Abstract: A bonding layer 3 is formed over a piezoelectric material substrate, and the bonding layer 3 is made of or more material selected from the group consisting of silicon nitride, aluminum nitride, alumina, tantalum pentoxide, mullite, niobium pentoxide and titanium oxide. Neutralized beam A is irradiated onto a surface 4 of the bonding layer and a surface of a supporting body to activate the surface of the bonding layer and the surface of the supporting body. The surface of the bonding layer and the surface of the supporting body are bonded by direct bonding.

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. 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. The bonding layer has a composition of Si(1-x)Ox (0.008?x?0.408).

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: 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: A composite substrate 10 is formed by bonding together a piezoelectric substrate 12 and a support substrate 14 that has a lower thermal expansion coefficient than the piezoelectric substrate. The support substrate 14 is formed by directly bonding together a first substrate 14a and a second substrate 14b at a strength that allows separation with a blade, the first and second substrates being formed of the same material, and a surface of the first substrate 14a is bonded to the piezoelectric substrate 12, the surface being opposite to another surface of the first substrate 14a bonded to the second substrate 14b.

Abstract: A composite substrate 10 is formed by bonding together a piezoelectric substrate 12 and a support substrate 14 that has a lower thermal expansion coefficient than the piezoelectric substrate. The support substrate 14 is formed by directly bonding together a first substrate 14a and a second substrate 14b at a strength that allows separation with a blade, the first and second substrates being formed of the same material, and a surface of the first substrate 14a is bonded to the piezoelectric substrate 12, the surface being opposite to another surface of the first substrate 14a bonded to the second substrate 14b.

Abstract: A composite substrate 10 includes a semiconductor substrate 12 and an insulating support substrate 14 that are laminated together. The support substrate 14 includes first and second substrates 14a and 14b made of the same material and bonded together with a strength that allows the first and second substrates 14a and 14b to be separated from each other with a blade. The semiconductor substrate 12 is laminated on a surface of the first substrate 14a opposite a surface thereof bonded to the second substrate 14b.

Abstract: A composite substrate 10 includes a piezoelectric substrate 12 and a support layer 14 bonded to the piezoelectric substrate 12. The support layer 14 is made of a material having no crystalline anisotropy in a bonded surface thereof and has a smaller thickness than the piezoelectric substrate 12. The piezoelectric substrate 12 and the support layer 14 are bonded together with an adhesive layer 16 therebetween. The composite substrate 10 has a total thickness of 180 ?m or less. The base thickness ratio Tr=t2/(t1+t2) is 0.1 to 0.4, where t1 is the thickness of the piezoelectric substrate 12, and t2 is the thickness of the support layer 14. The thickness t1 is 100 ?m or less. The thickness t2 is 50 ?m or less.

Abstract: A composite substrate 10 includes a supporting substrate 12 and a piezoelectric substrate 14 which are bonded to each other. In this embodiment, the supporting substrate 12 and the piezoelectric substrate 14 are bonded to each other by an adhesive layer 16. In the composite substrate 10, since the supporting substrate 12 is composed of a translucent alumina ceramic, alignment is easily performed during FCB compared with the case where the supporting substrate is composed of an opaque ceramic. Furthermore, preferably, the linear transmittance and the total light transmittance from the front of the supporting substrate 12 in the visible light range (360 to 750 nm) are 10% or more and 70% or more, respectively.

Abstract: A composite substrate for an acoustic wave element includes a support substrate 1 and a propagation substrate 3 for propagating an acoustic wave. The propagation substrate is bonded to the support substrate 1 and composed of a piezoelectric single crystal. The propagation substrate 3 includes a surface lattice distortion layer 11 in which crystal lattices of the piezoelectric single crystal are distorted.

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: An acoustic wave device 10 is an end surface reflection-type acoustic wave device and includes a substantially rectangular-parallelepiped composite substrate 15 in which a piezoelectric substrate 12 and a supporting substrate 14 are joined together, with a pair of IDT electrodes 16 and 18 provided on the substrate 12 in such a manner as to be intercalated with each other. A chipping size in a first side face 12a of the substrate 12 is 1/10 of a wavelength ? of an acoustic wave or smaller, the face 12a extending orthogonally to a direction of acoustic-wave propagation. A chipping size in a second side face 12b of the substrate 12 is larger than the chipping size in the face 12a and is, for example, 1/2 of the wavelength ? or larger and 50 times the wavelength ? or smaller, the face 12b extending in the direction of acoustic-wave propagation.

Abstract: A piezoelectric substrate 22 and a support substrate 27 are prepared (a), these are joined to each other with an adhesive layer 26 therebetween to form a composite substrate 20 (b), and a surface of the piezoelectric substrate 22 is polished to thin the piezoelectric substrate 22 (c). Then, grooves 28 dividing the piezoelectric substrate 22 into parts having a size for a piezoelectric device are formed by half-dicing the composite substrate 20 (d). By forming the grooves 28, the adhesive layer 26 is exposed in the grooves 28. By immersing the composite substrate in solvent, the adhesive layer 26 is removed by the solvent, and the piezoelectric substrate 22 is detached from the support substrate (e), (f), and a piezoelectric device 10 is obtained using the detached piezoelectric substrate 12 (g).

Abstract: A composite substrate 10 includes a semiconductor substrate 12 and an insulating support substrate 14 that are laminated together. The support substrate 14 includes first and second substrates 14a and 14b made of the same material and bonded together with a strength that allows the first and second substrates 14a and 14b to be separated from each other with a blade. The semiconductor substrate 12 is laminated on a surface of the first substrate 14a opposite a surface thereof bonded to the second substrate 14b.

Abstract: A composite substrate for an acoustic wave element includes a support substrate 1 and a propagation substrate 3 for propagating an acoustic wave. The propagation substrate is bonded to the support substrate 1 and composed of a piezoelectric single crystal. The propagation substrate 3 includes a surface lattice distortion layer 11 in which crystal lattices of the piezoelectric single crystal are distorted.

Abstract: A composite substrate 10 is formed by bonding together a piezoelectric substrate 12 and a support substrate 14 that has a lower thermal expansion coefficient than the piezoelectric substrate. The support substrate 14 is formed by directly bonding together a first substrate 14a and a second substrate 14b at a strength that allows separation with a blade, the first and second substrates being formed of the same material, and a surface of the first substrate 14a is bonded to the piezoelectric substrate 12, the surface being opposite to another surface of the first substrate 14a bonded to the second substrate 14b.

Abstract: A composite substrate 10 is a substrate formed by bonding a piezoelectric substrate 12 and a support substrate 14 having a coefficient of thermal expansion lower than that of the piezoelectric substrate 12. The support substrate 14 has a first surface 14a bonded to the piezoelectric substrate 12 and a second surface 14b opposite to the first surface 14a. The coefficient of thermal expansion of the support substrate 14 is decreased along a thickness direction from the second surface 14b to an intermediate position 14c located between the first surface 14a and the second surface 14b.

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: A metal film is formed on at least a surface of a second substrate composed of ceramic (step c), and a first substrate composed of a group nitride is bonded to the second substrate through the metal film (step d). Since the metal film generally has higher thermal conductivity than oxide films, a composite substrate having high heat dissipation can be produced as compared with a case where the first substrate is bonded to the second substrate through an oxide film. In addition, a step of out diffusion is not required because of nonuse of an oxide film, thereby simplifying the process.