Composite structure and associated production method
AssigneeSoitec
InventorsPascal Guenard, Ionut Radu, Didier Landru, Eric Desbonnets
Life of this patent
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Abstract
A composite structure for an acoustic wave device comprising a heterostructure includes: a useful layer of piezoelectric material, having a first face and a second face, the first face being arranged at a first bonding interface on a support substrate having a coefficient of thermal expansion less than that of the useful layer, wherein the composite structure further comprises a functional layer, an entire surface of which is arranged at a second bonding interface on the second face of the useful layer and having a coefficient of thermal expansion less than that of the useful layer. Methods are used for producing such a composite structure.
Claims18
A composite structure for an acoustic wave device comprising a heterostructure, including:
- a useful layer of piezoelectric material, having a first face and a second face, the first face being arranged at a first bonding interface between the useful layer and a support substrate, the support substrate having a lower coefficient of thermal expansion than that of the useful layer;
- and
- a functional layer, the functional layer being substantially planar and having a substantially planar main face, the entirety of the substantially planar main face being arranged on the second face of the useful layer at a second bonding interface between the functional layer and the useful layer, the functional layer having a lower coefficient of thermal expansion than that of the useful layer,
- wherein the functional layer exhibits a substantially uniform thickness along a longitudinal axis of the composite structure, and
- wherein an adhesion energy of the first bonding interface between the useful layer and the support substrate of the heterostructure is greater than or equal to 1500 mJ/m2.
A composite structure for an acoustic wave device comprising a heterostructure, including:
- a useful layer of piezoelectric material, having a first face and a second face, the first face being arranged at a first bonding interface between the useful layer and a support substrate, the support substrate having a lower coefficient of thermal expansion than that of the useful layer;
- and
- a functional layer, the functional layer being substantially planar and having a substantially planar main face, the entirety of the substantially planar main face being arranged on the second face of the useful layer at a second bonding interface between the functional layer and the useful layer, the functional layer having a lower coefficient of thermal expansion than that of the useful layer,
- wherein the functional layer exhibits a substantially uniform thickness along a longitudinal axis of the composite structure, and
- wherein the adhesion energy of the second bonding interface between the functional layer and the heterostructure is less than 1000 mJ/m2.
Dependencies are inferred from the claim text.