JP2003118104A - Sputtering target for forming ferroelectric film, ferroelectric film using the same, ferroelectric element and actuator using the same, inkjet head and inkjet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sputtering target for forming ferroelectric films whereby ferroelectric films having high piezoelectric characteristics and insulating properties can be formed. SOLUTION: The sputtering target for forming ferroelectric films of a perovskite type including Pb, Zr and Ti has a relative density of not smaller than 85% and satisfies 0.3<Zr<0.8(Zr+Ti=1) and 1.0<Pb/(Zr+Ti)<1.5.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a sputtering target for forming a ferroelectric film, a ferroelectric film using the sputtering target,
The present invention relates to a ferroelectric element, an actuator using the same, an inkjet head, and an inkjet recording device.

[0002]

2. Description of the Related Art For example, in an ink jet recording apparatus for printing by ejecting ink from a nozzle by displacement of an actuator, a ferroelectric element utilizing the piezoelectric characteristics of a ferroelectric dielectric film is used.

Ferroelectric films such as PZT films are required to have high piezoelectric characteristics in order to obtain a large amount of displacement and high insulation characteristics in order to obtain sufficient insulation at a driving voltage.

[0004]

Here, the ferroelectric film is formed by sputtering using a sputtering target, but in the past, the analysis of the relationship between the piezoelectric characteristic and the insulation characteristic and the characteristic of the sputtering target is not always necessary. It has not been done well.

Therefore, an object of the present invention is to provide a sputtering target for forming a ferroelectric film, which can obtain a ferroelectric film having high piezoelectric characteristics and insulating properties.

[0006]

In order to solve this problem, the sputtering target for forming a ferroelectric film of the present invention is a perovskite type sputtering target for forming a ferroelectric film containing Pb, Zr and Ti. hand,
Relative density of 85% or more, 0.3 <Zr <0.8 (Zr +
Ti = 1), and 1.0 <Pb / (Zr + Ti) <1.
5 is set.

This makes it possible to obtain a ferroelectric film having high piezoelectric characteristics and insulating properties.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention is a sputtering target for forming a perovskite type ferroelectric film containing Pb, Zr and Ti, the relative density of which is 85% or more, and the relative density of the target is 0.1%. 3 <Zr <0.8 (Zr + T
i = 1), and 1.0 <Pb / (Zr + Ti) <1.5
It is a sputtering target for forming a ferroelectric film, which has the effect of making it possible to obtain a ferroelectric film having high piezoelectric characteristics and insulating properties.

The invention according to claim 2 of the present invention is directed to Pb,
A sputtering target for perovskite type ferroelectric film formation containing Zr and Ti, having a relative density of 9
5% or more, 0.3 <Zr <0.8 (Zr + Ti = 1),
Further, it is a sputtering target for forming a ferroelectric film in which 1.0 <Pb / (Zr + Ti) <1.5, and it is possible to obtain an effect that a ferroelectric film having higher piezoelectric characteristics and insulating properties can be obtained. Have.

The invention according to claim 3 of the present invention is a ferroelectric film formed by the sputtering target for forming a ferroelectric film according to claim 1 or 2, and is a ferroelectric film having high piezoelectric characteristics and insulating properties. It has the effect of making it possible to obtain a dielectric film.

A fourth aspect of the present invention is the ferroelectric film according to the third aspect, which has a film thickness of 1 to 10 μm and a relative dielectric constant of 150 to 500, and has a higher piezoelectric property. Also, it has an effect of making it possible to obtain an insulating ferroelectric film.

The invention according to claim 5 of the present invention is the first electrode, the ferroelectric film according to claim 3 or 4 formed on the first electrode, and the ferroelectric film formed on the ferroelectric film. And a second electrode that has been formed, and has an effect that stable operation characteristics can be obtained.

The invention according to claim 6 of the present invention is an actuator using the ferroelectric element according to claim 5, and has an effect of enabling stable displacement operation.

According to a seventh aspect of the present invention, there is provided an ink jet head comprising: the actuator according to the sixth aspect; and a plurality of pressure chambers in which ink liquid is contained and on which the displacement of the actuator acts. Therefore, there is an effect that it becomes possible to perform stable ink ejection.

The invention according to claim 8 of the present invention is an ink jet recording apparatus provided with the ink jet head according to claim 7, and it is possible to perform high quality printing by stable ink ejection. Have.

FIG. 1 shows an embodiment of the present invention.
Starting from FIG. In addition, in these drawings, the same members are denoted by the same reference numerals, and duplicate description is omitted.

