JPH10214945A - Ferroelectric thin film coated substrate, capacitor structure element and method for manufacturing ferroelectric thin film coated substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smooth densely a surface of a thin film by a method wherein a first oxide ferroelectric thin film is formed on a substrate, and a metal oxide film is formed thereon, and a second oxide ferroelectric thin film composed of the same structure element as the first oxide ferroelectric thin film and having different orientation is disposed thereon, sequently. SOLUTION: In a capacitor structure element, a silicon oxide layer 2, an adhering layer 3, a lower electrode 4, and a bismuth titanate thin film 5 of c-axial priority orientation as a first oxide ferroelectric thin film are formed on a silicon substrate 1. Further, a titanium oxide film 6 as a metal oxide film, a bismuth titanate thin film 7 of (117) priority orientation as a second oxide ferroelectric thin film and an upper electrode 8 are sequently formed thereon, respectively. A metal oxide film resides on a substrate, and a ferroelectric thin film composed of the same material and having different orientation is formed up and down. Therefore, it is possible to suppress a generation of unevenness on the surface of a thin film and to realize film quality of a smooth surface by effects of the metal oxide film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ferroelectric thin film-coated substrate used for a ferroelectric memory element, a pyroelectric sensor element, a piezoelectric element, etc., a capacitor structure element, and a method of manufacturing a ferroelectric thin film-coated substrate. Things.

[0002]

2. Description of the Related Art With the development of a method for forming a ferroelectric thin film,
Many device applications are being studied using the material properties. For example, an infrared sensor using a pyroelectric effect, a touch sensor using a piezoelectric effect, an optical switch using an electro-optical effect, and the like have an extremely wide application range. In particular, recently, a 1-gigabit class large-capacity memory has been realized by utilizing the high dielectric constant characteristics and increasing the integration of devices by miniaturizing capacitors such as DRAMs. On the other hand, ferroelectric memories utilizing spontaneous polarization characteristics of ferroelectrics have been actively developed. This ferroelectric memory has features such as non-volatility, high-speed operation, low power consumption, and a large number of times of rewriting, which are not found in conventional non-volatile memories, and is therefore greatly expected as a next-generation memory device.

The following characteristics are required for a ferroelectric material used for such a ferroelectric memory or the like. That is, a ferroelectric material having a large remanent polarization (Pr), a small coercive electric field (Ec), a low leak current, and a small characteristic deterioration (fatigue) due to repetition of polarization reversal. It is necessary that the thin film has a film thickness of 200 nm or less in order to reduce the thickness and to match the semiconductor fine processing process.

At present, for the purpose of application to ferroelectric memories and the like, high-quality thin films of bismuth titanate Bi ₄ Ti ₃ O ₁₂ having a Bi-based layered perovskite structure are being studied by various film forming methods. . The ferroelectric properties of the bulk crystal of bismuth titanate are as follows: Pr = 50 μC / c in the a-axis direction.
m ² , Ec = 50 kV / cm, Pr = 4 μC in the c-axis direction
/ Cm ² and Ec = 4 kV / cm, and have extremely large anisotropy. When this material is thinned and applied to a device, it is desired to use a large Pr component in the a-axis direction in order to cope with a decrease in the amount of detection signals due to miniaturization of elements accompanying high integration. In addition, it is desirable to use a small Ec component in the c-axis direction for low voltage drive device applications. Therefore, if the orientation of the bismuth titanate thin film can be arbitrarily controlled, the application range is expected to be further widened.

[0005] The thinning of bismuth titanate is carried out by MOCVD.
Attempts have been made by a method such as a sol-gel method, a laser ablation method, and a sputtering method. However, most of the reports so far are mostly c-axis oriented films with small Pr. Furthermore, since the surface morphology is composed of coarse crystal grains, surface irregularities are severe, and a thin film having a small thickness tends to cause a leak current due to a local shortage of the film thickness, so that sufficient ferroelectric characteristics have not been obtained.

[0006]

As described above, in the above prior art, in order to apply a ferroelectric thin film to a highly integrated device, the fineness of the surface of the thin film required for fine processing and low leakage current is reduced. There are various problems such as control of flatness, remanent polarization and coercive electric field.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the anisotropy can be effectively applied to a device by controlling the orientation of an oxide ferroelectric thin film. An object of the present invention is to provide a ferroelectric thin film-coated substrate made of a dense and smooth surface oxide ferroelectric thin film, a capacitor structure element, and a method of manufacturing the ferroelectric thin film-coated substrate.

