Method and apparatus for adjusting the resonant frequency of a thin film resonator
AssigneeAgere Systems Inc.
InventorEdward B. Harris
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Abstract
A thin film resonator comprising a piezoelectric material and having a controllable or tunable resonant frequency. The resonator is formed on a substrate having a cavity formed therein below the piezoelectric film material. A bending electrode is disposed within the cavity and the application of a voltage between the bending electrode and one of the resonator electrodes, creates an electric field that causes the substrate region to bend. These stresses caused by the bending are transferred to the thin film resonator, subjecting the piezoelectric film to stresses and thereby changing the resonant properties of the thin film resonator.
Claims20
A method for tuning the resonant frequency of a film resonator disposed on a semiconductor substrate, the substrate further having first and second electrodes disposed thereon, said method comprising applying a voltage between the two electrodes such that the semiconductor substrate and the film resonator are deformed in response to the applied voltage, wherein the resonant frequency of the film resonator is changed in response to the applied voltage.
A method for forming a thin film resonator, comprising:
- providing a semiconductor substrate having an upper surface;
- forming a first electrode on the upper surface;
- forming a piezoelectric material over the first electrode;
- forming a cavity within the semiconductor substrate, wherein the cavity extends at least partially below the piezoelectric material;
- forming a second electrode in the cavity.
A tunable film resonator comprising:
- a semiconductor substrate;
- first and second electrodes disposed on said substrate;
- a piezoelectric material disposed on said substrate;
- wherein the application of a voltage between said first and said second electrodes deforms said piezoelectric material to change the resonant frequency thereof.
A tunable film resonator, comprising:
- a semiconductor substrate having an upper surface;
- a first electrode on the upper surface;
- a piezoelectric material overlying said first electrode;
- a cavity within said substrate extending at least partially below said piezoelectric material;
- a second electrode in the cavity.
Dependencies are inferred from the claim text.