JP2006269391A - Manufacturing method of ferroelectric thin film and manufacturing method of piezoelectric element as well as composition for ferroelectric thin film formation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a ferroelectric thin film with excellent ferroelectric characteristics without microcrystalline particles in the film, a manufacturing method of piezoelectric element, and a composition for formation of a ferroelectric thin film. <P>SOLUTION: In the method, a precursor film made of a composition for forming a ferroelectric thin film at least containing colloidal solution containing at least Pb as a material constituting the ferroelectric thin film and a carbon material is formed on an object for treatment, and is crystallized to form the ferroelectric thin film, at which time, a temperature-raising speed is to be 120°C/sec or more. Further, the manufacturing method of the piezoelectric element and the composition for formation of the ferroelectric thin film are also disclosed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a ferroelectric thin film composed of a piezoelectric thin film, a method for manufacturing a piezoelectric element realized by the method for manufacturing a ferroelectric thin film, and a strong film used for forming a ferroelectric thin film. The present invention relates to a composition for forming a dielectric thin film.

  Ferroelectric thin films containing crystals typified by lead zirconate titanate (PZT) have spontaneous polarization, high dielectric constant, electro-optic effect, piezoelectric effect, pyroelectric effect, etc. It is applied to a wide range of device development. Such a ferroelectric thin film, for example, after applying a ferroelectric thin film forming composition (precursor) obtained by adding a polyhydric alcohol such as polyethylene glycol to an aqueous solution containing a Pb compound on a substrate, It is formed by drying and baking this (for example, refer patent document 1).

  Here, the composition for forming a ferroelectric thin film contains a polymer organic compound such as a polyhydric alcohol in order to prevent the ferroelectric thin film from cracking. Such a ferroelectric thin film A large number of microcrystalline particles are scattered in the ferroelectric thin film formed by the forming composition. For this reason, in the ferroelectric thin film in which such a large number of microcrystalline particles are scattered, crystallization is inhibited by the microcrystalline particles and the film quality is deteriorated. In addition, the piezoelectric element having this ferroelectric thin film has a problem that high piezoelectric characteristics cannot be obtained (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 10-100500 (Claims) Japanese Patent Laid-Open No. 11-307834 (paragraph [0012])

  In view of such circumstances, the present invention provides a method of manufacturing a ferroelectric thin film, a method of manufacturing a piezoelectric element, and a composition for forming a ferroelectric thin film having no ferroelectric crystal characteristics in the film and having excellent ferroelectric characteristics. The task is to do.

A first aspect of the present invention that solves the above problems is a precursor comprising a ferroelectric thin film forming composition containing at least a colloidal solution containing at least Pb as a material constituting the ferroelectric thin film and a carbon material. A ferroelectric thin film characterized by forming a film on an object and crystallizing the precursor film to form the ferroelectric thin film at a heating rate of 120 ° C./sec or more. In the manufacturing method.
In the first aspect, by forming the ferroelectric thin film by crystallizing the precursor film at a rate of temperature rise of 120 ° C./sec or more, generation of crystal nuclei generated from the inside of the precursor film is achieved. Delayed by the carbon material contained in the precursor film, this increases the rate of crystal nuclei generated from the surface of the object rather than the rate of crystal nuclei generated from inside the precursor film, and microcrystals in the film A ferroelectric thin film having no particles and having excellent ferroelectric properties can be formed.

According to a second aspect of the present invention, in the first aspect, the step of forming the ferroelectric thin film includes at least a firing step of firing the precursor film, and the precursor film is obtained by firing the precursor film. In the method of manufacturing a ferroelectric thin film, the crystallization of is started.
In the second aspect, the generation of crystal nuclei generated from the inside of the amorphous precursor film that has been degreased is set to a precursor by setting the temperature rising rate at least in the firing step to 120 ° C./sec or more. A ferroelectric thin film that is delayed by the carbon material contained in the film, has no microcrystalline particles in the film, and has excellent ferroelectric characteristics can be formed.

