Electroacoustic component and method for the production thereof
AssigneeEpcos AG
InventorsWerner Ruile, Ulrike Rosler
Life of this patent
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Abstract
An electroacoustic component including a layer system disposed between two substrates and electroacoustic structures for exciting a guided bulk acoustic wave, the electroacoustic structures being devoid of cavities. The layer system includes a piezo-electric layer, at least one metal layer, and a planarizing layer, which includes a planar interface provided with a substrate disposed directly thereabove. Such a component can be produced at a low cost by direct wafer bonding of two wafers. The electroacoustic component structures are electrically connected to the external contacts through perpendicular electrical connections.
Claims50
An electroacoustic component, comprising:
- a first substrate;
- a layer system disposed at said first substrate to define a first interface therebetween, said layer system having:
- a piezo-electric layer;
- a first metal layer disposed on said piezo-electric layer, said first metal layer having electrode structures and contact surfaces, said electrode structures being disposed next to one another and forming a functional unit;
- a region of said piezo-electric layer disposed adjacent said functional unit forming an active region in which a guided bulk acoustic wave of a wavelength λ can propagate;
- and
- a dielectric planarizing layer;
- and
- a second substrate;
- said piezo-electric layer being disposed between said first substrate and said first metal layer;
- said first metal layer being disposed between said piezo-electric layer and said dielectric planarizing layer;
- and
- said dielectric planarizing layer being disposed between said first metal layer and said second substrate;
- said layer system and said second substrate defining a second interface therebetween;
- said piezo-electric layer and said first and second substrates being formed to have a smaller propagation velocity of said guided bulk acoustic wave in said piezo-electric layer than a propagation velocity of said guided bulk acoustic wave in said first and second substrates;
- and
- said layer system and said first and second interfaces being devoid of cavities.
An electroacoustic component, comprising:
- a first substrate;
- a layer system disposed at said first substrate to define a first interface therebetween, said layer system having:
- a piezo-electric layer;
- a first metal layer disposed at said piezo-electric layer opposite said first substrate, said first metal layer having electrode structures and contact surfaces, said electrode structures being disposed next to one another and forming a functional unit;
- a region of said piezo-electric layer disposed adjacent said functional unit forming an active region in which a guided bulk acoustic wave of a wavelength λ is expanded;
- a dielectric planarizing layer disposed at said first metal layer at least on a side of said first metal layer opposite said piezo-electric layer;
- and
- a second substrate disposed at a side of said dielectric planarizing layer opposite said first metal layer, said layer system and said second substrate defining a second interface;
- said piezo-electric layer and said first and second substrates being formed to have a smaller expansion speed of said guided bulk acoustic wave in said piezo-electric layer than an expansion speed of said bulk wave in said first and second substrates;
- and
- said layer system and said first and second interfaces being devoid of cavities.
Dependencies are inferred from the claim text.