A method for treating a solid layer includes: providing a multi-layer assembly having a carrier substrate and a solid layer bonded to the carrier substrate by a bonding layer, the solid layer having an exposed surface including a defined surface structure, the defined surface structure resulting from a removal, which is effected by a crack, from a donor substrate, at least in sections; processing the solid layer, which is arranged on the carrier substrate; and separating the solid layer from the carrier substrate by a destruction of the bonding layer.

A method is used to prepare the remainder of a donor substrate, from which a layer has been removed by delamination in a plane weakened by ion implantation. The remainder comprises, on a main face, an annular step corresponding to a non-removed part of the donor substrate. The method comprises the deposition of a smoothing oxide on the main face of the remainder in order to fill the inner space defined by the annular step and to cover at least part of the annular step, as well as heat treatment for densification of the smoothing oxide. A substrate is produced by the method, and the substrate may be used in subsequent processes.

A method for manufacturing a microelectronic device with a membrane suspended above at least one final cavity, may involve providing a supporting substrate having at least one elementary cavity, and a donor substrate. The method may include assembling the supporting and donor substrate, then thinning the donor substrate so as to form the membrane. Advantageously, the method may include forming at least one membrane anchoring pillar. After the forming of the at least one anchoring pillar, and after the assembling, the method may include etching the surface layer of the supporting substrate so as to widen the at least one elementary cavity, to form the final cavity, the etching being configured to selectively etch the surface layer with respect to the anchoring pillar.

A method is used to prepare the remainder of a donor substrate, from which a layer has been removed by delamination in a plane weakened by ion implantation. The remainder comprises, on a main face, an annular step corresponding to a non-removed part of the donor substrate. The method comprises the deposition of a smoothing oxide on the main face of the remainder in order to fill the inner space defined by the annular step and to cover at least part of the annular step, as well as heat treatment for densification of the smoothing oxide. A substrate is produced by the method, and the substrate may be used in subsequent processes.

A method for manufacturing a microelectronic device with a membrane suspended above at least one final cavity, may involve providing a supporting substrate having at least one elementary cavity, and a donor substrate. The method may include assembling the supporting and donor substrate, then thinning the donor substrate so as to form the membrane. Advantageously, the method may include forming at least one membrane anchoring pillar. After the forming of the at least one anchoring pillar, and after the assembling, the method may include etching the surface layer of the supporting substrate so as to widen the at least one elementary cavity, to form the final cavity, the etching being configured to selectively etch the surface layer with respect to the anchoring pillar.

A method for transferring a superficial layer to a carrier substrate having cavities comprises: —providing a donor substrate, —providing the carrier substrate having a first face and comprising cavities, each cavity opening at the first face and having a bottom and peripheral walls, —creating at least one temporary pillar in at least one of the cavities, the pillar having an upper surface that is coplanar with the first face of the carrier substrate, joining the donor substrate and the carrier substrate at the first face of the carrier substrate, —thinning the donor substrate to form the superficial layer, and removing the at least one temporary pillar.

The invention relates to a method for transferring a semiconductor layer (2) from a donor substrate (1) comprising a weakening plane (F) to a receiver substrate (3) comprising a bonding face (4) that has open cavities (C). This method comprises the implementation, by putting the donor substrate and the bonding face of the receiver substrate in contact, of an assembly wherein said cavities are buried and the separation of the assembly by fracture along the weakening plane.

The bonding face of the receiver substrate includes, apart from the open cavities, a bonding surface that comes into contact with the donor substrate when the assembly is implemented. Said bonding surface comprising a region devoid of cavities (5, 6) one dimension of which is at least 100 μm and which has a surface area of at least 1 mm.sup.2, and an intercavity space that occupies from 15 to 50% of the bonding face of the receiver substrate.

The invention relates to a method for transferring a semiconductor layer from a donor substrate to a receiver substrate having an open cavity, comprising the steps of forming an embrittlement plane in the donor substrate, making, by bringing the donor substrate and the receiver substrate into contact, a packaging in which said cavity is buried, and separating the packaging by fracturing along the embrittlement plane, said separating causing a transfer of the semiconductor layer to the receiver substrate and a sealing of the cavity by the semiconductor layer.

This method comprises, prior to making the packaging, a step of implanting diffusing species into the donor substrate or into the receiver substrate and, subsequently to making the packaging and prior to separating the packaging, a step of diffusing said species into the cavity.

In various embodiments, a method of processing a monocrystalline substrate is provided. The method may include severing the substrate along a main processing side into at least two monocrystalline substrate segments, and forming a micromechanical structure comprising at least one monocrystalline substrate segment of the at least two substrate segments.

A method for producing a device comprising a membrane of piezoelectric nature above at least one cavity comprises: a) providing a carrier substrate having a cavity opening out onto its front face, the cavity having a lateral dimension larger than 30 m; b) providing a donor substrate having a buried weakened plane delimiting a surface layer; c) depositing, on the front face of the donor substrate, a stiffening layer made of piezoelectric material having a thickness greater than 500 nanometers; d) joining the carrier substrate and donor substrate; and e) splitting the donor substrate at the buried weakened plane so as to transfer the membrane comprising the surface layer and the stiffening layer to the carrier substrate.