FIG. 1 is a perspective view showing an overall schematic structure of an ink jet recording apparatus using a ferroelectric element manufactured by a sputtering target for forming a ferroelectric film according to an embodiment of the present invention. 2 is a cross-sectional view showing the overall configuration of an inkjet head in the inkjet recording apparatus of FIG. 1, FIG. 3 is a perspective view showing the main parts of FIG. 2, and FIG.
FIG. 5 is a cross-sectional view showing the structure of the actuator part of the inkjet head of FIG. 5, FIG. 5 is a graph showing the relationship between the Zr ratio and the piezoelectric characteristic in the ferroelectric film produced by the sputtering target for forming the ferroelectric film, and FIG. FIG. 7 is a graph showing the relationship between Pb / (Zr + Ti) and piezoelectric characteristics in a ferroelectric film produced by a sputtering target for forming a body film, and FIG. 7 shows a ferroelectric film produced by the sputtering target for forming a ferroelectric film. FIG. 8 is a graph showing the relationship between the target relative density and the piezoelectric characteristics, FIG. 8 is a graph showing the relationship between the target relative density and the dielectric breakdown voltage in the ferroelectric film formed by the sputtering target for forming the ferroelectric film, and FIG. A graph showing the relationship between the film thickness and piezoelectric characteristics of a ferroelectric film produced by a sputtering target for forming a ferroelectric film. FIG 10 is a graph showing the relationship between the relative dielectric constant and the dielectric breakdown voltage of the ferroelectric film formed by ferroelectric film forming sputtering target.

The ink jet type recording apparatus 40 shown in FIG.
Is equipped with an inkjet head 41 of the present invention for recording by utilizing the piezoelectric effect of a ferroelectric element, and ink droplets ejected from this inkjet head 41 are made to land on a recording medium 42 such as paper to form a recording medium 42. It is to record. The inkjet head 41 is mounted on a carriage 44 provided on a carriage shaft 43 arranged in the main scanning direction X, and reciprocates in the main scanning direction X as the carriage 44 reciprocates along the carriage shaft 43. Move. Further, the inkjet recording apparatus 40 includes a plurality of rollers (moving means) 45 for moving the recording medium 42 in the sub-scanning direction Y which is substantially perpendicular to the width direction of the inkjet head 41 (that is, the main scanning direction X). .

FIG. 2 shows the overall construction of the ink jet head 41 according to the embodiment of the present invention, and FIG. 3 shows the construction of the essential parts thereof. 2 and 3, A is a pressure chamber component, and the pressure chamber opening 1 is formed therein. B is an actuator portion arranged so as to cover the upper end opening surface of the pressure chamber opening portion 1, and C is an ink liquid flow path component arranged so as to cover the lower end opening surface of the pressure chamber opening portion 1. The pressure chamber opening 1 of the pressure chamber component A is partitioned by the actuator unit B and the ink flow channel component C located above and below to form a pressure chamber 2. In the actuator section B, an individual electrode (second electrode) 3 located above the pressure chamber 2 is arranged. These pressure chambers 2 and individual electrodes 3 are arranged in a zigzag pattern, as can be seen from FIG. In the ink liquid flow path component C, a common liquid chamber 5 that is shared between the pressure chambers 2 arranged in the ink liquid supply direction, a supply port 6 that connects the common liquid chamber 5 to the pressure chamber 2, and a pressure chamber 2 An ink flow path 7 through which the ink liquid flows is formed. D is a nozzle plate having nozzle holes 8 communicating with the ink flow paths 7. Further, in FIG. 2, E is an IC chip, which supplies a voltage to a large number of individual electrodes 3 via the bonding wires BW.

Next, the structure of the actuator section B will be described with reference to FIG.

In the figure, the actuator section B is a sectional view in a direction orthogonal to the ink liquid supply direction shown in FIG. In the figure, a pressure chamber component A having four pressure chambers 2 arranged in the orthogonal direction is drawn for reference.

The actuator section B is displaced and vibrated by the individual electrode 3 located above each pressure chamber 2, the ferroelectric film 10 located immediately below the individual electrode 3, and the piezoelectric effect of the ferroelectric film 10. And a common electrode 11 also serving as a diaphragm. The diaphragm / common electrode 11 is made of a conductive material and also serves as a common electrode (first electrode) common to the pressure chambers 2. Further, the actuator section B is provided in each pressure chamber 2
The vertical wall 13 located above the partition wall 2a that partitions each other
have. In the figure, reference numeral 14 is an adhesive that bonds the pressure chamber component A and the actuator portion B together. Each vertical wall 13
Even when a part of the adhesive 14 protrudes to the outside of the partition wall 2a at the time of bonding with the adhesive 14, the adhesive 14 does not adhere to the diaphragm / common electrode 11 and the diaphragm / common electrode 1
1 has a role of expanding the distance between the upper surface of the pressure chamber 2 and the lower surface of the diaphragm / common electrode 11 so that the displacement and the vibration can occur as expected. However, the diaphragm and the common electrode may be separate bodies.

The individual electrode 3, the ferroelectric film 10 and the diaphragm / common electrode 11 constitute a ferroelectric element.

