[go: up one dir, main page]
More Web Proxy on the site http://driver.im/

WO2012141104A1 - Ferroelectric thin film and method for producing same - Google Patents

Ferroelectric thin film and method for producing same Download PDF

Info

Publication number
WO2012141104A1
WO2012141104A1 PCT/JP2012/059560 JP2012059560W WO2012141104A1 WO 2012141104 A1 WO2012141104 A1 WO 2012141104A1 JP 2012059560 W JP2012059560 W JP 2012059560W WO 2012141104 A1 WO2012141104 A1 WO 2012141104A1
Authority
WO
WIPO (PCT)
Prior art keywords
potassium sodium
sodium niobate
thin film
heat treatment
temperature increase
Prior art date
Application number
PCT/JP2012/059560
Other languages
French (fr)
Japanese (ja)
Inventor
宏 白木
Original Assignee
株式会社村田製作所
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社村田製作所 filed Critical 株式会社村田製作所
Publication of WO2012141104A1 publication Critical patent/WO2012141104A1/en

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
    • C04B35/495—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on vanadium, niobium, tantalum, molybdenum or tungsten oxides or solid solutions thereof with other oxides, e.g. vanadates, niobates, tantalates, molybdates or tungstates
    • 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
    • H10N30/077—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 liquid phase deposition
    • H10N30/078—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 liquid phase deposition by sol-gel deposition
    • 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
    • H10N30/8542—Alkali metal based oxides, e.g. lithium, sodium or potassium niobates
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3201—Alkali metal oxides or oxide-forming salts thereof
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3231—Refractory metal oxides, their mixed metal oxides, or oxide-forming salts thereof
    • C04B2235/3251—Niobium oxides, niobates, tantalum oxides, tantalates, or oxide-forming salts thereof
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/60—Aspects relating to the preparation, properties or mechanical treatment of green bodies or pre-forms
    • C04B2235/606—Drying
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
    • C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
    • C04B2235/6562—Heating rate
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
    • C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
    • C04B2235/6567—Treatment time
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
    • C04B2235/96—Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
    • C04B2235/963—Surface properties, e.g. surface roughness