According to a third aspect of the present invention, in the first or second aspect, the carbon material is carbon black, soot, carbon whisker, glassy carbon, carbon fiber, coke, graphite, activated carbon, vapor grown carbon fiber, meso The ferroelectric thin film manufacturing method is characterized by being at least one selected from the group consisting of carbon microbeads, carbon microcoils, carbon nanotubes, and fullerenes.
In the third aspect, the generation of crystal nuclei generated from the inside of the precursor film can be effectively delayed by including these specific carbon materials in the composition for forming a ferroelectric thin film.

According to a fourth aspect of the present invention, there is provided a method for producing a ferroelectric thin film according to any one of the first to third aspects, further comprising a polymer organic material.
In the fourth aspect, cracks can be effectively prevented from occurring in the ferroelectric thin film.

According to a fifth aspect of the present invention, there is provided the method for producing a ferroelectric thin film according to any one of the first to fourth aspects, wherein the carbon material is a fine particle.
In the fifth aspect, by making the carbon material into fine particles, generation of crystal nuclei generated from the inside of the precursor film is effectively delayed, and fine crystal particles are formed in the ferroelectric thin film. Can be effectively prevented.

A sixth aspect of the present invention is the method for producing a ferroelectric thin film according to the fifth aspect, wherein the carbon material has a particle diameter of 50 nm or less.
In the sixth aspect, by making the particle diameter of the carbon material 50 nm or less, the generation of crystal nuclei generated from the inside of the precursor film is more effectively delayed, and fine crystal particles are formed in the ferroelectric thin film. It is possible to effectively prevent the formation.

A seventh aspect of the present invention is the method for producing a ferroelectric thin film according to the sixth aspect, wherein the carbon material has a particle diameter of 10 nm or less.
In the seventh aspect, by making the particle diameter of the carbon material 10 nm or less, the generation of crystal nuclei generated from the inside of the precursor film is more effectively delayed, and fine crystal particles are formed in the ferroelectric thin film. It is possible to effectively prevent the formation.

According to an eighth aspect of the present invention, in any one of the first to seventh aspects, a content of carbon atoms contained in the composition for forming a ferroelectric thin film is 0.1 to 10 mol with respect to 1 mol of the Pb atom. The method of manufacturing a ferroelectric thin film is characterized in that:
In the eighth aspect, the generation of crystal nuclei generated from the inside of the precursor film is more effectively delayed by making the content of carbon atoms contained in the composition for forming a ferroelectric thin film within a predetermined range. Thus, carbon atoms can be effectively prevented from remaining in the ferroelectric thin film.

A ninth aspect of the present invention is the method for producing a ferroelectric thin film according to any one of the first to eighth aspects, further comprising Zr and Ti as metals constituting the ferroelectric thin film. .
In the ninth aspect, it is possible to form a ferroelectric thin film made of lead zirconate titanate (PZT) having good film quality and excellent ferroelectric characteristics.

A tenth aspect of the present invention includes a step of forming a lower electrode on one side of the substrate, a step of forming a piezoelectric layer made of a ferroelectric thin film on the lower electrode, and an upper surface of the piezoelectric layer. At least a step of forming an electrode, and in the step of forming the piezoelectric layer, at least a colloidal solution containing at least Pb as a material constituting the ferroelectric thin film and a carbon material are included on the lower electrode. A precursor film made of a composition for forming a ferroelectric thin film is formed, and the temperature rise rate when forming the ferroelectric thin film by crystallizing the precursor film is 120 ° C./sec or more. A method of manufacturing the piezoelectric element.
In the tenth aspect, by generating a ferroelectric thin film by crystallizing the precursor film at a rate of temperature rise of 120 ° C./sec or more, generation of crystal nuclei generated from the inside of the precursor film is achieved. Delayed by the carbon material contained in the precursor film, this increases the rate of formation of crystal nuclei generated from the surface of the lower electrode than the rate of formation of crystal nuclei generated from inside the precursor film. Therefore, a piezoelectric element (piezoelectric layer) having excellent piezoelectric characteristics can be formed.

