Hitachi Cable, Inc.

Sumitomo Chemical Company, Limited

Sciocs Company Limited

Hitachi Metals, Ltd.

Hitachi, Ltd.

Akira Nomoto

Kenji Shibata

Kazufumi Suenaga

Kazutoshi Watanabe

Fumimasa Horikiri

Hideki Sato

Tomoichi Kamo

Katsuzo Aihara

Masahiro Seido

Junichi Sato

A piezoelectric film element includes a substrate, and a piezoelectric film including an alkali niobate-based perovskite structure expressed in a composition formula (KNa)NbO(0.4&#x2266;x&#x2266;0.7) formed on the substrate, the piezoelectric film including an etching cross section including a tapered inclined portion which is enlarged toward an outside. The inclined portion includes a slope angle made by a slope connecting an upper surface edge and a bottom surface edge of the piezoelectric film and a bottom surface of the piezoelectric film, and the slope angle is not greater than 70&#xb0;.

Piezoelectric film element, and piezoelectric film device including piezoelectric film including alkali niobate-based perovskite structure

A method for manufacturing a piezoelectric film wafer includes an etching step for carrying out a dry etching on a piezoelectric film formed on a substrate by using a gas containing Ar, and a step of changing a rate of the dry etching by detecting a change in an emission peak intensity of Na in emitted ion plasma the piezoelectric film. The piezoelectric film is made of an alkali niobate-based perovskite structure expressed in a composition formula (KNa)NbO(0.4&#x2266;x&#x2266;0.7).

Method for manufacturing a piezoelectric film wafer, piezolelectric film element, and piezoelectric film device

There is provided a piezoelectric film-attached substrate, including a piezoelectric film having a specific thickness, wherein a reflection spectrum shows a relation between a light obtained in such a way that the surface of the piezoelectric film is irradiated with an irradiation light having a specific wavelength and the irradiation light is reflected on the surface of the piezoelectric film, and a light obtained in such a way that the irradiation light is transmitted through the piezoelectric film and is reflected on the surface of the lower electrode, which is the reflection spectrum at least at one point on a center part and an outer peripheral part of the piezoelectric film, and such a reflection spectrum has at least one of the maximum value and the minimum value respectively, wherein the reflectance at least in one maximum value is 0.4 or more.

Piezoelectric film-attached substrate, piezoelectric film element and method of manufacturing the same

A piezoelectric element includes a substrate, and at least a lower electrode layer, a piezoelectric film represented by a general formula of (NaKLi)NbO(0&#x2266;x&#x2266;1, 0&#x2266;y&#x2266;1, 0&#x2266;z&#x2266;0.2, x+y+z=1); and an upper electrode layer successively formed on the substrate. The piezoelectric film has a crystal structure of pseudo-cubic crystal, tetragonal crystal, orthorhombic crystal, monoclinic crystal or rhombohedral crystal, or has a state that at least two of the crystal structures coexist. The piezoelectric film is preferentially oriented to certain specific axes that are not more than two axes of crystal axes in the crystal structures. At least one of domain crystal component of a c-axis orientation domain crystal component and an a-axis orientation domain crystal component exists as the components of the crystal axes oriented.

Piezoelectric element and piezoelectric device

A method for manufacturing a piezoelectric film wafer includes a first processing step for carrying out an ion etching on a KNN piezoelectric film formed on a substrate by using a gas containing Ar, and a second processing step for carrying out a reactive ion etching by using a mixed etching gas containing a fluorine-based reactive gas and Ar after the first processing step.

Method for manufacturing a piezoelectric film wafer, piezoelectric film element, and piezoelectric film device

A manufacturing method of a piezoelectric film element includes forming a piezoelectric film including a lead-free alkali niobate based compound having a perovskite structure represented by a compositional formula of (KNa)NbOon a substrate, and dry-etching the piezoelectric film by using a low-pressure plasma including a fluorine system reactive gas.

Manufacturing method of piezoelectric film element, piezoelectric film element and piezoelectric device

There is provided a piezoelectric film having an alkali niobate-based perovskite structure expressed by a general formula (NaKLi)NbO(0&#x2266;x&#x2266;1, 0&#x2266;y&#x2266;1, 0&#x2266;z&#x2266;0.2, x+y+z=1), wherein the alkali niobate has a crystal structure of a pseudo-cubic crystal, a tetragonal crystal, an orthorhombic crystal, a monoclinic crystal, a rhombohedral crystal, or has a crystal structure of coexistence of them, and when total of K&#x2014;O bonding and K-Metal bonding is set as 100% in a binding state around K-atom of the alkali niobate, a K&#x2014;O bonding ratio is 46.5% or more and a K-Metal bonding ratio is 53.5% or less, wherein the Metal indicates a metal atom included in the piezoelectric film.

Piezoelectric film and method for manufacturing the same, piezoelectric film element and method for manufacturing the same, and piezoelectric film device

Disclosed are a piezoelectric thin film element and a piezoelectric thin film device which have improved piezoelectric properties and high performance and can be produced in improved yields. The piezoelectric thin film element () comprises: a substrate (), and a piezoelectric thin film () which is arranged on the substrate (), has at least one crystal structure represented by general formula (NaKLi)NbO(0&#x2266;x&#x2266;1, 0&#x2266;y&#x2266;1, 0&#x2266;z&#x2266;0.2, x+y+z=1) and selected from the group consisting of pseudo-cubic crystal, a hexagonal crystal, and an orthorhombic crystal, and contains an inert gas element at a ratio of 80 ppm or less by mass.

