operating at high driving levels. Based on previously published reports (Roesler, U. et al., 1996; Kubat, F. et al., 2002; 2003) about the calculation of the acoustic power, dynamic stresses and displacements in a homogenous isotropic Al-layer for a given driving condition, we expand this method for the calculation of the SAW-induced stress in an electrode of a SAW-device. The quantitative calculation of this stress is based on the combination of the widely used P-matrix based model, which yields the distribution of the potential power (Kubat et al., 2002) for a given driving level and a FEM tool (Smole, P. et al., 2002), which provides the relative stresses inside an electrode.