Abstract: A support for a composite substrate includes an interlayer arranged on a base substrate. The interlayer includes a trapping layer in contact with the base substrate, which trapping layer includes a silicon-rich oxide having an atomic concentration of silicon of between 40% and 99.9%. The interlayer also comprises a dielectric layer in contact with the trapping layer. A transition zone is disposed between the trapping layer and the dielectric layer and has a thickness greater than 50 nm in which the atomic concentration of silicon varies continuously. A composite substrate incorporates such a support and a method is used for manufacturing the support.

Abstract: A method of preparing thin mono-domain layer made of lithium-containing ferroelectric material includes providing a first layer having a free surface. and performing a surface treatment exposing a free face of the first layer to a treatment atmosphere comprising at least 0.02% carbon dioxide to form a lithium-rich passivation layer, and performing a removal treatment to remove the lithium-rich passivation layer.

Abstract: A piezoelectric-on-insulator (POI) substrate includes a carrier substrate comprising a trapping layer on a free surface of the carrier substrate, a piezoelectric layer, an intermediate structure sandwiched between the piezoelectric layer and the trapping layer of the carrier substrate, wherein the intermediate structure comprises at least one tantalum oxide (Ta2O5)-based diffusion barrier layer that prevents the diffusion of metal elements and has a thickness/EM greater than a predetermined thickness, the predetermined thickness being determined according to the thickness of the trapping layer such that the metal element dose in the trapping layer is lower than a predetermined threshold dose. A method may be used to manufacture such a piezoelectric-on-insulator (POI) substrate.

Abstract: A piezoelectric-on-insulator (POI) substrate includes a carrier substrate, a trapping layer on a free surface of the carrier substrate, a piezoelectric layer, in particular, a lithium tantalate or lithium niobate piezoelectric layer, and an intermediate structure sandwiched between the piezoelectric layer and the trapping layer of the carrier substrate. The intermediate structure includes at least one tantalum nitride-based or silicon carbon nitride based diffusion barrier layer preventing the diffusion of metal elements. A method is used to manufacture such a piezoelectric-on-insulator substrate.

Abstract: A support for a semiconductor structure includes a base substrate, a first silicon dioxide insulating layer positioned on the base substrate and having a thickness greater than 20 nm, and a charge trapping layer having a resistivity higher than 1000 ohm·cm and a thickness greater than 5 microns positioned on the first insulating layer.

Abstract: A hybrid structure for a surface acoustic wave device comprises a useful layer of piezoelectric material having a first free surface and a second surface disposed on a support substrate that has a lower coefficient of thermal expansion than that of the useful layer, wherein the useful layer comprises an area of nanocavities.

Abstract: A process for fabricating a semiconductor or piezoelectric structure comprises the following successive steps: (a) providing a donor substrate comprising a piezoelectric or semiconductor layer, (b) providing a receiver substrate, (c) treating a free surface of the donor substrate and/or a free surface of the receiver substrate, (d) bonding the donor substrate to the receiver substrate, the at least one treated free surface being at the interface between the donor substrate and the receiver substrate, and (e) transferring a portion of the piezoelectric or semiconductor layer from the donor substrate to the receiver substrate. The treatment of the free surface of the donor substrate and/or of the free surface of the receiver substrate comprises the following successive steps: (c1) chemical-mechanical polishing, and (c2) removing material from a peripheral region of the polished surface.

Abstract: A method for transferring a thin layer onto a carrier substrate comprises preparing a carrier substrate using a preparation method involving supplying a base substrate having, on a main face, a charge-trapping layer and forming a dielectric layer having a thickness greater than 200 nm on the charge-trapping layer. Once the dielectric layer is formed, the ionized deposition and sputtering of the dielectric layer are simultaneously performed. The transfer method also comprises assembling, by way of molecular adhesion and with an unpolished free face of the dielectric layer, a donor substrate to the dielectric layer of the carrier substrate, the donor substrate having an embrittlement plane defining the thin layer. Finally, the method comprises splitting the donor substrate at the embrittlement plane to release the thin layer and to transfer it onto the carrier substrate.

Abstract: A method is used to fabricate a structure comprising a thin layer bonded to a carrier by way of a dielectric layer, the carrier comprising a charge-trapping layer placed on the surface of a base substrate. The method includes applying a surface treatment to an exposed surface of the main face of the carrier and/or to an exposed surface of the main face of the donor substrate to form thereon a layer that acts as a barrier to the diffusion of certain atomic species. This surface treatment involves exposing the exposed surface to an oxygen-containing plasma, and then exposing the exposed surface to a nitrogen-containing plasma.

Abstract: A method for assembly by molecular adhesion of two substrates each having a main face, at least one of the two substrates bearing a dielectric surface layer on its main face, comprises (a) contacting the main faces of the two substrates, then (b) initiating and propagating a bonding wave between the main faces of the two substrates to assemble them with one another. Prior to the contacting of the main faces, sulfur is introduced into the dielectric surface layer at a dose of more than 3.0 E13 at/cm^2 into this layer. A joined structure is obtained via the method.

