A plurality of conductive via connections are fabricated on a substrate located at positions where MTJ devices are to be fabricated, wherein a width of each of the conductive via connections is smaller than or equivalent to a width of the MTJ devices. The conductive via connections are surrounded with a dielectric layer having a height sufficient to ensure that at the end of a main MTJ etch, an etch front remains in the dielectric layer surrounding the conductive via connections. Thereafter, a MTJ film stack is deposited on the plurality of conductive via connections surrounded by the dielectric layer. The MTJ film stack is etched using an ion beam etch process (IBE), etching through the MTJ film stack and into the dielectric layer surrounding the conductive via connections to form the MTJ devices wherein by etching into the dielectric layer, re-deposition on sidewalls of the MTJ devices is insulating.

A piezoelectric device includes a container and an AT-cut crystal element. The AT-cut crystal element has at least one side surface intersecting with a Z-axis of the crystallographic axis of the crystal constituted of three surfaces. The first surface is a surface equivalent to a surface formed by rotating the principal surface by 43.5 with an X-axis of the crystal as a rotation axis. The second surface is a surface equivalent to a surface formed by rotating the principal surface by 575 with the X-axis. The third surface is a surface equivalent to a surface formed by rotating the principal surface by 425 with the X-axis. When two corner portions on a side of a second side opposed to the first side of the AT-cut crystal element are viewed in plan view, each of the two corner portions have an approximately right angle.

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 device with a membrane comprising a support, a membrane made of a polymer material suspended on said support and at least one actuating module arranged opposite a face of the membrane and separate from said membrane, said actuating module comprising at least one actuator comprising at least one piezoelectric material and a beam connected to the support and separate from the membrane, the piezoelectric material being connected to the beam, such that, when a difference in electric potential is applied to the piezoelectric material, a bimetal effect appears between the piezoelectric material and the beam deforming the beam in the direction of the membrane, causing the deformation of the membrane, said device also comprising at least one electrostatic actuator configured for compressing at least one part of the membrane on the at least one part of the actuating module.

A process for fabricating a substrate for a radiofrequency device by joining a piezoelectric layer to a carrier substrate by way of an electrically insulating layer, the piezoelectric layer having a rough surface at its interface with the electrically insulating layer, the process being characterized in that it comprises the following steps: providing a piezoelectric substrate having a rough surface for reflecting a radiofrequency wave, depositing a dielectric layer on the rough surface of the piezoelectric substrate, providing a carrier substrate, depositing a photo-polymerizable adhesive layer on the carrier substrate, bonding the piezoelectric substrate to the carrier substrate by way of the dielectric layer and of the adhesive layer, in order to form an assembled substrate, irradiating the assembled substrate with a light flux in order to polymerize the adhesive layer, the adhesive layer and the dielectric layer together forming the electrically insulating layer.

A method of forming a piezoelectric microphone with an interlock/stopper and a micro-bump and a resulting device are provided. Embodiments include forming a membrane over a Si substrate having a first and second sacrificial layer disposed on opposite surfaces thereof, the membrane being formed on the first sacrificial layer, forming a first HM over the membrane, forming first and second vias through the first HM, forming a first pad layer in the first and second vias and over an exposed top thin film, forming a trench to the first sacrificial layer between the first and second vias and a gap between the trench and second via, patterning a second HM over the membrane, in the first and second vias, the trench and the gap, and forming a second pad layer over the second HM and in exposed areas around the first and second vias to form pad structures.

Disclosed is a method of manufacturing a piezoelectric thin film resonator on a non-silicon substrate, including the following steps: depositing a copper thin film on a silicon wafer; coating photoresist on the copper thin film to perform photoetching so as to remove photoresist in an air gap region under the piezoelectric thin film resonator to be disposed; electroplating-depositing a copper layer, and removing photoresist to obtain a stepped peel sacrifice layer; coating polyimide and performing imidization by heat treatment, making a sandwich structure of the piezoelectric thin film resonator above the polyimide layer; performing etching for the polyimide layer in a region not covered by the piezoelectric thin film resonator by oxygen plasma; placing the obtained device into a copper corrosion solution to dissolve the copper around and under the piezoelectric thin film resonator, attaching a drum coated with polyvinyl alcohol glue onto the piezoelectric thin film resonator, releasing and peeling it from the silicon wafer and then transferring it to a desired non-silicon substrate; washing the drum with hot water to separate the drum from the piezoelectric thin film resonator so as to complete the manufacturing process.

A piezoelectric element includes a first electrode layer, a piezoelectric layer, and a second electrode layer. The first electrode layer, the piezoelectric layer, and the second electrode layer are stacked in sequence on one another. The first electrode layer has a first part overlapping the piezoelectric layer in a plan view, and a second part at least partially separated from the first part and not overlapping the piezoelectric layer in the plan view. The second electrode layer has a third part overlapping the piezoelectric layer in the plan view, and a fourth part separated from the third part. The fourth part is in contact with the first part and the second part.

A subtractive forming method for piezoresistive material stacks includes applying an etch chemistry to an exposed first portion of a piezoresistive material stack. The etch chemistry includes a citric acid component for removing a first element of a piezoelectric layer of the piezoresistive material stack selectively to a surface oxide. At least one second element of the piezoelectric layer remains. The method further includes heating the piezoresistive material stack after said applying the etch chemistry to vaporize the at least one second element. A second portion of the piezoresistive material stack is protected from the removal and the heating by a mask.

In a non-limiting embodiment, a device may include a substrate, and a hybrid active structure disposed over the substrate. The hybrid active structure may include an anchor region and a free region. The hybrid active structure may be connected to the substrate at least at the anchor region. The anchor region may include at least a segment of a piezoelectric stack portion. The piezoelectric stack portion may include a first electrode layer, a piezoelectric layer over the first electrode layer, and a second electrode layer over the piezoelectric layer. The free region may include at least a segment of a mechanical portion. The piezoelectric stack portion may overlap the mechanical portion at edges of the piezoelectric stack portion.