According to an eleventh aspect of the present invention, in the tenth aspect, the step of forming the piezoelectric layer includes at least a baking step of baking the precursor film, and the precursor film is formed by baking the precursor film. In the method of manufacturing a piezoelectric element, crystallization is started.
In the eleventh aspect, the precursor film includes generation of crystal nuclei generated from the inside of the amorphous precursor film by setting the temperature rising rate at least in the firing step to 120 ° C./sec or more. A piezoelectric element which is delayed by the carbon material, has no microcrystalline particles in the film, and has excellent piezoelectric characteristics can be formed.

According to a twelfth aspect of the present invention, there is provided a composition for forming a ferroelectric thin film, comprising at least a colloidal solution containing at least Pb as a material constituting the ferroelectric thin film and a carbon material.
In the twelfth aspect, when a precursor film made of a ferroelectric thin film forming composition is formed on an object and then crystallized, a crystal nucleus generated from the inside of the precursor film is generated. A ferroelectric thin film that is delayed by the carbon material contained in the precursor film, has no microcrystalline particles in the film, and has excellent ferroelectric characteristics can be formed.

According to a thirteenth aspect of the present invention, in the twelfth aspect, the carbon material is carbon black, soot, carbon whisker, glassy carbon, carbon fiber, coke, graphite, activated carbon, vapor grown carbon fiber, mesocarbon micro. The composition for forming a ferroelectric thin film is at least one selected from the group consisting of beads, carbon microcoils, carbon nanotubes, and fullerenes.
In the thirteenth aspect, the generation of crystal nuclei generated from the inside of the precursor film can be effectively delayed by including these specific carbon materials in the composition for forming a ferroelectric thin film.

A fourteenth aspect of the present invention is the ferroelectric thin film forming composition according to the twelfth or thirteenth aspect, further comprising a polymer organic material.
In the fourteenth aspect, cracks can be effectively prevented from occurring in the ferroelectric thin film.

A fifteenth aspect of the present invention is the ferroelectric thin film forming composition according to any one of the twelfth to fourteenth aspects, wherein the carbon material is a fine particle.
In the fifteenth aspect, by forming the carbon material into fine particles, the generation of crystal nuclei generated from the inside of the precursor film is effectively delayed, and fine crystal particles are formed in the ferroelectric thin film. Can be effectively prevented.

A sixteenth aspect of the present invention is the ferroelectric thin film forming composition according to the fifteenth aspect, wherein the carbon material has a particle diameter of 50 nm or less.
In the sixteenth aspect, when the particle diameter of the carbon material is 50 nm or less, the generation of crystal nuclei generated from the inside of the precursor film is more effectively delayed, and fine crystal particles are formed in the ferroelectric thin film. It is possible to effectively prevent the formation.

A seventeenth aspect of the present invention is the ferroelectric thin film forming composition according to the sixteenth aspect, wherein the carbon material has a particle diameter of 10 nm or less.
In the seventeenth aspect, when the particle diameter of the carbon material is 10 nm or less, the generation of crystal nuclei generated from the inside of the precursor film is more effectively delayed, and fine crystal particles are formed in the ferroelectric thin film. It is possible to effectively prevent the formation.

An eighteenth aspect of the present invention is the ferroelectric thin film according to any one of the twelfth to seventeenth aspects, wherein the carbon atom content is 0.1 to 10 mol with respect to 1 mol of the Pb atom. In the forming composition.
In the eighteenth aspect, by setting the content of carbon atoms within a predetermined range, the generation of crystal nuclei generated from the inside of the precursor film is more effectively delayed, and the carbon atoms are contained in the ferroelectric thin film. Can be effectively prevented from remaining.

A nineteenth aspect of the present invention provides the composition for forming a ferroelectric thin film according to any one of the twelfth to eighteenth aspects, further comprising Zr and Ti as metals constituting the ferroelectric thin film. is there.
In the nineteenth aspect, a ferroelectric thin film made of lead zirconate titanate (PZT) having good film quality and excellent ferroelectric characteristics can be formed.

