WO2015174265A1 - 強誘電体薄膜、圧電薄膜付き基板、圧電アクチュエータ、インクジェットヘッドおよびインクジェットプリンタ - Google Patents
強誘電体薄膜、圧電薄膜付き基板、圧電アクチュエータ、インクジェットヘッドおよびインクジェットプリンタ Download PDFInfo
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- WO2015174265A1 WO2015174265A1 PCT/JP2015/062720 JP2015062720W WO2015174265A1 WO 2015174265 A1 WO2015174265 A1 WO 2015174265A1 JP 2015062720 W JP2015062720 W JP 2015062720W WO 2015174265 A1 WO2015174265 A1 WO 2015174265A1
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- 239000010409 thin film Substances 0.000 title claims abstract description 188
- 239000000758 substrate Substances 0.000 title claims description 135
- 239000010408 film Substances 0.000 claims abstract description 268
- 239000010936 titanium Substances 0.000 claims abstract description 104
- 239000010955 niobium Substances 0.000 claims abstract description 78
- 229910052726 zirconium Inorganic materials 0.000 claims abstract description 42
- 229910052451 lead zirconate titanate Inorganic materials 0.000 claims abstract description 39
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 39
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- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims abstract description 26
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 claims abstract description 23
- HFGPZNIAWCZYJU-UHFFFAOYSA-N lead zirconate titanate Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ti+4].[Zr+4].[Pb+2] HFGPZNIAWCZYJU-UHFFFAOYSA-N 0.000 claims abstract description 10
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- 239000010703 silicon Substances 0.000 claims description 7
- 229910052746 lanthanum Inorganic materials 0.000 claims description 4
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- HTXDPTMKBJXEOW-UHFFFAOYSA-N dioxoiridium Chemical compound O=[Ir]=O HTXDPTMKBJXEOW-UHFFFAOYSA-N 0.000 description 1
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- VSZWPYCFIRKVQL-UHFFFAOYSA-N selanylidenegallium;selenium Chemical compound [Se].[Se]=[Ga].[Se]=[Ga] VSZWPYCFIRKVQL-UHFFFAOYSA-N 0.000 description 1
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Images
Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
- B41J2/01—Ink jet
- B41J2/135—Nozzles
- B41J2/14—Structure thereof only for on-demand ink jet heads
- B41J2/14201—Structure of print heads with piezoelectric elements
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
- B41J2/01—Ink jet
- B41J2/135—Nozzles
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- B41J2/1607—Production of print heads with piezoelectric elements
- B41J2/161—Production of print heads with piezoelectric elements of film type, deformed by bending and disposed on a diaphragm
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- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
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- B41J2/135—Nozzles
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- B41J2/1621—Manufacturing processes
- B41J2/1623—Manufacturing processes bonding and adhesion
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- B—PERFORMING OPERATIONS; TRANSPORTING
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- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
- B41J2/01—Ink jet
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- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
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- B—PERFORMING OPERATIONS; TRANSPORTING
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- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
- B41J2/01—Ink jet
- B41J2/135—Nozzles
- B41J2/16—Production of nozzles
- B41J2/1621—Manufacturing processes
- B41J2/1632—Manufacturing processes machining
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- B—PERFORMING OPERATIONS; TRANSPORTING
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- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
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- B41J2/1621—Manufacturing processes
- B41J2/164—Manufacturing processes thin film formation
- B41J2/1642—Manufacturing processes thin film formation thin film formation by CVD [chemical vapor deposition]
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
- B41J2/01—Ink jet
- B41J2/135—Nozzles
- B41J2/16—Production of nozzles
- B41J2/1621—Manufacturing processes
- B41J2/164—Manufacturing processes thin film formation
- B41J2/1645—Manufacturing processes thin film formation thin film formation by spincoating
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
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- B41J2/164—Manufacturing processes thin film formation
- B41J2/1646—Manufacturing processes thin film formation thin film formation by sputtering
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N30/00—Piezoelectric or electrostrictive devices
- H10N30/20—Piezoelectric or electrostrictive devices with electrical input and mechanical output, e.g. functioning as actuators or vibrators
- H10N30/204—Piezoelectric or electrostrictive devices with electrical input and mechanical output, e.g. functioning as actuators or vibrators using bending displacement, e.g. unimorph, bimorph or multimorph cantilever or membrane benders
- H10N30/2047—Membrane type
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N30/00—Piezoelectric or electrostrictive devices
- H10N30/704—Piezoelectric or electrostrictive devices based on piezoelectric or electrostrictive films or coatings
- H10N30/706—Piezoelectric or electrostrictive devices based on piezoelectric or electrostrictive films or coatings characterised by the underlying bases, e.g. substrates
- H10N30/708—Intermediate layers, e.g. barrier, adhesion or growth control buffer layers
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N30/00—Piezoelectric or electrostrictive devices
- H10N30/80—Constructional details
- H10N30/85—Piezoelectric or electrostrictive active materials
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N30/00—Piezoelectric or electrostrictive devices
- H10N30/80—Constructional details
- H10N30/85—Piezoelectric or electrostrictive active materials
- H10N30/853—Ceramic compositions
- H10N30/8548—Lead-based oxides
- H10N30/8554—Lead-zirconium titanate [PZT] based
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2202/00—Embodiments of or processes related to ink-jet or thermal heads
- B41J2202/01—Embodiments of or processes related to ink-jet heads
- B41J2202/03—Specific materials used
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N30/00—Piezoelectric or electrostrictive devices
- H10N30/01—Manufacture or treatment
- H10N30/07—Forming of piezoelectric or electrostrictive parts or bodies on an electrical element or another base
- H10N30/074—Forming of piezoelectric or electrostrictive parts or bodies on an electrical element or another base by depositing piezoelectric or electrostrictive layers, e.g. aerosol or screen printing
- H10N30/076—Forming of piezoelectric or electrostrictive parts or bodies on an electrical element or another base by depositing piezoelectric or electrostrictive layers, e.g. aerosol or screen printing by vapour phase deposition
Definitions
- the present invention relates to a ferroelectric thin film made of lead zirconate titanate niobate (PNZT), a substrate with a piezoelectric thin film provided with the ferroelectric thin film, a piezoelectric actuator, an ink jet head, and an ink jet printer.
- PTZT lead zirconate titanate niobate
- piezoelectric materials such as lead zirconate titanate (PZT) have been used as electromechanical conversion elements such as drive elements and sensors.
- MEMS Micro Electro Mechanical Systems
- Si silicon
- high-precision processing using semiconductor process technology such as film formation and photolithography can be performed, and miniaturization and high density can be realized.
- the elements can be collectively processed on a large-area wafer, the cost can be reduced.
- there is an advantage that the conversion efficiency of mechanical electricity is improved and the characteristics of the drive element and the sensitivity of the sensor are improved.
- An inkjet printer is known as an application example of a device using such a MEMS element.
- a two-dimensional image is recorded on a recording medium by controlling the ejection of ink while moving an inkjet head having a plurality of channels for ejecting liquid ink relative to the recording medium such as paper or cloth. Formed.
- the ink can be ejected by using a pressure actuator (piezoelectric, electrostatic, thermal deformation, etc.) or by generating bubbles in the ink inside the tube by heat.
- a pressure actuator piezoelectric, electrostatic, thermal deformation, etc.
- the piezoelectric actuator has advantages such as high output, modulation, high responsiveness, and choice of ink, and has been frequently used in recent years.
- it is suitable to use an inkjet head using a thin film piezoelectric body.
- the ink jet head is required to be capable of ejecting ink having a high viscosity of 10 cp (0.01 Pa ⁇ s) or more.
- the piezoelectric thin film (ferroelectric thin film) requires high piezoelectric characteristics (piezoelectric constant d 31 ) and displacement generation force (film thickness of 1 ⁇ m or more).
- methods for forming a piezoelectric material such as PZT on a substrate such as Si include chemical film formation methods such as CVD (Chemical Vapor Deposition), physical methods such as sputtering and ion plating, and sol-gel.
- CVD Chemical Vapor Deposition
- physical methods such as sputtering and ion plating
- sol-gel sol-gel
- the growth method in the liquid phase such as the method is known.
- the upper limit of the thickness of the thin film obtained by these manufacturing methods is about 10 ⁇ m. If the film thickness exceeds that, cracks and film peeling occur, and desired characteristics cannot be obtained.
- the deposited PZT exhibits a good piezoelectric effect when the crystal has the perovskite structure shown in FIG.
- the perovskite structure ideally has a cubic unit cell, and is arranged at each vertex of the cubic A, metal B arranged at the body center, and arranged at each face center of the cubic crystal. It is an ABO 3 type crystal structure composed of oxygen O. Crystals having a perovskite structure include tetragonal crystals, orthorhombic crystals, rhombohedral crystals and the like in which cubic crystals are distorted.
- the PZT thin film formed on the electrode on the Si substrate becomes a polycrystal composed of an aggregate of a plurality of crystals due to a difference in lattice constant from the crystal of the electrode.
- this polycrystal is composed of granular crystals (granular crystals) with a particle size of several hundreds of nanometers, or a width of several hundreds of nanometers and one elongated crystal grain in the film thickness direction.
- a certain columnar crystal is gathered together.
- columnar crystals it is known that the more the crystals grown on the same crystal plane in the film thickness direction (the higher the orientation), the higher the piezoelectric properties of the film.
- One method of improving the piezoelectric characteristics is to improve the relative dielectric constant and the piezoelectric characteristics by adding impurities to the piezoelectric body so that non-180 ° domain rotation of the domain can easily occur.