Definitions

  • the present invention relates to a ferroelectric thin film used for a piezoelectric thin film element and a manufacturing method thereof.
  • Piezoelectric materials are currently widely used as materials for functional electronic parts such as actuators and sensors.
  • a piezoelectric material used for these applications a perovskite ferroelectric material represented by a general formula Pb (Zr, Ti) O 3 called PZT is mainly used.
  • PZT contains harmful Pb (lead), it is an undesirable material for protecting the natural environment.
  • KNN potassium sodium niobate
  • PLD pulse laser deposition
  • CSD chemical solution deposition
  • Patent Document 1 proposes a method for producing a potassium sodium niobate (KNN) thin film by a chemical solution deposition (CSD) method.
  • KNN potassium sodium niobate
  • CSD chemical solution deposition
  • the piezoelectric thin film element 20 having the potassium sodium niobate (KNN) thin film 26 is produced.
  • an object of the present invention is to provide a ferroelectric thin film having excellent electrical characteristics, in particular, leakage current characteristics and ferroelectric characteristics, and a method for producing the same.
  • the present invention is a method for producing a ferroelectric thin film, wherein a potassium sodium niobate thin film represented by the general formula (K, Na) NbO 3 is formed using a chemical solution deposition method, A chemical solution deposition solution is applied on a substrate, and a first heat treatment and a second heat treatment are performed to form a potassium sodium niobate layer. The above steps are repeated a predetermined number of times to laminate a potassium sodium niobate layer. Forming a potassium sodium niobate thin film, the thickness of the potassium sodium niobate layer formed in one step is 100 nm or less, and the heating rate of the first heat treatment is 100 ° C./min or more.
  • a method for producing a ferroelectric thin film characterized in that the temperature increase rate of the second heat treatment is 15 ° C./min or less.
  • the present invention has a leakage current of 2.5 ⁇ 10 5 when a voltage of 100 kV / cm of electric field strength is applied, the main component of which is potassium sodium niobate represented by the general formula (K, Na) NbO 3. -7
  • K, Na potassium sodium niobate represented by the general formula (K, Na) NbO 3.
  • potassium sodium niobate has a perovskite structure, and although the molar ratio of (K, Na) to Nb is basically 1: 1, it is 1: It may be off from 1 (stoichiometric ratio).
  • the first heat treatment (drying treatment) is rapidly performed at a temperature increase rate of 100 ° C./min or more.
  • the second heat treatment (firing treatment) is performed slowly at a rate of temperature increase of 15 ° C./min or less.
  • the complex formed by reflux is in a stable state up to a relatively high temperature, and decomposes rapidly at around 500 ° C.
  • the temperature increase rate of the second heat treatment is high, the volume reduction rate becomes high, and the surface smoothness of the potassium sodium niobate thin film is remarkably deteriorated. Therefore, by setting the rate of temperature rise at the temperature at which the complex is decomposed to 15 ° C./min or less, the rate of volume reduction by heating is reduced, and the surface smoothness of the potassium sodium niobate thin film is improved.
  • potassium sodium niobate has poor sinterability. Therefore, if the film thickness before firing is large, K and Na are not uniformly distributed in the potassium sodium niobate thin film when fired. More specifically, an Na excess layer is formed on the upper part of the potassium sodium niobate thin film, and a K excess layer is easily formed on the lower part. Therefore, by setting the thickness of the potassium sodium niobate layer obtained after the end of one firing to 100 nm or less, nonuniform distribution of K and Na is suppressed, and the leakage current characteristics of the potassium sodium niobate thin film Ferroelectric properties are improved.
  • the surface smoothness of the potassium sodium niobate thin film is improved and the non-uniform distribution of K and Na in the potassium sodium niobate thin film is suppressed, so that excellent leakage current characteristics and ferroelectric characteristics are obtained.
  • a potassium sodium niobate thin film having the following is obtained:
  • FIG. 1 is a flowchart showing an embodiment of a method for manufacturing a ferroelectric thin film according to the present invention.
  • FIG. 2 is a schematic cross-sectional view of a piezoelectric thin film element 10 having a ferroelectric thin film obtained by the manufacturing method of FIG.
  • the piezoelectric thin film element 10 includes a substrate 12, a lower electrode 14 formed on the substrate 12, a ferroelectric thin film 16 formed on the lower electrode 14, and an upper electrode 18 formed on the ferroelectric thin film 16. It is composed of.
  • a silicon substrate (Si substrate) is used as the substrate 12.
  • the substrate 12 may be a substrate such as a glass substrate, a quartz glass substrate, a GaAs substrate, a GaN substrate, a CaF 2 substrate, a sapphire substrate, an MgO substrate, a SrTiO 3 substrate, a LaAlO 3 substrate, or a stainless steel substrate.
  • the ferroelectric thin film 16, that is, the potassium sodium niobate (KNN) thin film 16, is formed by using a chemical solution deposition method.
  • Step S1 in FIG. 1 is a step of preparing a raw material for forming a potassium sodium niobate layer, which is the ferroelectric thin film 16.
  • the raw materials potassium ethoxide, sodium ethoxide, pentaethoxyniobium, and manganese acetylacetonate are 0.57: 0.67: 0.95 in molar ratio. : Prepared to be 0.02.
  • step S2 in FIG. 1 is a step of mixing the raw materials. That is, in step S2, raw materials potassium ethoxide, sodium ethoxide, pentaethoxyniobium, and manganese acetylacetonate are mixed in a 2-methoxyethanol solvent in a glove box.
  • step S3 in FIG. 1 a potassium sodium niobate precursor solution is prepared. That is, in step S3, the mixed solution is refluxed at 125 ° C. for 16 hours in a nitrogen atmosphere, whereby a 0.3 M concentration potassium sodium niobate (KNN) precursor solution (also known as a chemical solution deposition solution) is obtained. Called).
  • KNN potassium sodium niobate
  • step S4 in FIG. 1 is a step of forming the lower electrode 14 on the substrate. That is, in step S4, the lower electrode 14 is formed on the Si substrate 12 by magnetron DC sputtering. As a material of the lower electrode 14, Pt or the like is used.
  • the sputtering conditions are a sputtering output of 100 W, a sputtering time of 5 minutes, a temperature of the substrate 12 of 300 ° C., and a degree of vacuum of 5 millitorr. At this time, the thickness of the lower electrode 14 was 250 nm.
  • step S5 in FIG. 1 is a step of applying the chemical solution deposition solution created in step 3 to the lower electrode. That is, in step S5, the potassium sodium niobate precursor solution is spin-coated on the lower electrode 14 in a dry gas.
  • the thickness of the film to which the chemical solution deposition solution is applied is such that the thickness of the fired potassium sodium niobate layer 16a is 100 nm or less.
  • the film thickness of the chemical solution deposition solution applied to form the potassium sodium niobate layer 16a is preferably 5 nm to 120 nm.
  • a first heat treatment (preliminary heat treatment or drying treatment) is performed.
  • the first heat treatment step which is Step S6, is performed at a temperature increase temperature of 100 ° C./min or more. That is, the potassium sodium niobate precursor solution applied on the lower electrode 14 was heated at a rate of temperature increase of 100 ° C./min or higher using a hot plate previously heated to a temperature of 350 ° C. For 3 minutes.
  • the temperature increase rate of the process of 1st heat processing 100 to 3000 degreeC / min is preferable.
  • step S7 in FIG. 1 is a step of performing the second heat treatment (main heat treatment or firing treatment) to form the potassium sodium niobate layer 16a.
  • the step of the second heat treatment which is Step S7, is performed at a temperature increase rate of 15 ° C./min or less. That is, the dried potassium sodium niobate precursor film has a temperature increase of 15 ° C./min or less in the temperature range of 350 ° C. to 700 ° C. (including the temperature around 500 ° C. at which the complex formed by reflux is rapidly decomposed).
  • the temperature is increased at a temperature rate, and firing is performed at a temperature of 700 ° C. for 10 minutes.
  • the temperature increase rate in the second heat treatment step is preferably 0.1 ° C./min or more and 15 ° C./min or less.
  • the potassium sodium niobate layer 16a is formed.
  • the thickness of the potassium sodium niobate layer 16a formed in one step is 100 nm or less.
  • 4 nm or more and 100 nm or less are preferable.
  • step S8 in FIG. 1 is a step of determining whether or not the formation of the potassium sodium niobate layer 16a in steps S5 to S7 has been repeated a predetermined number of times. That is, in step S8, it is determined whether or not the process of forming the potassium sodium niobate layer 16a has been repeated a predetermined number of times. If the predetermined number of times has not been reached, the process returns to step S5 and again the potassium sodium niobate layer 16a. The process of forming 16a is performed. On the contrary, if the predetermined number of times has been reached, it is determined that the potassium sodium niobate thin film 16 having a predetermined thickness has been formed, and the process proceeds to the next step S9.
  • step S9 in FIG. 1 is a step of forming the upper electrode 18 on the potassium sodium niobate thin film 16 formed by the above steps.
  • the upper electrode 18 is formed on the potassium sodium niobate thin film 16 by magnetron DC sputtering.
  • a material of the upper electrode 18 Pt or the like is used.
  • the sputtering conditions are a sputtering output of 100 W, a sputtering time of 5 minutes, a temperature of the substrate 12 of 150 ° C., and a degree of vacuum of 5 millitorr. At this time, the film thickness of the upper electrode 18 was formed at 250 nm. Thus, the piezoelectric thin film element 10 is obtained.
  • the first heat treatment (drying treatment) is rapidly performed at a temperature increase rate of 100 ° C./min or more.
  • hydrolysis of the raw material in the chemical solution deposition solution that has not reacted when refluxed is suppressed, and the prepared potassium sodium niobate thin film 16 has improved surface smoothness and leakage current. Characteristics and ferroelectric characteristics are improved.
  • the second heat treatment (firing treatment) is performed slowly at a rate of temperature increase of 15 ° C./min or less.
  • the rate of temperature rise at the temperature at which the complex decomposes (around 500 ° C.) to 15 ° C./min or less, the rate of volume reduction due to heating is reduced, and the surface smoothness of the potassium sodium niobate thin film 16 is reduced. improves.
  • the thickness of the potassium sodium niobate layer 16a obtained after the completion of one firing is set to 100 nm or less, the uneven distribution of K and Na is suppressed, and the leakage current of the potassium sodium niobate thin film 16 is reduced. Characteristics and ferroelectric characteristics are improved.
  • Table 1 shows that after the first heat treatment, the potassium sodium niobate precursor solution was rapidly heated to 350 ° C. and dried at 350 ° C. for 3 minutes using a hot plate at a heating rate of 100 ° C./min or more.
  • the surface roughness of the potassium sodium niobate thin film 16 and the leak current value in an electric field of 100 kV / cm when the temperature increase rate of the second heat treatment is variously changed are shown.
  • the rate of temperature increase in the second heat treatment is 100 ° C./min (sample number 1), 50 ° C./min (sample number 2), 30 ° C./min (sample number 3), 15 ° C./min (sample number 4), 10 C./min (sample number 5) and 5 ° C./min (sample number 6).
  • the surface roughness (arithmetic mean roughness Ra) of the potassium sodium niobate thin film 16 was measured using a scanning probe microscope “NanoScope” (trade name, manufactured by Digital Instruments).
  • the leakage current value in an electric field of 100 kV / cm was measured using a measuring apparatus “Electrometer 6517 type” (trade name, manufactured by Keithley). When the arithmetic average roughness Ra was 4 nm or less and the leakage current was 1 ⁇ 10 ⁇ 5 A / cm 2 or less, it was determined as a good product (G), and otherwise it was determined as a defective product (NG
  • the surface of the potassium sodium niobate thin film 16 becomes white and the surface roughness is too large.
  • the arithmetic average roughness Ra could not be measured.
  • the leak current value also increased as it exceeded the allowable measurement current value of the measuring apparatus, and could not be measured.
  • the potassium sodium niobate thin film 16 of sample number 3 has an arithmetic average roughness Ra of 8.6 nm and a leakage current value of 4.5 ⁇ 10 ⁇ 3 A / cm 2, which is a very large value. It was.
  • the heating rate of the second heat treatment is 15 ° C./min or less, such as Sample No. 4, Sample No. 5 and Sample No. 6 in the scope of the present invention
  • the arithmetic average The roughness Ra is 3.2 nm, 3.1 nm and 3.0 nm, and the leakage current values are 1.1 ⁇ 10 ⁇ 7 A / cm 2 , 7.7 ⁇ 10 ⁇ 8 A / cm 2 and 5.7 ⁇ . It was 10 ⁇ 8 A / cm 2 , which was a very small value.
  • the rate of temperature increase in the second heat treatment is as low as 15 ° C./min or less, the rate of volume change of potassium sodium niobate during firing becomes slow, and the arithmetic average roughness Ra and the leakage current value Is improved.
  • the potassium sodium niobate thin film 16 of sample numbers 1 to 6 was examined for the distribution of K and Na in the cross section by the energy dispersive X-ray spectroscopy (EDX) method.
  • EDX energy dispersive X-ray spectroscopy
  • K and Na were distributed unevenly.
  • the potassium sodium niobate thin film 16 of Sample No. 3 also showed an improvement compared to Sample Nos. 1 and 2, but K and Na were distributed unevenly.
  • K and Na were uniformly distributed.
  • Table 2 shows that after the first heat treatment, the potassium sodium niobate precursor solution was slowly heated to 350 ° C. and dried at 350 ° C. for 3 minutes at a heating rate of 10 ° C./min using a hot plate.
  • the surface roughness of the potassium sodium niobate thin film 16 and the leak current value in an electric field of 100 kV / cm when the temperature increase rate of the second heat treatment is variously changed are shown.
  • the heating rate of the second heat treatment is 100 ° C./min (sample number 7), 50 ° C./min (sample number 8), 30 ° C./min (sample number 9), 15 ° C./min (sample number 10), 10 C./min (sample number 11) and 5 ° C./min (sample number 12).
  • Table 3 shows the surface roughness of the potassium sodium niobate thin film 16 and the electric field of 100 kV / cm when the thickness of the potassium sodium niobate layer 16a obtained by one application, drying and baking is variously changed.
  • the thickness of the potassium sodium niobate layer 16a is 300 nm (sample number 13), 150 nm (sample number 14), 100 nm (sample number 15), 50 nm (sample number 6), and 30 nm (sample number 16). Note that the number of coating, drying, and firing was adjusted so that the final film thickness of the potassium sodium niobate thin film 16 was 300 nm.
  • the arithmetic average roughness Ra was a good value of 3.0 to 3.3 nm in all samples.
  • the leakage current value is 2.9 ⁇ 10 ⁇ 3 A / cm 2 and 8 .9 ⁇ 10 ⁇ 4 / cm 2 and a large value.
  • the thickness of the potassium sodium niobate layer 16a obtained after one firing is 100 nm or less as in Sample No. 15, Sample No. 6 and Sample No. 16, the leakage current value is 2.5 ⁇ 10. -7 A / cm 2 , 5.7 ⁇ 10 ⁇ 8 A / cm 2, and 3.4 ⁇ 10 ⁇ 8 / cm 2 , showing better leakage current characteristics than Sample Nos. 13 and 14.
  • the reason for obtaining a good leak current is that the non-uniform distribution of K and Na is improved by reducing the thickness of the potassium sodium niobate layer 16a obtained after one firing to 100 nm or less. This is because the.
  • the rate of temperature increase in the first heat treatment and the second heat treatment and the thickness of the potassium sodium niobate layer 16a obtained after one firing are set within the scope of the present invention, so that the surface smoothness is achieved. It is possible to produce a potassium sodium niobate thin film having excellent properties and insulation properties.
  • FIG. 3 shows that the hysteresis curve of the potassium sodium niobate thin film 16 of sample number 3 (defective product) and sample number 5 (good product) is a ferroelectric measuring device “Precision Premeal II” (trade name, manufactured by Radian Technology). ) Shows the result of measurement.
  • the present invention improves the surface smoothness and insulation of the potassium sodium niobate thin film 16 to provide a ferroelectric thin film element or piezoelectric thin film element having excellent ferroelectric characteristics. realizable.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Ceramic Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Dispersion Chemistry (AREA)
  • Semiconductor Memories (AREA)
  • Formation Of Insulating Films (AREA)

Abstract

[Problem] To provide a ferroelectric thin film having excellent electrical characteristics, and a method for producing the ferroelectric thin film. [Solution] A first heat treatment (drying process) is implemented in step S6. A potassium sodium niobate precursor solution, which has been applied on a lower electrode, is heated up at a rate of temperature increase of at least 100°C/minute using a hot plate that has been pre-heated to a temperature of 350°C, and dried for three minutes. Next, a second heat treatment (baking process) is implemented in step S7. The dried potassium sodium niobate precursor film is heated up to 350°C at a rate of temperature increase of at least 100°C/minute using a heated hot plate. The potassium sodium niobate precursor film is then heated up at a rate of temperature increase of not more than 15°C/minute within a temperature range of 350°C to 700°C, and baked for 10 minutes at 700°C. A potassium sodium niobate layer is thus formed. The thickness of the potassium sodium niobate layer formed in a single application of the abovementioned step is 100 nm or less.