The individual electrode 3 is, for example, Pt (platinum).
The ferroelectric film 10 is made of, for example, lead zirconate titanate (P
ZT), the diaphragm / common electrode 11 is, for example, Cr (chromium), Mo (molybdenum) or Ta (tantalum),
Has been formed. The individual electrode 3 has a thickness of 0.1 to 0.
The ferroelectric film 10 has a thickness of 1 to 10 μm, particularly preferably 3 to 5 μm. This is determined in consideration of the stress balance with the diaphragm and the total film thickness of the whole. In this case, the diaphragm / common electrode 11 has a thickness of 3 to 5 μm.
, Respectively.

Here, the present inventor conducted various analyzes on the ferroelectric film 10 described above. The sputtering target is of the perovskite type containing Pb, Zr and Ti.

First, the manufacturing process of the sputtering target will be described.

For example, the PZT target Pb _1.1 (Zr _0.5
In producing Ti _0.5 ) O _3.1 , PbO, ZrO ₂
Powdered raw materials of TiO ₂ and TiO ₂ are prepared so as to have a desired composition, and these raw materials are mixed well.

Then, this powder raw material is added to about 1000 to 13
After performing atmospheric calcination at a temperature of about 00 ° C, crushing and crushing into PZ
A predetermined amount of T powder is prepared. 0.1 mol of Pb in this powder
O is added and thoroughly mixed to obtain a raw material powder before main firing. Then, this raw material powder is set in a carbon mold, and the raw material powder is subjected to main firing by a vacuum hot pressing method.

Here, the vacuum hot pressing apparatus used in the vacuum hot pressing method is one in which a pair of upper and lower hot presses are provided in a vacuum container.

In the vacuum hot press method, first, the upper hot press of this vacuum hot press apparatus is raised and a carbon disk-shaped bottom die is installed on the lower hot press, and the bottom die is placed on this bottom die. A hollow cylindrical molding die made of carbon having the same diameter as the bottom die is installed. At this time,
A carbon sheet having a thickness of about 2 mm is lined on the surface of the bottom mold, and a carbon sheet is also stretched over the entire circumference on the inner side wall of the molding die so as to partially overlap the carbon sheet.

After the raw material powder is filled in the space of the forming die, the carbon sheet is placed on the upper side of the raw material powder so that the carbon sheet stretched over the forming die partially overlaps.

When the raw material powder is wrapped in the carbon sheet in this way, a carbon upper plate is placed on the carbon sheet above the raw material powder and the upper hot press is lowered. Then, the pressure in the vacuum container is set to about 10-1P.
Hold at about a and 20-50M between upper and lower hot presses
Hot pressing is performed at about 900 to 1000 ° C. for about 2 hours while maintaining a pressure of about Pa to produce a disc-shaped sintered body.

After that, the surface of the target thus obtained is subjected to wet grinding and polishing to increase the flatness, thereby obtaining the target. Then, according to such a method, the airtightness is improved by the carbon sheet, so that the evaporation of PbO can be suppressed as much as possible, and a sintered body having substantially the same composition as the raw material can be obtained.

The method for producing the target is not limited to the vacuum hot pressing method as described above, and various other methods such as atmospheric pressure sintering method and hot isostatic pressing method may be used. Is also possible.

The obtained sintered body target was adhered to the backing plate serving as a cathode with an alloy of In and Ga or the like, and argon gas or argon / oxygen gas was introduced in a vacuum to a cathode from a DC or RF power source. A film is formed by applying an electric field to generate plasma, extracting target molecules, and depositing a target material on the substrate of the anode.

Next, FIG. 5 shows the relationship between the Zr ratio and the piezoelectric characteristic in the ferroelectric film produced by the sputtering target for forming the ferroelectric film.

As shown in the drawing, when Zr + Ti = 1, if the Zr ratio is 0.3 to 0.8, that is, if 0.3 <Zr <0.8 (Zr + Ti = 1), Z
It was found that the problem that the r was crystallized alone to make it difficult to form the perovskite layer was suppressed, and that good piezoelectric characteristics were exhibited.

Further, Pb / (Zr +) in the ferroelectric film produced by the sputtering target for forming the dielectric film.
The relationship between Ti) and piezoelectric characteristics is shown in FIG.

As shown in FIG. 6, 1.0 <Pb / (Zr
+ Ti) <1.5 shows good piezoelectric characteristics.

Generally, a problem in forming an oxide thin film such as a PZT film is that each metal element is not sufficiently oxidized, and the oxygen deficiency causes a decrease in piezoelectric characteristics and withstand voltage. . Therefore, in the composition of PZT, Pb, which is an element that is particularly easily oxidized, is replaced by Pb / (Zr +
It is considered that when Ti) is excessively added to 1.0 or more, other metal elements are likely to be in a sufficiently oxidized state with the oxidation of Pb, and as a result, the piezoelectric characteristics and the withstand voltage are improved. .

