Saw resonator comprising layers for attenuating parasitic waves
AssigneesCommissariat A L'energie At Tomique Et Aux Energies Alternatives, Soitec
InventorsThu Trang Vo, Jean-Sebastien Moulet, Alexandre Reinhardt, Isabelle Huyet, Alexis Drouin, Yann Sinquin
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Abstract
The invention relates to a SAW resonator (100) comprising at least: a substrate (102); a layer (108) of piezoelectric material arranged on the substrate; a first attenuation layer (112) arranged between the substrate and the layer of piezoelectric material, and/or, when the substrate comprises at least two different layers (104, 106), a second attenuation layer (114) arranged between the two layers of the substrate; and in which the at least one attenuation layer is/are heterogeneous.
Claims9
A surface acoustic wave resonator, SAW, comprising at least:
- a substrate;
- a layer of piezoelectric material arranged on the substrate;
- and
- at least one of a first attenuation layer arranged between the substrate and the layer of piezoelectric material and, when the substrate comprises at least two separate layers, a second attenuation layer arranged between the two layers of the substrate;
- wherein the at least one of the first attenuation layer and the second attenuation layer is able to diffuse or absorb at least one portion of parasitic acoustic waves, and comprises at least one of:
- porous silicon, and
- polysilicon in which are arranged doped regions that render the attenuation layer or layers heterogeneous, the doped regions being selectively doped differently from a remainder of the at least one of the first attenuation layer and the second attenuation layer.
A method for producing a surface acoustic wave resonator, SAW, comprising:
- producing at least one of a first attenuation layer on a substrate and, when the substrate comprises at least two separate layers, a second attenuation layer between the two layers of the substrate, said at least one of the first attenuation layer and the second attenuation layer comprising at least one of:
- porous silicon, and
- polysilicon in which are arranged doped regions that render the attenuation layer or layers heterogeneous, the doped regions being selectively doped differently from a remainder of the at least one of the first attenuation layer and the second attenuation layer;
- and
- producing a layer of piezoelectric material on the substrate or, when the first attenuation layer is present on the substrate, on the first attenuation layer;
- wherein said at least one of the first attenuation layer and the second attenuation layer is able to diffuse or absorb at least one portion of parasitic acoustic waves.
A surface acoustic wave resonator, SAW, comprising at least:
- a substrate;
- a layer of piezoelectric material arranged on the substrate;
- and
- at least one of a first attenuation layer arranged between the substrate and the layer of piezoelectric material and, when the substrate comprises at least two separate layers, a second attenuation layer arranged between the two layers of the substrate,
- wherein said at least one of the first attenuation layer and the second attenuation layer is able to diffuse or absorb at least one portion of parasitic acoustic waves, and comprises at least one of porous silicon and polysilicon in which are arranged doped regions that render the attenuation layer or layers heterogeneous, and
- when the first attenuation layer or the second attenuation layer comprises porosities or cavities, the porosities or the cavities of at least one of the first attenuation layer and the second attenuation layer each have a substantially spherical or cylindrical shape.
Dependencies are inferred from the claim text.