Method for shaping thin film resonators to shape acoustic modes therein

摘要

A process for configuring a thin film resonator to advantageously shape a desired acoustic mode of the resonator such that the electrical and acoustic performance of the resonator is enhanced. As a result of the contouring or shaping, a minimum amount of acoustic energy occurs near the edge of the resonator, from which energy may leak or at which undesired waves may be created by a desired mode. The process is used during batch-fabrication of thin-film resonators which are used in high frequency RF filtering or frequency control applications. Utilizing photolithography, the shaping can be achieved in a manner derived from the known methods used to manufacture lens arrays. Using the process, the lateral motion of acoustic waves within the resonator may be controlled and the acoustic energy of the sound wave positioned at a desired location within the resonator.