A LiNbO3 ultrasonic phased array transducer of more than 100 MHz
Résumé
High-frequency ultrasonic transducer arrays are essential for high resolution imaging in clinical analysis and Non-Destructive Evaluation (NDE). However, the structure design and fabrication of the kerfed ultrasonic array is quite challenging when very high frequency (≥ 100 MHz) is required. Inductively Coupled Plasma (ICP) deep etching process is used to etch 36°/Y-cut lithium niobate (LiNbO3) crystals. Furthermore, a finite element tool, COMSOL, is employed to calculate the electrical properties of the arrays, including crosstalk effect and electrical impedance. At last, arrays with a pitch of 40 μm are fabricated and characterized by a network analyzer. The measured results agree well with the theoretical predictions.