JP4662112B2 - Ferroelectric thin film and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention more particularly, to a method of manufacturing preferential crystal orientation can be controlled ferroelectric thin film.
[0002]
[Prior art]
Conventionally, various film forming methods such as a sol-gel method, a vapor deposition method, a sputtering method, and a CVD method have been reported as methods for producing a thin film of a ferroelectric compound typified by a perovskite oxide. In particular, the arc discharge reactive ion plating method developed by the present inventors in recent years is an excellent method capable of forming a ferroelectric thin film at high speed even at a relatively low film forming temperature.
[0003]
In this method, as shown in FIG. 1, the source metal is heated and evaporated in a high-density oxygen plasma generated in a vacuum vessel 1 by a plasma gun 3, and each metal vapor and oxygen in the vacuum vessel 1 or on a substrate 8. Reacts with each other to form a ferroelectric oxide.
[0004]
Usually, for this type of film formation, a Pt / Ti lower electrode layer is sputter-deposited on a Si substrate (SiO ₂ / Si) with a thermal oxide film as a base substrate. Then, by forming a ferroelectric thin film thereon, a sample having a thin film structure shown in FIG. 13 is obtained. The crystal structure of the ferroelectric thin film thus formed largely depends on the crystal structure of the Pt / Ti layer that is the base.
[0005]
In FIG. 13, 101 is a Si substrate, 102 is a SiO ₂ substrate, 103 is a Ti electrode layer, 104 is a Pt electrode layer, and 105 is a ferroelectric thin film layer.
[0006]
[Problems to be solved by the invention]
By the way, in the ferroelectric thin film as described above, the Pt layer is usually a polycrystalline thin film layer preferentially oriented in the (111) plane, and the ferroelectric thin film layer grown thereon is It can only be a film with no preferential orientation or a thin film with the same (111) preferential orientation as the Pt layer by devising the film formation process.
[0007]
For this reason, it is difficult to produce a (001) / (100) preferentially oriented film required for various ferroelectric / piezoelectric devices. Even when a (111) preferentially oriented ferroelectric thin film is produced, It was necessary to raise the substrate temperature at the time of film formation by 50 ° C. to 100 ° C. or lower the film formation speed to half or less of that of the non-oriented film.
[0008]
Thus, conventionally, it has been difficult and time-consuming to form a ferroelectric thin film layer preferentially oriented on a polycrystalline Pt layer. Therefore, in order to obtain the above preferred orientation, various buffer layers (Y ₂ O ₃ , MgO, TiN, etc.) capable of heteroepitaxial growth are first grown on a Si substrate without a thermal oxide film, and a Pt layer is further formed thereon. It was necessary to perform heteroepitaxial growth. This process requires a significantly higher temperature (650 ° C. or higher) than the normal polycrystalline Pt layer formation temperature (˜200 ° C.), and the growth rate of each layer is also slower than the polycrystalline film (<1 μm / hr). For this reason, a device to which a conventional heteroepitaxial process can be applied has been limited to a ferroelectric RAM (FRAM) that can be used even if the thickness of the thin film is 200 nm or less.
[0009]
In addition, it is very difficult to control the crystal orientation of a thin film for a device that cannot obtain a sufficient amount of displacement and generation force unless it has a film thickness of 1 μm or more, such as a piezoelectric device. In particular, it was difficult to obtain a ferroelectric thin film having a (001) or (100) preferred orientation different from the preferred orientation axis (111) of the polycrystalline Pt layer.
[0010]
As a solution, many methods have been reported for forming a (001) / (100) preferential alignment film by previously forming a (001) or (100) oriented seed layer as a base for ferroelectric film formation. Has been. As the most famous example, lead titanate (PT) with respect to lead zirconate titanate (PZT) is known.
[0011]
However, in this case, the dielectric constant and ferroelectric characteristics of PT, which is the seed layer, are lower than that of PZT, which is the target ferroelectric, and the ferroelectric characteristics of the thin film as a whole are lower than that of the film of PZT alone. There was a problem. In addition, in a thick film having a thickness of 1 μm or more, the effect of the underlying seed layer is reduced as the deposition of the thin film proceeds, and the preferential orientation tends to decrease. Further, in the piezoelectric application, there is a problem that mechanical breakdown is easily caused at the interface between the seed layer and the main thin film layer.
[0012]
As described above, in the conventional method, the crystal orientation control for a thick film in which the thickness of the ferroelectric oxide thin film exceeds 1 μm is performed in both the method using the heteroepitaxial film and the method using the preferentially oriented seed layer. It was extremely difficult.
[0013]
The present invention has been made in view of the above problems, the thickness to provide a method of manufacturing a 1μm or more relatively thick strong controllable preferential crystal orientation in film dielectric thin film It is an object.
[0014]
[Means for Solving the Problems]
Method of manufacturing a ferroelectric thin film according to the present invention is configured as follows.
[0015]
(1) A polycrystalline Pt film is formed on a substrate made of a single crystal, polycrystalline, or amorphous material, a seed layer is formed on the Pt film by a chemical solution deposition method, and then an arc is formed. A main thin film is formed by a discharge reactive ion plating method to form a ferroelectric oxide film having a crystal orientation preferentially selected from either (100) or (111). A method of manufacturing a ferroelectric thin film having uniaxial preferred orientation.
(2) The method for producing a ferroelectric thin film according to (1) above, wherein the seed layer and the main thin film have the same composition.
(3) The (100) is preferentially oriented at a calcination temperature in the range of 400 to 450 ° C., and (111) is preferentially oriented at the calcination temperature in the range of 450 to 510 ° C. A method for producing a ferroelectric thin film according to 1) or (2).
(4) The method for producing a ferroelectric thin film according to (2) above, wherein the ferroelectric is a ferroelectric compound represented by ABO ₃ .
(5) The method for producing a ferroelectric thin film according to (4), wherein the ferroelectric compound is a lead-based ferroelectric oxide.
(6) The method for producing a ferroelectric thin film according to (5), wherein the ferroelectric compound is any one of a lead-based ferroelectric oxide of PT, PZT, and PLZT.
(7) The method for producing a ferroelectric thin film according to any one of (1) to (6), wherein the film thickness is formed to be 1 μm or more.
[0033]
DETAILED DESCRIPTION OF THE INVENTION
A ferroelectric thin film and a manufacturing method thereof according to the present invention, a chemical solution deposition (C h emical Solution Deposition; CSD method) and is intended for using arc discharge reactive ion plating method, a single crystal, polycrystal, Two or more kinds of ferroelectric oxide thin films having a plurality of types of preferential crystal orientations are formed on a polycrystalline Pt film formed on any amorphous substrate. A ferroelectric thin film and a method for manufacturing the same.
[0034]
The chemical solution deposition (CSD) method, by rapid heating in an oxygen atmosphere after coating a precursor solution of a ferroelectric oxide on a substrate, subjected to solvent removal and crystallization, finally It is widely known as a method for forming a ferroelectric thin film of about 100 nm.
And its manufacturing method.
[0035]
When forming a ferroelectric thin film on a Pt (111) electrode substrate by the CSD method, the present inventor has controlled the preferential crystal orientation of the thin film by strictly controlling the heat treatment temperature of the rapid heating. It has already been reported that it can be controlled ("PZT-based ferroelectric thin film formation method" Patent Publication No. 2995290 (registered on October 29, 1999)). For example, in the case of a PZT (Zr / Ti = 53/47) thin film, a (100) preferential orientation film is obtained by heat treatment at 450 ° C., and a (111) preferential orientation film is obtained by heat treatment at 510 ° C. By using this method, the crystal orientation of the ferroelectric thin film can be controlled even on the polycrystalline Pt (111) preferential orientation film.
[0036]
In the present invention, as shown in FIG. 2, a ferroelectric thin film preferentially oriented in the (100) or (111) plane is first formed by the above-mentioned CSD method, and this film is used as a seed layer. Preferential crystal orientation is controlled even in relatively thick films (hereinafter referred to as “thick films”) having a film thickness of 1 μm or more by performing high-speed deposition of ferroelectric thin films by the arc discharge reactive ion plating method. It is possible.
[0037]
In addition, since the seed layer and the thick film can have the same composition, the relative dielectric constant and ferroelectric characteristics of the entire thick film structure are not impaired. Rather, the presence of the seed layer densifies the structure of the thick film deposited by the ion plating method, and improves dielectric characteristics and ferroelectric characteristics (PE hysteresis) coupled with control of crystal orientation. Furthermore, since the composition is the same, the interface between the seed layer and the thick film is joined almost seamlessly at the atomic level, and the mechanical strength is also excellent.
[0038]
In the present invention, it is not necessary to perform the seed layer formation and the thick film formation consistently. Even when a seed layer formed in the atmosphere is used, the seed layer surface is cleaned and activated by high-density plasma by arc discharge, and the preferential orientation of the seed layer is maintained while performing the above-mentioned seamless thick film growth. The This is in contrast to the fact that strict atmosphere control is required for orientation control by MBE, sputtering, and CVD.
[0039]
As described above, according to the present invention, the crystal orientation of the ferroelectric thick film is achieved by a simple process of (1) formation of a preferentially oriented seed layer by the CSD method and (2) thick film formation by the arc discharge reactive ion plating method. The property can be controlled to two preferred orientations (100) or (111). As a result, the preferentially oriented ferroelectric thick film has superior ferroelectricity and piezoelectricity as compared with the conventional randomly oriented thick film.
[0040]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0041]
FIG. 1 is a diagram schematically showing the configuration of the aforementioned reactive arc discharge ion plating apparatus used in the embodiment. In the figure, 1 is a vacuum vessel (vacuum tank), 2 is a carrier gas introduced into the vacuum vessel 1, 3 is a pressure gradient arc discharge plasma gun (UR gun), 4 is a plasma gun intermediate electrode, A plasma gun anode, 6 is a plasma control magnetic field generation source, 7 is an evaporation source, 8 is a substrate, 9 is a substrate heating heater, 10 is a gas introduction pipe for a reaction gas 11, and 12 is a shutter.
[0042]
FIG. 2 is a cross-sectional view showing the structure of the ferroelectric thin film manufactured in the example. 101 is a Si substrate, 102 is a SiO ₂ layer, 103 is a Ti electrode layer, 104 is a Pt electrode layer, and 105 is a strong layer. A dielectric thin film layer 106 is a ferroelectric seed layer.
[0043]
FIG. 3 is a flowchart showing a seed layer forming process by the chemical solution deposition method. In the figure, S1 is a spin coating process (3000 rpm, 40 s), S2 is a drying process (RT or 120 ° C.), and S3 is a pyrolysis process (400-520). C., 3-5 min) and S4 are firing processing steps (RTA 30 ° C./s, 650-700 ° C., 1 min), and these processing steps are repeated.
[0044]
Example 1
Ferroelectric multi-element oxide seed layers were formed by the CSD process shown in FIG. As the substrate, Ti (50 nm) and Pt (200 nm) were sequentially deposited on a Si substrate (thickness: 300 to 550 μm) with a thermal oxide film of 500 to 1000 nm by DC magnetron sputtering (Pt / Ti / SiO _2). / Si) was used. Then, a thin film (film thickness: 100 nm) of a ternary complex oxide ferroelectric PZT [Pb (Zr _x Ti _{1 -x} ) O ₃ ] was prepared as a seed layer material.
[0045]
In this example, a film composition of X = 63 (Zr / Ti = 53/47) was formed. A CSD raw material obtained by stirring and mixing a metal alkoxide solution of Pb, Zr, and Ti was applied onto a substrate by spin coating, and then calcined at 450 ° C. to remove the solvent in the film. Thereafter, crystallization of PZT was promoted by rapid thermal annealing at 700 ° C. for 10 minutes in an oxygen stream, and finally a PZT seed layer having a thickness of 100 nm was obtained. When the crystal structure of the seed layer was analyzed by X-ray diffraction, it was found that the seed layer was a perovskite type PZT with a (100) plane preferentially oriented.
[0046]
FIG. 4 is a diagram showing an X-ray diffraction pattern of the (100) preferentially oriented PZT seed layer (film thickness: 100 nm).
[0047]
A PZT thick film having the same composition was formed on the PZT seed layer by the arc discharge reactive ion plating apparatus shown in FIG. Each material of Pb, Zr, and Ti was used as the material of the evaporation source 7 and evaporated independently by resistance heating and electron beam heating. The evaporation amount of each metal raw material was measured by a crystal vibration type film thickness monitor, and feedback control was performed on the heating source so as to maintain a constant evaporation amount during film formation. An arc discharge was generated by introducing 50 to 100 sccm of He as the carrier gas 2 into the pressure gradient arc discharge plasma gun 3 and applying a DC bias voltage. The discharge voltage was controlled at 100 to 120V, and the discharge current was controlled at 50 to 100A.
[0048]
The high-density plasma (plasma density> 10 ¹² cm ⁻³ ) generated by this arc discharge was introduced into the vacuum chamber 1 by a magnetic field of about 50 to 300 gauss generated by the magnetic field generator 6 for plasma control. In this state, oxygen of 200 to 300 sccm was introduced as the reaction gas 11 from the gas introduction tube 10 to generate high-density oxygen plasma and active species of oxygen in the vacuum vessel 1.
[0049]
A thin film was formed on the substrate 8 heated to about 500 to 550 ° C. by the heater 9 in the presence of the oxygen active species. The evaporation amounts of Pb, Zr, and Ti were adjusted so that the final thick film composition was the same as that of the seed layer (Zr / Ti = 53/47).
[0050]
In the formation of the PZT thick film by the ion plating method, the film forming speed was as high as 3 μm / hr or more, and the film thickness was about 2 μm. FIG. 5A shows the result of X-ray diffraction of the thick film thus obtained. It was confirmed that the perovskite type PZT was preferentially oriented in the (100) plane as in the case of the seed layer. For comparison, an X-ray diffraction pattern of a PZT thick film formed directly on Pt without using a seed layer is shown in FIG. 5B. In this case, no preferential orientation is observed, and the orientation is random. I understood it.
[0051]
Thus, it was confirmed that the crystal orientation of the PZT thick film (film thickness: 2 μm) formed thereon can be controlled by using the preferentially oriented seed layer. When the film structure of the interface between the seed layer and the PZT thick film was evaluated by cross-sectional FE-SEM observation, as shown in FIG. 6, it was clear that the interface between the two did not show clear contrast and was joined almost seamlessly. Became.
[0052]
Next, ferroelectric and piezoelectric characteristics were measured for the capacitor cell in which the Pt upper electrode was formed on the obtained PZT film, and the effect of the seed layer was investigated. As a comparison, the characteristics of a PZT thick film formed on Pt without a seed layer were also evaluated.
First, the evaluation results of the ferroelectric characteristics will be described.
[0053]
FIG. 7 is a diagram showing a PE hysteresis curve of a PZT capacitor cell (pressure film). A very well-saturated PE hysteresis curve was observed with and without the seed layer. However, the saturation polarization and the residual polarization are larger in the PZT thick film formed on the seed layer. This is considered to be because the direction of the spontaneous polarization domain is aligned with that of the random orientation by the (100) preferential orientation film formation.
[0054]
FIG. 8 is a diagram showing a piezoelectric displacement curve of the capacitor cell, where (a) is (100) preferred orientation and (b) is non-oriented. Again, regardless of the presence or absence of the seed layer, a good butterfly-shaped displacement curve is observed, indicating that the obtained PZT thick film has high piezoelectric characteristics. It can be seen that the (100) preferential alignment film formed on the seed layer is displaced more greatly than the piezoelectric displacement. This is also considered to be because the domain orientation is aligned by the preferential orientation.
[0055]
When the piezoelectric constant was calculated for the (100) preferentially oriented film by the bending model, a value of lateral effect piezoelectric constant d ₃₁ = −110 pm / V was obtained. This value was almost comparable to the constant of bulk ceramics PZT, and showed very good characteristics as a PZT thick film.
[0056]
Thus, it was found that the (100) preferentially oriented PZT thick film having excellent ferroelectric characteristics and piezoelectric characteristics can be produced by the method of this example. That is, it was found that a uniaxial preferred orientation ferroelectric thin film capable of controlling the preferential crystal orientation can be manufactured even with a relatively thick film having a thickness of 1 μm or more.
[0057]
Example 2
A PZT (zr / Ti = 53/47) seed layer was formed on a substrate (Pt / Ti / SiO ₂ / Si) by the same process as in Example 1 using the same CSD raw material as in Example 1. However, by performing calcination for removing the CSD solvent at 510 ° C., which is higher than the temperature of Example 1 (450 ° C.), a PZT seed layer having a thickness of 100 nm and preferentially oriented on the (111) plane was obtained.
[0058]
FIG. 9 is a diagram showing an X-ray diffraction pattern of the PZT seed layer (film thickness: 100 nm) that is preferentially oriented.
[0059]
Next, a PZT thick film having a thickness of about 2 μm was formed on the seed layer by the arc discharge ion plating method under the same conditions as in Example 1. The result of X-ray diffraction with respect to the obtained PZT thick film is shown in FIG. For comparison, FIG. 5B shows a case where a film is formed directly on Pt without using a seed layer. It was found that the perovskite type PZT was (111) preferentially oriented like the seed layer. As in Example 1, it was found from the results of FE-SEM observation that the (111) preferentially oriented PZT thick film was also joined to the seed layer almost seamlessly.
[0060]
When the ferroelectric characteristics and the piezoelectric characteristics were evaluated in comparison with the randomly oriented sample, as shown in the PE hysteresis curve of FIG. 11 and the piezoelectric displacement curve of FIG. 12, both the ferroelectric characteristics and the piezoelectric characteristics were formed on the seed layer. The deposited (111) preferentially oriented PZT thick film showed superior characteristics. In particular, in the case of the (111) preferentially oriented film, the saturation polarization and the remanent polarization became significantly larger than those of the random orientation. This is considered to be the result of preferential orientation in the <111> direction, which is the spontaneous polarization direction, of the PZT thick film having the composition Zr / Ti = 53/47.
[0061]
Further, when the piezoelectric constant was calculated using the same model as in Example 1, the value of the lateral effect piezoelectric constant d ₃₁ = −75 pm / V was obtained. This value is smaller than the value of Example 1, and for the PZT thick film having the composition of this example, the (100) preferential orientation is more advantageous than the (111) preferential orientation for the piezoelectric characteristics. It was. However, as described above, the remanent polarization of the (111) preferentially oriented PZT thick film is extremely large, and it is considered that application to a pyroelectric device using the temperature change of spontaneous polarization is effective.
[0062]
As described above, also in the method of this example, a (111) preferentially oriented PZT thick film excellent in ferroelectric characteristics and piezoelectric characteristics can be produced as in the above-described examples. That is, in the present invention, the following operation is obtained.
[0063]
(1) The crystal orientation of the ferroelectric thick film can be set to (100) or (111) by a simple process of forming a preferentially oriented seed layer by the CSD method and subsequently forming a thick film by the arc discharge reactive ion plating method. Two preferred orientations can be controlled. As a result, the preferentially oriented ferroelectric thin film has superior ferroelectricity and piezoelectricity compared to conventional random oriented thin films. Although depending on the film composition, the (100) preferential alignment film generally has excellent piezoelectric characteristics, and the (111) preferential alignment film tends to have excellent ferroelectric characteristics and pyroelectric characteristics. In the present invention, even when a ferroelectric thin film having the same composition is formed, the preferential crystal orientation can be freely controlled between (100) and (111) according to the purpose of the device to be applied. is there.
[0064]
(2) If there is a polycrystalline Pt layer preferentially oriented on the (111) plane, a ferroelectric oxide thin film preferentially oriented to (100) and (111) can be formed thereon. It is not necessary to prepare an epitaxial substrate specially as in a conventional dry process (MBE, sputtering, CVD, etc.). For this reason, a wide range of materials such as a Si wafer with a thermal oxide film, glass, and various metals can be used as the substrate. As a result, the degree of freedom in device design is much greater than in the conventional method.
[0065]
(3) In the conventional method, as the film thickness increases, the influence of the underlying layer decreases, and preferential crystal orientation can be maintained only for thin films having a film thickness of 1 μm or less. In the present invention, the preferential orientation of the seed layer is maintained until the completion of film formation by the ion plating method, and the preferential crystal orientation can be controlled even for a relatively thick film (thick film) having a film thickness of 1 μm or more. is there. In the examples, the result of a thick film having a thickness of 2 μm is shown, but a thick ferroelectric oxide film having a preferential orientation can be produced even with a thickness of 10 μm. The thick film does not require a poling process for aligning the polarization axis because of the preferred orientation structure, and the device fabrication process can be simplified.
[0066]
(4) Since the composition of the seed layer and that of the thin film can be made the same, the relative dielectric constant and ferroelectric characteristics of the entire film structure are not impaired. Furthermore, since the composition is the same, the interface between the seed layer and the thin film is joined almost seamlessly at the atomic level, and the mechanical strength is also excellent.
[0067]
(5) There is no need to consistently perform seed layer formation and thin film formation. Even when a seed layer formed in the atmosphere is used, the seed layer surface is cleaned and activated by high-density plasma by arc discharge, and the preferred orientation of the seed layer is maintained while performing the above-described seamless thin film growth. . This is in contrast to the fact that strict atmosphere control is required for orientation control by MBE, sputtering, and CVD.
[0068]
The product range in which the present invention can be used includes piezoelectric transformers or piezoelectric impulses, micromirrors or lens-driven optical switches, optical shutters, optical modulators, and the like, and inkjet printer head drive sources.
[0069]
Various sensors such as vibration gyroscopes, acceleration sensors, infrared (thermal) sensors, optical sensors, ultrasonic sensors, or ultrasonic motors, ultrasonic actuators, optical scanners, waveguide optical switches, optical shutters, optical modulators And a photographic paper writing micro light source unit.
[0070]
【The invention's effect】
As described above, according to the present invention, the following effects can be obtained.
[0071]
(1) With a simple process, a ferroelectric thin film capable of controlling the preferential crystal orientation can be obtained even with a relatively thick film having a thickness of 1 μm or more. This preferentially oriented ferroelectric thin film has superior ferroelectricity and piezoelectricity as compared with a conventional randomly oriented thin film, and is also excellent in pyroelectric characteristics.
[0072]
(2) If there is a polycrystalline Pt layer preferentially oriented on the (111) plane, a ferroelectric oxide thin film preferentially oriented to (100) and (111) can be formed thereon. It is not necessary to prepare an epitaxial substrate specially as in a conventional dry process (MBE, sputtering, CVD, etc.). For this reason, a wide range of materials such as a Si wafer with a thermal oxide film, glass, and various metals can be used as the substrate. As a result, the degree of freedom in device design is much greater than in the conventional method.
[0073]
(3) In the conventional method, the influence of the substrate is reduced as the film thickness is increased, and preferential crystal orientation can be maintained only for a thin film having a film thickness of 1 μm or less. In the present invention, the preferential orientation of the seed layer is maintained until the completion of film formation by the ion plating method, and the preferential crystal orientation can be controlled even for a relatively thick film (thick film) having a film thickness of 1 μm or more. Yes, it is possible to produce a ferroelectric oxide thick film with a preferential orientation even from a thick film having a thickness of 2 μm to a thickness of 10 μm. The thick film does not require a poling process for aligning the polarization axis because of the preferred orientation structure, and the device fabrication process can be simplified.
[0074]
(4) Since the seed layer and the thin film can have the same composition, the relative dielectric constant and ferroelectric characteristics of the entire film structure are not impaired. Furthermore, since the composition is the same, the interface between the seed layer and the thin film is joined almost seamlessly at the atomic level, and the mechanical strength is also excellent.
[0075]
(5) It is not necessary to perform the seed layer formation and the thin film formation consistently. Even when a seed layer formed in the atmosphere is used, the seed layer surface is cleaned and activated by high-density plasma by arc discharge, and the preferred orientation of the seed layer is maintained while performing the above-described seamless thin film growth. . This is in contrast to the fact that strict atmosphere control is required for orientation control by MBE, sputtering, and CVD.
[Brief description of the drawings]
[1] Seed layer forming process by reactive arc discharge ion cross-sectional view showing the structure of a ferroelectric thin film according to the schematic view Figure 2 of the present invention showing the configuration of a plating apparatus [3] chemical solution deposition FIG. 4 is a diagram showing an X-ray diffraction pattern of the PZT seed layer of Example 1. FIG. 5 is a diagram showing an X-ray diffraction pattern of the PZT thick film of Example 1. FIG. 6 is formed on the seed layer. FIG. 7 is a diagram showing a cross-sectional FE-SEM image of a PZT thick film formed. FIG. 7 is a diagram showing a PE hysteresis curve of the PZT thick film of Example 1. FIG. FIG. 9 is a diagram showing an X-ray diffraction pattern of a PZT seed layer of Example 2. FIG. 10 is a diagram showing an X-ray diffraction pattern of a PZT thick film of Example 2. FIG. 11 is a graph showing a PZT thickness of Example 2. FIG. 12 is a diagram showing the PE hysteresis curve of the membrane. Figure 13 is a sectional view showing the structure of a conventional ferroelectric thin film of a piezoelectric displacement curve of the PZT thick film

Claims (7)

Single crystal, polycrystal, forming a Pt film of polycrystalline on a substrate made of any material of an amorphous, on the Pt film, the seed layer is formed by chemical solution deposition, then arcing reactive A uniaxial priority characterized by forming a main thin film by an ion plating method to form a ferroelectric oxide film having a preferential crystal orientation in either (100) or (111) A method for producing an oriented ferroelectric thin film. Method of manufacturing a ferroelectric thin film according to claim 1, characterized in that the composition of the seed layer and the main film the same. 400-450 is preferentially oriented in at calcination temperature (100) in the range of ° C., is characterized in that so as to preferentially oriented in the (111) at a calcination temperature in the range of 450-510 ° C. claim 1 or 2 The manufacturing method of the ferroelectric thin film as described. _{3. The} method of manufacturing a ferroelectric thin film according to claim 2, wherein the ferroelectric is a ferroelectric compound represented by ABO3. 5. The method for producing a ferroelectric thin film according to claim 4, wherein the ferroelectric compound is a lead-based ferroelectric oxide. 6. The method for producing a ferroelectric thin film according to claim 5 , wherein the ferroelectric compound is any one of a lead-based ferroelectric oxide of PT, PZT, and PLZT. Method of manufacturing a ferroelectric thin film of claims 1 to 6, wherein any one, characterized in that so as to form a thickness of more than 1 [mu] m.

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