Imaging of surface acoustic waves on GaAs using 2D confocal Raman microscopy and atomic force microscopy

Surface acoustic wave devices have been fabricated on a GaAs (100)substrate to demonstrate the capability of 2D Raman microscopy as an imaging technique for acoustic waves on the surface of a piezoelectric substrate. Surface acoustic waves are generated using a two-port interdigitated transducer platform, which is modified to produce surface standing waves. We have derived an analytical model to relate Raman peak broadening to the near-surface strain field of the GaAs surface produced by the surface acoustic waves. Atomic force microscopy is used to confirm the presence of a standing acoustic wave, resolving a total vertical displacement of 3nm at the antinode of the standing wave. Stress calculations are performed for both imaging techniques and are in good agreement, demonstrating the potential of this Raman analysis.

Automated summary

Surface acoustic wave devices were fabricated on a GaAs (100) substrate to demonstrate the capability of 2D Raman microscopy as an imaging technique for acoustic waves on the surface of a piezoelectric substrate. An analytical model was derived to relate Raman peak broadening to the near-surface strain field of the GaAs surface produced by the surface acoustic waves, and atomic force microscopy was used to confirm the presence of a standing acoustic wave. Stress calculations for both imaging techniques were in good agreement, demonstrating the potential of this Raman analysis.