A high electromechanical coupling coefficient SHO Lamb wave lithium niobate micromechanical resonator and a method for fabrication

(ProQuest: ... denotes formulae and/or non-USASCII text omitted) We present a high coupling coefficient, ..., micromechanical resonator based on the propagation of SHO Lamb waves in thin, suspended plates of single crystal X-cut lithium niobate (LiNbO sub(3)). The thin plates are fabricated using ion implantation of He to create a damaged layer of LiNbOa below the wafer surface. This damaged layer is selectively wet etched in a hydrofluoric (HF) acid based chemistry to form thin, suspended plates of LiNbOa without the wafer bonding, layer fracturing and chemical mechanical polishing in previously reported LiNbO sub(3) microfabrication approaches. The highest coupling coefficient is found for resonators with acoustic propagation rotated 170[degrees] from the y-axis, where a fundamental mode SHO Lamb wave resonator with a plate width of 20 [mu]m and a corresponding resonant frequency of 101 MHz achieves a ... of 12.4%, a quality factor of 1300 and a resonator figure of merit (M) of 185. The ... and M are among the highest reported for micromechanical resonators.