Ultrasounds are a great tool for defects detection particularly for optically non-transparent materials. Hence, working at very high frequency (#GHz) allows the detection of nanoscale contact defects at the interface between two materials and especially in the presence of air, which has negligible acoustic impedance, making it possible to achieve very high sensitivity.

For several years, we have been using the high frequency acoustic method for the wetting evaluation of nanostructures in our laboratory. In close collaboration with STMicroelectronics company, we deal with the study of wetting state in the context of wet cleaning processes optimization in the microelectronics industry.