Hereinafter, the present invention will be described in detail based on embodiments.
The composition for forming a ferroelectric thin film of the present invention contains a colloidal solution (sol) used to form a ferroelectric thin film, and specifically becomes a material constituting the ferroelectric thin film. As a metal material (for example, an organometallic compound or the like), it comprises a colloidal solution containing at least Pb and a carbon material. Such a composition for forming a ferroelectric thin film is supplied (for example, coated) on an object to form a precursor film, and then crystallizing the precursor film to form a ferroelectric thin film. To form. In the present invention, the temperature rise rate when the ferroelectric film is formed by crystallization of the precursor film in this way is set to 120 ° C./sec or more, so that the crystal nuclei generated from the inside of the precursor film are increased. Production is delayed by the carbon material contained in the precursor film, and there is an effect that a ferroelectric thin film having excellent ferroelectric characteristics can be formed with almost no microcrystalline particles in the film. is there. Here, the “microcrystalline particles formed in the ferroelectric thin film” are crystal grains different from the main crystal (columnar crystal) of the ferroelectric thin film that directly contributes to the ferroelectric characteristics, and from the main crystal. Is a small crystal particle, and if there are many fine crystal particles in the ferroelectric thin film, the ferroelectric characteristics of the entire film are reduced.

  The composition for forming a ferroelectric thin film of the present invention comprises a complex having at least one metal as a core constituting a material for a ferroelectric thin film, a cluster complex in which two or more of these complexes are assembled, or a complex thereof. Contains a colloidal solution containing agglomerated colloidal aggregates. In addition, as a complex, the metal which becomes a material which comprises a ferroelectric thin film serves as a nucleus, and this includes, for example, a ligand derived from alcohols, acetic acid, acetylacetonate, water (OH), amines, and the like. The combination is mentioned.

  For example, when the metal contained in the ferroelectric thin film forming composition is Pb, Zr and Ti, that is, in the colloid solution of the PZT thin film forming composition, various colloidal particles, specifically, Pb is added. Colloidal particles containing alone (eg, colloidal particles consisting of lead acetate), colloidal particles containing Pb and Zr (eg, colloidal particles consisting of lead acetate and zirconium acetylacetonate stabilized by water molecules), and Pb And colloidal particles containing Ti (for example, colloidal particles composed of titanium alkoxides chelated and stabilized with amines and lead acetate).

  Here, in the present invention, as the carbon material to be included in such a composition for forming a ferroelectric thin film, for example, carbon black, soot, carbon whisker, glassy carbon, carbon fiber, coke, graphite, activated carbon, gas It is preferably at least one selected from the group consisting of phase-grown carbon fibers, mesocarbon microbeads, carbon microcoils, carbon nanotubes, and fullerenes. Thus, by including these specific carbon materials in the composition for forming a ferroelectric thin film, the generation of crystal nuclei generated from the inside of the precursor film can be effectively delayed.

  The carbon material is preferably fine particles. Specifically, the carbon material may have a particle diameter of 50 nm or less, preferably 10 nm or less. Thus, by making the particle diameter of the carbon material not more than a predetermined value, the generation of crystal nuclei generated from the inside of the precursor film is more effectively delayed, and fine crystal particles are formed in the ferroelectric thin film. Can be effectively prevented.

  Furthermore, in the present invention, the content of the carbon material to be included in the composition for forming a ferroelectric thin film is such that the content of carbon atoms is 0.1 to 10 mol, preferably 3 to 7 mol, relative to 1 mol of Pb atoms. More preferably, it is 5 mol. The lower limit was set for the carbon material content in order to more effectively delay the formation of crystal nuclei generated from the inside of the precursor film, and the upper limit was set in the ferroelectric thin film. This is to effectively prevent carbon atoms from remaining on the surface.

  In the present invention, it is preferable that the above-mentioned composition for forming a ferroelectric thin film contains a polymer organic material. This is because it is possible to effectively prevent cracks in the ferroelectric thin film. Examples of the polymer organic material include polyhydric alcohols such as polyethylene glycol, diethylene glycol, and glycerin.

