PROTECTED RESONATOR

摘要

A bulk acoustic wave resonator structure that isolates the core resonator from both environmental effects and aging effects. The structure has a piezoelectric layer at least partially disposed between two electrodes. The structure is protected against contamination, package leaks, and changes to the piezoelectric material due to external effects while still providing inertial resistance. The structure has one or more protective elements that limit aging effects to at or below a specified threshold. The resonator behavior is stabilized across the entire bandwidth of the resonance, not just at the series resonance. Examples of protective elements include a collar of material around the core resonator so that perimeter and edge-related environmental and aging phenomena are kept away from the core resonator, a Bragg reflector formed above or below the piezoelectric layer and a cap formed over the piezoelectric layer. The resonator structure is suspended in a cavity in a cap structure.

主权项

1. A resonator device comprising:
a resonator component comprising: a piezoelectric layer formed on a substrate at least a portion of the piezoelectric layer being disposed between two electrodes, the piezoelectric layer having two defined regions, an active resonator core region and a perimeter collar region; a Bragg structure formed either above the piezoelectric layer, below the piezoelectric layer or both above and below the piezoelectric layer wherein the Bragg structure has a lateral extent that is at least coextensive with the piezoelectric layer; and a dielectric spacer that defines the lateral extent of the active interior region,wherein the resonator component is disposed in a cavity defined by a cap structure, the cap structure having a first portion from which the resonator is suspended in the cavity and a second portion that is affixed to the first portion by interconnects defining a distance between the first portion and the second portion that exceeds the distance that the resonator structure extends from the first portion, wherein the cap structure maintains the cavity surrounding the resonator under resonator operating conditions.