Description

強誘電体薄膜およびその製造方法Ferroelectric thin film and manufacturing method thereof
　本発明は、圧電体薄膜素子などに用いられる強誘電体薄膜およびその製造方法に関する。 The present invention relates to a ferroelectric thin film used for a piezoelectric thin film element and a manufacturing method thereof.
　圧電体は、現在、アクチュエータやセンサ等の機能性電子部品の材料として幅広く利用されている。これらの用途に用いられる圧電体材料として、ＰＺＴと称される一般式Ｐｂ（Ｚｒ，Ｔｉ）Ｏ3で表示されるペロブスカイト型強誘電体材料が、主に用いられている。ところが、ＰＺＴは、有害なＰｂ（鉛）を含んでいるため、自然環境の保護上好ましくない材料である。 Piezoelectric materials are currently widely used as materials for functional electronic parts such as actuators and sensors. As a piezoelectric material used for these applications, a perovskite ferroelectric material represented by a general formula Pb (Zr, Ti) O 3 called PZT is mainly used. However, since PZT contains harmful Pb (lead), it is an undesirable material for protecting the natural environment.
　そこで、現在、様々な非鉛圧電体材料の研究開発が活発に行われている。この非鉛圧電体材料の中の一つが、ＫＮＮと称される一般式（Ｋ，Ｎａ）ＮｂＯ3で表示されるペロブスカイト型強誘電体材料である。ＫＮＮ（ニオブ酸カリウムナトリウム）は、ＰＺＴに匹敵する圧電特性を示すため、非常に注目されている。ニオブ酸カリウムナトリウム（ＫＮＮ）薄膜は、現在、スパッタリング法、パルスレーザー堆積（ｐｕｌｓｅ　ｌａｓｅｒ　ｄｅｐｏｓｉｔｉｏｎ；ＰＬＤ）法、化学溶液堆積（ｃｈｅｍｉｃａｌ　ｓｏｌｕｔｉｏｎ　ｄｅｐｏｓｉｔｉｏｎ；ＣＳＤ）法などの種々の方法で作成が試みられている。特に、化学溶液堆積（ＣＳＤ）法は、ニオブ酸カリウムナトリウム（ＫＮＮ）薄膜を容易に作成できるため、広く用いられている。 Therefore, research and development of various lead-free piezoelectric materials are currently being actively conducted. One of the lead-free piezoelectric materials is a perovskite ferroelectric material represented by a general formula (K, Na) NbO 3 called KNN. KNN (potassium sodium niobate) has received much attention because it exhibits piezoelectric properties comparable to PZT. A potassium sodium niobate (KNN) thin film is currently being prepared by various methods such as sputtering, pulse laser deposition (PLD), and chemical solution deposition (CSD). . In particular, the chemical solution deposition (CSD) method is widely used because a potassium sodium niobate (KNN) thin film can be easily formed.
　例えば、特許文献１には、化学溶液堆積（ＣＳＤ）法によるニオブ酸カリウムナトリウム（ＫＮＮ）薄膜の製造方法が提案されている。Ｋ／Ｎａ／Ｎｂ＝０．５５／０．５５／１の金属組成に相当するカリウムエトキシドとナトリウムエトキシドとペンタエトキシニオブとが、エタノールと２－メトキシエタノールとの等重量混合溶媒中で混合される。混合された溶液は、１２５℃で６時間還流されることによって、前駆体溶液となる。さらに、前駆体溶液は、図４に示すように、下部電極２４を設けた基板２２の表面上にスピンコート塗布（回転数：２０００ｒｐｍ）された後、４２０℃で１０分間乾燥される。この前駆体溶液の塗布および乾燥工程は、所定回数繰り返される。その後、上部電極２８の前駆体溶液が塗布され、６５０℃で１０分間焼成される。こうして、ニオブ酸カリウムナトリウム（ＫＮＮ）薄膜２６を有した圧電体薄膜素子２０が作成される。 For example, Patent Document 1 proposes a method for producing a potassium sodium niobate (KNN) thin film by a chemical solution deposition (CSD) method. Potassium ethoxide, sodium ethoxide and pentaethoxyniobium corresponding to a metal composition of K / Na / Nb = 0.55 / 0.55 / 1 were mixed in an equal weight mixed solvent of ethanol and 2-methoxyethanol. Is done. The mixed solution is refluxed at 125 ° C. for 6 hours to become a precursor solution. Further, as shown in FIG. 4, the precursor solution is spin-coated (rotation speed: 2000 rpm) on the surface of the substrate 22 provided with the lower electrode 24 and then dried at 420 ° C. for 10 minutes. This precursor solution application and drying steps are repeated a predetermined number of times. Thereafter, the precursor solution of the upper electrode 28 is applied and baked at 650 ° C. for 10 minutes. Thus, the piezoelectric thin film element 20 having the potassium sodium niobate (KNN) thin film 26 is produced.
特開２００９－１０３６７号公報JP 2009-10367 A
　しかし、従来の化学溶液堆積（ＣＳＤ）法は、高品質のニオブ酸カリウムナトリウム（ＫＮＮ）薄膜を作成することをできなかった。例えば、特許文献１は、前駆体溶液塗布および乾燥工程を合計２０回繰り返した後に、６５０℃で１０分間焼成してニオブ酸カリウムナトリウム薄膜２６を作成している。このように焼成前の膜厚が厚い場合、焼成した際に、ＫとＮａが、ニオブ酸カリウムナトリウム薄膜２６内に均一に分布しないという不具合がある。つまり、ニオブ酸カリウムナトリウム薄膜２６の上部にはＮａ過剰層２６ａが形成され、下部にはＫ過剰層２６ｂが形成され易い。このようなＫ、Ｎａの不均一な分布が発生すると、ニオブ酸カリウムナトリウム薄膜２６に所定の電圧を印加した時のリーク電流が急激に大きくなり、ニオブ酸カリウムナトリウム薄膜２６の強誘電体特性が低下する原因となる。 However, conventional chemical solution deposition (CSD) methods have failed to produce high quality potassium sodium niobate (KNN) thin films. For example, in Patent Document 1, the precursor solution coating and drying steps are repeated 20 times in total, and then fired at 650 ° C. for 10 minutes to form the potassium sodium niobate thin film 26. Thus, when the film thickness before baking is thick, there exists a malfunction that K and Na are not uniformly distributed in the potassium sodium niobate thin film 26, when baking. That is, the Na excess layer 26a is easily formed on the upper portion of the potassium sodium niobate thin film 26, and the K excess layer 26b is easily formed on the lower portion. When such a non-uniform distribution of K and Na occurs, the leakage current when a predetermined voltage is applied to the potassium sodium niobate thin film 26 increases rapidly, and the ferroelectric characteristics of the potassium sodium niobate thin film 26 are increased. It will cause a drop.
　それゆえに、本発明の目的は、優れた電気特性、特に、リーク電流特性および強誘電体特性に優れた強誘電体薄膜およびその製造方法を提供することである。 Therefore, an object of the present invention is to provide a ferroelectric thin film having excellent electrical characteristics, in particular, leakage current characteristics and ferroelectric characteristics, and a method for producing the same.
　本発明は、一般式（Ｋ，Ｎａ）ＮｂＯ3で表示されるニオブ酸カリウムナトリウム薄膜を、化学溶液堆積法を用いて形成する強誘電体薄膜の製造方法であって、
　化学溶液堆積用溶液を基板上に塗布して第一熱処理および第二熱処理をしてニオブ酸カリウムナトリウム層を形成する工程を有し、前記工程を所定回数繰り返してニオブ酸カリウムナトリウム層を積層してニオブ酸カリウムナトリウム薄膜を形成し、前記工程１回で形成されるニオブ酸カリウムナトリウム層の厚みが１００ｎｍ以下であり、かつ、第一熱処理の昇温速度が１００℃／分以上であり、第二熱処理の昇温速度が１５℃／分以下であること、を特徴とする、強誘電体薄膜の製造方法である。
　また、本発明は、一般式（Ｋ，Ｎａ）ＮｂＯ3で表示されるニオブ酸カリウムナトリウムを主成分とし、かつ、電界強度１００ｋＶ／ｃｍの電圧を印加した際のリーク電流が２．５×１０-7Ａ／ｃｍ2以下である、強誘電体薄膜である。 The present invention is a method for producing a ferroelectric thin film, wherein a potassium sodium niobate thin film represented by the general formula (K, Na) NbO 3 is formed using a chemical solution deposition method,
A chemical solution deposition solution is applied on a substrate, and a first heat treatment and a second heat treatment are performed to form a potassium sodium niobate layer. The above steps are repeated a predetermined number of times to laminate a potassium sodium niobate layer. Forming a potassium sodium niobate thin film, the thickness of the potassium sodium niobate layer formed in one step is 100 nm or less, and the heating rate of the first heat treatment is 100 ° C./min or more. A method for producing a ferroelectric thin film, characterized in that the temperature increase rate of the second heat treatment is 15 ° C./min or less.
In addition, the present invention has a leakage current of 2.5 × 10 5 when a voltage of 100 kV / cm of electric field strength is applied, the main component of which is potassium sodium niobate represented by the general formula (K, Na) NbO 3. -7 A ferroelectric thin film of A / cm 2 or less.
　ここで、ニオブ酸カリウムナトリウムは、ペロブスカイト構造であり、（Ｋ，Ｎａ）とＮｂとのモル比は基本的に１：１であるけれども、本発明の作用効果を損なわない程度にて、１：１（化学量論比）から外れてもよい。 Here, potassium sodium niobate has a perovskite structure, and although the molar ratio of (K, Na) to Nb is basically 1: 1, it is 1: It may be off from 1 (stoichiometric ratio).
　本発明では、化学溶液堆積用溶液が、基板上に塗布された後、第一熱処理（乾燥処理）が、１００℃／分以上の昇温速度で急速に実行される。これにより、還流されたときに未反応であった、化学溶液堆積用溶液中の原料の加水分解が抑えられ、作成されたニオブ酸カリウムナトリウム薄膜は、その表面平滑性が向上し、リーク電流特性や強誘電体特性が向上する。 In the present invention, after the chemical solution deposition solution is applied on the substrate, the first heat treatment (drying treatment) is rapidly performed at a temperature increase rate of 100 ° C./min or more. As a result, hydrolysis of the raw material in the chemical solution deposition solution, which was unreacted when refluxed, is suppressed, and the prepared potassium sodium niobate thin film has improved surface smoothness and leakage current characteristics. And ferroelectric properties are improved.
　さらに、本発明では、第一熱処理の後に、第二熱処理（焼成処理）が、１５℃／分以下の昇温速度で緩慢に実行される。還流により形成される錯体は、比較的高温まで安定な状態であり、５００℃付近で急激に分解する。その時、大きな体積減少を伴うため、第二熱処理の昇温速度が速い場合、体積減少の速度が速くなり、ニオブ酸カリウムナトリウム薄膜の表面平滑性が著しく悪化する。そこで、錯体が分解する温度での昇温速度が、１５℃／分以下に設定されることによって、加熱による体積減少の速度が遅くなり、ニオブ酸カリウムナトリウム薄膜の表面平滑性が向上する。 Furthermore, in the present invention, after the first heat treatment, the second heat treatment (firing treatment) is performed slowly at a rate of temperature increase of 15 ° C./min or less. The complex formed by reflux is in a stable state up to a relatively high temperature, and decomposes rapidly at around 500 ° C. At this time, since a large volume reduction is accompanied, when the temperature increase rate of the second heat treatment is high, the volume reduction rate becomes high, and the surface smoothness of the potassium sodium niobate thin film is remarkably deteriorated. Therefore, by setting the rate of temperature rise at the temperature at which the complex is decomposed to 15 ° C./min or less, the rate of volume reduction by heating is reduced, and the surface smoothness of the potassium sodium niobate thin film is improved.
