Method of making tunable thin film acoustic resonators
AssigneeHewlett-Packard Company
InventorsRichard C. Ruby, Paul Philip Merchant
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Abstract
An acoustical resonator comprising top and bottom electrodes that sandwich a PZ layer. The resonance frequency of the acoustical resonator may be adjusted after fabrication by utilizing heating elements included in the acoustical resonator and/or by adjusting the thickness of a tuning layer. In the preferred embodiment of the present invention, the electrodes comprise Mo layers. One embodiment of the present invention is constructed on a Si.sub.3 N.sub.4 membrane. A second embodiment of the present invention is constructed such that it is suspended over a substrate on metallic columns. In the preferred embodiment of the present invention, the electrodes are deposited by a method that minimizes the stress in the electrodes.
Claims12
A method for fabricating an acoustical resonator, the method comprising:
- depositing a sacrificial layer on a substrate;
- etching vias in said sacrificial layer;
- depositing metal in said vias;
- depositing a bottom metallic layer on said sacrificial layer;
- depositing a PZ layer on said bottom metallic layer;
- depositing a top metallic layer on said PZ layer;
- and
- removing said sacrificial layer leaving a portion of said bottom metallic layer separated from said substrate.
Dependencies are inferred from the claim text.