Magnetron sputtering of ZnO thick film for high frequency focused ultrasonic transducer

In this study, ZnO thick films suitable for high frequency focused ultrasonic transducers with high piezoelectric properties, and low tensile stress were prepared by DC magnetron sputtering. The ZnO films were analyzed in detail by X-ray diffraction and scanning electron microscope. The sputtering growth process of ZnO films was optimized by improving the structural zone models (SZM). Based on the optimized process, a focused ultrasonic transducer, with a fused quartz acoustic lens structure, was fabricated by sputtering the ZnO thick films. The finite element method was used to complete the design, simulation, and evaluation of the transducer. Test results show that there was no crack in the piezoelectric layer of the transducer. The transducer had a center frequency of 50 MHz, with a high - 6 dB bandwidth of 119%.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

In this study, ZnO thick films suitable for high frequency focused ultrasonic transducers were prepared by optimizing the sputtering growth process. The transducers fabricated using the optimized process showed stable performance without cracks and had a high center frequency and bandwidth.