| AVS 65th International Symposium & Exhibition | |
| Vacuum Technology Division | Tuesday Sessions |
| Session VT-TuP |
| Session: | Vacuum Technology Division - Poster Session |
| Presenter: | Brian Rummel, University of New Mexico |
| Authors: | B. Rummel, University of New Mexico M.D. Henry, Sandia National Laboratory S.M. Han, University of New Mexico |
| Correspondent: | Click to Email |
Surface acoustic wave (SAW) devices are commonly found in sensors and RF filters, and utilizing a facile technique to image the transmitted signal would prove useful in characterizing device operation and optimization. We show how Raman spectroscopy can offer analytical insight into the mechanical strain imposed by SAWs traveling along the surface of various III-V substrates. SAWs are generated using a single port interdigital transducer (IDT) design, modified to produce free surface standing waves. These standing waves provide a means to differentiate between nodes and antinodes of the acoustic wave. The temporal period of the SAWs does not easily allow in-situ, real-time measurement of the waves; however, a broadening of the Raman peaks corresponds to an averaging of the peak shifts over the integration time of the spectrometer. An analytical fitting model has been derived to effectively calculate the maximum strain induced by the acoustic waves, thus allowing one to characterize the SAWs. IDTs were deposited onto a GaAs (110) substrate to study the potential of Raman analysis for SAW devices. Wavelengths ranging from 3.2 μm to 10 μm were used to study insertion loss, attenuation, diffraction parameters, and the mechanical coupling coefficient. Future applications of this technique to probe growth defects in ScAlN/Si substrates will also be discussed.