- zirconium (Zr) or titanium (Ti) located at the B site is replaced with niobium (Nb), which is an element having a higher valence than that of one.
- Nb niobium
- Nb added is about several percent in terms of molar ratio, and if it is attempted to add more than that, it cannot be fired properly due to the difference in valence with the original PZT. A piezoelectric element could not be obtained.
- Patent Document 1 shows that when a PNZT film is formed by a sol-gel method, it is possible to add 10 mol% or more of Nb by adding a sintering aid such as Si together with Nb.
- Patent Document 2 PNZT is formed in a non-equilibrium state by a sputtering method so that Nb can be added in an amount of 10 mol% or more without using a sintering aid.
- a PNZT film excellent in ferroelectricity can be obtained, and a high piezoelectric constant d 31 can be obtained with a composition of Pb 1.12 Zr 0.43 Ti 0.44 Nb 0.13 O 3. It is disclosed.
- JP 2008-270704 A see claim 1, paragraphs [0010], [0011], [0014], [0022], [0023], [0085] to [0092], [0102], etc.
- Japanese Patent Laid-Open No. 2008-081802 see claims 1, 6, 7, paragraphs [0007], [0026], [0027], [0086] to [0093], etc.
- the ratio of Zr in the PNZT film affects not only the piezoelectric characteristics but also the withstand voltage. Therefore, it is desirable to appropriately set the range of the Zr ratio in the PNZT film from the viewpoint of improving durability.
- Patent Document 2 does not describe any film stress.
- Patent Document 3 mentions stress in the temperature-falling process during film formation or after film formation, but does not describe any adjustment of film stress to obtain high piezoelectric characteristics with a composition unique to the thin film. .
- the present invention has been made to solve the above-mentioned problems, and the purpose thereof is to appropriately define the range of the composition ratio of PNZT, and appropriately define the range of film stress as necessary.
- a ferroelectric thin film capable of realizing high piezoelectric characteristics with a composition specific to a thin film of PNZT, and capable of improving withstand voltage to improve durability, a substrate with a piezoelectric thin film including the ferroelectric thin film, and a piezoelectric actuator
- An inkjet head and an inkjet printer are provided.
- a ferroelectric thin film according to one aspect of the present invention is a ferroelectric thin film made of lead zirconate titanate niobate, wherein the ratio a of lead to the sum of zirconium, titanium, and niobium is 100% in molar ratio.
- the ratio b of niobium to the sum of zirconium, titanium, and niobium is 10% or more and 20% or less in terms of molar ratio
- the ratio c of zirconium to the sum of zirconium and titanium is 52% or more in terms of mole ratio. It is 59% or less, and the film stress is 100 MPa or more and 250 MPa or less.
- a ferroelectric thin film according to another aspect of the present invention is a ferroelectric thin film made of lead zirconate titanate niobate, wherein the ratio a of lead to the sum of zirconium, titanium, and niobium is 100 in terms of molar ratio.
- the ratio b of niobium to the sum of zirconium, titanium, and niobium is 10% to 20% in terms of molar ratio
- the ratio c of zirconium to the sum of zirconium and titanium is molar ratio. It is 54% or more and 59% or less.
- FIG. 1 is an explanatory diagram illustrating a schematic configuration of an inkjet printer according to an embodiment of the present invention.
- FIG. It is a top view which shows the schematic structure of the actuator of the inkjet head with which the said inkjet printer is provided.
- FIG. 2B is a cross-sectional view taken along line A-A ′ in the plan view of FIG. 2A. It is sectional drawing of the said inkjet head. It is sectional drawing which shows the manufacturing process of the said inkjet head. It is sectional drawing which shows the other structure of the said inkjet head. It is sectional drawing which shows the manufacturing process of the board
- the numerical value range includes the values of the lower limit A and the upper limit B.
- FIG. 1 is an explanatory diagram illustrating a schematic configuration of an inkjet printer 1 according to the present embodiment.
- the ink jet printer 1 is a so-called line head type ink jet recording apparatus in which an ink jet head 21 is provided in a line shape in the width direction of a recording medium in the ink jet head unit 2.
- the ink jet printer 1 includes an ink jet head unit 2, a feed roll 3, a take-up roll 4, two back rolls 5 and 5, an intermediate tank 6, a liquid feed pump 7, a storage tank 8, and a fixing tank. And a mechanism 9.
- the inkjet head unit 2 ejects ink from the inkjet head 21 toward the recording medium P to perform image formation (drawing) based on image data, and is disposed in the vicinity of one back roll 5. Details of the inkjet head 21 will be described later.
- the feeding roll 3, the take-up roll 4 and the back rolls 5 are members each having a cylindrical shape that can rotate around its axis.
- the feeding roll 3 is a roll that feeds the long recording medium P wound around the circumferential surface toward the position facing the inkjet head unit 2.
- the feeding roll 3 is rotated by driving means (not shown) such as a motor, thereby feeding the recording medium P in the X direction in FIG.
- the take-up roll 4 is taken out from the take-out roll 3 and takes up the recording medium P on which the ink is ejected by the inkjet head unit 2 around the circumferential surface.
- Each back roll 5 is disposed between the feed roll 3 and the take-up roll 4.
- One back roll 5 located on the upstream side in the conveyance direction of the recording medium P is opposed to the inkjet head unit 2 while winding the recording medium P fed by the feeding roll 3 around and supporting the recording medium P.
- Transport toward The other back roll 5 conveys the recording medium P from a position facing the inkjet head unit 2 toward the take-up roll 4 while being wound around and supported by a part of the peripheral surface.
- the intermediate tank 6 temporarily stores the ink supplied from the storage tank 8.
- the intermediate tank 6 is connected to a plurality of ink tubes 10, adjusts the back pressure of ink in each inkjet head 21, and supplies ink to each inkjet head 21.
- the liquid feed pump 7 supplies the ink stored in the storage tank 8 to the intermediate tank 6, and is arranged in the middle of the supply pipe 11.
- the ink stored in the storage tank 8 is pumped up by the liquid feed pump 7 and supplied to the intermediate tank 6 through the supply pipe 11.
- the fixing mechanism 9 fixes the ink ejected to the recording medium P by the inkjet head unit 2 on the recording medium P.
- the fixing mechanism 9 includes a heater for heat-fixing the discharged ink on the recording medium P, a UV lamp for curing the ink by irradiating the discharged ink with UV (ultraviolet light), and the like. Yes.
- the recording medium P fed from the feeding roll 3 is conveyed to the position facing the inkjet head unit 2 by the back roll 5, and ink is ejected from the inkjet head unit 2 to the recording medium P. Thereafter, the ink ejected onto the recording medium P is fixed by the fixing mechanism 9, and the recording medium P after ink fixing is taken up by the take-up roll 4.
- the line head type inkjet printer 1 ink is ejected while the recording medium P is conveyed while the inkjet head unit 2 is stationary, and an image is formed on the recording medium P.
- the ink jet printer 1 may be configured to form an image on a recording medium by a serial head method.
- the serial head method is a method of forming an image by ejecting ink by moving an inkjet head in a direction orthogonal to the transport direction while transporting a recording medium.
- FIG. 2A is a plan view showing a schematic configuration of an actuator 21a (substrate with piezoelectric thin film, piezoelectric actuator) of the inkjet head 21, and
- FIG. 2B is a cross-sectional view taken along the line AA ′ in the plan view.
- FIG. 3 is a cross-sectional view of the inkjet head 21 formed by bonding the nozzle substrate 31 to the actuator 21a of FIG. 2B.
- the inkjet head 21 has a thermal oxide film 23, a lower electrode 24, a piezoelectric thin film 25, and an upper electrode 26 in this order on a substrate 22 having a plurality of pressure chambers 22a (openings).
- the substrate 22 is composed of a semiconductor substrate made of a single crystal Si (silicon) alone having a thickness of, for example, about 300 to 750 ⁇ m, or an SOI (Silicon On Insulator) substrate.
- FIG. 2B shows a case where the substrate 22 is configured by an SOI substrate.
- the SOI substrate is obtained by bonding two Si substrates through an oxide film.
- the upper wall of the pressure chamber 22a in the substrate 22 (the wall positioned on the piezoelectric thin film formation side with respect to the pressure chamber 22a) constitutes a vibration plate 22b serving as a driven film. Displacement (vibration) applies pressure to the ink in the pressure chamber 22a.
- the thermal oxide film 23 is made of, for example, SiO 2 (silicon oxide) having a thickness of about 0.1 ⁇ m, and is formed for the purpose of protecting and insulating the substrate 22.
- the lower electrode 24 is a common electrode provided in common to the plurality of pressure chambers 22a, and is configured by laminating a Ti (titanium) layer and a Pt (platinum) layer.
- the Ti layer is formed in order to improve the adhesion between the thermal oxide film 23 and the Pt layer.
- the thickness of the Ti layer is, for example, about 0.02 ⁇ m, and the thickness of the Pt layer is, for example, about 0.1 ⁇ m.
- the piezoelectric thin film 25 is composed of a ferroelectric thin film made of PNZT (lead zirconate titanate niobate) obtained by adding Nb (niobium) to PZT, for example, and is provided corresponding to each pressure chamber 22a.
- the film thickness of the piezoelectric thin film 25 is, for example, not less than 1 ⁇ m and not more than 10 ⁇ m.
- the ratio a of Pb (lead) to the sum of Zr (zirconium), Ti, and Nb is 100% or more in terms of molar ratio, and Zr, Ti, Nb,
- the ratio b of Nb with respect to the sum of the ratios is 10% or more and 20% or less in terms of a molar ratio
- the ratio c of Zr to the sum of Zr and Ti is 52% or more and 59% or less in terms of mole ratios
- the film stress is 100 MPa or more and 250 MPa or less.
