Piezoelectric shear wave resonator and method of making same
AssigneeThe United States of America as represented by the United States Department of Energy
InventorsJin S. Wang, Kenneth M. Lakin, Allen R. Landin
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Abstract
An acoustic shear wave resonator comprising a piezoelectric film having its C-axis substantially inclined from the film normal such that the shear wave coupling coefficient significantly exceeds the longitudinal wave coupling coefficient, whereby the film is capable of shear wave resonance, and means for exciting said film to resonate. The film is prepared by deposition in a dc planar magnetron sputtering system to which a supplemental electric field is applied. The resonator structure may also include a semiconductor material having a positive temperature coefficient of resonance such that the resonator has a temperature coefficient of resonance approaching 0 ppm/.degree.C.
Claims7
A piezoelectric shear wave resonator having a predetermined temperature coefficient of resonance comprising:
- a composite comprising a first film of piezoelectric material having a 6 mm symmetry, said film having its C-axis substantially inclined at an acute angle with respect to the film normal, such that the shear wave coupling coefficient of said film significantly exceeds the longitudinal wave coupling coefficient of said film, and a second film of p.sup.+ silicon semiconductor material having a positive temperature coefficient of resonance, and a substrate supporting the composite at its periphery, the ratio of thickness of the semiconductor film to the piezoelectric film determining the temperature coefficient of resonance.
Dependencies are inferred from the claim text.