　また、ニオブ酸カリウムナトリウムは難焼結性を有する。従って、仮に、焼成前の膜厚が厚いならば、焼成した際に、ＫとＮａがニオブ酸カリウムナトリウム薄膜中に均一に分布しない。より具体的には、ニオブ酸カリウムナトリウム薄膜の上部にはＮａ過剰層が形成され、下部にはＫ過剰層が形成され易い。そこで、１回の焼成の終了後に得られるニオブ酸カリウムナトリウム層の厚みが、１００ｎｍ以下に設定されることによって、ＫとＮａの不均一分布が抑えられ、ニオブ酸カリウムナトリウム薄膜のリーク電流特性や強誘電体特性が向上する。 Also, potassium sodium niobate has poor sinterability. Therefore, if the film thickness before firing is large, K and Na are not uniformly distributed in the potassium sodium niobate thin film when fired. More specifically, an Na excess layer is formed on the upper part of the potassium sodium niobate thin film, and a K excess layer is easily formed on the lower part. Therefore, by setting the thickness of the potassium sodium niobate layer obtained after the end of one firing to 100 nm or less, nonuniform distribution of K and Na is suppressed, and the leakage current characteristics of the potassium sodium niobate thin film Ferroelectric properties are improved.
　本発明によれば、ニオブ酸カリウムナトリウム薄膜の表面平滑性が向上され、かつ、ニオブ酸カリウムナトリウム薄膜中のＫ、Ｎａの不均一分布が抑えられるため、優れたリーク電流特性や強誘電体特性を有するニオブ酸カリウムナトリウム薄膜が得られる。 According to the present invention, the surface smoothness of the potassium sodium niobate thin film is improved and the non-uniform distribution of K and Na in the potassium sodium niobate thin film is suppressed, so that excellent leakage current characteristics and ferroelectric characteristics are obtained. A potassium sodium niobate thin film having the following is obtained:
　この発明の上述の目的，その他の目的，特徴および利点は、図面を参照して行う以下の発明を実施するための形態の説明から一層明らかとなろう。 The above-described object, other objects, features, and advantages of the present invention will become more apparent from the following description of embodiments for carrying out the invention with reference to the drawings.
本発明に係る強誘電体薄膜の製造方法の一実施形態を示すフローチャートである。It is a flowchart which shows one Embodiment of the manufacturing method of the ferroelectric thin film based on this invention. 図１の製造方法で得られた圧電体薄膜素子の断面図である。It is sectional drawing of the piezoelectric material thin film element obtained with the manufacturing method of FIG. 圧電体薄膜素子のヒステリシス曲線を示すグラフである。It is a graph which shows the hysteresis curve of a piezoelectric material thin film element. 従来の製造方法で得られた圧電体薄膜素子の断面図である。It is sectional drawing of the piezoelectric material thin film element obtained with the conventional manufacturing method.
　　１０　圧電体薄膜素子
　　１２　基板
　　１４　下部電極
　　１６　ニオブ酸カリウムナトリウム薄膜
　　１６ａ　ニオブ酸カリウムナトリウム層
　　１８　上部電極 DESCRIPTION OF SYMBOLS 10 Piezoelectric thin film element 12 Substrate 14 Lower electrode 16 Potassium sodium niobate thin film 16a Potassium sodium niobate layer 18 Upper electrode
　（ニオブ酸カリウムナトリウム薄膜の製造）
　図１は、本発明に係る強誘電体薄膜の製造方法の一実施形態を示すフローチャートである。図２は、図１の製造方法で得られた強誘電体薄膜を有する圧電体薄膜素子１０の概略構成断面図である。圧電体薄膜素子１０は、基板１２、基板１２上に形成された下部電極１４、下部電極１４上に形成された強誘電体薄膜１６、および、強誘電体薄膜１６上に形成された上部電極１８にて構成されている。 (Production of potassium sodium niobate thin film)
FIG. 1 is a flowchart showing an embodiment of a method for manufacturing a ferroelectric thin film according to the present invention. FIG. 2 is a schematic cross-sectional view of a piezoelectric thin film element 10 having a ferroelectric thin film obtained by the manufacturing method of FIG. The piezoelectric thin film element 10 includes a substrate 12, a lower electrode 14 formed on the substrate 12, a ferroelectric thin film 16 formed on the lower electrode 14, and an upper electrode 18 formed on the ferroelectric thin film 16. It is composed of.
　基板１２は、例えば、シリコン基板（Ｓｉ基板）が用いられる。なお、基板１２は、ガラス基板、石英ガラス基板、ＧａＡｓ基板、ＧａＮ基板、ＣａＦ2基板、サファイア基板、ＭｇＯ基板、ＳｒＴｉＯ3基板、ＬａＡｌＯ3基板、ステンレス基板などの基板を用いてもよい。 For example, a silicon substrate (Si substrate) is used as the substrate 12. The substrate 12 may be a substrate such as a glass substrate, a quartz glass substrate, a GaAs substrate, a GaN substrate, a CaF 2 substrate, a sapphire substrate, an MgO substrate, a SrTiO 3 substrate, a LaAlO 3 substrate, or a stainless steel substrate.
　強誘電体薄膜１６、すなわち、ニオブ酸カリウムナトリウム（ＫＮＮ）薄膜１６は、化学溶液堆積法を用いて作成される。図１におけるステップＳ１は、強誘電体薄膜１６であるニオブ酸カリウムナトリウム層を形成するための原料を準備する工程である。まず、図１に示すように、ステップＳ１で、原料であるカリウムエトキシド、ナトリウムエトキシド、ペンタエトキシニオブ、および、マンガンアセチルアセトナトが、モル比で０．５７：０．６７：０．９５：０．０２となるように準備される。 The ferroelectric thin film 16, that is, the potassium sodium niobate (KNN) thin film 16, is formed by using a chemical solution deposition method. Step S1 in FIG. 1 is a step of preparing a raw material for forming a potassium sodium niobate layer, which is the ferroelectric thin film 16. First, as shown in FIG. 1, in step S1, the raw materials potassium ethoxide, sodium ethoxide, pentaethoxyniobium, and manganese acetylacetonate are 0.57: 0.67: 0.95 in molar ratio. : Prepared to be 0.02.
　次に、図１におけるステップＳ２は、上記原料を混合する工程である。すなわち、ステップＳ２で、原料のカリウムエトキシド、ナトリウムエトキシド、ペンタエトキシニオブ、および、マンガンアセチルアセトナトが、グローブボックスの中で、２－メトキシエタノール溶媒に混合される。 Next, step S2 in FIG. 1 is a step of mixing the raw materials. That is, in step S2, raw materials potassium ethoxide, sodium ethoxide, pentaethoxyniobium, and manganese acetylacetonate are mixed in a 2-methoxyethanol solvent in a glove box.
　次に、図１におけるステップＳ３は、ニオブ酸カリウムナトリウム前駆体溶液が作成される。すなわち、ステップＳ３で、その混合溶液は、窒素雰囲気中において、１２５℃で１６時間還流されることによって、濃度が０．３Ｍのニオブ酸カリウムナトリウム（ＫＮＮ）前駆体溶液（化学溶液堆積用溶液とも称される）とされる。 Next, in step S3 in FIG. 1, a potassium sodium niobate precursor solution is prepared. That is, in step S3, the mixed solution is refluxed at 125 ° C. for 16 hours in a nitrogen atmosphere, whereby a 0.3 M concentration potassium sodium niobate (KNN) precursor solution (also known as a chemical solution deposition solution) is obtained. Called).
　一方、図１におけるステップＳ４は、基板上に下部電極１４を形成する工程である。すなわち、ステップＳ４で、下部電極１４が、Ｓｉ基板１２上に、マグネトロンＤＣスパッタリング法によって形成される。下部電極１４の材料としては、Ｐｔなどが用いられる。スパッタリング条件は、スパッタ出力が１００Ｗ、スパッタ時間が５分、基板１２の温度が３００℃、真空度が５ミリｔｏｒｒである。このとき、下部電極１４の膜厚は、２５０ｎｍで形成された。 On the other hand, step S4 in FIG. 1 is a step of forming the lower electrode 14 on the substrate. That is, in step S4, the lower electrode 14 is formed on the Si substrate 12 by magnetron DC sputtering. As a material of the lower electrode 14, Pt or the like is used. The sputtering conditions are a sputtering output of 100 W, a sputtering time of 5 minutes, a temperature of the substrate 12 of 300 ° C., and a degree of vacuum of 5 millitorr. At this time, the thickness of the lower electrode 14 was 250 nm.
　次に、図１におけるステップＳ５は、ステップ３において作成された化学溶液堆積用溶液を下部電極１４に塗布する工程である。すなわち、ステップＳ５で、ニオブ酸カリウムナトリウム前駆体溶液が、乾燥ガス中において、下部電極１４上にスピンコート塗布される。ここで、化学溶液堆積用溶液を塗布する膜厚の厚さは、焼成後のニオブ酸カリウムナトリウム層１６ａの膜厚が１００ｎｍ以下となるような厚さである。なお、ニオブ酸カリウムナトリウム層１６ａを形成するために塗布される化学溶液堆積用溶液の膜厚は、５ｎｍ以上１２０ｎｍ以下が好ましい。 Next, step S5 in FIG. 1 is a step of applying the chemical solution deposition solution created in step 3 to the lower electrode. That is, in step S5, the potassium sodium niobate precursor solution is spin-coated on the lower electrode 14 in a dry gas. Here, the thickness of the film to which the chemical solution deposition solution is applied is such that the thickness of the fired potassium sodium niobate layer 16a is 100 nm or less. The film thickness of the chemical solution deposition solution applied to form the potassium sodium niobate layer 16a is preferably 5 nm to 120 nm.
　次に、図１におけるステップＳ６で、第一熱処理（予備熱処理または乾燥処理）を実行する工程である。このステップＳ６である第一熱処理の工程は、昇温温度が１００℃／分以上で実行される。すなわち、下部電極１４上に塗布されたニオブ酸カリウムナトリウム前駆体溶液が、予め３５０℃の温度に加熱されたホットプレートを用いて、昇温速度が１００℃／分以上で昇温され、３５０℃で３分間乾燥される。なお、第一熱処理の工程の昇温速度は、１００℃／分以上３０００℃／分以下が好ましい。 Next, in step S6 in FIG. 1, a first heat treatment (preliminary heat treatment or drying treatment) is performed. The first heat treatment step, which is Step S6, is performed at a temperature increase temperature of 100 ° C./min or more. That is, the potassium sodium niobate precursor solution applied on the lower electrode 14 was heated at a rate of temperature increase of 100 ° C./min or higher using a hot plate previously heated to a temperature of 350 ° C. For 3 minutes. In addition, as for the temperature increase rate of the process of 1st heat processing, 100 to 3000 degreeC / min is preferable.
