A semiconductor module and a method for manufacturing the same are provided. The semiconductor module includes a substrate comprising a front side and at least one semiconductor device formed on the front side, a shielding structure formed on the at least one semiconductor device, and a piezoelectric layer formed on the shielding structure.

A composite substrate includes a single crystal support substrate containing first element as a main component; an oxide single crystal layer provided on the single crystal support substrate and containing a second element (excluding oxygen) as a main component; and an amorphous layer provided in between the single crystal support substrate and the oxide single crystal layer and containing a first element, a second element, and Ar, the amorphous layer having a first amorphous region in which proportion of the first element is higher than proportion of the second element, and a second amorphous region in which the proportion of the second element is higher than the proportion of the first element, concentration of Ar contained in the first amorphous region being higher than concentration of Ar contained in the second amorphous region and being 3 atom % or more.

Described herein is a method of bonding a piezoelectric substrate to a support substrate to form a composite substrate. The piezoelectric substrate has one surface which is positively polarized, and a second surface which is negatively polarized. The method described herein includes the steps of bonding the positively polarized surface of the piezoelectric substrate to one surface of the support substrate by a direct bonding method.

A piezoelectric monocrystalline substrate is composed of a material represented by LiAO.sub.3 (A represents at least one element selected from the group consisting of niobium and tantalum), a bonding layer is compose of a material of an oxide of at least one element selected from the group consisting of niobium and tantalum, and an interface layer is provided along an interface between the piezoelectric monocrystalline substrate 6 and bonding layer, and the interface layer has a composition of E.sub.xO.sub.(1-x) (E represents at least one element selected from the group consisting of niobium and tantalum and 0.29≤x≤0.89).

A micro-vibration sensor and preparation method thereof. The method includes a metal sheet is coated with first curing material, and first curing material is cured into first cured layer; piezoelectric thin film element is attached to edge of first cured layer; one side, attached with piezoelectric thin film element, of first cured layer is vertically placed into second curing material, and second curing material is cured into second cured layer; and metal sheet is removed to obtain micro-vibration sensor. Due to fact that piezoelectric thin film element is arranged at a crack tip, during micro-vibration, stress in stress field of crack tip is rapidly increased due to crack stress deformation, and stress signal is efficiently converted into electric signal; and micro-vibration sensor has characteristics of being low in detection limit and high in accuracy.

A SAW device includes a SAW element, a conductor connected to the SAW element, an LT substrate including the SAW element, and a case for housing the LT substrate including the SAW element. The case includes a cover part, a lateral part, and a bottom part. The bottom part is including a sapphire substrate, the LT substrate is positioned on a first surface of the sapphire substrate, the first surface serving as an inner surface of the case, and a second surface opposite to the first surface serves as an outer surface of the case. The conductor includes a via conductor provided in a through-hole continuously penetrating through the sapphire substrate and the LT substrate.

A vibrator includes: a base portion; a vibrating arm including an arm portion which extends from the base portion, and a weight portion which is located on a tip end side of the arm portion and which has a first main surface and a second main surface that are in a front-back relationship; and a weight film disposed at the first main surface of the weight portion. The first main surface includes a planar surface and an inclined surface inclined with respect to the planar surface. A method for manufacturing a vibrator includes: a preparation step of preparing the above-described vibrator; and a removing step of removing a part of the weight film by emitting an energy ray to the weight film. In the removing step, the weight film disposed at the planar surface is removed and the weight film disposed at the inclined surface is not removed by emitting the energy ray to the weight film from a normal direction of the planar surface.

A composite wafer having an oxide single-crystal film transferred onto a support wafer, the film being a lithium tantalate or lithium niobate film, and the composite wafer being unlikely to have cracking or peeling caused in the lamination interface between the film and the support wafer. More specifically, a method of producing the composite wafer, including steps of: implanting hydrogen atom ions or molecule ions from a surface of the oxide wafer to form an ion-implanted layer inside thereof; subjecting at least one of the surface of the oxide wafer and a surface of the support wafer to surface activation treatment; bonding the surfaces together to obtain a laminate; heat-treating the laminate at 90° C. or higher at which cracking is not caused; and exposing the heat-treated laminate to visible light to split along the ion-implanted layer to obtain the composite wafer.

A piezoelectric element includes a piezoelectric layer, a first electrode layer, and a second electrode layer. The piezoelectric layer includes first and second surfaces opposed to each other. The first electrode layer is located on the first surface. The second electrode layer is located on the second surface. At least a portion of the second electrode layer faces the first electrode layer with the piezoelectric layer interposed therebetween. The second electrode layer mainly includes silicon. The piezoelectric layer is monocrystalline.

A piezoelectric element includes a laminate and a first internal electrode. The laminate includes a pair of main faces, a pair of end faces, and a pair of side faces. The first internal electrode includes four electrode portions and a connector. The four electrode portions include a first pair of electrode portions and a second pair of electrode portions. The connector connects the first pair of electrode portions. The connector is spaced apart from each of the second pair of electrode portions by a first distance. Each of the four electrode portions includes a main electrode part. The main electrode part is spaced apart from the pair of end faces by a second distance. The main electrode part is spaced apart from the pair of side faces by a third distance. The first distance is longer than each of the second distance and the third distance.