Abstract: A bonded body includes a supporting substrate, a piezoelectric single crystal substrate and a bonding layer provided between the supporting substrate and piezoelectric single crystal substrate. The bonding layer has a composition of Si(1-x)Ox (x represents an oxygen ratio). The oxygen ratio x at a central part in a thickness direction of the bonding layer is higher than an oxygen ratio x at an end part of the bonding layer on a side of the piezoelectric single crystal substrate and an oxygen ratio x at an end part of the bonding layer on a side of the supporting substrate. The oxygen ratio at the central part in the thickness direction of the bonding layer is 0.013 or higher and 0.666 or lower.

Abstract: A bonded body includes a supporting substrate composed of a polycrystalline ceramic material or monocrystalline material, a piezoelectric single crystal substrate and a bonding layer provided between the supporting substrate and piezoelectric single crystal substrate. The bonding layer has a composition of Si(1-x)Ox (x represents an oxygen ratio). The oxygen ratio is increased or decreased from an end part of the bonding layer on the side of the piezoelectric single crystal substrate to an end part of the bonding layer on the side of the supporting substrate. The maximum value of the oxygen ratio x in the bonding layer is 0.013 or higher and 0.666 or lower, and the minimum value of the oxygen ratio is 0.001 or higher and 0.408 or lower.

Abstract: In an acoustic wave device including a piezoelectric material substrate and supporting body bonded with each other through a bonding layer, it is an object to provide the acoustic wave device having the structure for further improving the propagation loss and temperature characteristics of frequency of an acoustic wave. An acoustic wave device includes a piezoelectric material substrate, an electrode on the piezoelectric material substrate, a supporting body, and a bonding layer for bonding the piezoelectric material substrate and the supporting body. The bonding layer is composed of quartz crystal.

Abstract: A bonded body includes a supporting substrate, a piezoelectric material substrate composed of a material selected from the group consisting of lithium niobate, lithium tantalate and lithium niobate-lithium tantalate, and an amorphous layer present between the supporting substrate and piezoelectric material substrate. The amorphous layer contains one or more metal element selected from the group consisting of niobium and tantalum, an element constituting the supporting substrate and oxygen element. The concentration of the metal element in the amorphous layer is higher than the concentration of oxygen element and 20 to 65 atom %.

Abstract: It is formed, over a supporting body made of a ceramic, a bonding layer composed of one or more material selected from the group consisting of mullite, alumina, tantalum pentoxide, titanium oxide and niobium pentoxide. Neutralized beam is irradiated onto a surface of the bonding layer to activate the surface of the bonding layer. The surface of the bonding layer and the piezoelectric single crystal substrate are bonded by direct bonding.

Abstract: A bonded body includes a supporting substrate and piezoelectric material layer. The supporting substrate is composed of sialon. The material of the piezoelectric material layer is LiAO3 (A represents one or more element selected from the group consisting of niobium and tantalum). It is included an interface layer present along an interface between the supporting body and piezoelectric material layer and a supporting substrate-side intermediate layer present between the interface layer and supporting substrate. Each of the interface layer and supporting substrate-side intermediate layer contains nitrogen, oxygen, aluminum, silicon and one or more element selected from the group consisting of niobium and tantalum as main components.

Abstract: It is proposed a bonded body having a supporting substrate and piezoelectric material layer. The supporting substrate is composed of mullite, and the material of the piezoelectric material layer is LiAO3 (A represents one or more element selected from the group consisting of niobium and tantalum). It is included an interface layer present along an interface between the supporting body and piezoelectric material layer and a supporting substrate-side intermediate layer present between the interface layer and supporting substrate. Each of the interface layer and supporting substrate-side intermediate layer contains oxygen, aluminum, silicon and one or more element selected from the group consisting of niobium and tantalum as main components.

Abstract: A method for producing an elastic wave device includes steps of (a) preparing a first substrate and a second substrate, (b) irradiating a bonding surface of the first substrate and a bonding surface of the second substrate with one of plasma, neutral atom beams, and ion beams of an inert gas, (c) bonding the bonding surface of the first substrate and the bonding surface of the second substrate in a vacuum at room temperature so as to set a strength that allows the first and second substrates to be separated by insertion of a blade; (d) forming a composite substrate by bonding a piezoelectric substrate to another surface of the first substrate; (e) forming electrode on a surface of the piezoelectric substrate of the composite substrate; and then (f) removing the second substrate from the first substrate by separation with the blade.

Abstract: A composite substrate production method of the invention includes (a) a step of mirror polishing a substrate stack having a diameter of 4 inch or more, the substrate stack including a piezoelectric substrate and a support substrate bonded to each other, the mirror polishing being performed on the piezoelectric substrate side until the thickness of the piezoelectric substrate reaches 3 ?m or less; (b) a step of creating data of the distribution of the thickness of the mirror-polished piezoelectric substrate; and (c) a step of performing machining with an ion beam machine based on the data of the thickness distribution so as to produce a composite substrate have some special technical features.