  Here, when such a macromolecular organic material is contained alone in the composition for forming a ferroelectric thin film, it causes a large number of microcrystalline particles to be formed in the film. Since the carbon material is contained in addition to the polymer organic material, the carbon material effectively prevents the formation of microcrystalline particles in the film. Accordingly, the coexistence of the polymer organic material and the carbon material in the composition for forming a ferroelectric thin film effectively prevents the ferroelectric thin film from being cracked by the polymer organic material, while the film is made of the carbon material. It is possible to effectively prevent the formation of microcrystalline particles therein. In addition, by including the polymer organic material in this way, the thickness of the precursor film per layer can be formed relatively thick, and a composition for forming a ferroelectric thin film having a desired thickness can be formed. The film process can be simplified.

  Hereinafter, a method for producing (forming) a ferroelectric thin film using the above-described composition for forming a ferroelectric thin film will be described in detail. Here, a metal film formed on a substrate will be described as an example of an object for forming a ferroelectric thin film. First, a composition process for forming a ferroelectric thin film is applied on a metal film formed on a substrate to form a ferroelectric thin film precursor film. Next, after performing a drying process for drying the precursor film and a degreasing process for degreasing the organic component in the precursor film in this order, a baking process for baking the precursor film for crystallization is performed. Do. And in this invention, the temperature increase rate shall be 120 degrees C / sec or more in the baking process of this precursor film | membrane. Here, the “temperature increase rate” refers to the crystallization rate of the compound contained in the precursor film. For example, when the firing (crystallization) temperature is set to 500 to 600 ° C., the firing start temperature is 500. It is the speed when passing through ° C. In addition, the heating temperature in the degreasing process and the drying process before the firing process is set lower than the firing start temperature.

  As a result, the generation of crystal nuclei generated from the inside of the precursor film is delayed by the carbon material contained in the precursor film, whereby the surface of the metal film that is the base rather than the generation rate of the crystal nuclei generated from inside the precursor film The generation rate of crystal nuclei generated from the is increased. That is, the generation of crystal nuclei generated from the inside of the precursor film is suppressed to be small by the carbon material. And, since the columnar crystals are well formed from the metal surface side of the precursor film, and the crystal growth is not hindered by the generation of the microcrystalline particles, the crystal orientation can be improved, thereby the metal film surface A ferroelectric thin film is formed by the columnar crystals formed from the above. On the other hand, the carbon material in the film moves to the surface side of the precursor film along with the formation of the columnar crystals, and as a result, oxygen and the carbon material chemically react on the surface side of the precursor film, and carbon dioxide gas. Thus, it is detached and removed from the film. That is, since the carbon material is separated and removed from the film by crystallization of the precursor film, it does not remain in the film.

  Thus, in the present invention, in order to increase the generation rate of crystal nuclei generated from the surface of the metal film that is the base rather than the generation rate of crystal nuclei generated from the inside of the precursor film, the increase in the crystallization process of the precursor film is performed. The temperature rate is controlled, specifically, at least the temperature rising rate in the firing step is set to 120 ° C./sec or more. Thereby, there are almost no microcrystalline particles in the film, the crystal structure becomes a columnar structure, and a ferroelectric thin film having excellent piezoelectric characteristics and ferroelectric characteristics can be formed.

Here, the ferroelectric thin film formed by the above-described composition for forming a ferroelectric thin film is, for example, a ferroelectric material (piezoelectric material) such as lead zirconate titanate (PZT), niobium or nickel. , Including a relaxor ferroelectric crystal or the like to which a metal such as magnesium, bismuth or yttrium is added. As the composition, for example, PbTiO ₃ (PT), PbZrO ₃ (PZ), Pb (Zr _x Ti _1-x ) O ₃ (PZT), Pb (Mg _1/3 Nb _2/3 ) O ₃ -PbTiO ₃ (PMN-PT), Pb (Zn _1/3 Nb _2/3 ) O ₃ -PbTiO ₃ (PZN-PT), Pb (Ni _1/3 Nb _2/3 ) O ₃ -PbTiO ₃ (PNN-PT), _{Pb (In 1/2 Nb 1/2) O} 3 -PbTiO 3 (PIN-PT), Pb (Sc 1/2 Ta 1/2) O 3 -PbTiO 3 (PST-PT), Pb (Sc 1/2 _{nb 1/2) O 3 -PbTiO 3 (} PSN-PT), biScO 3 -PbTiO 3 (BS-PT), BiYbO 3 -PbTiO 3 (BY-PT) and the like.