　次に、図１におけるステップＳ７は、第二熱処理（本熱処理または焼成処理）を実行し、ニオブ酸カリウムナトリウム層１６ａを形成する工程である。このステップＳ７である第二熱処理の工程は、昇温速度が１５℃／分以下で実行される。すなわち、乾燥されたニオブ酸カリウムナトリウム前駆体膜は、３５０℃～７００℃の温度範囲（還流により形成される錯体が急激に分解する温度５００℃付近を含む）において、１５℃／分以下の昇温速度で昇温され、７００℃の温度で１０分間焼成される。なお、第二熱処理の工程の昇温速度は、０．１℃／分以上１５℃／分以下が好ましい。 Next, step S7 in FIG. 1 is a step of performing the second heat treatment (main heat treatment or firing treatment) to form the potassium sodium niobate layer 16a. The step of the second heat treatment, which is Step S7, is performed at a temperature increase rate of 15 ° C./min or less. That is, the dried potassium sodium niobate precursor film has a temperature increase of 15 ° C./min or less in the temperature range of 350 ° C. to 700 ° C. (including the temperature around 500 ° C. at which the complex formed by reflux is rapidly decomposed). The temperature is increased at a temperature rate, and firing is performed at a temperature of 700 ° C. for 10 minutes. In addition, the temperature increase rate in the second heat treatment step is preferably 0.1 ° C./min or more and 15 ° C./min or less.
　こうして、ニオブ酸カリウムナトリウム層１６ａが形成される。前記工程１回で形成されるニオブ酸カリウムナトリウム層１６ａの厚みは、１００ｎｍ以下である。なお、焼成後である前記工程１回で形成されるニオブ酸カリウムナトリウム層１６ａの厚みは、４ｎｍ以上１００ｎｍ以下が好ましい。 Thus, the potassium sodium niobate layer 16a is formed. The thickness of the potassium sodium niobate layer 16a formed in one step is 100 nm or less. In addition, as for the thickness of the potassium sodium niobate layer 16a formed by the said process 1 time after baking, 4 nm or more and 100 nm or less are preferable.
　次に、図１におけるステップＳ８は、ステップＳ５ないしステップＳ７によるニオブ酸カリウムナトリウム層１６ａの形成を所定回数繰り返されたか否かを判定する工程である。すなわち、ステップＳ８で、ニオブ酸カリウムナトリウム層１６ａを形成する前記工程が、所定回数繰り返されたか否かが判定され、所定回数に達していなければ、ステップＳ５に戻って、再びニオブ酸カリウムナトリウム層１６ａを形成する前記工程が実行される。逆に、所定回数に達していれば、所定の膜厚のニオブ酸カリウムナトリウム薄膜１６が形成されたと判断され、次のステップＳ９に移行される。 Next, step S8 in FIG. 1 is a step of determining whether or not the formation of the potassium sodium niobate layer 16a in steps S5 to S7 has been repeated a predetermined number of times. That is, in step S8, it is determined whether or not the process of forming the potassium sodium niobate layer 16a has been repeated a predetermined number of times. If the predetermined number of times has not been reached, the process returns to step S5 and again the potassium sodium niobate layer 16a. The process of forming 16a is performed. On the contrary, if the predetermined number of times has been reached, it is determined that the potassium sodium niobate thin film 16 having a predetermined thickness has been formed, and the process proceeds to the next step S9.
　次に、図１におけるステップＳ９は、上記ステップにより形成されたニオブ酸カリウムナトリウム薄膜１６に上部電極１８を形成する工程である。ステップＳ９で、上部電極１８が、ニオブ酸カリウムナトリウム薄膜１６上に、マグネトロンＤＣスパッタリング法によって形成される。上部電極１８の材料としては、Ｐｔなどが用いられる。スパッタリング条件は、スパッタ出力が１００Ｗ、スパッタ時間が５分、基板１２の温度が１５０℃、真空度が５ミリｔｏｒｒである。このとき、上部電極１８の膜厚は、２５０ｎｍで形成された。
　こうして、圧電体薄膜素子１０が得られる。 Next, step S9 in FIG. 1 is a step of forming the upper electrode 18 on the potassium sodium niobate thin film 16 formed by the above steps. In step S9, the upper electrode 18 is formed on the potassium sodium niobate thin film 16 by magnetron DC sputtering. As a material of the upper electrode 18, Pt or the like is used. The sputtering conditions are a sputtering output of 100 W, a sputtering time of 5 minutes, a temperature of the substrate 12 of 150 ° C., and a degree of vacuum of 5 millitorr. At this time, the film thickness of the upper electrode 18 was formed at 250 nm.
Thus, the piezoelectric thin film element 10 is obtained.
　本発明では、化学溶液堆積用溶液が、基板１２上に塗布された後、第一熱処理（乾燥処理）が、１００℃／分以上の昇温速度で急速に実行される。これにより、還流されたときに未反応であった、化学溶液堆積用溶液中の原料の加水分解が抑えられ、作成されたニオブ酸カリウムナトリウム薄膜１６は、その表面平滑性が向上し、リーク電流特性や強誘電体特性が向上する。 In the present invention, after the chemical solution deposition solution is applied on the substrate 12, the first heat treatment (drying treatment) is rapidly performed at a temperature increase rate of 100 ° C./min or more. As a result, hydrolysis of the raw material in the chemical solution deposition solution that has not reacted when refluxed is suppressed, and the prepared potassium sodium niobate thin film 16 has improved surface smoothness and leakage current. Characteristics and ferroelectric characteristics are improved.
　さらに、本発明では、第一熱処理の後に、第二熱処理（焼成処理）が、１５℃／分以下の昇温速度で緩慢に実行される。錯体が分解する温度（５００℃付近）での昇温速度が、１５℃／分以下に設定されることによって、加熱による体積減少の速度が遅くなり、ニオブ酸カリウムナトリウム薄膜１６の表面平滑性が向上する。 Furthermore, in the present invention, after the first heat treatment, the second heat treatment (firing treatment) is performed slowly at a rate of temperature increase of 15 ° C./min or less. By setting the rate of temperature rise at the temperature at which the complex decomposes (around 500 ° C.) to 15 ° C./min or less, the rate of volume reduction due to heating is reduced, and the surface smoothness of the potassium sodium niobate thin film 16 is reduced. improves.
　また、１回の焼成の終了後に得られるニオブ酸カリウムナトリウム層１６ａの厚みが、１００ｎｍ以下に設定されることによって、ＫとＮａの不均一分布が抑えられ、ニオブ酸カリウムナトリウム薄膜１６のリーク電流特性や強誘電体特性が向上する。 Further, by setting the thickness of the potassium sodium niobate layer 16a obtained after the completion of one firing to 100 nm or less, the uneven distribution of K and Na is suppressed, and the leakage current of the potassium sodium niobate thin film 16 is reduced. Characteristics and ferroelectric characteristics are improved.
　（ニオブ酸カリウムナトリウム薄膜の評価）
　表１は、第一熱処理が、ホットプレートを用いて１００℃／分以上の昇温速度で、ニオブ酸カリウムナトリウム前駆体溶液を、急速に３５０℃に加熱して３５０℃で３分間乾燥した後、第二熱処理の昇温速度が種々に変更された場合の、ニオブ酸カリウムナトリウム薄膜１６の表面粗さ、および、１００ｋＶ／ｃｍの電界におけるリーク電流値を示す。第二熱処理の昇温速度は、１００℃／分（試料番号１）、５０℃／分（試料番号２）、３０℃／分（試料番号３）、１５℃／分（試料番号４）、１０℃／分（試料番号５）、および、５℃／分（試料番号６）である。ニオブ酸カリウムナトリウム薄膜１６の表面粗さ（算術平均粗さＲａ）は、走査型プローブ顕微鏡「ＮａｎｏＳｃｏｐｅ」（商品名、デジタル・インストルメンツ社製）を用いて測定した。１００ｋＶ／ｃｍの電界におけるリーク電流値は、測定装置「エレクトロメータ６５１７型」（商品名、ケイスレイ社製）を用いて測定した。算術平均粗さＲａが４ｎｍ以下で、かつ、リーク電流が１×１０-5Ａ／ｃｍ2以下の場合は、良品（Ｇ）、それ以外の場合は不良品（ＮＧ）と判定した。 (Evaluation of potassium sodium niobate thin film)
Table 1 shows that after the first heat treatment, the potassium sodium niobate precursor solution was rapidly heated to 350 ° C. and dried at 350 ° C. for 3 minutes using a hot plate at a heating rate of 100 ° C./min or more. The surface roughness of the potassium sodium niobate thin film 16 and the leak current value in an electric field of 100 kV / cm when the temperature increase rate of the second heat treatment is variously changed are shown. The rate of temperature increase in the second heat treatment is 100 ° C./min (sample number 1), 50 ° C./min (sample number 2), 30 ° C./min (sample number 3), 15 ° C./min (sample number 4), 10 C./min (sample number 5) and 5 ° C./min (sample number 6). The surface roughness (arithmetic mean roughness Ra) of the potassium sodium niobate thin film 16 was measured using a scanning probe microscope “NanoScope” (trade name, manufactured by Digital Instruments). The leakage current value in an electric field of 100 kV / cm was measured using a measuring apparatus “Electrometer 6517 type” (trade name, manufactured by Keithley). When the arithmetic average roughness Ra was 4 nm or less and the leakage current was 1 × 10 −5 A / cm 2 or less, it was determined as a good product (G), and otherwise it was determined as a defective product (NG).
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　試料番号１および試料番号２のニオブ酸カリウムナトリウム薄膜１６のように、第二熱処理の昇温速度が速い場合は、ニオブ酸カリウムナトリウム薄膜１６の表面が白くなり、表面粗さが大き過ぎるため、算術平均粗さＲａを測定することができなかった。リーク電流値も、測定装置の許容測定電流値を超えるほど大きくなり、測定することができなかった。また、試料番号３のニオブ酸カリウムナトリウム薄膜１６は、算術平均粗さＲａが８．６ｎｍであり、リーク電流値が４．５×１０-3Ａ／ｃｍ2であり、非常に大きな値であった。 When the heating rate of the second heat treatment is fast like the sample number 1 and sample number 2 potassium sodium niobate thin film 16, the surface of the potassium sodium niobate thin film 16 becomes white and the surface roughness is too large. The arithmetic average roughness Ra could not be measured. The leak current value also increased as it exceeded the allowable measurement current value of the measuring apparatus, and could not be measured. In addition, the potassium sodium niobate thin film 16 of sample number 3 has an arithmetic average roughness Ra of 8.6 nm and a leakage current value of 4.5 × 10 −3 A / cm 2, which is a very large value. It was.