Abstract: In an acoustic wave device including a piezoelectric material substrate and supporting body bonded with each other through a bonding layer, it is an object to provide the acoustic wave device having the structure for further improving the propagation loss and temperature characteristics of frequency of an acoustic wave. An acoustic wave device includes a piezoelectric material substrate, an electrode on the piezoelectric material substrate, a supporting body, and a bonding layer for bonding the piezoelectric material substrate and the supporting body. The bonding layer is composed of quartz crystal.

Abstract: A bonded body includes a supporting body composed of a ceramic, a bonding layer provided over a surface of the supporting body and composed of one or more material selected from the group consisting of mullite, alumina, tantalum pentoxide, titanium oxide and niobium pentoxide, and a piezoelectric single crystal substrate bonded with the bonding layer. The surface of the supporting body has an arithmetic average roughness Ra of 0.5 nm or larger and 5.0 nm or smaller.

Abstract: A piezoelectric monocrystalline substrate is composed of a material represented by LiAO3 (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 ExO(1-x) (E represents at least one element selected from the group consisting of niobium and tantalum and 0.29?x?0.89).

Abstract: An acoustic wave device includes a piezoelectric material substrate, an intermediate layer on the piezoelectric material substrate and composed of one or more materials selected from the group consisting of silicon oxide, aluminum nitride and sialon, a bonding layer on the intermediate layer and composed of one or more materials selected from the group consisting of tantalum pentoxide, niobium pentoxide, titanium oxide, mullite, alumina, a high resistance silicon and hafnium oxide, a supporting body composed of a polycrystalline ceramic and bonded to the bonding layer by direct bonding, and an electrode on the piezoelectric material substrate.

Abstract: An object is to improve insulation in a bonding layer and to improve a bonding strength of a supporting body and piezoelectric single crystal substrate, in a bonded body having the supporting body made of a polycrystalline material or single crystal material, the piezoelectric single crystal substrate and the bonding layer provided between the supporting body and piezoelectric single crystal substrate, wherein the bonded body includes the supporting body, piezoelectric single crystal substrate and the bonding layer provided between the supporting body and piezoelectric single crystal substrate, and the bonding layer has a composition of Si(1-x)Ox (0.008?x?0.408).

Abstract: An acoustic wave device is an end surface reflection-type acoustic wave device and includes a substantially rectangular-parallelepiped composite substrate in which a piezoelectric substrate and a supporting substrate are joined together, with a pair of IDT electrodes provided on the substrate in such a manner as to be intercalated with each other. A chipping size in a first side face of the substrate is 1/10 of a wavelength ? of an acoustic wave or smaller, the face extending orthogonally to a direction of acoustic-wave propagation. A chipping size in a second side face of the substrate is larger than the chipping size in the face and is, for example, ½ of the wavelength ? or larger and 50 times the wavelength ? or smaller, the face extending in the direction of acoustic-wave propagation.

Abstract: In the composite substrate 10, the piezoelectric substrate 12 and the support substrate 14 are bonded by direct bonding using an ion beam. One surface of the piezoelectric substrate 12 is a negatively-polarized surface 12a and another surface of the piezoelectric substrate 12 is a positively-polarized surface 12b. An etching rate at which the negatively-polarized surface 12a is etched with a strong acid may be higher than an etching rate at which the positively-polarized surface 12b is etched with the strong acid. The positively-polarized surface 12b of the piezoelectric substrate 12 is directly bonded to the support substrate 14. The negatively-polarized surface 12a of the piezoelectric substrate 12 may be etched with the strong acid.

Abstract: It is formed, over a supporting body made of a ceramic, a bonding layer composed of one or more material selected from the group consisting of mullite, alumina, tantalum pentoxide, titanium oxide and niobium pentoxide. Neutralized beam is irradiated onto a surface of the bonding layer to activate the surface of the bonding layer. The surface of the bonding layer and the piezoelectric single crystal substrate are bonded by direct bonding.

Abstract: In the composite substrate, the piezoelectric substrate and the support substrate are bonded by direct bonding using an ion beam. One surface of the piezoelectric substrate is a negatively-polarized surface and another surface of the piezoelectric substrate is a positively-polarized surface. An etching rate at which the negatively-polarized surface is etched with a strong acid may be higher than an etching rate at which the positively-polarized surface is etched with the strong acid. The positively-polarized surface of the piezoelectric substrate is directly bonded to the support substrate. The negatively-polarized surface of the piezoelectric substrate may be etched with the strong acid.

Abstract: A bonded body includes a supporting body composed of a ceramic, a bonding layer provided over a surface of the supporting body and composed of one or more material selected from the group consisting of mullite, alumina, tantalum pentoxide, titanium oxide and niobium pentoxide, and a piezoelectric single crystal substrate bonded with the bonding layer. The surface of the supporting body has an arithmetic average roughness Ra of 0.5 nm or larger and 5.0 nm or smaller.