Abstract: The invention relates to a method for transferring a thin film onto a support substrate, which comprises: providing a bonded assembly that comprises a donor substrate and the support substrate, assembled by direct bonding at their respective front faces, following a bonding interface, the bonded assembly having a local unbonded area within this bonding interface, the donor substrate further comprising a buried brittle plane; separating along the buried brittle plane, initiated at the local unbonded area after microcrack growth in said plane by thermal activation, the separation resulting in the transfer of a thin film from the donor substrate to the support substrate. The method is characterised in that the local unbonded area is generated solely by a roughened area, produced deliberately on at least one of the front faces of the donor and support substrates prior to assembly, free of topology and having a predetermined roughness with an amplitude of between 0.5 nm RMS and 60.0 nm RMS.

Abstract: A method of manufacturing a donor substrate for the transfer of a piezoelectric layer onto a support substrate comprises providing a handling substrate and providing a piezoelectric substrate. A polymer layer is deposited on the handling substrate or the piezoelectric substrate. An intermediate layer is formed on a free surface of the piezoelectric substrate, and the piezoelectric substrate is assembled on the handling substrate such that the intermediate layer formed on the piezoelectric substrate is between the polymer layer and the piezoelectric substrate to form the donor substrate. A donor substrate may be manufactured by such a method, and such a donor substrate may be used for transferring a piezoelectric layer to another substrate.

Abstract: A method of manufacturing a donor substrate for the transfer of a piezoelectric layer onto a support substrate comprises providing a handling substrate and a piezoelectric substrate. A surface activation treatment is carried out on the surface of the piezoelectric substrate to form an activated surface on the piezoelectric substrate. A polymer layer is deposited on the activated surface of the piezoelectric substrate or on the handling substrate. The piezoelectric substrate is then assembled on the handling substrate in such a way that the polymer layer is between the activated surface of the piezoelectric substrate and the handling substrate. The donor substrate may be used to transfer a layer of piezoelectric material from the donor substrate onto a support substrate.

Abstract: A method for fabricating a semiconductor-on-insulator structure involves providing a donor substrate comprising a weakened zone delimiting a layer to be transferred, providing a receiver substrate, and bonding the donor substrate to the receiver substrate. The layer to be transferred is located on the bonding-interface side. A bonding wave is initiated at a first region on the periphery of the interface, and the wave is propagated toward a second region on the periphery of the interface opposite the first region. The difference in speed of propagation of the bonding wave between a central portion of the interface and a peripheral portion of the interface is controlled such that the speed of propagation of the bonding wave is lower in the central portion than in the peripheral portion. The donor substrate is detached along the weakened zone to transfer the layer to be transferred to the receiver substrate.

Abstract: A method for manufacturing a substrate includes the following steps: (a) providing a support substrate with a first coefficient of thermal expansion, having on one of its faces a first plurality of trenches parallel to each other in a first direction, and a second plurality of trenches parallel to each other in a second direction; (b) transferring a useful layer from a donor substrate to the support substrate, the useful layer having a second coefficient of thermal expansion; wherein an intermediate layer is inserted between the front face of the support substrate and the useful layer, the intermediate layer having a coefficient of thermal expansion between the first and second coefficients of thermal expansion.

Abstract: A method for fabricating a semiconductor-on-insulator structure involves providing a donor substrate comprising a weakened zone delimiting a layer to be transferred, providing a receiver substrate, and bonding the donor substrate to the receiver substrate. The layer to be transferred is located on the bonding-interface side. A bonding wave is initiated at a first region on the periphery of the interface, and the wave is propagated toward a second region on the periphery of the interface opposite the first region. The difference in speed of propagation of the bonding wave between a central portion of the interface and a peripheral portion of the interface is controlled such that the speed of propagation of the bonding wave is lower in the central portion than in the peripheral portion. The donor substrate is detached along the weakened zone to transfer the layer to be transferred to the receiver substrate.

Abstract: A process for producing a receiver substrate for a semiconductor-on-insulator structure for radiofrequency application comprises the following steps:—providing a semiconductor substrate comprising a base substrate made of monocrystalline material and a charge-trapping layer made of polycrystalline silicon arranged on the base substrate;—oxidizing the charge-trapping layer to form an oxide layer arranged on the charge-trapping layer. The oxidation of the charge-trapping layer is performed at least partly at a temperature lower than or equal to 875° C., in the following manner:—starting the oxidization at a first temperature (T1) between 750° C. and 1000° C.;—decreasing the temperature down to a second temperature (T2), lower than the first temperature (T1), between 750° C. and 875° C.;—continuing the oxidization at the second temperature (T2).

Abstract: The present disclosure relates to a method for mechanically separating layers, in particular in a double layer transfer process. The present disclosure relates more in particular to a method for mechanically separating layers, comprising the steps of providing a semiconductor compound comprising a layer of a handle substrate and an active layer with a front main side and a back main side opposite the front main side, wherein the layer of the handle substrate is attached to the front main side of the active layer, then providing a layer of a carrier substrate onto the back main side of the active layer, and then initiating mechanical separation of the layer of the handle substrate, wherein the layer of the handle substrate and the layer of the carrier substrate are provided with a substantially symmetrical mechanical structure.

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.

Abstract: A hybrid structure for a surface acoustic wave device comprises a useful layer of piezoelectric material having a first free surface and a second surface disposed on a support substrate that has a lower coefficient of thermal expansion than that of the useful layer, wherein the useful layer comprises an area of nanocavities.