　一方、本発明の範囲内である試料番号４、試料番号５および試料番号６のニオブ酸カリウムナトリウム薄膜１６のように、第二熱処理の昇温速度が１５℃／分以下のものは、算術平均粗さＲａが３．２ｎｍ、３．１ｎｍおよび３．０ｎｍであり、リーク電流値が１．１×１０-7Ａ／ｃｍ2、７．７×１０-8Ａ／ｃｍ2および５．７×１０-8Ａ／ｃｍ2であり、非常に小さい値であった。このように、第二熱処理（焼成処理）の昇温速度が１５℃／分以下と遅い場合、焼成時のニオブ酸カリウムナトリウムの体積変化の速度が遅くなり、算術平均粗さＲａおよびリーク電流値が改善される。 On the other hand, when the heating rate of the second heat treatment is 15 ° C./min or less, such as Sample No. 4, Sample No. 5 and Sample No. 6 in the scope of the present invention, the arithmetic average The roughness Ra is 3.2 nm, 3.1 nm and 3.0 nm, and the leakage current values are 1.1 × 10 −7 A / cm 2 , 7.7 × 10 −8 A / cm 2 and 5.7 ×. It was 10 −8 A / cm 2 , which was a very small value. Thus, when the rate of temperature increase in the second heat treatment (firing process) is as low as 15 ° C./min or less, the rate of volume change of potassium sodium niobate during firing becomes slow, and the arithmetic average roughness Ra and the leakage current value Is improved.
　また、試料番号１～試料番号６のニオブ酸カリウムナトリウム薄膜１６は、エネルギー分散Ｘ線分光（ＥＤＸ）法により、断面におけるＫとＮａの分布が調べられた。その結果、試料番号１および試料番号２のニオブ酸カリウムナトリウム薄膜１６は、ＫとＮａが不均一に分布していた。また、試料番号３のニオブ酸カリウムナトリウム薄膜１６も、試料番号１，２に比較すると改善は見られるけれども、ＫとＮａが不均一に分布していた。一方、本発明の範囲内である試料番号４～試料番号６のニオブ酸カリウムナトリウム薄膜１６は、ＫとＮａが均一に分布していた。 In addition, the potassium sodium niobate thin film 16 of sample numbers 1 to 6 was examined for the distribution of K and Na in the cross section by the energy dispersive X-ray spectroscopy (EDX) method. As a result, in the potassium sodium niobate thin film 16 of Sample No. 1 and Sample No. 2, K and Na were distributed unevenly. Further, the potassium sodium niobate thin film 16 of Sample No. 3 also showed an improvement compared to Sample Nos. 1 and 2, but K and Na were distributed unevenly. On the other hand, in the potassium sodium niobate thin film 16 of Sample No. 4 to Sample No. 6 within the scope of the present invention, K and Na were uniformly distributed.
　表２は、第一熱処理が、ホットプレートを用いて１０℃／分の昇温速度で、ニオブ酸カリウムナトリウム前駆体溶液を、緩慢に３５０℃に加熱して３５０℃で３分間乾燥した後、第二熱処理の昇温速度が種々に変更された場合の、ニオブ酸カリウムナトリウム薄膜１６の表面粗さ、および、１００ｋＶ／ｃｍの電界におけるリーク電流値を示す。第二熱処理の昇温速度は、１００℃／分（試料番号７）、５０℃／分（試料番号８）、３０℃／分（試料番号９）、１５℃／分（試料番号１０）、１０℃／分（試料番号１１）、および、５℃／分（試料番号１２）である。 Table 2 shows that after the first heat treatment, the potassium sodium niobate precursor solution was slowly heated to 350 ° C. and dried at 350 ° C. for 3 minutes at a heating rate of 10 ° C./min using a hot plate. The surface roughness of the potassium sodium niobate thin film 16 and the leak current value in an electric field of 100 kV / cm when the temperature increase rate of the second heat treatment is variously changed are shown. The heating rate of the second heat treatment is 100 ° C./min (sample number 7), 50 ° C./min (sample number 8), 30 ° C./min (sample number 9), 15 ° C./min (sample number 10), 10 C./min (sample number 11) and 5 ° C./min (sample number 12).
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　試料番号７～試料番号９のニオブ酸カリウムナトリウム薄膜１６のように、第二熱処理時の昇温速度が速い場合、ニオブ酸カリウムナトリウム薄膜１６の表面が白くなり、表面粗さが大き過ぎるため、算術平均粗さＲａを測定することができなかった。リーク電流値も、測定装置の許容測定電流値を超えるほど大きくなり、測定することができなかった。また、昇温速度が遅い試料番号１０、試料番号１１および試料番号１２も、算術平均粗さＲａが９．８ｎｍ、９．４ｎｍおよび９．０ｎｍであり、リーク電流値が２．５×１０-2Ａ／ｃｍ2、８．７×１０-3Ａ／ｃｍ2および６．２×１０-3Ａ／ｃｍ2であり、非常に大きな値であった。このように、第一熱処理（乾燥処理）の昇温速度が１０℃／分と遅い場合、ニオブ酸カリウムナトリウム薄膜１６の算術平均粗さＲａおよびリーク電流値が悪くなる。 When the temperature rise rate during the second heat treatment is fast like the sample No. 7 to No. 9 potassium sodium niobate thin film 16, the surface of the potassium sodium niobate thin film 16 becomes white and the surface roughness is too large. The arithmetic average roughness Ra could not be measured. The leak current value also increased as it exceeded the allowable measurement current value of the measuring apparatus, and could not be measured. In addition, Sample No. 10, Sample No. 11 and Sample No. 12, which have a slow temperature increase rate, also have arithmetic average roughness Ra of 9.8 nm, 9.4 nm and 9.0 nm, and a leakage current value of 2.5 × 10 − They were 2 A / cm 2 , 8.7 × 10 −3 A / cm 2 and 6.2 × 10 −3 A / cm 2 , which were very large values. Thus, when the temperature increase rate of the first heat treatment (drying process) is as slow as 10 ° C./min, the arithmetic average roughness Ra and the leakage current value of the potassium sodium niobate thin film 16 are deteriorated.
　表３は、１回の塗布、乾燥および焼成によって得られるニオブ酸カリウムナトリウム層１６ａの厚みが種々に変更された場合の、ニオブ酸カリウムナトリウム薄膜１６の表面粗さ、および、１００ｋＶ／ｃｍの電界におけるリーク電流値を示す。ニオブ酸カリウムナトリウム層１６ａの厚みは、３００ｎｍ（試料番号１３）、１５０ｎｍ（試料番号１４）、１００ｎｍ（試料番号１５）、５０ｎｍ（試料番号６）、および、３０ｎｍ（試料番号１６）である。なお、最終的なニオブ酸カリウムナトリウム薄膜１６の膜厚は、全て３００ｎｍになるように、塗布、乾燥および焼成回数が調整された。 Table 3 shows the surface roughness of the potassium sodium niobate thin film 16 and the electric field of 100 kV / cm when the thickness of the potassium sodium niobate layer 16a obtained by one application, drying and baking is variously changed. The leak current value at. The thickness of the potassium sodium niobate layer 16a is 300 nm (sample number 13), 150 nm (sample number 14), 100 nm (sample number 15), 50 nm (sample number 6), and 30 nm (sample number 16). Note that the number of coating, drying, and firing was adjusted so that the final film thickness of the potassium sodium niobate thin film 16 was 300 nm.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　その結果、算術平均粗さＲａは、全ての試料において、３．０～３．３ｎｍと良好な値であった。 As a result, the arithmetic average roughness Ra was a good value of 3.0 to 3.3 nm in all samples.
　ところが、試料番号１３，１４のように、１回の焼成後に得られるニオブ酸カリウムナトリウム層１６ａの厚みが１００ｎｍより大きい場合、リーク電流値は、２．９×１０-3Ａ／ｃｍ2および８．９×１０-4／ｃｍ2と大きな値を示す。一方、試料番号１５、試料番号６および試料番号１６のように、１回の焼成後に得られるニオブ酸カリウムナトリウム層１６ａの厚みが１００ｎｍ以下の場合、それぞれ、リーク電流値は、２．５×１０-7Ａ／ｃｍ2、５．７×１０-8Ａ／ｃｍ2および３．４×１０-8／ｃｍ2であり、試料番号１３，１４よりも良好なリーク電流特性が示された。このように、良好なリーク電流を得られた理由は、１回の焼成後に得られるニオブ酸カリウムナトリウム層１６ａの厚みが１００ｎｍ以下と薄くなることによって、ＫとＮａの不均一な分布が改善されたからである。 However, when the thickness of the potassium sodium niobate layer 16a obtained after one firing is larger than 100 nm as in sample numbers 13 and 14, the leakage current value is 2.9 × 10 −3 A / cm 2 and 8 .9 × 10 −4 / cm 2 and a large value. On the other hand, when the thickness of the potassium sodium niobate layer 16a obtained after one firing is 100 nm or less as in Sample No. 15, Sample No. 6 and Sample No. 16, the leakage current value is 2.5 × 10. -7 A / cm 2 , 5.7 × 10 −8 A / cm 2, and 3.4 × 10 −8 / cm 2 , showing better leakage current characteristics than Sample Nos. 13 and 14. Thus, the reason for obtaining a good leak current is that the non-uniform distribution of K and Na is improved by reducing the thickness of the potassium sodium niobate layer 16a obtained after one firing to 100 nm or less. This is because the.
　以上のように、第一熱処理および第二熱処理の昇温速度と、１回の焼成後に得られるニオブ酸カリウムナトリウム層１６ａの厚みとが、本発明の範囲内に設定されることにより、表面平滑性および絶縁性に優れたニオブ酸カリウムナトリウム薄膜を作成することが可能となる。 As described above, the rate of temperature increase in the first heat treatment and the second heat treatment and the thickness of the potassium sodium niobate layer 16a obtained after one firing are set within the scope of the present invention, so that the surface smoothness is achieved. It is possible to produce a potassium sodium niobate thin film having excellent properties and insulation properties.
　図３は、試料番号３（不良品）および試料番号５（良品）のニオブ酸カリウムナトリウム薄膜１６のヒステリシス曲線が、強誘電体測定装置「プレシジョン・プレミールII」（商品名、ラディアン・テクノロジー社製）を用いて測定された結果を示す。図３における試料番号５によると、本発明は、ニオブ酸カリウムナトリウム薄膜１６の表面平滑性および絶縁性を改善して、優れた強誘電体特性を有する強誘電体薄膜素子や圧電体薄膜素子を実現できる。 FIG. 3 shows that the hysteresis curve of the potassium sodium niobate thin film 16 of sample number 3 (defective product) and sample number 5 (good product) is a ferroelectric measuring device “Precision Premeal II” (trade name, manufactured by Radian Technology). ) Shows the result of measurement. According to the sample number 5 in FIG. 3, the present invention improves the surface smoothness and insulation of the potassium sodium niobate thin film 16 to provide a ferroelectric thin film element or piezoelectric thin film element having excellent ferroelectric characteristics. realizable.
　なお、この発明は、前記実施形態に限定されるものではなく、その要旨の範囲内で種々に変形される。 In addition, this invention is not limited to the said embodiment, In the range of the summary, it deform | transforms variously.

