Fabrication and characterization of half-kerfed LiNbO3-based high-frequency (>100MHz) ultrasonic array transducers

The effect of kerf depth is investigated on the performances of array transducers. A finite element tool, COMSOL, is employed to simulate the properties of acoustic field and to calculate the electrical properties of the arrays, including crosstalk effect and electrical impedance. Furthermore, Inductively Coupled Plasma (ICP) deep etching process is used to etch 36°/Y-cut lithium niobate (LiNbO
₃
) crystals and the limitation of etching aspect ratio is studied. Several arrays with different profiles are realized under optimized processes. At last, arrays with different pitches are fabricated and characterized by a network analyzer.