Ngk Insulators, Inc.

Ngk Ceramic Device Co., Ltd.

Ryosuke Hattori

Tomoyoshi Tai

Yuji Hori

Takahiro Yamadera

Kengo Suzuki

Keiichiro Asai

Yasunori Iwasaki

Yudai Uno

Jungo Kondo

Masahiko Namerikawa

Shoichiro Yamaguchi

Akiyoshi Ide

Sugio Miyazawa

Tatsuro Takagaki

Hidetsugu Shimokata

There is provided a composite substrate in which peeling is significantly suppressed, light propagation loss is small when used as an electro-optical element, and high-speed and low-voltage drive is possible, and which can achieve an extremely thin electro-optical element capable of maintaining excellent reliability even under a severe high-temperature environment. A composite substrate for an electro-optical element according to an embodiment of the present invention includes: an electro-optical crystal substrate having an electro-optical effect; a first high dielectric layer; a second high dielectric layer; and a support substrate in the stated order. The first high dielectric layer and the second high dielectric layer are directly joined to each other, and an amorphous layer is formed at a joining interface between the first high dielectric layer and the second high dielectric layer.

Composite substrate for electro-optical element

A bonded body includes a supporting substrate, piezoelectric material substrate and a multilayer film between the supporting substrate and piezoelectric material substrate. The multilayer film includes a lamination structure having a first layer, second layer, third layer and fourth layer in that order. The first layer and third layer are composed of silicon oxides, and the second layer and fourth layer are composed of metal oxides. The refractive index of the second layer is higher than the refractive index of the first layer and refractive index of the third layer. The refractive index of the second layer is different from the refractive index of the fourth layer.

Bonded body and acoustic wave element

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 is on the intermediate layer and is composed of one or more materials selected from the group consisting of tantalum pentoxide, niobium pentoxide, titanium oxide, mullite, alumina, and a high resistance silicon and hafnium oxide. A supporting body is composed of a polycrystalline ceramic and is bonded to the bonding layer by direct bonding, and an electrode is on the piezoelectric material substrate.

Acoustic wave devices and a method of producing the same

A method of producing periodic polarization inversion structures requires the provision of first electrode piece part-arrays, each having electrode piece parts on a first main face of a ferroelectric crystal substrate. A voltage is applied on the first electrode piece part-arrays to form first periodic polarization inversion structures. Second electrode piece part-arrays are provided, each having electrode piece parts between the adjacent plural first periodic polarization inversion structures. A voltage is applied on the second electrode piece part-arrays to form second polarization inversion structures.

Method of producing periodic polarization inversion structures

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.

Method of producing a composite substrate

A bonded body includes a supporting substrate; a piezoelectric single crystal 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, and the amorphous layer contains one or more metal atoms selected from the group consisting of niobium and tantalum, an atom constituting the supporting substrate, and an argon atom. A concentration of the argon atom in a central part of the amorphous layer is higher than a concentration of the argon atom in a peripheral part of the amorphous layer.

Joined body of piezoelectric single-crystal substrate and support substrate

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 %.

Joined body of piezoelectric material substrate and support substrate

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.

Composite substrate, elastic wave device, and method for producing elastic wave device

In the composite substrate, the piezoelectric substrateand the support substrateare bonded by direct bonding using an ion beam. One surface of the piezoelectric substrateis a negatively-polarized surfaceand another surface of the piezoelectric substrateis a positively-polarized surface. An etching rate at which the negatively-polarized surfaceis etched with a strong acid may be higher than an etching rate at which the positively-polarized surfaceis etched with the strong acid. The positively-polarized surfaceof the piezoelectric substrateis directly bonded to the support substrate. The negatively-polarized surfaceof the piezoelectric substratemay be etched with the strong acid.

Composite substrate

A composite substrateis formed by bonding together a piezoelectric substrateand a support substratethat has a lower thermal expansion coefficient than the piezoelectric substrate. The support substrateis formed by directly bonding together a first substrateand a second substrateat 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 substrateis bonded to the piezoelectric substrate, the surface being opposite to another surface of the first substratebonded to the second substrate

A composite substrateincludes a semiconductor substrateand an insulating support substratethat are laminated together. The support substrateincludes first and second substratesandmade of the same material and bonded together with a strength that allows the first and second substratesandto be separated from each other with a blade. The semiconductor substrateis laminated on a surface of the first substrateopposite a surface thereof bonded to the second substrate

Composite substrate, semiconductor device, and method for manufacturing semiconductor device

A composite substrate according to the present invention includes a piezoelectric substrate that is a single-crystal lithium tantalate or lithium niobate substrate, a support substrate that is a single-crystal silicon substrate, and an amorphous layer joining together the piezoelectric substrate and the support substrate. The amorphous layer contains 3 to 14 atomic percent of argon. The amorphous layer includes, in order from the piezoelectric substrate toward the composite substrate, a first layer, a second layer, and a third layer. The first layer contains a larger amount of a constituent element (such as tantalum) of the piezoelectric substrate than the second and third layers. The third layer contains a larger amount of a constituent element (silicon) of the support substrate than the first and second layers. The second layer contains a larger amount of argon than the first and third layers.

The present invention provides a composite substrate comprising a piezoelectric substrate that is a single-crystal lithium tantalate or lithium niobate substrate, a support substrate that is a single-crystal silicon substrate, and an amorphous layer containing argon and joining together the piezoelectric substrate and the support substrate. The amorphous layer includes, in order from the piezoelectric substrate toward the composite substrate, a first layer, a second layer, and a third layer. The first layer contains a larger amount of a constituent element of the piezoelectric substrate than the second and third layers, the third layer contains a larger amount of a constituent element of the support substrate than the first and second layers, and the second layer contains a larger amount of argon than the first and third layers.

Composite substrate and method for manufacturing the same

In a composite substrate, a bonding surfaceof a piezoelectric substrateis an irregular surface which is partially planarized. The irregular surface which is partially planarized includes a plurality of protrusionseach having a flat portionon the tip thereof. The piezoelectric substrateand the supporting substrateare directly bonded to each other at the flat portionsBy forming the bonding surfaceinto an irregular surface (rough surface) and providing flat portionsat the same time, it is possible to secure a sufficient contact area between the piezoelectric substrateand the supporting substrate. Accordingly, in the composite substrate in which the piezoelectric substrateand the supporting substrateare bonded to each other, the bonding surfacecan be roughened and direct bonding can be performed.

Growing community of inventors

Ichinomiya, Japan

Ryosuke Hattori