  The ferroelectric thin film forming composition according to the present invention described above and the ferroelectric thin film formed by using this ferroelectric thin film forming composition can be applied to a wide range of device development. The application is not particularly limited, but for example, microactuator, filter, delay line, lead selector, tuning fork oscillator, tuning fork clock, transceiver, piezoelectric pickup, piezoelectric earphone, piezoelectric microphone, SAW filter, RF modulator, resonator, It can be applied to delay elements, multi-strip couplers, piezoelectric accelerometers, piezoelectric speakers, and the like.

Hereinafter, an ink jet recording head which is an example of a liquid jet head in which the present invention is applied to a piezoelectric actuator will be described in detail with reference to FIGS. FIG. 1 is an exploded perspective view illustrating an outline of an ink jet recording head which is an example of a liquid ejecting head, and FIG. 2 is a plan view and a cross-sectional view taken along line AA ′ of FIG. As shown in FIGS. 1 and 2, the flow path forming substrate 10 is a silicon single crystal substrate having a plane orientation (110) in the present embodiment, and silicon oxide (SiO ₂₎ previously formed by thermal oxidation on one surface thereof. ), And an elastic film 50 having a thickness of 0.5 to 2 μm is formed.

  The flow path forming substrate 10 is provided with a plurality of pressure generating chambers 12 partitioned by a plurality of partition walls 11 by anisotropically etching a silicon single crystal substrate from one side thereof. In addition, on the outside of one end portion in the direction (longitudinal direction) orthogonal to the direction in which the pressure generating chambers 12 are arranged (width direction), a communication portion 13 that communicates with a reservoir portion 32 of a protective substrate 30 described later. Is formed. The communication portion 13 is in communication with each other at one end in the longitudinal direction of each pressure generating chamber 12 via an ink supply path 14.

  A mask film 51 for forming the pressure generating chamber 12 is provided on the opening surface side of the flow path forming substrate 10, and the ink supply path 14 of each pressure generating chamber 12 is provided on the mask film 51. A nozzle plate 20 having a nozzle opening 21 communicating with the vicinity of the end on the opposite side is fixed with an adhesive, a heat welding film, or the like.

  On the other hand, an insulating film 55 having a thickness of, for example, about 0.4 μm is formed on the elastic film 50 opposite to the opening surface of the flow path forming substrate 10. For example, a lower electrode film 60 having a thickness of about 0.2 μm, a piezoelectric layer 70 made of a ferroelectric thin film having a thickness of about 1 μm, and a thickness of about 0.05 μm, for example. The piezoelectric film 300 is formed by laminating the electrode film 80 by a process described later.

  The piezoelectric element 300 refers to a portion including the lower electrode film 60, the piezoelectric layer 70, and the upper electrode film 80. In general, one electrode of the piezoelectric element 300 is used as a common electrode, and the other electrode and the piezoelectric layer 70 are patterned for each pressure generating chamber 12. In addition, here, a portion that is configured by any one of the patterned electrodes and the piezoelectric layer 70 and in which piezoelectric distortion is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion. In the present embodiment, the lower electrode film 60 is used as a common electrode of the piezoelectric element 300 and the upper electrode film 80 is used as an individual electrode of the piezoelectric element 300. However, there is no problem even if this is reversed for convenience of a drive circuit and wiring. In any case, a piezoelectric active part is formed for each pressure generating chamber 12. Further, here, the piezoelectric element 300 and the vibration plate that is displaced by driving the piezoelectric element 300 are collectively referred to as a piezoelectric actuator. In the present embodiment, the elastic film 50, the insulator film 55, and the lower electrode film 60 function as a diaphragm.

