The present invention relates to a heterostructure, in particular, a piezoelectric structure, comprising a cover layer, in particular, a layer of piezoelectric material, the material of the cover layer having a first coefficient of thermal expansion, assembled to a support substrate, the support substrate having a second coefficient of thermal expansion substantially different from the first coefficient of thermal expansion, at an interface wherein the cover layer comprises at least a recess extending from the interface into the cover layer, and its method of fabrication.

The present invention relates to a heterostructure, in particular, a piezoelectric structure, comprising a cover layer, in particular, a layer of piezoelectric material, the material of the cover layer having a first coefficient of thermal expansion, assembled to a support substrate, the support substrate having a second coefficient of thermal expansion substantially different from the first coefficient of thermal expansion, at an interface wherein the cover layer comprises at least a recess extending from the interface into the cover layer, and its method of fabrication.

A process for fabricating a component includes an operation of transferring at least one layer of one or more piezoelectric or pyroelectric or ferroelectric materials forming part of a donor substrate to a final substrate, the process comprising a prior step of joining the layer to a temporary substrate via production of a fragile separating region between the donor substrate of single-crystal piezoelectric or pyroelectric or ferroelectric material and the temporary substrate, the region comprising at least two layers of different materials in order to ensure two compounds apt to generate an interdiffusion of one or more constituent elements of at least one of the two compounds make contact, the fragile region allowing the temporary substrate to be separated.

A method for producing a layer of composition AA′BO.sub.3, wherein A consists of at least one element selected from the group consisting of: Li, Na, K, Ca, Mg, Ba, Sr, Pb, La, Bi, Y, Dy, Gd, Tb, Ce, Pr, Nd, Sm, Eu, Ho, Zr, Sc, Ag and Tl, and B consists of at least one element selected from the group consisting of: Nb, Ta, Sb, Ti, Zr, Sn, Ru, Fe, V, Sc, C, Ga, Al, Si, Mn, Zr and Tl, is described. The method includes providing a donor substrate of composition ABO.sub.3, forming a layer of composition ABO.sub.3 by thinning the donor substrate, and exposing the layer of composition ABO.sub.3 to a medium containing ions of an element A′ belonging to the same list of elements as A, A′ being different from A, such that the ions penetrate into the layer of composition ABO.sub.3 to form the layer of composition AA′BO.sub.3.

A method for producing a layer of composition AA′BO.sub.3, wherein A consists of at least one element selected from the group consisting of: Li, Na, K, Ca, Mg, Ba, Sr, Pb, La, Bi, Y, Dy, Gd, Tb, Ce, Pr, Nd, Sm, Eu, Ho, Zr, Sc, Ag and Tl, and B consists of at least one element selected from the group consisting of: Nb, Ta, Sb, Ti, Zr, Sn, Ru, Fe, V, Sc, C, Ga, Al, Si, Mn, Zr and Tl, is described. The method includes providing a donor substrate of composition ABO.sub.3, forming a layer of composition ABO.sub.3 by thinning the donor substrate, and exposing the layer of composition ABO.sub.3 to a medium containing ions of an element A′ belonging to the same list of elements as A, A′ being different from A, such that the ions penetrate into the layer of composition ABO.sub.3 to form the layer of composition AA′BO.sub.3.

A method for transferring a piezoelectric layer from a donor substrate onto a support substrate comprises the steps of: a) providing a predetermined splitting area in a piezoelectric donor substrate, b) attaching the piezoelectric donor substrate to a support substrate to form an assembly, and c) detaching the piezoelectric layer from the piezoelectric donor substrate comprising applying an electric field. By using the electric field, the detachment step can be carried out at low temperatures. A detachment chamber for carrying out at least a portion of such a method includes one or two chucks comprising first and/or second electrodes for applying an electric field to a piezoelectric layer.

A method for transferring a piezoelectric layer from a donor substrate onto a support substrate comprises the steps of: a) providing a predetermined splitting area in a piezoelectric donor substrate, b) attaching the piezoelectric donor substrate to a support substrate to form an assembly, and c) detaching the piezoelectric layer from the piezoelectric donor substrate comprising applying an electric field. By using the electric field, the detachment step can be carried out at low temperatures. A detachment chamber for carrying out at least a portion of such a method includes one or two chucks comprising first and/or second electrodes for applying an electric field to a piezoelectric layer.

A process for transferring a thin layer consisting of a first material to a support substrate consisting of a second material having a different thermal expansion coefficient, comprises providing a donor substrate composed of an assembly of a thick layer formed of the first material and of a handle substrate having a thermal expansion coefficient similar to that of the support substrate, and the donor substrate having a main face on the side of the thick layer introducing light species into the thick layer to generate a plane of weakness therein and to define the thin layer between the plane of weakness and the main face of the donor substrate; assembling the main face of the donor substrate with a face of the support substrate; and detachment of the thin layer at the plane of weakness, the detachment comprising application of a heat treatment.

A process for transferring a thin layer consisting of a first material to a support substrate consisting of a second material having a different thermal expansion coefficient, comprises providing a donor substrate composed of an assembly of a thick layer formed of the first material and of a handle substrate having a thermal expansion coefficient similar to that of the support substrate, and the donor substrate having a main face on the side of the thick layer introducing light species into the thick layer to generate a plane of weakness therein and to define the thin layer between the plane of weakness and the main face of the donor substrate; assembling the main face of the donor substrate with a face of the support substrate; and detachment of the thin layer at the plane of weakness, the detachment comprising application of a heat treatment.

The present disclosure provides a manufacturing method for a piezoelectric ceramic chip, a piezoelectric ceramic chip assembly and a display device. The manufacturing method includes: transferring a piezoelectric ceramic layer and a bottom electrode covering the piezoelectric ceramic layer formed on a substrate to a base plate, forming an insulating layer with an opening on the base plate, so that edges of the piezoelectric ceramic layer and the bottom electrode are covered by the insulating layer, and the piezoelectric ceramic layer is exposed from the opening; etching the base plate by immersing the base plate in an etching solution for etching a material of the bottom electrode; and forming a top electrode in the opening of the insulating layer, so that the top electrode is spaced apart from the insulating layer.