ARRAY OF BAW RESONATORS WITH MASK CONTROLLED RESONANT FREQUENCIES
First Claim
1. A method for forming a resonator comprising:
- forming a first conductive layer on a substrate;
forming a layer for converting one of electrical energy or mechanical energy to the other on the first conductive layer;
forming over said layer for converting one of electrical energy or mechanical energy to the other a mass load layer for adjusting the acoustic path length of the resonator to achieve a desired predetermined resonant frequency;
patterning the mass load layer by one of adding material thereto or removing portions therefrom to form apertures therein that extend at least one of either partially into or entirely through the mass load layer; and
forming a second conductive layer on the mass load layer, wherein at least a portion of the apertures that extend entirely through the mass load layer are filled by the second conductive layer material.
2 Assignments
0 Petitions
Accused Products
Abstract
Methods that create an array of BAW resonators by patterning a mass load layer to control the resonant frequency of the resonators and resonators formed thereby, are disclosed. Patterning the surface of a mass load layer and introducing apertures with dimensions smaller than the acoustic wavelength, or dimpling the mass load layer, modifies the acoustic path length of the resonator, thereby changing the resonant frequency of the device. Patterns of variable density allow for further tuning the resonators and for individualized tuning of a resonator in an array of resonators. Patterning a reflowable material for the mass load layer, thereby providing a variable pattern density and distribution followed by elevating the temperature of the mass load layer above its melting point causes the material to liquefy and fill into the apertures to redistribute the mass load layer, thereby, upon subsequent cooling, providing resonators with a predetermined desired resonant frequency.
11 Citations
20 Claims
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1. A method for forming a resonator comprising:
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forming a first conductive layer on a substrate; forming a layer for converting one of electrical energy or mechanical energy to the other on the first conductive layer; forming over said layer for converting one of electrical energy or mechanical energy to the other a mass load layer for adjusting the acoustic path length of the resonator to achieve a desired predetermined resonant frequency; patterning the mass load layer by one of adding material thereto or removing portions therefrom to form apertures therein that extend at least one of either partially into or entirely through the mass load layer; and forming a second conductive layer on the mass load layer, wherein at least a portion of the apertures that extend entirely through the mass load layer are filled by the second conductive layer material. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method for forming a resonator comprising:
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forming a first conductive layer on a substrate; forming a piezoelectric material over the first conductive layer; forming a second conductive layer over the piezoelectric layer; forming over said second conductive layer a mass load layer; patterning the mass load layer by adding material to or removing portions from, thereby introducing apertures into the mass load layer, wherein the apertures extend only partially through the mass load layer, wherein the pattern is selected to provide a predetermined resonant frequency to the resonator. - View Dependent Claims (15, 16, 17, 18)
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19. A method for forming a resonator comprising:
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forming a first conductive layer on a substrate; forming a piezoelectric material over the first conductive layer; forming a second conductive layer over the piezoelectric layer; forming over said piezoelectric layer a mass load layer for adjusting the incremental acoustic path of the resonator to achieve a desired predetermined change in the acoustic path length of the resonator; patterning the mass load layer by removing portions thereof, thereby introducing apertures into the mass load layer; and heating the mass load layer to a deformable or flowable state such that the patterned mass load layer at least partially moves into the removed portions. - View Dependent Claims (20)
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Specification