  Here, such a piezoelectric layer 70 is formed by applying and drying the above-described composition for forming a ferroelectric thin film, that is, a so-called sol in which a metal organic substance is dissolved and dispersed in a catalyst, and is further baked at a high temperature. It is formed using a so-called sol-gel method. In firing, a composition for forming a ferroelectric thin film is applied onto the lower electrode film 60 to form a precursor film. In this embodiment, for example, the temperature rise during firing is performed by an RTP (rapid heating furnace) or the like. The speed was set to 120 ° C./sec or higher. Of course, the method for forming the piezoelectric layer 70 is not particularly limited, and for example, the piezoelectric layer 70 may be formed by another solution method such as the MOD method. In the present embodiment, the piezoelectric layer 70 described above is a thin film in which the crystal structure is rhombohedral, the crystal is grown in a columnar shape, and the crystal plane orientation is (100) or (001). is there. A columnar thin film refers to a state in which substantially cylindrical crystals are aggregated over the surface direction with the central axis substantially coincided with the thickness direction to form a thin film.

  Further, on the piezoelectric element 300 side of the flow path forming substrate 10, a protective substrate 30 having a piezoelectric element holding portion 31 capable of ensuring a space that does not hinder the movement in a region facing the piezoelectric element 300 is interposed via an adhesive. Are joined. Since the piezoelectric element 300 is formed in the piezoelectric element holding part 31, it is protected in a state hardly affected by the external environment. In addition, as for the piezoelectric element holding | maintenance part 31, the space may be sealed and does not need to be sealed.

  Further, the protective substrate 30 is provided with a reservoir portion 32 that constitutes at least a part of the reservoir 100 serving as a common ink chamber for the pressure generating chambers 12, and the reservoir portion 32 is configured as described above. The reservoir 100 is configured to communicate with the ten communication portions 13 and serve as a common ink chamber for the pressure generation chambers 12. A through hole 33 that penetrates the protective substrate 30 in the thickness direction is provided in a region between the piezoelectric element holding portion 31 and the reservoir portion 32 of the protective substrate 30. The lead electrode 90 drawn from each piezoelectric element 300 is exposed in the through hole 33 in the vicinity of its end.

  Further, a compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded onto the protective substrate 30. The fixing plate 42 is made of a hard material such as metal. Since the region of the fixing plate 42 facing the reservoir 100 is an opening 43 that is completely removed in the thickness direction, one surface of the reservoir 100 is sealed only with a flexible sealing film 41. Has been.

  In such an ink jet recording head of this embodiment, ink is taken in from an external ink supply means (not shown), filled with ink from the reservoir 100 to the nozzle opening 21, and then driven according to a drive signal from a drive IC (not shown). Then, a driving voltage is applied between each of the lower electrode film 60 and the upper electrode film 80 corresponding to the pressure generating chamber 12, and the elastic film 50, the insulator film 55, the lower electrode film 60, and the piezoelectric layer 70 are bent and deformed. By doing so, the pressure in each pressure generating chamber 12 increases, and ink droplets are ejected from the nozzle openings 21.

  The ink jet recording head of the present embodiment described above is excellent because the piezoelectric layer 70 has a good film quality (dense) and a crystal structure of a columnar structure, and there are no microcrystalline particles in the film. It has piezoelectric properties. Therefore, the ink ejection characteristics of the head are stabilized, and the reliability of the head can be improved.

  In the present embodiment, an ink jet recording head that discharges ink as an example of a liquid ejecting head has been described as an example. However, the present invention is not limited to this. For example, a recording head used in an image recording apparatus such as a printer, a liquid crystal display, or the like. Examples include color material ejection heads used in the production of color filters, electrode material ejection heads used in electrode formation for organic EL displays, FEDs (surface emitting displays), and bioorganic matter ejection heads used in biochip production. .