Claims (2)

  1. 　一般式（Ｋ，Ｎａ）ＮｂＯ3で表示されるニオブ酸カリウムナトリウムを主成分とする薄膜を、化学溶液堆積法を用いて形成する強誘電体薄膜の製造方法であって、
    　化学溶液堆積用溶液を基板上に塗布して第一熱処理および第二熱処理をしてニオブ酸カリウムナトリウム層を形成する工程を有し、前記工程を所定回数繰り返して前記ニオブ酸カリウムナトリウム層を積層して前記ニオブ酸カリウムナトリウム薄膜を形成し、前記工程１回で形成されるニオブ酸カリウムナトリウム層の厚みが１００ｎｍ以下であり、かつ、前記第一熱処理の昇温速度が１００℃／分以上であり、前記第二熱処理の昇温速度が１５℃／分以下であること、を特徴とする、強誘電体薄膜の製造方法。     A method for producing a ferroelectric thin film in which a thin film mainly composed of potassium sodium niobate represented by the general formula (K, Na) NbO 3 is formed using a chemical solution deposition method,
    A chemical solution deposition solution is applied on a substrate, and a first heat treatment and a second heat treatment are performed to form a potassium sodium niobate layer. The steps are repeated a predetermined number of times to laminate the potassium sodium niobate layer. The potassium sodium niobate thin film is formed, the thickness of the potassium sodium niobate layer formed in one step is 100 nm or less, and the temperature increase rate of the first heat treatment is 100 ° C./min or more. A method for producing a ferroelectric thin film, characterized in that the temperature increase rate of the second heat treatment is 15 ° C./min or less.
  2. 　一般式（Ｋ，Ｎａ）ＮｂＯ3で表示されるニオブ酸カリウムナトリウムを主成分とし、かつ、電界強度１００ｋＶ／ｃｍの電圧を印加した際のリーク電流が２．５×１０-7Ａ／ｃｍ2以下である、強誘電体薄膜。 The main component is potassium sodium niobate represented by the general formula (K, Na) NbO 3 , and the leakage current is 2.5 × 10 −7 A / cm 2 when a voltage of electric field strength of 100 kV / cm is applied. A ferroelectric thin film which is as follows.
PCT/JP2012/059560 2011-04-14 2012-04-06 Ferroelectric thin film and method for producing same WO2012141104A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2011090379 2011-04-14
JP2011-090379 2011-04-14