[0008]

In order to solve the above problems, according to the first aspect of the present invention, a first oxide ferroelectric thin film is formed on a substrate, and the first oxide ferroelectric thin film is formed on the first oxide ferroelectric thin film. A first oxide ferroelectric thin film formed on the metal oxide film and a second oxide ferroelectric thin film formed of the same constituent elements and having different orientations; Are sequentially arranged to form a ferroelectric thin film-coated substrate.

That is, according to the first aspect of the present invention, when forming an oxide ferroelectric thin film on a substrate, a metal oxide film is interposed therebetween and an oxide ferroelectric film having different orientations is formed above and below the metal oxide film. A body thin film is formed. By changing the ratio of the thickness of the upper and lower oxide ferroelectric thin films,
It is possible to effectively control the orientation of the entire multilayer ferroelectric thin film.

Further, in the invention according to claim 2, in the above-mentioned substrate coated with a ferroelectric thin film, the first oxide ferroelectric thin film and the second oxide ferroelectric thin film are used as at least a part of the elements constituting the metal oxide film. Of the oxide ferroelectric thin film.

According to the ferroelectric thin film-coated substrate according to the second aspect, at least a part of the elements constituting the metal oxide film in the middle of the upper and lower oxide ferroelectric thin films is replaced with the oxide ferroelectric thin film. Since the constituent elements are the same as the constituent elements of the body thin film, the surface morphology of the oxide ferroelectric thin film located on the top can be densified and smoothed. In addition, as long as all the elements constituting the metal oxide film include those constituting the oxide ferroelectric thin film, it is possible to prevent impurities from being mixed into the oxide ferroelectric thin film. it can.

Further, in the invention according to claim 3, in the above ferroelectric thin film-coated substrate, the first oxide ferroelectric thin film and the second oxide ferroelectric thin film are made of bismuth titanate. The metal oxide film is made of titanium oxide.

According to the third aspect of the present invention, the large anisotropy of bismuth titanate can be effectively applied to a device. Furthermore, since the metal oxide film is composed of titanium oxide and titanium element constituting the bismuth titanate thin film which is an oxide ferroelectric thin film, the surface of the bismuth titanate thin film located on the top is used. The morphology can be densified and smoothed.

According to a fourth aspect of the present invention, in the above ferroelectric thin film-coated substrate, the first oxide ferroelectric thin film is a bismuth titanate thin film having c-axis preferred orientation, and the second oxide ferroelectric thin film is The dielectric thin film is a bismuth titanate thin film of (117) preferential orientation.

According to the fourth aspect of the present invention, the (117) preferential orientation having a ferroelectric characteristic of a bismuth titanate thin film having a c-axis preferential orientation exhibiting a small coercive electric field and an a-axis orientation component exhibiting a large remanent polarization. By superimposing on the ferroelectric property of the bismuth titanate thin film, the ferroelectric property of the entire ferroelectric thin film can be controlled. In other words, utilizing the characteristics of bismuth titanate, whose electrical properties differ greatly depending on the orientation, by superimposing two different orientation components,
It is possible to effectively extract characteristics corresponding to the intermediate orientation between them.

According to a fifth aspect of the present invention, there is provided a capacitor structure element comprising the above-mentioned ferroelectric thin film-coated substrate, wherein the substrate is electrically conductive at least in a portion in contact with the first oxide ferroelectric thin film. A first electrode made of a conductive material, and a second electrode made of a conductive material on the second oxide ferroelectric thin film.

According to the fifth aspect of the present invention, a device can be formed from the substrate covered with the ferroelectric thin film.

In the invention according to claim 6, after forming a first oxide ferroelectric thin film on a substrate and forming a metal oxide film on the first oxide ferroelectric thin film, Forming a second oxide ferroelectric thin film on the metal oxide film, the second oxide ferroelectric thin film being composed of the same constituent elements as the first oxide ferroelectric thin film and having different orientations; A method for manufacturing a ferroelectric thin film-coated substrate that controls ferroelectric characteristics by changing the ratio of the thickness of the thin film to the thickness of the second oxide ferroelectric thin film.

According to the sixth aspect of the present invention, it is possible to manufacture the above ferroelectric thin film-coated substrate.