- the ratio a is 100% to 105% in molar ratio
- the ratio b is 10% to 20% in molar ratio
- the ratio c is 54% to 59% in molar ratio.
- the upper electrode 26 is an individual electrode provided corresponding to each pressure chamber 22a, and is configured by laminating a Ti layer and a Pt layer.
- the Ti layer is formed in order to improve the adhesion between the piezoelectric thin film 25 and the Pt layer.
- the thickness of the Ti layer is, for example, about 0.02 ⁇ m, and the thickness of the Pt layer is, for example, about 0.1 to 0.2 ⁇ m.
- the upper electrode 26 is provided so as to sandwich the piezoelectric thin film 25 from the film thickness direction with the lower electrode 24. Note that a layer made of gold (Au) may be formed instead of the Pt layer.
- the lower electrode 24, the piezoelectric thin film 25, and the upper electrode 26 constitute a thin film piezoelectric element 27 for discharging ink in the pressure chamber 22a to the outside.
- the thin film piezoelectric element 27 is driven based on a voltage (drive signal) applied from the drive circuit 28 to the lower electrode 24 and the upper electrode 26.
- the ink jet head 21 is formed by arranging the thin film piezoelectric element 27 and the pressure chamber 22a vertically and horizontally.
- a nozzle substrate 31 is bonded to the opposite side of the pressure chamber 22a from the diaphragm 22b.
- the nozzle substrate 31 is formed with ejection holes (nozzle holes) 31a for ejecting ink stored in the pressure chambers 22a to the outside as ink droplets.
- Ink supplied from the intermediate tank 6 is stored in the pressure chamber 22a.
- the piezoelectric thin film 25 when a voltage is applied from the drive circuit 28 to the lower electrode 24 and the upper electrode 26, the piezoelectric thin film 25 is in a direction perpendicular to the thickness direction (substrate) according to the potential difference between the lower electrode 24 and the upper electrode 26. (Direction parallel to the surface of 22). Then, due to the difference in length between the piezoelectric thin film 25 and the diaphragm 22b, a curvature is generated in the diaphragm 22b, and the diaphragm 22b is displaced (curved or vibrated) in the thickness direction.
- inkjet head 21a of the present embodiment since the piezoelectric characteristics of the piezoelectric thin film 25 of the piezoelectric actuator 21a are high, ink ejection using high-viscosity ink is possible, which is advantageous for high-speed and high-definition drawing. Ink jet printer 1 can be realized.
- the piezoelectric actuator 21a substrate with a piezoelectric thin film
- another upper electrode 26 is formed on the opposite side of the piezoelectric thin film 25 from the lower electrode 24. Therefore, the piezoelectric thin film 25 is applied according to the applied voltage. Can be expanded and contracted reliably.
- FIG. 4 is a cross-sectional view showing the manufacturing process of the inkjet head 21.
- the substrate 22 is prepared.
- crystalline silicon (Si) often used in MEMS (Micro Electro Mechanical Systems) can be used.
- MEMS Micro Electro Mechanical Systems
- two Si substrates 22 c and 22 d are joined via an oxide film 22 e.
- An SOI structure is used.
- the substrate 22 is put in a heating furnace and held at about 1500 ° C. for a predetermined time, and thermal oxide films 23a and 23b made of SiO 2 are formed on the surfaces of the Si substrates 22c and 22d, respectively.
- thermal oxide films 23a and 23b made of SiO 2 are formed on the surfaces of the Si substrates 22c and 22d, respectively.
- Ti and Pt layers are sequentially formed on one thermal oxide film 23a by a sputtering method to form the lower electrode 24.
- the substrate 22 is reheated to about 600 ° C., and a PNZT layer 25a serving as a displacement film is formed by sputtering.
- a photosensitive resin 35 is applied to the substrate 22 by a spin coating method, and unnecessary portions of the photosensitive resin 35 are removed by exposure and etching through a mask, and the shape of the piezoelectric thin film 25 to be formed is transferred. .
- the shape of the layer 25 a is processed using a reactive ion etching method to form the piezoelectric thin film 25.
- Ti and Pt layers are sequentially formed by sputtering on the lower electrode 24 so as to cover the piezoelectric thin film 25 to form a layer 26a.
- a photosensitive resin 36 is applied onto the layer 26a by a spin coating method, and unnecessary portions of the photosensitive resin 36 are removed by exposure and etching through a mask, and the shape of the upper electrode 26 to be formed is transferred. To do.
- the shape of the layer 26a is processed using a reactive ion etching method to form the upper electrode 26.
- a photosensitive resin 37 is applied to the back surface (thermal oxide film 23b side) of the substrate 22 by a spin coat method, and unnecessary portions of the photosensitive resin 37 are removed by exposure and etching through a mask.
- the shape of the pressure chamber 22a to be formed is transferred.
- the substrate 22 is removed using a reactive ion etching method to form a pressure chamber 22a to be an actuator 21a.
- the substrate 22 of the actuator 21a and the nozzle substrate 31 having the discharge holes 31a are bonded using an adhesive or the like. Thereby, the inkjet head 21 is completed.
- an intermediate glass having a through hole at a position corresponding to the discharge hole 31a is used, the thermal oxide film 23b is removed, and the substrate 22 and the intermediate glass, and the intermediate glass and the nozzle substrate 31 are anodic bonded to each other. Also good. In this case, the three parties (substrate 22, intermediate glass, nozzle substrate 31) can be joined without using an adhesive.
- the electrode material constituting the lower electrode 24 is not limited to the above-described Pt, and for example, Au (gold), Ir (iridium), IrO 2 (iridium oxide), RuO 2 (ruthenium oxide). ), LaNiO 3 (lanthanum nickelate), SrRuO 3 (strontium ruthenate) or a metal, or a combination thereof.
- FIG. 5 is a cross-sectional view showing another configuration of the inkjet head 21.
- a seed layer 29 may be provided between the lower electrode 24 and the piezoelectric thin film 25.
- the seed layer 29 is an orientation control layer for controlling the crystal orientation of the piezoelectric thin film 25.
- Such seed layer 29 is made of, for example, PLT (lead lanthanum titanate), but may be made of LaNiO 3 or SrRuO 3 .
- FIG. 6 is a cross-sectional view showing a manufacturing process of a substrate with a piezoelectric thin film in which a piezoelectric thin film is formed on the substrate.
- a thermal oxide film 42 of about 100 nm was formed on a substrate 41 made of a single crystal Si wafer having a thickness of about 400 ⁇ m. Standard values such as a wafer thickness of 300 ⁇ m to 725 ⁇ m and a diameter of 3 to 8 inches may be used.
- the thermal oxide film 42 can be formed by exposing the Si wafer to a high temperature of about 1200 ° C. in an oxygen atmosphere using a wet oxidation furnace.
- the substrate 41 and the thermal oxide film 42 correspond to the substrate 22 and the thermal oxide film 23 in FIG. 2B, respectively.
- a Ti layer having a thickness of about 10 nm was formed as an adhesion layer by sputtering, and a Pt layer was further formed to have a thickness of about 150 nm to form the lower electrode 43.
- the sputtering conditions of Ti at this time were Ar flow rate: 20 sccm, pressure: 0.9 Pa, RF power applied to the target: 100 W, and substrate temperature: 400 ° C.
- the sputtering conditions for Pt were Ar flow rate: 20 sccm, pressure: 0.8 Pa, RF power applied to the target: 150 W, and substrate temperature: 400 ° C.
- the lower electrode 43 corresponds to the lower electrode 24 in FIG. 2B.
- the film formation of Ti and Pt was performed using a binary sputtering apparatus having two targets of Ti and Pt in the chamber. Thereby, the laminated structure of the Pt / Ti / Si substrate can be continuously formed without taking vacuum.
- the adhesion layer may be made of TiOx instead of Ti.
- TiOx can be formed by reactive sputtering by introducing oxygen during Ti sputtering, or by heating at about 700 ° C. in an oxygen atmosphere in an RTA (Rapid Thermal Annealing) furnace after Ti film formation. It can also be formed.
- a PNZT film having a thickness of about 4 ⁇ m was formed on Pt to form a piezoelectric thin film 44 made of PNZT.
- the substrate 40 with the piezoelectric thin film in which the piezoelectric thin film 44 is formed on the substrate 41 is formed.
- the piezoelectric thin film 44 corresponds to the piezoelectric thin film 25 in FIG. 2B.
- the sputtering conditions for PNZT were Ar flow rate: 20 sccm, O 2 flow rate: 0.6 sccm, pressure: 0.5 Pa, substrate temperature: 600 ° C., and RF power applied to the target: 500 W.
- a sputtering target having a Zr / Ti ratio of 57/43 in molar ratio with Nb added at 10 mol% was used. Note that Pb contained in the target is likely to be re-evaporated at the time of high-temperature film formation, and the formed thin film tends to be Pb deficient. Therefore, it is necessary to add Pb more than the stoichiometric ratio of the perovskite crystal. Although the target Pb amount depends on the film formation temperature, it is desirable to increase it by 10 to 30% from the stoichiometric ratio.
- the crystal structure of the film was a pseudo-cubic crystal, and the (100) orientation degree was 90%.
- the (100) orientation refers to the crystal orientation of the perovskite, which includes not only the ⁇ 100> direction in which the polarization direction is parallel to the surface of the substrate, but also an equivalent direction (for example, ⁇ (001> direction) is also included. Since the degree of (100) orientation of the film is 90% as described above, the remaining 10% can be considered to be (111) orientation.
