An RF integrated circuit device can includes a substrate and a High Electron Mobility Transistor (HEMT) device on the substrate including a ScAlN layer configured to provide a buffer layer of the HEMT device to confine formation of a 2DEG channel region of the HEMT device. An RF piezoelectric resonator device can be on the substrate including the ScAlN layer sandwiched between a top electrode and a bottom electrode of the RF piezoelectric resonator device to provide a piezoelectric resonator for the RF piezoelectric resonator device.

A method for processing a lithium tantalate crystal substrate includes providing a lithium tantalate crystal substrate, roughening the lithium tantalate crystal substrate, providing a catalytic agent, bringing the lithium tantalate crystal substrate and the catalytic agent into contact with each other after the lithium tantalate crystal substrate is roughened, and subjecting the lithium tantalate crystal substrate to a reduction treatment. The reduction treatment is conducted at a temperature not higher than a Curie temperature of the lithium tantalate crystal substrate. The catalytic agent is selected from the group consisting of metal powder, metal gas, and metal carbonate powder.

A method for fabricating an array of front ends for an array of packaged electronic components that each comprise:

an electrical element packaged within a package comprising
a front part of a package comprising an inner section with a cavity therein opposite the resonator defined by the raised frame and an outer section sealing said cavity; and
a back part of the package comprising a back cavity in an inner back section, and an outer back section sealing the cavity, said back package further comprising a first and a second via through the back end around said at least one back cavity for coupling to front and back electrodes of the electronic component; the vias terminating in external contact pads that are coupleable in a flip chip configuration to a circuit board; the method comprising the stages of: i. Obtaining a carrier substrate having an active membrane layer attached thereto by its rear surface, with a front electrode on the front surface of the active membrane layer; ii. Obtaining an inner front end section; iii. Attaching the inner front end section to the exposed front surface of the front electrode; iv. Detaching the carrier substrate from the rear surface of the active membrane layer; v. Optionally thinning the inner front section; vi. Processing the rear surface by removing material to create an array of at least one island of active membrane on at least one island of front electrode; vii. Creating an array of at least one front cavity by selectively removing at least outer layer of the inner front end section, such that there is one cavity opposite each island of membrane on the front side of the front electrode on the opposite side to the island of active membrane; viii. Applying an outer front end section to the inner front end section and bonding the outer front end section to an outer surface of the inner front end section such that the outer front end section spans across and seals the at least one cavity of the array of front cavities.

A bonded body includes a supporting substrate, a silicon oxide layer provided on the supporting substrate, and a piezoelectric material substrate provided on the silicon oxide layer and composed of a material selected from the group consisting of lithium niobate, lithium tantalate and lithium niobate-lithium tantalate. The surface resistivity of the piezoelectric material substrate on the side of the silicon oxide layer is 1.710.sup.1 5/ or higher.

A method of manufacturing surface acoustic wave device chips includes grinding a reverse side of a wafer with a surface acoustic wave device formed in each area demarcated by a plurality of crossing projected dicing lines on a face side of the wafer; before or after grinding, applying a laser beam to the reverse side of the wafer such that the laser beam is focused at a position within the wafer, the position being closer to the face side of the wafer than a position corresponding to a reverse side of each of the surface acoustic wave device chips to be produced from the wafer, thereby forming a modified layer for diffusing an acoustic wave; and after grinding and applying the laser beam, dividing the wafer along the projected dicing lines into a plurality of the surface acoustic wave device chips.

A method for healing defects in a layer of composition ABO.sub.3 where A consists of at least one element selected from: Li, Na, K, H, Ca, Mg, Ba, Sr, Pb, La, Bi, Y, Dy, Gd, Tb, Ce, Pr, Nd, Sm, Eu, Ho, Zr, Sc, Ag, Tl and B consists of at least one element selected from: Nb, Ta, Sb, Ti, Zr, Sn, Ru, Fe, V, Sc, C, Ga, Al, Si, Mn, Zr, Tl, the layer being obtained by a layer transfer method in which ionic species are implanted into a substrate of composition ABO.sub.3 so as to form a weakened zone delineating the layer, the substrate then being detached along the weakened zone in order to obtain a layer that is detached from the rest of the donor substrate, wherein the method comprises exposing the layer to a medium containing ions of a constituent element A so as to make the ions penetrate into the transferred layer.

A bonded body includes a supporting substrate, a silicon oxide layer provided on the supporting substrate, and a piezoelectric material substrate provided on the silicon oxide layer and composed of a material selected from the group consisting of lithium niobate, lithium tantalate and lithium niobate-lithium tantalate. An average value of a nitrogen concentration of the silicon oxide layer is higher than a nitrogen concentration at an interface between the silicon oxide layer and supporting substrate and higher than a nitrogen concentration at an interface between the silicon oxide layer and piezoelectric material substrate.

A bonded body includes a supporting substrate, a piezoelectric material substrate of a material selected from the group consisting of lithium niobate, lithium tantalate and lithium niobate-lithium tantalate, and a bonding layer bonding the supporting substrate and piezoelectric material substrate. The material of the bonding layer is silicon oxide. Provided that the bonding layer is divided into a piezoelectric material substrate-side bonding part and supporting substrate-side bonding part, the piezoelectric material substrate-side bonding part has a nitrogen concentration higher than a nitrogen concentration of the supporting substrate-side bonding part.

A method and structure for a transfer process for an acoustic resonator device. In an example, a bulk acoustic wave resonator (BAWR) with an air reflection cavity is formed. A piezoelectric thin film is grown on a crystalline substrate. One or more patterned electrodes are deposited on the surface of the piezoelectric film. An etched sacrificial layer is deposited over the one or more electrodes and a planarized support layer is deposited over the sacrificial layer. The support layer is etched to form one or more cavities overlying the electrodes to expose the sacrificial layer. The sacrificial layer is etched to release the cavities around the electrodes. Then, a cap layer is fusion bonded to the support layer to enclose the electrodes in the support layer cavities.

A method and structure for a transfer process for an acoustic resonator device. In an example, a bulk acoustic wave resonator (BAWR) with an air reflection cavity is formed. A piezoelectric thin film is grown on a crystalline substrate. Patterned electrodes are deposited on the surface of the piezoelectric film. An etched sacrificial layer is deposited over the electrodes and a planarized support layer is deposited over the sacrificial layer. The device can include temperature compensation layers (TCL) that improve the device TCF. These layers can be thin layers of oxide type materials and can be configured between the top electrode and the piezoelectric layer, between the bottom electrode and the piezoelectric layer, between two or more piezoelectric layers, and any combination thereof. In an example, the TCLs can be configured from thick passivation layers overlying the top electrode and/or underlying the bottom electrode.