[0020]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a structure of a capacitor structure element constituted by a ferroelectric thin film-coated substrate according to an embodiment of the present invention. As shown in FIG. 1, this capacitor structure element is a silicon (Si) substrate 1, a silicon oxide (SiO ₂ ) layer 2, an adhesive layer 3, a lower electrode 4, and a first oxide ferroelectric thin film. The bismuth titanate thin film 5 having c-axis preferred orientation, the titanium oxide film 6 as a metal oxide film, and the second oxide ferroelectric thin film (11)
7) Bismuth titanate thin film 7 with preferred orientation, upper electrode 8
Are sequentially formed.

In the present embodiment, a silicon single crystal wafer was used as the silicon substrate 1, and a silicon oxide thin film obtained by thermally oxidizing the surface of the silicon single crystal wafer was used as the SiO ₂ layer 2. A tantalum (Ta) thin film was used as the adhesive layer 3, a platinum (Pt) thin film was used as the lower electrode 4, and a platinum (Pt) thin film was used as the upper electrode 7. Further, since the bismuth titanate thin films 5 and 7 were used as the first oxide ferroelectric thin film and the second oxide ferroelectric thin film, these metal oxide films could be used for these oxide ferroelectric thin films. In order to prevent impurities from mixing, a titanium oxide film 6 composed of titanium and oxygen which are constituent elements of the bismuth titanate thin film was employed. That is, all of the constituent elements of the metal oxide film are constituent elements of the oxide ferroelectric thin film.

Next, a method for manufacturing the capacitor structure element of the first embodiment shown in FIG. 1 will be described. First, P
The fabrication of the t / Ta / SiO ₂ / Si substrate will be described. A silicon single crystal wafer (10
0) By thermally oxidizing the surface, the thickness is 300 nm.
Forming a SiO ₂ layer 2. Then, the adhesive layer 3 T
The thin film a was formed with a thickness of 30 nm, and the Pt thin film as the lower electrode layer 4 was formed with a thickness of 200 nm by sputtering.

Here, these materials and film thickness are not limited to the present embodiment, and a polycrystalline silicon substrate or a GaAs substrate may be used instead of a silicon single crystal substrate. Further, the adhesive layer is for preventing the peeling of the film between the substrate and the lower electrode layer during the film formation, and the film thickness only needs to be such that the peeling of the film can be prevented. Although Ti) and the like can be used, it is preferable to use Ta because an alloy of Ti and Pt is easily formed at a high temperature. Further, the SiO ₂ layer used for the insulating layer does not have to be formed by thermal oxidation,
SiO ₂ formed by vacuum evaporation, MOCVD, etc.
A film, a silicon nitride film, or the like can be used, as long as the material and the film thickness are sufficiently insulating.

The lower electrode also needs to have a thickness enough to function sufficiently as an electrode layer, and the material is not limited to Pt, but may be a conductive material used for ordinary electrode materials. It can be appropriately selected in relation to other thin films. Further, the film formation method is not limited to the sputtering method, and may be performed using a normal thin film formation technique such as a vacuum evaporation method. Further, the substrate structure is not limited to the above.

Here, a relatively thick bismuth titanate thin film is formed on the Pt / Ta / SiO ₂ / Si substrate produced as described above by MOCVD, and its surface morphology and orientation are determined. The observation result will be described.

Table 1 shows the conditions for forming the bismuth titanate thin film at this time.

[0027]

[Table 1]

As shown in Table 1, the formation of the bismuth titanate thin film was performed using triortho tolyl bismuth (B
i a _{(o-C 7 H 7)} 3), were used, respectively of titanium tetraisopropoxide as a Ti source _{(Ti (i-OC 3 H} 7) 4). These raw materials are heated and vaporized to the raw material temperatures shown in Table 1, respectively (Bi raw material 160 ° C, Ti raw material 50 ° C).
Using an Ar carrier gas, oxygen (O ₂ ) gas as a reaction gas was supplied to the substrate surface heated and held by the substrate holder in the film formation chamber. Here, the flow rate of the Ar gas is set to 200 sccm for the Bi raw material, set to 50 sccm for the Ti raw material, and the flow rate of the O ₂ gas is set to 1000 sccc.
m). Note that, in this film formation step, if the degree of vacuum in the film formation chamber is 10 Torr or more, a gas phase reaction easily occurs. Under these conditions, the substrate temperature was set to 600 ° C., and a bismuth titanate thin film having a thickness of 100 nm was formed.

