Characterization of thin-film adhesion and phonon lifetimes in Al/Si membranes by picosecond ultrasonics
Résumé
We quantitatively study interfacial adhesion in a two-layer membrane system consisting of Al and Siwith femtosecond time-resolved laser spectroscopy. High-frequency acoustic pulses in the sub-THz regime are utilized to characterize the membrane system. In order to explain the distinct features ofthe measured data, a spring model for the Al/Si interface is employed. We show that acousticdissipation in this system needs to be included for accurate modeling of the interface adhesion over abroad frequency range.