- the cross-sectional shape of the formed PNZT film was confirmed with a scanning electron microscope (SEM), it was found that a columnar crystal having a film thickness of 4 ⁇ m was obtained. Since the crystal structure of the formed PNZT film becomes a columnar crystal, a film made of a single crystal grain is obtained in the film thickness direction, and the volume of the crystal grain becomes larger than that of the granular crystal. For this reason, more polarization domains are present in the single crystal, which can improve the piezoelectric characteristics due to polarization rotation.
- SEM scanning electron microscope
- the Zr / Ti ratio was 56.8 / 43.2 in terms of molar ratio (Zr composition). The ratio was 56.8 mol%) and the Nb composition ratio (addition ratio) was 10.5 mol%, indicating that a film having a composition close to the target composition was obtained.
- the Pb composition ratio of the film was 104.1 mol%.
- the warpage of the wafer before and after film formation was measured using a contact-type step gauge to determine the film stress. The film stress is obtained by the following equation from the warpage of the wafer before and after film formation.
- d is the film thickness
- D is the thickness of the wafer
- Es is the longitudinal elastic modulus of the wafer
- ⁇ s is the Poisson's ratio of the wafer
- a is the substrate radius
- h 2 is the warpage of the wafer after film formation
- h 1 is the component. Represents the warpage of the wafer before film formation.
- Es is 160 [GPa] and ⁇ s is 0.2.
- the film stress of PNZT of this example was 150 MPa.
- the end of the piezoelectric element 50 is clamped by the fixed portion 51 so that the movable length of the cantilever is 10 mm, and the cantilever structure is used.
- a maximum voltage of 0 V was applied to the lower electrode, and a minimum voltage of ⁇ 20 V was applied to the lower electrode at a frequency of 500 Hz.
- the piezoelectric constant d 31 was obtained from the obtained piezoelectric displacement by a known method.
- the IV withstand voltage was evaluated using a semiconductor parameter analyzer B1500A manufactured by Agilent. As a result, the withstand voltage was 72V, and the withstand voltage exceeding the target 70V was obtained.
- Example 2 On a Pt / Ti / Si substrate produced in the same manner as in Example 1, a PLT as the seed layer 45 shown in FIG.
- the seed layer 45 corresponds to the seed layer 29 in FIG.
- the sputtering conditions for PLT were Ar flow rate: 30 sccm, O 2 flow rate: 0.6 sccm, pressure: 0.5 Pa, substrate temperature: 700 ° C., and RF power applied to the target: 300 W.
- a PNZT film having a thickness of about 3 ⁇ m was formed on the PLT using a sputtering apparatus, thereby forming the piezoelectric thin film 44.
- the sputtering conditions for PNZT were Ar flow rate: 20 sccm, O 2 flow rate: 0.5 sccm, pressure: 0.4 Pa, substrate temperature: 550 ° C., and RF power applied to the target: 600 W. Further, a sputtering target having a Zr / Ti ratio of 54/46 in molar ratio and Nb added at 12 mol% was used.
- the PNZT film was multi-oriented.
- the Zr / Ti ratio was 54.1 / 45.9 in terms of molar ratio, and the Nb composition ratio was 12.1% by mole. It was found that a film having a close composition was obtained. Incidentally, the Pb composition ratio of the film was 102.5 mol%.
- membrane stress of PNZT was 100 MPa.
- the IV withstand voltage was evaluated in the same manner as in Example 1, the withstand voltage was 80 V, and the withstand voltage exceeding the target 70 V was obtained.
- Example 3 On the PLT / Pt / Ti / Si substrate produced in the same manner as in Example 2, PNZT was formed to a thickness of about 6 ⁇ m by using a sputtering apparatus, and the piezoelectric thin film 44 was formed.
- the sputtering conditions for PNZT were Ar flow rate: 20 sccm, O 2 flow rate: 0.5 sccm, pressure: 0.4 Pa, substrate temperature: 650 ° C., and RF power applied to the target: 600 W. Further, a sputtering target having a Zr / Ti ratio of 54/46 in molar ratio and Nb added at 15 mol% was used.
- the (100) orientation degree of the film was 99%.
- membrane was confirmed by SEM, it turned out that the columnar crystal with a film thickness of 6 micrometers is obtained.
- the Zr / Ti ratio is 55.4 / 44.6 in terms of molar ratio, and the Nb composition ratio is 15.4 mol%. It was found that a film having a close composition was obtained.
- the Pb composition ratio of the film was 104.4 mol%.
- membrane stress of PNZT was 250 MPa.
- the IV withstand voltage was evaluated in the same manner as in Example 1, the withstand voltage was 72 V, and the withstand voltage exceeding the target 70 V was obtained.
- Example 4 On the PLT / Pt / Ti / Si substrate produced in the same manner as in Example 2, a PNZT film was formed to a thickness of about 5 ⁇ m using a sputtering apparatus to form a piezoelectric thin film 44.
- the sputtering conditions for PNZT were the same as in Example 3.
- As the sputtering target one having a Zr / Ti ratio of 58/42 and adding 18 mol% of Nb was used.
- the (100) orientation degree of the film was 98%.
- membrane was confirmed by SEM, it turned out that the columnar crystal with a film thickness of 5 micrometers is obtained.
- the Zr / Ti ratio is 58.9 / 41.1 in terms of molar ratio, and the Nb composition ratio is 18.2% by mole. It was found that a film having a close composition was obtained.
- the Pb composition ratio of the film was 105.0 mol%.
- membrane stress of PNZT was 200 MPa.
- the IV withstand voltage was evaluated in the same manner as in Example 1, the withstand voltage was 80 V, and the withstand voltage exceeding the target 70 V was obtained.
- Example 5 On the PLT / Pt / Ti / Si substrate produced in the same manner as in Example 2, a PNZT film was formed to a thickness of about 3 ⁇ m using a sputtering apparatus to form a piezoelectric thin film 44.
- the sputtering conditions for PNZT were the same as in Example 3.
- the sputtering target used was a Zr / Ti ratio of 58/42, with Nb added at 20 mol%.
- the (100) orientation degree of the film was 98%.
- membrane was confirmed by SEM, it turned out that the columnar crystal with a film thickness of 3 micrometers is obtained.
- the Zr / Ti ratio was 57.8 / 42.2 in terms of molar ratio, and the Nb composition ratio was 20.0 mol%. It was found that a film having a close composition was obtained. Incidentally, the Pb composition ratio of the film was 101.9 mol%.
- membrane stress of PNZT was 150 MPa.
- the IV withstand voltage was evaluated in the same manner as in Example 1, the withstand voltage was 85 V, and the withstand voltage exceeding the target 70 V was obtained.
- Example 6 On a Pt / Ti / Si substrate produced in the same manner as in Example 1, PNZT was formed to a thickness of about 4 ⁇ m by using a sputtering apparatus, and a piezoelectric thin film 44 was formed.
- the sputtering conditions for PNZT were Ar flow rate: 20 sccm, O 2 flow rate: 0.6 sccm, pressure: 0.5 Pa, substrate temperature: 650 ° C., and RF power applied to the target: 500 W. Further, a sputtering target having a Zr / Ti ratio of 52/48 in molar ratio and adding 10 mol% of Nb was used.
- the (100) orientation degree of the film was 90%.
- membrane was confirmed by SEM, it turned out that the columnar crystal with a film thickness of 4 micrometers is obtained.
- the Zr / Ti ratio was 52.5 / 47.5 in terms of molar ratio, and the Nb composition ratio was 10.1 mol%. It was found that a film having a close composition was obtained.
- the Pb composition ratio of the film was 103.0 mol%.
- membrane stress of PNZT was 180 MPa.
- Example 2 when the IV withstand voltage was evaluated in the same manner as in Example 1, the withstand voltage was 71 V, and the withstand voltage exceeding the target 70 V was obtained.
- PNZT On a Pt / Ti / Si substrate produced in the same manner as in Example 1, PNZT was formed to a thickness of about 4 ⁇ m by using a sputtering apparatus, and a piezoelectric thin film 44 was formed.
- the sputtering conditions for PNZT were Ar flow rate: 20 sccm, O 2 flow rate: 0.6 sccm, pressure: 0.5 Pa, substrate temperature: 500 ° C., and RF power applied to the target: 500 W. Further, a sputtering target having a Zr / Ti ratio of 52/48 in molar ratio and adding 10 mol% of Nb was used.
- the (100) orientation degree of the film was 90%.
- membrane was confirmed by SEM, it turned out that the columnar crystal with a film thickness of 4 micrometers is obtained.
- the Zr / Ti ratio was 52.1 / 47.9 in terms of molar ratio, and the Nb composition ratio was 9.5 mol%. It was found that a film having a close composition was obtained.
- the Pb composition ratio of the film was 103.6 mol%.
- membrane stress of PNZT was 90 MPa.
- Example 2 On a Pt / Ti / Si substrate produced in the same manner as in Example 1, a PNZT film was formed to a thickness of about 6 ⁇ m using a sputtering apparatus, and a piezoelectric thin film 44 was formed.
- the sputtering conditions for PNZT were the same as in Example 1.
- the sputtering target used was a Zr / Ti ratio of 60/40, with 22 mol% of Nb added.
- the (100) orientation degree of the film was 90%.
- membrane was confirmed by SEM, it turned out that the columnar crystal with a film thickness of 6 micrometers is obtained.
- the Zr / Ti ratio was 60.1 / 39.9 in terms of molar ratio, and the Nb composition ratio was 21.5 mol%. It was found that a film having a close composition was obtained.
- the Pb composition ratio of the film was 106.1 mol%.
- membrane stress of PNZT was 260 MPa. Due to such high stress, a part of the film was cracked.
- the withstand voltage was 58 V, and did not reach the target of 70 V.
- Example 3 On a Pt / Ti / Si substrate manufactured in the same manner as in Example 1, a PZT film was formed to a thickness of about 4 ⁇ m using a sputtering apparatus to form a piezoelectric thin film 44.
- the sputtering conditions for PZT are the same as the sputtering conditions for PNZT in Example 1.
- the sputtering target used was a Zr / Ti ratio of 52/48 in terms of molar ratio.
- the (100) orientation degree of the film was 90%. Further, when the cross-sectional shape of the formed PZT film was confirmed by SEM, it was found that a columnar crystal having a film thickness of 4 ⁇ m was obtained. Furthermore, as a result of analyzing the composition of the PZT film by EDX, the Zr / Ti ratio was 52.2 / 47.8 in terms of molar ratio, and it was found that a film having a composition close to the target composition was obtained. Incidentally, the Pb composition ratio of the film was 104.1 mol%. Moreover, as a result of measuring the film
- the IV withstand voltage was evaluated in the same manner as in Example 1, the withstand voltage was 56 V, and did not reach the target of 70 V.
- Example 4 On a Pt / Ti / Si substrate manufactured in the same manner as in Example 1, a PZT film was formed to a thickness of about 4 ⁇ m using a sputtering apparatus to form a piezoelectric thin film 44.
- the sputtering conditions for PZT are the same as the sputtering conditions for PNZT in Example 1, and a sputtering target having a Zr / Ti ratio of 55/45 in molar ratio was used.
- the (100) orientation degree of the film was 90%. Further, when the cross-sectional shape of the formed PZT film was confirmed by SEM, it was found that a columnar crystal having a film thickness of 4 ⁇ m was obtained. Furthermore, as a result of analyzing the composition of the PZT film by EDX, the Zr / Ti ratio was 54.5 / 45.5 in terms of molar ratio, and it was found that a film having a composition close to the target composition was obtained. Incidentally, the Pb composition ratio of the film was 103.9 mol%. Further, as a result of measuring the film stress by measuring the warpage of the wafer before and after the film formation, the film stress of PZT was 110 MPa.
- the IV withstand voltage was evaluated in the same manner as in Example 1, the withstand voltage was 75 V, and the withstand voltage exceeding the target of 70 V was obtained.
- Example 5 On a Pt / Ti / Si substrate manufactured in the same manner as in Example 1, a PZT film was formed to a thickness of about 4 ⁇ m using a sputtering apparatus to form a piezoelectric thin film 44.
- the sputtering conditions for PZT are the same as the sputtering conditions for PNZT in Example 1, and a sputtering target having a Zr / Ti ratio of 60/40 in molar ratio was used.
- the (100) orientation degree of the film was 90%. Further, when the cross-sectional shape of the formed PZT film was confirmed by SEM, it was found that a columnar crystal having a film thickness of 4 ⁇ m was obtained. Furthermore, as a result of analyzing the composition of the PZT film by EDX, the Zr / Ti ratio was 60.3 / 39.7 in terms of molar ratio, and it was found that a film having a composition close to the target composition was obtained. Incidentally, the Pb composition ratio of the film was 103.6 mol%. Moreover, as a result of measuring the film
- Example 2 when the IV withstand voltage was evaluated in the same manner as in Example 1, the withstand voltage was 78 V, and the withstand voltage exceeding the target 70 V was obtained.
- PNZT On a Pt / Ti / Si substrate produced in the same manner as in Example 1, PNZT was formed to a thickness of about 4 ⁇ m by using a sputtering apparatus, and a piezoelectric thin film 44 was formed.
- the sputtering conditions for PNZT were the same as in Example 2.
- a Zr / Ti ratio of 52/48 in terms of molar ratio was added with 12 mol% of Nb.
- the (100) orientation degree of the film was 90%.
- membrane was confirmed by SEM, it turned out that the columnar crystal with a film thickness of 4 micrometers is obtained.
- the Zr / Ti ratio was 51.9 / 48.1 in terms of molar ratio, and the Nb composition ratio was 12.4 mol%. It was found that a film having a close composition was obtained.
- the Pb composition ratio of the film was 103.8 mol%.
- membrane stress of PNZT was 120 MPa.
- PNZT On a Pt / Ti / Si substrate produced in the same manner as in Example 1, PNZT was formed to a thickness of about 4 ⁇ m by using a sputtering apparatus, and a piezoelectric thin film 44 was formed.
- the sputtering conditions for PNZT were Ar flow rate: 20 sccm, O 2 flow rate: 0.8 sccm, pressure: 0.5 Pa, substrate temperature: 450 ° C., and RF power applied to the target: 500 W. Further, a sputtering target having a Zr / Ti ratio of 52/48 in molar ratio and adding 10 mol% of Nb was used.
- the (100) orientation degree of the film was 90%.
- membrane was confirmed by SEM, it turned out that the columnar crystal with a film thickness of 4 micrometers is obtained.
- the Zr / Ti ratio was 52.2 / 47.8 in terms of molar ratio, and the Nb composition ratio was 10.6 mol%. It was found that a film having a close composition was obtained.
- the Pb composition ratio of the film was 111.0 mol%.
- membrane stress of PNZT was 80 MPa.
- the IV withstand voltage was evaluated in the same manner as in Example 1, the withstand voltage was 45 V, and did not reach the target of 70 V.
- PNZT On a Pt / Ti / Si substrate produced in the same manner as in Example 1, PNZT was formed to a thickness of about 4 ⁇ m by using a sputtering apparatus, and a piezoelectric thin film 44 was formed.
- the sputtering conditions for PNZT were Ar flow rate: 20 sccm, O 2 flow rate: 0.3 sccm, pressure: 0.5 Pa, substrate temperature: 700 ° C., and RF power applied to the target: 500 W. Further, a sputtering target having a Zr / Ti ratio of 55/45 in molar ratio and Nb added by 15 mol% was used.
- the (100) orientation degree of the film was 90%.
- membrane was confirmed by SEM, it turned out that the columnar crystal with a film thickness of 4 micrometers is obtained.
- the Zr / Ti ratio was 55.2 / 44.8 in terms of molar ratio, and the Nb composition ratio was 15.5 mol%. It was found that a film having a close composition was obtained.
- the Pb composition ratio of the film was 97.8 mol%.
- membrane stress of PNZT was 210 MPa.
- the withstand voltage was 90 V, and the withstand voltage exceeding the target of 70 V was obtained.
- Table 1 summarizes the measurement results in Examples 1 to 6 and Comparative Examples 1 to 8. Table 1 also shows the target values of the respective compositions and parameters, and the evaluation results of the films. In addition, the evaluation result of the film
- evaluation criteria X: The piezoelectric characteristic is less than the target value. ⁇ : The piezoelectric characteristic is equal to or higher than the target value, and the withstand voltage is lower than the target value. ⁇ : Both the piezoelectric characteristics and the withstand voltage are above the target values. A: Both the piezoelectric characteristics and the withstand voltage are equal to or higher than the target values, and the piezoelectric characteristics are very high (
- the PNZT film by appropriately adjusting the composition ratio and film stress of Nb, Pb, Zr, and Ti so as to be within the target value range, high piezoelectric characteristics (
- the Pb composition ratio (the ratio of Pb to the sum of Zr, Ti, and Nb) is 100% or more by molar ratio.
- the Nb composition ratio (the ratio b of Nb to the sum of Zr, Ti, and Nb) is 10% or more and 20% or less in terms of molar ratio.
- the Zr composition ratio (ratio c of Zr to the sum of Zr and Ti) is 52% or more and 59% or less in terms of molar ratio.
- the film stress is 100 MPa or more and 250 MPa or less.
- the film stress of the PNZT film is smaller than 100 MPa, the optimum composition is close to that of a bulk without stress, and it is difficult to obtain high piezoelectric characteristics with the composition unique to the thin film.
- the film stress is larger than 250 MPa, the film is cracked, or when the film is formed on the substrate, the film is easily peeled off and it is difficult to obtain high piezoelectric characteristics. Therefore, in the condition (1), by setting the film stress to 100 MPa or more and 250 MPa or less, it is possible to realize high piezoelectric characteristics without causing cracks or the like with the above-described thin film specific composition (ratio a to c). .
- the film stress is large, if it exceeds 190 MPa, the piezoelectric characteristics increase, and film peeling tends to occur when a film is formed on the substrate. Therefore, reinforcement is performed to prevent film peeling by a known method. It is desirable.
- the upper limit of the Pb composition ratio is not specified, but this means that the Pb composition ratio can be increased within the range where the film stress satisfies the condition of 100 MPa or more and 250 MPa or less. Actually, if the Pb composition ratio is increased, the film stress increases. Therefore, in order to suppress the film stress to 250 MPa or less, it is desirable to set the Pb composition ratio to 105 mol% or less.
- the Pb composition ratio (the ratio a of Pb to the sum of Zr, Ti, and Nb) is 100% to 105% in terms of molar ratio.
- the Nb composition ratio (the ratio b of Nb to the total of Zr, Ti, and Nb) is 10% or more and 20% or less in terms of molar ratio.
- the Zr composition ratio (ratio c of Zr to the sum of Zr and Ti) is 54% or more and 59% or less in terms of molar ratio.
- condition (2) the composition ratio of Zr is set to 54% or more and 59% or less in terms of molar ratio, and by further narrowing down than condition (1), the withstand voltage of the PNZT thin film is reliably improved to 72V or more. Thus, it can be said that the durability can be surely improved.
- the (100) orientation degree of the PNZT film is 90% or more, and the crystal orientation (main orientation) can be said to be (100) orientation.
- the piezoelectric characteristics are improved by utilizing the polarization rotation of the domain (for example, the change in the polarization direction from the ⁇ 100> direction parallel to the substrate surface to the ⁇ 001> direction perpendicular to the substrate surface). Can be made. Therefore, higher piezoelectric characteristics can be realized as compared with the (111) orientation in which such domain rotation does not occur.
- the above-described high film stress (thermal) is applied to the piezoelectric thin film 44 due to the difference in thermal expansion coefficient between the piezoelectric thin film 44 and the substrate 41 which are different materials. Stress). As a result, a piezoelectric characteristic in which d 31 exceeds ⁇ 200 pm / V can be obtained.
- the thermal expansion coefficient of Si is 2.6 ppm / K and the thermal expansion coefficient of PNZT is about 8 ppm / K
- the substrate 41 is made of Si and the piezoelectric thin film 44 is made of PNZT. It is considered that high film stress is reliably applied to the piezoelectric thin film 44 by high temperature film formation due to the difference in thermal expansion coefficient with the substrate 41. Thereby, high piezoelectric characteristics can be reliably realized in the piezoelectric thin film 44.
- the substrate 41 may be a single silicon substrate or the aforementioned SOI substrate as long as it contains Si.
- the seed layer 45 is formed between the substrate 41 and the piezoelectric thin film 44, the seed layer 45 is used as an undercoat layer, and a piezoelectric material having high crystallinity thereon. A thin film 44 can be formed. As a result, it is considered that a piezoelectric characteristic in which d 31 exceeds ⁇ 200 pm / V can be easily realized.
- the seed layer is a PLT having a perovskite structure, it is easy to form the piezoelectric thin film 44 as a single perovskite layer on the PLT, and it is considered that it is easier to realize high piezoelectric characteristics.
- the electrode (lower electrode 43) is formed between the substrate 41 and the piezoelectric thin film 44, a piezoelectric actuator (piezoelectric) configured by sandwiching the piezoelectric thin film 44 between a pair of electrodes (lower electrode 43 and upper electrode).
- a substrate 40 with a piezoelectric thin film suitable for the element 50) can be realized.
- Example 7 to 9, Comparative Examples 9 to 10 PNZT was deposited by the same method as in Example 2. At this time, the PNZT film was formed by changing the film formation time of PNZT to change the film thickness between 3.0 and 13.2 ⁇ m. And the piezoelectric characteristic of PNZT of each film thickness was evaluated. Table 2 shows the results of film stress and piezoelectric characteristics measured for PNZT having different film thicknesses in the same manner as in Example 1 and the like. In Comparative Example 10, since the film was cracked by high stress, the piezoelectric characteristics were not measured.
- the sputtering method is used to form the piezoelectric thin film (ferroelectric thin film), but the film manufacturing method is not limited to these.
- the composition ratio of PNZT shown in the present embodiment can be realized, for example, physical film forming methods such as pulse laser deposition (PLD) method and ion plating method, sol-gel method, MOCVD (Metal Organic Chemical Vapor Deposition)
- the piezoelectric thin film may be formed by using a chemical film forming method such as a method.
- the ferroelectric thin film, the substrate with the piezoelectric thin film, the piezoelectric actuator, the ink jet head, and the ink jet printer according to the present embodiment described above can be expressed as follows, thereby producing the following effects.
- the ferroelectric thin film of this embodiment is a ferroelectric thin film made of lead zirconate titanate niobate, and the ratio a of lead to the sum of zirconium, titanium, and niobium is 100% or more in molar ratio.
- the ratio b of niobium to the sum of zirconium, titanium and niobium is 10% or more and 20% or less in terms of molar ratio, and the ratio c of zirconium to the sum of zirconium and titanium is 52% or more and 59% or less in terms of mole ratio.
- the film stress is 100 MPa or more and 250 MPa or less.
- ratios (ratios a to c) of Pb, Nb, and Zr constituting PNZT to the above ranges different from the optimum ranges in bulk, high piezoelectric characteristics that cannot be realized with a PZT thin film (for example,
- the withstand voltage of the PNZT film can be improved and the durability can be improved.
- the Zr ratio (ratio c) is greater than 52% and less than 59% in terms of molar ratio from the viewpoint of surely improving the withstand voltage of the PNZT film and reliably improving the durability.
- the ratio a may be 105% or less in terms of molar ratio.
- the film stress in the above range can be reliably realized in the range of the ratio b and the ratio c described above.
- the ferroelectric thin film of this embodiment is a ferroelectric thin film made of lead zirconate titanate niobate, and the ratio of lead a to the sum of zirconium, titanium, and niobium is 100% or more and 105% in terms of molar ratio.
- the ratio b of niobium to the sum of zirconium, titanium, and niobium is 10% or more and 20% or less in terms of molar ratio
- the ratio c of zirconium to the sum of zirconium and titanium is 54% or more in terms of mole ratio. 59% or less.
- ratios a to c of Pb, Nb, and Zr constituting PNZT to the above ranges different from the optimum ranges in bulk, high piezoelectric characteristics that cannot be realized with a PZT thin film (for example,
- the ratio a and the ratio b are in the above range, by limiting the ratio c to the above range, the withstand voltage of the PNZT thin film can be reliably improved and the durability thereof can be reliably improved.
- the ratio b is 15% or more and 19% or less in terms of a molar ratio
- the ratio c is 55% or more and 59% or less in terms of a molar ratio.
- an even higher piezoelectric characteristic for example,
- the crystal orientation of the film is a pseudo cubic (100) orientation.
- the non-180 ° polarization rotation of the domain occurs in a lower electric field than other crystal structures, and this can be used to improve the piezoelectric characteristics.
- the crystal orientation of the film is the (111) orientation.
- the crystal structure of the film is preferably a columnar crystal.
- more polarization domains are present in the single crystal than in the case where the crystal structure of the film is a granular crystal, and an improvement in piezoelectric characteristics due to polarization rotation can be expected.
- the film thickness is desirably 1 ⁇ m or more and 10 ⁇ m or less.
- the thickness of the PNZT thin film is less than 1 ⁇ m, it is difficult to obtain a desired displacement generation force with the thin film, and application to a device such as a piezoelectric actuator becomes difficult.
- the film thickness exceeds 10 ⁇ m, cracks tend to occur in the film, making it difficult to obtain high piezoelectric characteristics. Therefore, by defining the thickness of the PNZT thin film within the above range, it is possible to obtain a desired displacement generating force with the thin film and easily apply it to the device, and obtain high piezoelectric characteristics.
- the substrate with a piezoelectric thin film of the present embodiment is a substrate with a piezoelectric thin film in which a piezoelectric thin film is formed on the substrate, and the piezoelectric thin film is composed of the ferroelectric thin film described above.
- high piezoelectric characteristics can be realized by applying high film stress to the piezoelectric thin film (ferroelectric thin film) due to the difference in thermal expansion coefficient from the substrate.
- the substrate is preferably made of a silicon substrate or an SOI substrate.
- an SOI (Silicon-on-insulator) substrate is a substrate in which two silicon substrates are bonded to each other with an oxide film interposed therebetween. Since Si and PNZT of a board
- a seed layer for controlling crystal orientation of the piezoelectric thin film is formed between the substrate and the piezoelectric thin film. In this case, it becomes easy to realize a high piezoelectric characteristic by forming a piezoelectric thin film having high crystallinity on the seed layer.
- the seed layer is preferably made of lead lanthanum titanate. Since PLT has a perovskite structure, it is easy to form a piezoelectric thin film on the PLT as a single perovskite layer, and it is easier to realize high piezoelectric characteristics.
- an electrode is formed between the substrate and the piezoelectric thin film.
- a substrate with a piezoelectric thin film suitable for a piezoelectric actuator configured by sandwiching a piezoelectric thin film between a pair of electrodes can be realized.
- the piezoelectric actuator of the present embodiment includes the above-described substrate with a piezoelectric thin film and another electrode formed on the opposite side of the piezoelectric thin film of the substrate with the piezoelectric thin film. In this case, it is possible to reliably realize a configuration in which the piezoelectric thin film is expanded and contracted according to the applied voltage.
- the ink jet head includes the above piezoelectric actuator and a nozzle substrate having a nozzle hole for ejecting ink accommodated in an opening formed in the substrate of the piezoelectric actuator to the outside.
- the piezoelectric characteristics of the piezoelectric actuator are high, it is possible to eject ink using high-viscosity ink.
- the ink jet printer includes the above ink jet head, and ejects ink from the ink jet head toward a recording medium.
- an inkjet printer advantageous for high-speed and high-definition drawing can be realized.
- the ferroelectric thin film of the present invention can be used for a substrate with a piezoelectric thin film in which a piezoelectric thin film is formed on a substrate, a piezoelectric actuator having the substrate with a piezoelectric thin film, an ink jet head, and an ink jet printer.
- Inkjet printer 21 Inkjet head 21a Actuator (substrate with piezoelectric thin film, piezoelectric actuator) 22 Substrate 22a Pressure chamber (opening) 24 Lower electrode 25 Piezoelectric thin film (ferroelectric thin film) 26 Upper electrode 29 Seed layer 31 Nozzle substrate 31a Discharge hole (nozzle hole) 40 Substrate with piezoelectric thin film 41 Substrate 43 Lower electrode 44 Piezoelectric thin film (ferroelectric thin film) 45 Seed layer
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Abstract
Description
図1は、本実施形態のインクジェットプリンタ1の概略の構成を示す説明図である。インクジェットプリンタ1は、インクジェットヘッド部2において、インクジェットヘッド21が記録媒体の幅方向にライン状に設けられた、いわゆるラインヘッド方式のインクジェット記録装置である。
次に、上記したインクジェットヘッド21の構成について説明する。図2Aは、インクジェットヘッド21のアクチュエータ21a(圧電薄膜付き基板、圧電アクチュエータ)の概略の構成を示す平面図であり、図2Bは、その平面図におけるA-A’線矢視断面図である。また、図3は、図2Bのアクチュエータ21aにノズル基板31を接合してなるインクジェットヘッド21の断面図である。
δ≧0
0.10≦y≦0.20
0.52≦x≦0.59
であり、かつ、膜応力が100MPa以上250MPa以下であるか、
0≦δ≦0.05
0.10≦y≦0.20
0.54≦x≦0.59
である。
次に、本実施形態のインクジェットヘッド21の製造方法について以下に説明する。図4は、インクジェットヘッド21の製造工程を示す断面図である。
図5は、インクジェットヘッド21の他の構成を示す断面図である。同図のように、下部電極24と圧電薄膜25との間にシード層29を設けるようにしてもよい。シード層29は、圧電薄膜25の結晶配向性を制御するための配向制御層である。このようなシード層29は、例えばPLT(チタン酸ランタン鉛)で構成されるが、LaNiO3やSrRuO3で構成されてもよい。
次に、圧電薄膜を構成するPNZTの組成比の具体例について、圧電薄膜の製法も含めて実施例として説明する。また、実施例との比較のため、比較例についても併せて説明する。図6は、基板上に圧電薄膜を成膜した圧電薄膜付き基板の製造工程を示す断面図である。
まず、厚さ400μm程度の単結晶Siウェハからなる基板41に、熱酸化膜42を100nm程度形成した。ウェハの厚みは300μm~725μm、直径は3インチ~8インチなど、標準的な値でよい。熱酸化膜42は、ウェット酸化用熱炉を用いてSiウェハを酸素雰囲気中に1200℃程度の高温にさらすことで形成できる。なお、基板41および熱酸化膜42は、図2Bの基板22および熱酸化膜23にそれぞれ対応するものである。
実施例1と同様にして作製したPt/Ti/Si基板上に、スパッタリング装置を用いて、図7に示すシード層45としてのPLTを100nm程度形成した。なお、シード層45は、図5のシード層29に対応するものである。PLTのスパッタ条件は、Ar流量:30sccm、O2流量:0.6sccm、圧力:0.5Pa、基板温度:700℃、ターゲットに印加するRFパワー:300Wであった。
実施例2と同様にして作製したPLT/Pt/Ti/Si基板上に、スパッタリング装置を用いて、PNZTを6μm程度成膜し、圧電薄膜44を形成した。PNZTのスパッタ条件は、Ar流量:20sccm、O2流量:0.5sccm、圧力:0.4Pa、基板温度:650℃、ターゲットに印加するRFパワー:600Wであった。また、スパッタのターゲットには、Zr/Ti比がモル比で54/46となっているものにNbを15モル%添加したものを用いた。
実施例2と同様にして作製したPLT/Pt/Ti/Si基板上に、スパッタリング装置を用いて、PNZTを5μm程度成膜し、圧電薄膜44を形成した。PNZTのスパッタ条件は、実施例3と同様であり、スパッタのターゲットには、Zr/Ti比がモル比で58/42となっているものにNbを18モル%添加したものを用いた。
実施例2と同様にして作製したPLT/Pt/Ti/Si基板上に、スパッタリング装置を用いて、PNZTを3μm程度成膜し、圧電薄膜44を形成した。PNZTのスパッタ条件は、実施例3と同様であり、スパッタのターゲットには、Zr/Ti比がモル比で58/42となっているものにNbを20モル%添加したものを用いた。
実施例1と同様にして作製したPt/Ti/Si基板上に、スパッタリング装置を用いて、PNZTを4μm程度成膜し、圧電薄膜44を形成した。PNZTのスパッタ条件は、Ar流量:20sccm、O2流量:0.6sccm、圧力:0.5Pa、基板温度:650℃、ターゲットに印加するRFパワー:500Wであった。また、スパッタのターゲットには、Zr/Ti比がモル比で52/48となっているものにNbを10モル%添加したものを用いた。
実施例1と同様にして作製したPt/Ti/Si基板上に、スパッタリング装置を用いて、PNZTを4μm程度成膜し、圧電薄膜44を形成した。PNZTのスパッタ条件は、Ar流量:20sccm、O2流量:0.6sccm、圧力:0.5Pa、基板温度:500℃、ターゲットに印加するRFパワー:500Wであった。また、スパッタのターゲットには、Zr/Ti比がモル比で52/48となっているものにNbを10モル%添加したものを用いた。
実施例1と同様にして作製したPt/Ti/Si基板上に、スパッタリング装置を用いて、PNZTを6μm程度成膜し、圧電薄膜44を形成した。PNZTのスパッタ条件は、実施例1と同様であり、スパッタのターゲットには、Zr/Ti比がモル比で60/40となっているものにNbを22モル%添加したものを用いた。
実施例1と同様にして作製したPt/Ti/Si基板上に、スパッタリング装置を用いて、PZTを4μm程度成膜し、圧電薄膜44を形成した。PZTのスパッタ条件は、実施例1のPNZTのスパッタ条件と同様であり、スパッタのターゲットには、Zr/Ti比がモル比で52/48となっているものを用いた。
実施例1と同様にして作製したPt/Ti/Si基板上に、スパッタリング装置を用いて、PZTを4μm程度成膜し、圧電薄膜44を形成した。PZTのスパッタ条件は、実施例1のPNZTのスパッタ条件と同様であり、スパッタのターゲットには、Zr/Ti比がモル比で55/45となっているものを用いた。
実施例1と同様にして作製したPt/Ti/Si基板上に、スパッタリング装置を用いて、PZTを4μm程度成膜し、圧電薄膜44を形成した。PZTのスパッタ条件は、実施例1のPNZTのスパッタ条件と同様であり、スパッタのターゲットには、Zr/Ti比がモル比で60/40となっているものを用いた。
実施例1と同様にして作製したPt/Ti/Si基板上に、スパッタリング装置を用いて、PNZTを4μm程度成膜し、圧電薄膜44を形成した。PNZTのスパッタ条件は、実施例2と同様であり、スパッタのターゲットには、Zr/Ti比がモル比で52/48となっているものにNbを12モル%添加したものを用いた。
実施例1と同様にして作製したPt/Ti/Si基板上に、スパッタリング装置を用いて、PNZTを4μm程度成膜し、圧電薄膜44を形成した。PNZTのスパッタ条件は、Ar流量:20sccm、O2流量:0.8sccm、圧力:0.5Pa、基板温度:450℃、ターゲットに印加するRFパワー:500Wであった。また、スパッタのターゲットには、Zr/Ti比がモル比で52/48となっているものにNbを10モル%添加したものを用いた。
実施例1と同様にして作製したPt/Ti/Si基板上に、スパッタリング装置を用いて、PNZTを4μm程度成膜し、圧電薄膜44を形成した。PNZTのスパッタ条件は、Ar流量:20sccm、O2流量:0.3sccm、圧力:0.5Pa、基板温度:700℃、ターゲットに印加するRFパワー:500Wであった。また、スパッタのターゲットには、Zr/Ti比がモル比で55/45となっているものにNbを15モル%添加したものを用いた。
(評価基準)
×・・・圧電特性が目標値未満である。
△・・・圧電特性が目標値以上であり、耐電圧が目標値未満である。
○・・・圧電特性および耐電圧の両方が目標値以上である。
◎・・・圧電特性および耐電圧の両方が目標値以上であり、かつ、圧電特性が非常に高い(|d31|≧260V)。
(1a)Pb組成比(ZrとTiとNbとの総和に対するPbの比率a)が、モル比で100%以上である。
(1b)Nb組成比(ZrとTiとNbとの総和に対するNbの比率b)が、モル比で10%以上20%以下である。
(1c)Zr組成比(ZrとTiとの総和に対するZrの比率c)が、モル比で52%以上59%以下である。
(1d)膜応力が、100MPa以上250MPa以下である。
(2a)Pb組成比(ZrとTiとNbとの総和に対するPbの比率a)が、モル比で100%以上105%以下である。
(2b)Nb組成比(ZrとTiとNbとの総和に対するNbの比率b)が、モル比で10%以上20%以下である。
(2c)Zr組成比(ZrとTiとの総和に対するZrの比率c)が、モル比で54%以上59%以下である。
実施例2と同様の手法でPNZTを成膜した。その際に、PNZTの成膜時間を変えることで、膜厚を3.0~13.2μmの間で変化させてPNZTを成膜した。そして、各膜厚のPNZTの圧電特性を評価した。表2は、膜厚の異なるPNZTについて、実施例1等と同様にして測定した膜応力と圧電特性の結果を示したものである。なお、比較例10については、高応力によって膜にクラックが入ったため、圧電特性を測定していない。
以上の実施例では、圧電薄膜(強誘電体薄膜)の形成にスパッタ法を用いているが、膜の製法はこれらに限定されるわけではない。本実施形態で示したPNZTの組成比率を実現できるのであれば、例えば、パルスレーザーデポジション(PLD)法やイオンプレーティング法などの物理成膜法、ゾルゲル法、MOCVD(Metal Organic Chemical Vapor Deposition)法などの化学成膜法を用いて圧電薄膜を成膜してもよい。
21 インクジェットヘッド
21a アクチュエータ(圧電薄膜付き基板、圧電アクチュエータ)
22 基板
22a 圧力室(開口部)
24 下部電極
25 圧電薄膜(強誘電体薄膜)
26 上部電極
29 シード層
31 ノズル基板
31a 吐出孔(ノズル孔)
40 圧電薄膜付き基板
41 基板
43 下部電極
44 圧電薄膜(強誘電体薄膜)
45 シード層
Claims (15)
- ニオブ酸チタン酸ジルコン酸鉛からなる強誘電体薄膜であって、
ジルコニウムとチタンとニオブとの総和に対する鉛の比率aが、モル比で100%以上であり、
ジルコニウムとチタンとニオブとの総和に対するニオブの比率bが、モル比で10%以上20%以下であり、
ジルコニウムとチタンとの総和に対するジルコニウムの比率cが、モル比で52%以上59%以下であり、
膜応力が、100MPa以上250MPa以下である、強誘電体薄膜。 - 前記比率aが、モル比で105%以下である、請求項1に記載の強誘電体薄膜。
- ニオブ酸チタン酸ジルコン酸鉛からなる強誘電体薄膜であって、
ジルコニウムとチタンとニオブとの総和に対する鉛の比率aが、モル比で100%以上105%以下であり、
ジルコニウムとチタンとニオブとの総和に対するニオブの比率bが、モル比で10%以上20%以下であり、
ジルコニウムとチタンとの総和に対するジルコニウムの比率cが、モル比で54%以上59%以下である、強誘電体薄膜。 - 前記比率bが、モル比で15%以上19%以下であり、
前記比率cが、モル比で55%以上59%以下である、請求項1から3のいずれかに記載の強誘電体薄膜。 - 膜の結晶配向が、擬立方晶の(100)配向である、請求項1から4のいずれかに記載の強誘電体薄膜。
- 膜の結晶構造が、柱状結晶である、請求項1から5のいずれかに記載の強誘電体薄膜。
- 膜厚が1μm以上10μm以下である、請求項1から6のいずれかに記載の強誘電体薄膜。
- 基板上に圧電薄膜を形成した圧電薄膜付き基板であって、
前記圧電薄膜は、請求項1から7のいずれかに記載の強誘電体薄膜で構成されている、圧電薄膜付き基板。 - 前記基板は、シリコン基板またはSOI基板からなる、請求項8に記載の圧電薄膜付き基板。
- 前記基板と前記圧電薄膜との間に、前記圧電薄膜の結晶配向性を制御するためのシード層が形成されている、請求項8または9に記載の圧電薄膜付き基板。
- 前記シード層は、チタン酸ランタン鉛からなる、請求項10に記載の圧電薄膜付き基板。
- 前記基板と前記圧電薄膜との間に電極が形成されている、請求項8から11のいずれかに記載の圧電薄膜付き基板。
- 請求項12に記載の圧電薄膜付き基板と、
前記圧電薄膜付き基板の前記圧電薄膜に対して前記電極とは反対側に形成される別の電極とを備えている、圧電アクチュエータ。 - 請求項13に記載の圧電アクチュエータと、
前記圧電アクチュエータの前記基板に形成される開口部に収容されるインクを外部に吐出するためのノズル孔を有するノズル基板とを備えている、インクジェットヘッド。 - 請求項14に記載のインクジェットヘッドを備え、前記インクジェットヘッドから記録媒体に向けてインクを吐出させる、インクジェットプリンタ。
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JP2016519199A JP6481686B2 (ja) | 2014-05-15 | 2015-04-27 | 強誘電体薄膜、圧電薄膜付き基板、圧電アクチュエータ、インクジェットヘッドおよびインクジェットプリンタ |
US15/308,489 US20170050439A1 (en) | 2014-05-15 | 2015-04-27 | Ferroelectric thin film, piezoelectric thin film-coated substrate, piezoelectric actuator, inkjet head, and inkjet printer |
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Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2018110483A1 (ja) * | 2016-12-12 | 2018-06-21 | パナソニックIpマネジメント株式会社 | 圧電機能膜、アクチュエータおよびインクジェットヘッド |
EP4307870A1 (en) | 2022-07-13 | 2024-01-17 | FUJIFILM Corporation | Piezoelectric laminate and piezoelectric element |
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DE112017000678B4 (de) * | 2016-02-05 | 2020-06-18 | Fujifilm Corporation | Piezoelektrisches Element |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2008258575A (ja) * | 2007-03-15 | 2008-10-23 | Seiko Epson Corp | 圧電素子、液体噴射ヘッド、および、プリンタ |
JP2009252786A (ja) * | 2008-04-01 | 2009-10-29 | Seiko Epson Corp | 酸化物原料溶液、酸化物膜、圧電素子、酸化物膜の形成方法および圧電素子の製造方法 |
JP2012009677A (ja) * | 2010-06-25 | 2012-01-12 | Fujifilm Corp | 圧電体膜および圧電素子 |
JP2013229510A (ja) * | 2012-04-26 | 2013-11-07 | Konica Minolta Inc | 圧電素子およびその製造方法 |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6312816B1 (en) * | 1998-02-20 | 2001-11-06 | Advanced Technology Materials, Inc. | A-site- and/or B-site-modified PbZrTiO3 materials and (Pb, Sr, Ca, Ba, Mg) (Zr, Ti, Nb, Ta)O3 films having utility in ferroelectric random access memories and high performance thin film microactuators |
JP2005150694A (ja) * | 2003-10-23 | 2005-06-09 | Seiko Epson Corp | 圧電体膜、圧電素子、圧電アクチュエーター、圧電ポンプ、インクジェット式記録ヘッド、インクジェットプリンター、表面弾性波素子、薄膜圧電共振子、周波数フィルタ、発振器、電子回路、および電子機器 |
JP4811556B2 (ja) * | 2004-04-23 | 2011-11-09 | セイコーエプソン株式会社 | 圧電素子、液体噴射ヘッドおよび液体噴射装置 |
JP4217906B2 (ja) * | 2004-09-17 | 2009-02-04 | セイコーエプソン株式会社 | 前駆体溶液の製造方法 |
JP4171918B2 (ja) * | 2005-03-29 | 2008-10-29 | セイコーエプソン株式会社 | 圧電体膜積層体およびその製造方法、表面弾性波素子、周波数フィルタ、発振器、電子回路、並びに、電子機器 |
JP4266036B2 (ja) * | 2007-04-26 | 2009-05-20 | 富士フイルム株式会社 | 圧電体、圧電素子、及び液体吐出装置 |
JP5280789B2 (ja) * | 2008-09-30 | 2013-09-04 | 富士フイルム株式会社 | 鉛含有ペロブスカイト型酸化物膜およびその作製方法、鉛含有ペロブスカイト型酸化物膜を用いる圧電素子、ならびにこれを用いる液体吐出装置 |
WO2011089748A1 (ja) * | 2010-01-21 | 2011-07-28 | 株式会社ユーテック | Pbnzt強誘電体膜、ゾルゲル溶液、成膜方法及び強誘電体膜の製造方法 |
US20130112910A1 (en) * | 2011-05-06 | 2013-05-09 | Seiko Epson Corporation | Precursor solution for piezoelectric films, method for manufacturing the same, and method for manufacturing piezoelectric film |
-
2015
- 2015-04-27 WO PCT/JP2015/062720 patent/WO2015174265A1/ja active Application Filing
- 2015-04-27 JP JP2016519199A patent/JP6481686B2/ja active Active
- 2015-04-27 US US15/308,489 patent/US20170050439A1/en not_active Abandoned
- 2015-04-27 EP EP15792322.8A patent/EP3144987B1/en active Active
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2008258575A (ja) * | 2007-03-15 | 2008-10-23 | Seiko Epson Corp | 圧電素子、液体噴射ヘッド、および、プリンタ |
JP2009252786A (ja) * | 2008-04-01 | 2009-10-29 | Seiko Epson Corp | 酸化物原料溶液、酸化物膜、圧電素子、酸化物膜の形成方法および圧電素子の製造方法 |
JP2012009677A (ja) * | 2010-06-25 | 2012-01-12 | Fujifilm Corp | 圧電体膜および圧電素子 |
JP2013229510A (ja) * | 2012-04-26 | 2013-11-07 | Konica Minolta Inc | 圧電素子およびその製造方法 |
Non-Patent Citations (1)
Title |
---|
See also references of EP3144987A4 * |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2018110483A1 (ja) * | 2016-12-12 | 2018-06-21 | パナソニックIpマネジメント株式会社 | 圧電機能膜、アクチュエータおよびインクジェットヘッド |
JP6417549B1 (ja) * | 2016-12-12 | 2018-11-07 | パナソニックIpマネジメント株式会社 | 圧電機能膜、アクチュエータおよびインクジェットヘッド |
CN109983592A (zh) * | 2016-12-12 | 2019-07-05 | 松下知识产权经营株式会社 | 压电功能膜、致动器以及喷墨头 |
CN109983592B (zh) * | 2016-12-12 | 2023-05-12 | 松下知识产权经营株式会社 | 压电功能膜、致动器以及喷墨头 |
EP4307870A1 (en) | 2022-07-13 | 2024-01-17 | FUJIFILM Corporation | Piezoelectric laminate and piezoelectric element |
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