Surface morphology (SEM (scanning electron microscope)) of the bismuth titanate thin film thus formed
(Photo) and XRD patterns are shown in FIGS. 2 and 3, respectively. In FIG. 3, (00n) (n is an integer) represents a diffraction peak due to the c-axis orientation component of bismuth titanate (layered perovskite phase), and Pt (111) represents the diffraction of (111) of Pt by the Pt lower electrode. It represents a peak.

For comparison, the same Pt / T as above was used.
a / SiO_Two/ MOCVD method on Si substrate,
Titanium isopropoxide (Ti (i-
OC _ThreeH₇)_Four) To supply a 5 nm thick titanium oxide film
Is formed, and then the Bi raw material and Ti
Bismuth titanate with a thickness of 100 nm
A thin film was formed. The film formation temperature at this time
Is also 600 ° C. Bismuth titanate thin formed here
Surface morphology of the film (SEM (scanning electron microscope)
True and XRD patterns are shown in FIGS. 4 and 5, respectively.
You. In FIG. 5, (00n) (n is an integer) is
C-axis orientation of bismuth titanate (layered perovskite phase)
(117) is a bismuth titanate.
Including a-axis component of mass (layered perovskite phase) (11
7) Pt (111) represents a diffraction peak due to the orientation component.
Indicates the diffraction peak of (111) of Pt by the Pt lower electrode.
The other diffraction peaks are bismuth titanate (layered
The peak is a diffraction peak of the (lobskite phase).

The results shown in FIGS. 2 and 3 and FIGS. 4 and 5 show that a single-layer bismuth titanate thin film having no titanium oxide film has a large plate-like shape having strong c-axis preferred orientation. It can be seen that it is composed of crystal grains. On the other hand, when a bismuth titanate thin film is formed on a titanium oxide film,
(117) The orientation is enhanced, and the improvement in surface smoothness due to the refinement of the crystal grain size is observed.

Next, the above Pt / Ta / SiO ₂ / Si
A bismuth titanate thin film 5 of c-axis preferred orientation as a first oxide ferroelectric thin film, a titanium oxide film 6 as a metal oxide film, and a second oxide ferroelectric thin film on a substrate ( 11
7) The bismuth titanate thin film 7 having the preferred orientation is sequentially
A method of continuously forming in the same film forming apparatus by using the VD method will be described.

If a bismuth titanate thin film is formed directly on a Pt / Ta / SiO ₂ / Si substrate under the above-mentioned MOCVD method, a c-axis preferential orientation film can be obtained. Under the conditions shown in Table 1, a 50 nm c-axis preferred orientation bismuth titanate thin film 5 was formed at a substrate temperature of 600 ° C. Then, formed after an interval of about 10 minutes, using the MOCVD method, Ti raw material (titanium isopropoxide _{(Ti (i-OC 3 H} 7) 4)) by supplying, titanium oxide film 6 having a thickness of 5nm Then, after an interval of about 10 minutes, the substrate temperature was changed to 50 nm (117) at a substrate temperature of 600 under the conditions shown in Table 1 as described above.
A bismuth titanate thin film 7 having a preferred orientation was formed. In addition,
Here, an interval of about 10 minutes is provided between the formation of the respective films in order to prevent the occurrence of sagging of the film boundaries.

The surface morphology (SEM (scanning electron microscope) photograph) and XRD pattern of the multilayer ferroelectric thin film thus formed are shown in FIGS. 6 and 7, respectively. In FIG. 7, (00n) (n is an integer) represents a diffraction peak due to a c-axis orientation component of bismuth titanate (layered perovskite phase), and (117) is an a-axis component of bismuth titanate (layered perovskite phase). (11
7) Pt (111) represents a diffraction peak due to the orientation component.
Represents a diffraction peak of (111) of Pt by the Pt lower electrode.

From the results shown in FIG. 6, by interposing a titanium oxide film 6 which is a metal oxide as an intermediate layer,
It can be seen that the surface morphology of the bismuth titanate thin film 7 formed thereon is made of fine crystals and has a smooth surface.
On the other hand, from the results shown in FIG. 7, the crystallinity of the multilayer ferroelectric thin film is in a state where the reflection of c-axis orientation and the reflection of (117) are mixed, and the XRD patterns shown in FIGS. It can be seen that the pattern is close to the superposed pattern. That is, from these facts, the possibility that two different types of bismuth titanate thin films 5 and 7 were stacked was shown.