Publications (1)

Publication Number Publication Date
WO2012141104A1 true WO2012141104A1 (en) 2012-10-18

Family

ID=47009277

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2012/059560 WO2012141104A1 (en) 2011-04-14 2012-04-06 Ferroelectric thin film and method for producing same

Country Status (1)

Country Link
WO (1) WO2012141104A1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014207429A (en) * 2013-03-19 2014-10-30 日立金属株式会社 Piezoelectric thin-film device, piezoelectric sensor, and vibration power generator
JP2015138972A (en) * 2014-01-23 2015-07-30 Tdk株式会社 Thin film piezoelectric element, thin film piezoelectric actuator, thin film piezoelectric sensor, hard disk drive, and ink-jet printer device
EP3382766A1 (en) * 2017-03-28 2018-10-03 Seiko Epson Corporation Piezoelectric film element
US10355196B2 (en) 2016-02-10 2019-07-16 Seiko Epson Corporation Piezoelectric element, piezoelectric element application device, and method of manufacturing piezoelectric element

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006035723A1 (en) * 2004-09-29 2006-04-06 Ngk Insulators, Ltd. Piezoelectric/electrostriction film type element and production method therefor
JP2007123683A (en) * 2005-10-31 2007-05-17 National Institute Of Advanced Industrial & Technology Ferroelectric thin film and manufacturing method thereof
JP2007314378A (en) * 2006-05-26 2007-12-06 Seiko Epson Corp Method for producing piezoelectric layer
JP2009010367A (en) * 2007-05-30 2009-01-15 Canon Inc Piezoelectric element, method of manufacturing piezoelectric element, piezoelectric actuator, and inkjet recording head
JP2010161330A (en) * 2008-12-08 2010-07-22 Hitachi Cable Ltd Piezoelectric thin film element
JP2011109037A (en) * 2009-11-20 2011-06-02 Hitachi Cable Ltd Piezoelectric thin film element, and piezoelectric thin film device

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006035723A1 (en) * 2004-09-29 2006-04-06 Ngk Insulators, Ltd. Piezoelectric/electrostriction film type element and production method therefor
JP2007123683A (en) * 2005-10-31 2007-05-17 National Institute Of Advanced Industrial & Technology Ferroelectric thin film and manufacturing method thereof
JP2007314378A (en) * 2006-05-26 2007-12-06 Seiko Epson Corp Method for producing piezoelectric layer
JP2009010367A (en) * 2007-05-30 2009-01-15 Canon Inc Piezoelectric element, method of manufacturing piezoelectric element, piezoelectric actuator, and inkjet recording head
JP2010161330A (en) * 2008-12-08 2010-07-22 Hitachi Cable Ltd Piezoelectric thin film element
JP2011109037A (en) * 2009-11-20 2011-06-02 Hitachi Cable Ltd Piezoelectric thin film element, and piezoelectric thin film device

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
YUJI NOGUCHI: "Defect Control for Materials Design of K0.5Na0.5NbO3 Single Crystals", JOURNAL OF THE JAPAN SOCIETY OF APPLIED ELECTROMAGNETICS AND MECHANICS, vol. 15, no. 4, 10 December 2007 (2007-12-10), pages 386 - 390 *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014207429A (en) * 2013-03-19 2014-10-30 日立金属株式会社 Piezoelectric thin-film device, piezoelectric sensor, and vibration power generator
JP2015138972A (en) * 2014-01-23 2015-07-30 Tdk株式会社 Thin film piezoelectric element, thin film piezoelectric actuator, thin film piezoelectric sensor, hard disk drive, and ink-jet printer device
US10355196B2 (en) 2016-02-10 2019-07-16 Seiko Epson Corporation Piezoelectric element, piezoelectric element application device, and method of manufacturing piezoelectric element
US11417828B2 (en) 2016-02-10 2022-08-16 Seiko Epson Corporation Piezoelectric element, piezoelectric element application device, and method of manufacturing piezoelectric element
EP3382766A1 (en) * 2017-03-28 2018-10-03 Seiko Epson Corporation Piezoelectric film element
US10937942B2 (en) 2017-03-28 2021-03-02 Seiko Epson Corporation Piezoelectric element and piezoelectric element-applied device

Similar Documents

Publication Publication Date Title
JP5418725B2 (en) Piezoelectric thin film element
Kang et al. (1− x) Ba (Zr 0.2 Ti 0.8) O 3–x (Ba 0.7 Ca 0.3) TiO 3 Ferroelectric Thin Films Prepared from Chemical Solutions
Ong et al. Processing effects for integrated PZT: residual stress, thickness, and dielectric properties
WO2015060004A1 (en) Lead-free dielectric thin film, composition for forming same and method for forming same
WO2012141104A1 (en) Ferroelectric thin film and method for producing same
CN117051368B (en) Preparation method of strontium niobate-doped titanate film and strontium niobate-doped titanate film
Zhou et al. The microstructure and energy storage properties of Ba0. 3Sr0. 7TiO3 crystallite thin films
WO2015060003A1 (en) Liquid composition for forming lead-free dielectric thin film, method for forming said thin film, and lead-free dielectric thin film formed by said method
WO2014185274A1 (en) Silicon substrate having ferroelectric film attached thereto
Vitanov et al. Deposition, structure evolution and dielectric properties of BaTiO3 and BaxSr1− xTiO3 thin films prepared by the sol–gel method
Zheng et al. The effects of annealing temperature on the properties of Bi3. 15Nd0. 85Ti3O12 thin films
Chen et al. Low temperature growth of (100)-oriented Ba (Zr0. 2Ti0. 8) O3-0.5 (Ba0. 7Ca0. 3) TiO3 thin films using a LaNiO3 seed layer
Dong et al. Effects of substrate on the crystalline structure and microwave dielectric properties of Bi1. 5Mg1. 0Nb1. 5O7 sol–gel thin films
Wang et al. Enhanced dielectric and piezoelectric properties of RF sputtered Pb (Zr0. 60, Ti0. 40) O3 thin films deposited on sol-gel derived Pb1+ x (Zr0. 40, Ti0. 60) O3 seed layer with various lead contents
CN104072131B (en) The manufacturing method and application thereof of ferroelectric thin film formation composition
JP5136986B2 (en) Piezoelectric manufacturing method and piezoelectric element
JP2019129188A (en) Thermistor and method for manufacturing the same, and thermistor sensor
JP2002324924A (en) Method of manufacturing piezoelectric element
JP3438509B2 (en) Ceramic thin film and method for producing the same
WO2020045446A1 (en) Thin film capacitor and electronic circuit board
JPH09213569A (en) Multilayer dielectric and capacitor
Čakare et al. Antiferroelectric PbZrO3 films prepared by sol-gel processing
JP2019096805A (en) Thermistor, manufacturing method thereof, and thermistor sensor
KR101138239B1 (en) A fabrication method of thin piezoelectric films with high piezoelectric constant
Nurbaya et al. Structural and electrical properties of sol–gel-derived lead titanate nanofilms with different Pb contents for MIM capacitors

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 12770645

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 12770645

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP