A MEMS sensor includes a silicon substrate that has a first surface and a second surface on a side opposite to the first surface and that has a cavity in the first surface, a silicon diaphragm that has a first surface and a second surface on aside opposite to the first surface and in which the second surface is joined directly to the first surface of the silicon substrate, and a piezoresistance formed at the first surface of the silicon diaphragm, and, in the MEMS sensor, a plane orientation of the first surface of the silicon substrate and a plane orientation of the first surface of the silicon diaphragm differ from each other.

Disclose is a method for fabricating a semiconductor device. The method includes: forming a groove such as by etching one side surface of a first substrate; attaching a second substrate including a silicon layer on the etched surface of the first substrate formed with the hollow groove; etching the second substrate so as to leave substantially only the silicon layer; forming a thin film structure on the surface of silicon layers of the second substrate; and separating the second substrate formed with the thin film structure from the first substrate. For example, the groove structure may be formed in the lower portion of the device in the process of fabricating the semiconductor device to facilitate the final device separation.

Aspects include a method of manufacturing a flexible electronic structure that includes a metal or doped silicon substrate. Aspects include depositing an adhesive layer on the top side of the structure. Aspects also include depositing a release layer and a glass layer on the top side of the structure. Aspects also include reducing a thickness of the silicon substrate on the bottom side of the structure.

A method for sealing cavities using membranes, the method including a) forming cavities arranged in a matrix, of a depth p, a characteristic dimension a, and spaced apart by a spacing b; and b) forming membranes, sealing the cavities, by transferring a sealing film. The method further includes a step a1), executed before step b), of forming a first contour on the front face and/or on the sealing face, the first contour comprising a first trench having a width L and a first depth p1, the formation of the first contour being executed such that after step b) the cavities are circumscribed by the first contour, said first contour being at a distance G from the cavities between one-fifth of b and five b.

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.

Disclose is a method for fabricating a semiconductor device. The method includes: forming a groove such as by etching one side surface of a first substrate; attaching a second substrate including a silicon layer on the etched surface of the first substrate formed with the hollow groove; etching the second substrate so as to leave substantially only the silicon layer; forming a thin film structure on the surface of silicon layers of the second substrate; and separating the second substrate formed with the thin film structure from the first substrate. For example, the groove structure may be formed in the lower portion of the device in the process of fabricating the semiconductor device to facilitate the final device separation.

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.

A MEMS sensor includes a silicon substrate that has a first surface and a second surface on a side opposite to the first surface and that has a cavity in the first surface, a silicon diaphragm that has a first surface and a second surface on aside opposite to the first surface and in which the second surface is joined directly to the first surface of the silicon substrate, and a piezoresistance formed at the first surface of the silicon diaphragm, and, in the MEMS sensor, a plane orientation of the first surface of the silicon substrate and a plane orientation of the first surface of the silicon diaphragm differ from each other.

Complementary metal oxide semiconductor (CMOS) ultrasonic transducers (CUTs) and methods for forming CUTs are described. The CUTs may include monolithically integrated ultrasonic transducers and integrated circuits for operating in connection with the transducers. The CUTs may be used in ultrasound devices such as ultrasound imaging devices and/or high intensity focused ultrasound (HIFU) devices.

A method for producing an at least partially transparent device is provided, including producing, on a first substrate, first and second separation layers one against the other; producing, on the second separation layer, an at least partially transparent functional layer; making the functional layer integral with a second at least partially transparent substrate; forming a mechanical separation at an interface between the separation layers; removing the second separation layer; producing a first at least partially transparent electrode layer on the functional layer; where the materials of the stack are chosen such that the interface between the separation layers corresponds to that, among all the interfaces of the stack, having the lowest adherence force.