Ultrahigh-Frequency Piezoelectric Thin Film for Determination of Silicon Attenuation Coefficient

Ultrasonic attenuation affects the quality of ultrasonic imaging and material characterization significantly, especially at ultrahigh frequencies (>100 MHz), where higher attenuation brings about additional challenges. However, the reliable ultrasonic attenuation coefficients are scarce in this frequency range. In this study, we propose a method of measuring ultrasound attenuation coefficient at ultrahigh frequencies. By the spectral analysis of multiple ultrasonic echoes, the aggregate attenuation coefficient was extracted. Ultrasonic diffraction attenuation and transmission loss at the material interface are calibrated by using circular flat transducer acoustic fields and acoustic transmission line theory, respectively. The attenuation coefficient of silicon at approximately 150 MHz was measured to be 10.52 dB/cm. This article presents a novel approach for evaluating ultrasonic attenuation in the ultrahigh-frequency range, reducing experimental errors and equipment costs. The proposed methodology also contributes to the development and characterization of ultrahigh-frequency ultrasonic transducers.