Surface Chemistry Related to SAW Resonator Aging

The electrical characteristics of surface acoustic wave devices depend critically on the physical and chemical properties of the device surface as well as on the interaction between the propagating wave in the substrate with its surrounding gaseous medium. tions were carried out in a dual chamber vacuum apparatus with a SAW resonator isolated in each chamber. One resonator, kept continually under vacuum, acted as a reference, while the second resonator was exposed to a variety of gases under controlled conditions. The nature of the chemical changes occurring on the surface were confirmed by examining the device surface by x-ray photoelectron spectroscopy. Experiments have been performed to study the physical and chemical absorption of reactive and non-reactive gases. experiments are needed to understand and model the aging mechanisms of SAW resonators. results will be presented. The gas-surface interac