Surface elastic wave device comprising a single-crystal piezoelectric film and a crystalline substrate with low visoelastic coefficients
AssigneesCommissariat A L'energie Atomique Et Aux Energies Alternatives, Centre National De La Recherche Scientifique
InventorsSébastien Grousset, Sylvain Ballandras
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Abstract
A surface elastic wave device comprises a stack including: a thin film made of a piezoelectric first material; a substrate made from a second material; and exciting means for generating at least one surface acoustic wave propagation mode in the piezoelectric film; wherein: the first material is a single-crystal material and the second material is a crystalline material, the thickness of the thin film of piezoelectric first material being smaller than or equal to 20 μm, and the first material and the second material having viscoelastic coefficients lower than or equal to those of quartz for the propagation mode induced by the exciting means.
Claims18
A surface elastic wave device comprising a stack including at least:
- a thin film made of a piezoelectric first material;
- a substrate made from a second material;
- exciting means for generating at least one surface acoustic wave propagation mode in said piezoelectric film;
- and
- a second intermediate film made of metal located between the substrate and the piezoelectric film, a thickness and nature of which film allow a frequency temperature coefficient of the propagation mode to be adjusted,
- wherein:
- the first material is a single-crystal material and the second material is a crystalline material,
- the thickness of the thin film of piezoelectric first material being smaller than or equal to 20 μm, and
- the first material and the second material having viscoelastic coefficients lower than or equal to those of quartz for the propagation mode induced by the exciting means.
Dependencies are inferred from the claim text.