Substrate for a temperature-compensated surface acoustic wave device or volume acoustic wave device
AssigneeSoitec
InventorsMarcel Broekaart, Thierry Barge, Pascal Guenard, Ionut Radu, Eric Desbonnets, Oleg Kononchuk
Life of this patent
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Abstract
A substrate for a surface acoustic wave device or bulk acoustic wave device, comprising a support substrate and an piezoelectric layer on the support substrate, wherein the support substrate comprises a semiconductor layer on a stiffening substrate having a coefficient of thermal expansion that is closer to the coefficient of thermal expansion of the material of the piezoelectric layer than that of silicon, the semiconductor layer being arranged between the piezoelectric layer and the stiffening substrate.
Claims30
A surface acoustic wave device, comprising:
- a piezoelectric layer;
- a stiffening substrate, wherein a ratio of a thickness of the piezoelectric layer to a thickness of the stiffening substrate is less than or equal to 0.125;
- a semiconductor layer disposed between the piezoelectric layer and the stiffening substrate;
- at least two interdigitated metallic comb electrodes on a surface of the piezoelectric layer for generating or receiving surface acoustic waves at the surface of the piezoelectric layer;
- a first dielectric layer between the piezoelectric layer and the semiconductor layer;
- and
- a charge trapping layer at an interface between the first dielectric layer and the semiconductor layer and/or an interface between the first dielectric layer and the piezoelectric layer.
A surface acoustic wave device, comprising:
- a stiffening substrate;
- a piezoelectric layer;
- a semiconductor layer disposed between the piezoelectric layer and the stiffening substrate;
- a first dielectric layer between the piezoelectric layer and the semiconductor layer;
- a charge trapping layer between the first dielectric layer and the semiconductor layer and/or between the first dielectric layer and the piezoelectric layer;
- and
- at least two interdigitated metallic comb electrodes on a surface of the piezoelectric layer for generating or receiving surface acoustic waves at the surface of the piezoelectric layer, wherein the electrodes are covered with a second dielectric layer.
A method of manufacturing a surface acoustic wave device, comprising:
- transferring a semiconductor layer from a first donor substrate onto a stiffening substrate to form a support substrate;
- forming a first dielectric layer over the semiconductor layer;
- transferring a piezoelectric layer onto the support substrate from a second donor substrate such that material of the first dielectric layer and the semiconductor layer are disposed between the piezoelectric layer and the stiffening substrate, wherein the stiffening substrate has a coefficient of thermal expansion closer to a coefficient of thermal expansion of a material of the piezoelectric layer than that of silicon;
- forming two interdigitated metallic comb electrodes on a surface of the piezoelectric layer;
- and
- forming a charge trapping layer at an interface between the first dielectric layer and the semiconductor layer and/or an interface between the first dielectric layer and the piezoelectric layer.
Dependencies are inferred from the claim text.