The following experiment was conducted in order to confirm that an arbitrary combination of two types of orientation components was possible with such a laminated film structure. That is, the film thickness ratio between the bismuth titanate thin film 5 as the first oxide ferroelectric thin film and the bismuth titanate thin film 7 as the second oxide ferroelectric thin film was set to 1: 1 in the above. Was also changed to 1: 4, and these were compared. The film formation conditions at this time are exactly the same as those described above, the thickness of the bismuth titanate thin film 5 as the first oxide ferroelectric thin film is 20 nm, and the thickness of the bismuth titanate as the second oxide ferroelectric thin film is The thickness of the bismuth thin film 7 was 80 nm, and the total thickness was constant. FIG. 8 shows the XRD pattern of this thin film. In FIG. 8, (00n) (n is an integer) represents a diffraction peak due to a c-axis orientation component of bismuth titanate (layered perovskite phase), and (117) is an a-axis component of bismuth titanate (layered perovskite phase). (117)
Represents a diffraction peak due to an orientation component, and Pt (111) is P
12 shows a diffraction peak of (111) of Pt by the t lower electrode.

When FIG. 8 is compared with FIG. 7, the film thickness ratio between the first oxide ferroelectric thin film and the second oxide ferroelectric thin film is 1
The film thickness ratio of 4: 1 is larger than that of 1: 1 by (1).
17) It can be seen that the intensity of the reflection has increased. Therefore, according to the present embodiment, the c-axis preferred orientation is effectively a
It was shown that a bismuth titanate thin film including the axis component up to the (117) preferred orientation can be continuously produced.

Next, Pt as an upper electrode 8 was formed on the surface of the two types of multilayer ferroelectric thin films having different thickness ratios between the first oxide ferroelectric thin film and the second oxide ferroelectric thin film. To produce a capacitor structure element as shown in FIG.
The ferroelectric properties were evaluated. FIG. 9 shows the respective hysteresis curves. From FIG. 9, the film thickness ratio of the first oxide ferroelectric thin film to the second oxide ferroelectric thin film of 1: 4 is larger than that of the film thickness ratio of 1: 1 ( 117) Reflection is large, Pr is obviously large, and
Ec is also slightly larger. From this,
According to the present invention, it has been shown that control of ferroelectric characteristics by changing the thickness ratio between the first oxide ferroelectric thin film and the second oxide ferroelectric thin film can be effectively realized. .

In the above embodiment, a bismuth titanate thin film was used as the first oxide ferroelectric thin film and the second oxide ferroelectric thin film, and a titanium oxide film was used as the metal oxide film. The present invention is not limited to this. That is, a ferroelectric material having a strong anisotropy of material properties, and a ferroelectric thin film having a different orientation is laminated via a metal oxide film to provide a material property corresponding to each orientation. Intermediate characteristics can be effectively realized. Other specific examples of the combination of the first oxide ferroelectric thin film / metal oxide / second oxide ferroelectric thin film include c-axis priority of tetragonal PZT (lead zirconate titanate). Orientation film / titanium oxide film / (111) preferred orientation film of rhombohedral PZT, (111) preferred orientation film of rhombohedral PZT / c-axis preferred orientation film of titanium oxide / tetragonal PZT, bismuth titanate (Bi ₄ Ti ₃ O ₁₂ ) c-axis preferred orientation film / bismuth oxide film / bismuth titanate (117) preferred orientation film.

Further, regarding the method of forming these films,
The method is not limited to the MOCVD method used in the above embodiment, and a sputtering method, an evaporation method, a laser ablation method, a sol-gel method, a MOD method, or the like can be used.

[0041]

As described above, according to the present invention, a ferroelectric thin film made of the same material and having different orientations is formed above and below a metal oxide film on a substrate. Therefore, by changing the film thickness ratio between the upper and lower ferroelectric thin films, the anisotropy of the ferroelectric thin films is used to make the material characteristics between the two different types of material characteristics. Can be realized effectively. Further, the effect of the metal oxide film can suppress the occurrence of unevenness on the surface of the thin film and realize a film having a smooth surface. Thus, sufficient ferroelectric characteristics can be obtained even with a film thickness of 200 nm or less, and it can be applied to a fine processing process.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing the structure of a capacitor structure element comprising a ferroelectric thin film-coated substrate according to an embodiment of the present invention.

FIG. 2 shows a Pt / Ta / SiO ₂ / Si substrate having a thickness of 100 nm.
5 is a photomicrograph showing the results of SEM observation of surface morphology when a m-bismuth titanate thin film was formed by MOCVD.

FIG. 3 shows a Pt / Ta / SiO ₂ / Si substrate having a thickness of 100 nm.
FIG. 4 is a diagram showing an XRD pattern when a m-bismuth titanate thin film is formed by MOCVD.

FIG. 4 shows a method of forming a 100 nm-thick bismuth titanate thin film on a Pt / Ta / SiO ₂ / Si substrate through a titanium oxide film by MOC.
SEM of surface morphology when formed by VD method
7 is a micrograph showing the observation result by the method.

FIG. 5: A 100 nm bismuth titanate thin film is formed on a Pt / Ta / SiO ₂ / Si substrate through titanium oxide by MOC.
It is a figure which shows the XRD pattern when formed by the VD method.

FIG. 6 shows a Pt / Ta / SiO ₂ / Si substrate having a film thickness of 5
5 is a micrograph showing the results of SEM observation of surface morphology when a 0 nm bismuth titanate thin film, a 5 nm thick titanium oxide film, and a 50 nm thick bismuth titanate thin film are sequentially formed by MOCVD.

FIG. 7 shows a film having a thickness of 5 on a Pt / Ta / SiO ₂ / Si substrate.
It is a figure which shows the XRD pattern when a 0-nm bismuth titanate thin film, a 5-nm-thick titanium oxide film, and a 50-nm-thick bismuth titanate thin film are sequentially formed by MOCVD.

FIG. 8 shows a film having a thickness of 2 on a Pt / Ta / SiO ₂ / Si substrate.
It is a figure which shows the XRD pattern when a 0-nm bismuth titanate thin film, a 5-nm-thick titanium oxide film, and a 80-nm-thick bismuth titanate thin film are sequentially formed by MOCVD.

FIG. 9 is a diagram showing ferroelectric hysteresis loops of two types of capacitor structure elements of the embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 silicon substrate 2 silicon oxide layer 3 adhesive layer 4 lower electrode 5 bismuth titanate thin film with c-axis preferred orientation 6 titanium oxide film 7 (117) bismuth titanate thin film with preferred orientation 8 upper electrode

Claims (6)

[Claims] 1. A first oxide ferroelectric thin film on a substrate,
The metal oxide film formed on the first oxide ferroelectric thin film and the first oxide ferroelectric thin film formed on the metal oxide film are composed of the same constituent elements and have the same orientation. And a second oxide ferroelectric thin film different from the above. 2. The method according to claim 1, wherein at least a part of the elements constituting the metal oxide film includes the elements constituting the first oxide ferroelectric thin film and the second oxide ferroelectric thin film. The ferroelectric thin film-coated substrate according to claim 1. 3. The ferroelectric thin film of the first oxide and the ferroelectric thin film of the second oxide are made of bismuth titanate, and the metal oxide film is made of titanium oxide. 3. The substrate coated with a ferroelectric thin film according to 2. 4. The first oxide ferroelectric thin film is a bismuth titanate thin film having c-axis preferred orientation, and the second oxide ferroelectric thin film is a bismuth titanate thin film having (117) preferred orientation. The ferroelectric thin film-coated substrate according to claim 3, wherein: 5. A capacitor structure element comprising the ferroelectric thin film-coated substrate according to any one of claims 1 to 4, wherein the substrate comprises at least the first oxide ferroelectric thin film. A capacitor structure element comprising: a first electrode made of a conductive material in a contacting part; and a second electrode made of a conductive material on the second oxide ferroelectric thin film. 6. A first oxide ferroelectric thin film is formed on a substrate, and a metal oxide film is formed on the first oxide ferroelectric thin film. A second oxide ferroelectric thin film made of the same constituent elements as the first oxide ferroelectric thin film and having different orientations is formed, and the thickness of the first oxide ferroelectric thin film and the thickness of the second oxide ferroelectric thin film are changed. 2. A method for manufacturing a ferroelectric thin film-coated substrate, characterized in that ferroelectric characteristics are controlled by changing a ratio of the thickness of the oxide ferroelectric thin film to the thickness of the thin film.