1 is an exploded perspective view illustrating an outline of a recording head according to an embodiment of the invention. 2A and 2B are a plan view and a cross-sectional view taken along line A-A ′ of the recording head according to the embodiment of the invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Flow path formation board | substrate, 12 Pressure generation chamber, 20 Nozzle plate, 21 Nozzle opening, 30 Protection board, 31 Piezoelectric element holding | maintenance part, 32 Reservoir part, 40 Compliance board | substrate, 60 Lower electrode film, 70 Ferroelectric thin film (piezoelectric body) Layer), 80 upper electrode film, 90 lead electrode, 100 reservoir, 300 piezoelectric element

Claims (19)

A precursor film made of a composition for forming a ferroelectric thin film containing at least a colloidal solution containing at least Pb and a carbon material, which is a material constituting the ferroelectric thin film, is formed on an object and the precursor film. A method for producing a ferroelectric thin film, characterized in that a rate of temperature rise when the ferroelectric thin film is formed by crystallizing is set to 120 ° C./sec or more. 2. The method of claim 1, wherein the step of forming the ferroelectric thin film includes at least a firing step of firing the precursor film, and the crystallization of the precursor film is started by firing the precursor film. A method for manufacturing a ferroelectric thin film. 3. The carbon material according to claim 1, wherein the carbon material is carbon black, soot, carbon whisker, glassy carbon, carbon fiber, coke, graphite, activated carbon, vapor grown carbon fiber, mesocarbon microbead, carbon microcoil, carbon nanotube. And a method for producing a ferroelectric thin film, which is at least one selected from the group consisting of fullerenes. 4. The method for producing a ferroelectric thin film according to claim 1, further comprising a polymer organic material. 5. The method for producing a ferroelectric thin film according to claim 1, wherein the carbon material is fine particles. 6. The method for manufacturing a ferroelectric thin film according to claim 5, wherein the carbon material has a particle diameter of 50 nm or less. 7. The method for producing a ferroelectric thin film according to claim 6, wherein the carbon material has a particle diameter of 10 nm or less. 8. The ferroelectric material according to claim 1, wherein a content of carbon atoms contained in the composition for forming a ferroelectric thin film is 0.1 to 10 mol with respect to 1 mol of the Pb atoms. Thin film manufacturing method. 9. The method for manufacturing a ferroelectric thin film according to claim 1, further comprising Zr and Ti as a metal constituting the ferroelectric thin film. At least a step of forming a lower electrode on one surface side of the substrate, a step of forming a piezoelectric layer made of a ferroelectric thin film on the lower electrode, and a step of forming an upper electrode on the piezoelectric layer. ,
The step of forming the piezoelectric layer comprises a ferroelectric thin film forming composition containing at least a colloidal solution containing at least Pb as a material constituting the ferroelectric thin film and a carbon material on the lower electrode. A method of manufacturing a piezoelectric element, characterized in that a temperature rise rate when forming a ferroelectric thin film by forming a precursor film and crystallizing the precursor film is 120 ° C./sec or more. The method of forming a piezoelectric layer according to claim 10, wherein the step of forming the piezoelectric layer includes at least a baking step of baking the precursor film, and the crystallization of the precursor film is started by baking the precursor film. A method for manufacturing a piezoelectric element. A composition for forming a ferroelectric thin film, comprising at least a colloidal solution containing at least Pb, which is a material constituting the ferroelectric thin film, and a carbon material. The carbon material according to claim 12, wherein the carbon material is carbon black, soot, carbon whisker, glassy carbon, carbon fiber, coke, graphite, activated carbon, vapor grown carbon fiber, mesocarbon microbead, carbon microcoil, carbon nanotube, and A composition for forming a ferroelectric thin film, which is at least one selected from the group consisting of fullerenes. 14. The composition for forming a ferroelectric thin film according to claim 12 or 13, further comprising a polymer organic material. The composition for forming a ferroelectric thin film according to any one of claims 12 to 14, wherein the carbon material is fine particles. The composition for forming a ferroelectric thin film according to claim 15, wherein the carbon material has a particle diameter of 50 nm or less. The composition for forming a ferroelectric thin film according to claim 16, wherein the carbon material has a particle diameter of 10 nm or less. 18. The composition for forming a ferroelectric thin film according to claim 12, wherein the content of carbon atoms is 0.1 to 10 mol with respect to 1 mol of the Pb atoms. The composition for forming a ferroelectric thin film according to any one of claims 12 to 18, further comprising Zr and Ti as a metal constituting the ferroelectric thin film.

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