Piezoelectric thin film element, and piezoelectric thin film device

A piezoelectric film element is provided, which is capable of improving piezoelectric properties, having on a substrate at least a lower electrode, a lead-free piezoelectric film, and an upper electrode, wherein at least the lower electrode out of the lower electrode and the upper electrode has a crystal structure of a cubic crystal system, a tetragonal crystal system, an orthorhombic crystal system, a hexagonal crystal system, a monoclinic crystal system, a triclinic crystal system, a trigonal crystal system, or has a composition in which one of these crystals exists or two or more of them coexist, and crystal axes of the crystal structure are preferentially oriented to a specific axis smaller than or equal to two axes of these crystals, and a ratio c/a' is set in a range of 0.992 or more and 0.999 or less, which is the ratio of a crystal lattice spacing c in a direction of a normal line to the substrate surface, with respect to a crystal lattice spacing a&#x2032; whose inclination angle from the substrate surface is in a range of 10&#xb0; or more and 30&#xb0; or less.

Piezoelectric film element using (Na,K,Li)NbO3

To provide a piezoelectric thin film on a substrate, having an alkali-niobium oxide-based perovskite structure expressed by a composition formula (KNa)NbO, wherein the composition ratio x of the piezoelectric thin film expressed by (KNa)NbOis in a range of 0.4&#x2266;x&#x2266;0.7, and a half width of a rocking curve of (001) plane by X-ray diffraction measurement is in a range of 0.5&#xb0; or more and 2.5&#xb0; or less.

Piezoelectric thin film element and piezoelectric thin film device using a piezoelectric thin film of alkali-niobium oxide series

To provide a piezoelectric thin film element comprising: a piezoelectric thin film on a substrate, having an alkali-niobium oxide-based perovskite structure expressed by a composition formula (KNa)NbO, wherein composition ratios x, y of the piezoelectric thin film expressed by (KNa)NbOare in a range of 0.4&#x2266;x&#x2266;0.7 and 0.7&#x2266;y&#x2266;0.94.

Piezoelectric thin film having a high piezoelectric constant and a low leak current

There is provided a piezoelectric thin film element, comprising: a substrate; and a piezoelectric thin filmhaving an alkali niobium oxide-based perovskite structure represented by a composition formula (KNa)NbOprovided on the substrate, wherein a carbon concentration of the piezoelectric thin filmis 2&#xd7;10/cmor less, or a hydrogen concentration of the piezoelectric thin filmis 4&#xd7;10/cmor less.

Piezoelectric thin-film element and piezoelectric thin-film device

A piezoelectric thin film element is provided, including on a substrate: a piezoelectric thin film expressed by a general formula (NaKLi)NbO(0&#x2266;x&#x2266;1, 0&#x2266;y&#x2266;1, 0&#x2266;z&#x2266;0.2, x+y+z=1); and an upper electrode laminated thereon, wherein the piezoelectric thin film has a crystal structure of any one of a pseudo-cubic crystal, a tetragonal crystal, or an orthorhombic crystal, or has a crystal structure of coexistence of at least two of the pseudo-cubic crystal, the tetragonal crystal, or the orthorhombic crystal, and in such crystal structures, there is a coexistence of (001) oriented crystal grains oriented in (001) direction, and (111) oriented crystal grains oriented in (111) direction, with an angle formed by at least one of the crystal axes of the crystal grains and a normal line of the substrate surface set to be in a range of 0&#xb0; to 10&#xb0;.

Piezoelectric thin film element and piezoelectric thin film device including the same

A piezoelectric thin film element, comprising a piezoelectric thin film lamination with at least a lower electrode, a piezoelectric thin film represented by a general formula (NaKLi)NbO(0&#x2266;x 1&#x2266;, 0&#x2266;y&#x2266;1, 0&#x2266;z&#x2266;0.2, x+y+z=1), and an upper electrode disposed on a substrate, wherein the piezoelectric thin film has a crystal structure of a pseudo-cubic crystal or a tetragonal crystal or an orthorhombic crystal, or has a composition in which one of these crystals exists or at least two or more of them coexist, and is preferentially oriented to a specific axis smaller than or equal to two axes of these crystals, and in the ratio of component (001) to component (111), volume fraction of the component (001) falls within a range of 60% or more and 100% or less, and the volume fraction of the component (111) falls within a range of 0% or more and 40% or less, in a case that the total of the component (001) and the component (111) is set to be 100%.

To provide a piezoelectric thin film element capable of improving piezoelectric characteristics and realize a piezoelectric thin film device with high performance and high reliability, comprising: a substrate; and a piezoelectric thin film formed on the substrate by a sputtering method, with perovskite oxide expressed by (NaKLi)NbO(0&#x2266;x&#x2266;1, 0&#x2266;y&#x2266;1, 0&#x2266;z&#x2266;0, 2, x+y+z=1) as a main phase, wherein an absolute value of an internal stress of the piezoelectric thin film is 1.6 GPa or less.

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Kasumigaura, Japan

Akira Nomoto