By the way, if the amount of Pb component is too large, the number of Pb atoms that are not bound to the bonds during crystal growth increases, which rather causes deterioration of the piezoelectric characteristics. This is the reason why the piezoelectric characteristics drastically decrease when Pb / (Zr + Ti) becomes 1.5 or more in FIG.

Therefore, by setting the component ratio Pb / (Zr + Ti) within the range of 1.0 to 1.5, the loss such as heat generation when a voltage is applied is reduced and the withstand voltage is improved.

The piezoelectric characteristic was measured by the cantilever method, and the piezoelectric constant (d31) of the piezoelectric film was calculated from the displacement amount.

As described above, from FIG. 5 and FIG. 6, the piezoelectric characteristics and the insulation are obtained when the target composition is 0.3 <Zr <0.8 (Zr + Ti = 1) and 1.0 <Pb / (Zr + Ti) <1.5. It was found that the characteristics were improved.

Next, the relationship between the target relative density and the piezoelectric and insulating properties will be described.

FIG. 7 shows the relationship between the relative density of the target and the piezoelectric characteristic in the ferroelectric film produced by the sputtering target for forming the dielectric film, and FIG. 8 shows the relationship between the target density and the dielectric breakdown characteristic.

Here, the relative density is a value that is arithmetically determined by the chemical formula used at the time of charging the raw materials and the lattice constant obtained by XRD measurement (the former is the mass of one lattice, the latter is its volume), and is the actual value of the sintered body. The density is calculated by the Archimedes method, and is defined by the ratio of this actual density to the relative density: actual density / relative density.

As shown in FIG. 7, it can be seen that when the target relative density is 85% or more, there is an inflection point and the piezoelectric characteristics are improved. Further, as shown in FIG. 8, it can be seen that the piezoelectric characteristics are improved with the inflection point when the target relative density is 85% or more, and further improved when the target relative density is 95% or more.

The piezoelectric characteristics are greatly dependent on the crystallinity of the film. Therefore, as the target relative density increases, the crystallinity is not obstructed by a trace amount of impurities. This difference in crystallinity is not due to a large difference observed by XRD analysis or the like, but is due to a microscopic structural change in crystallinity or discontinuity, and greatly depends on the characteristics of the target.

Therefore, in the region where the relative density is low and 85% or less, the characteristics of the formed ferroelectric film are low.
When the relative density is 85% or more, this effect is eliminated and the characteristics are stabilized.

Regarding the withstand voltage characteristic, the characteristic generally deteriorates as the amount of impurities in the film increases. Most of the impurities are a trace amount of metal in many cases. Therefore, the ferroelectric film formed by the target having a low relative density has a high leak current density and is easily broken by heat loss.
Since the ferroelectric film vibrates when a voltage is applied, the crystallinity of the film further acts, and if the crystallinity is disturbed, dielectric breakdown is more likely to occur.

Therefore, the withstand voltage characteristic is improved in the region where the relative density is 85% or more.

When the relative density is 95% or more, a better withstand voltage characteristic can be obtained because in the case of a high density target having a relative density of 95% or more, the pores (assistance of generation of particles of sputtering) are generated in the target. This is because the probability that there is a space that is considered to be) is low.

The dielectric breakdown voltage was measured using a ferroelectric film in which an upper electrode and a lower electrode were formed by sputtering or the like, and the upper electrode was formed into an individual electrode having an area of 1 mm ² by a photolithography process or the like. And, 1kH between both electrodes
When a sine wave of z was applied and the electrodes were broken, the electrodes were short-circuited, or the vibration state of the piezoelectric film was changed, the voltage value was defined as the dielectric breakdown voltage. The withstand voltage was evaluated by replacing with the dielectric breakdown voltage. Here, the film thickness of the ferroelectric film is 3 μm, the composition of the target is Zr = 0.55, Pb / Z
It was performed at r + Ti = 1.2.

Next, FIG. 9 shows the relationship between the film thickness and the piezoelectric characteristics of the ferroelectric film produced by the sputtering target for forming a dielectric film.

As shown in the figure, when the film thickness is 1 μm or less,
The film becomes a film whose piezoelectric characteristics are deteriorated due to the influence of the underlying electrode. On the other hand, when the thickness exceeds 10 μm, adverse effects such as generation of film cracks due to increase in film stress and inhibition of piezoelectric characteristics due to stress appear. Therefore, it is understood that the thickness of the ferroelectric film is preferably 1 to 10 μm. Therefore, it is preferable to use the ferroelectric film of this embodiment for the piezoelectric element.

Further, FIG. 10 shows the relationship between the relative dielectric constant and the dielectric breakdown voltage in the ferroelectric film produced by the sputtering target for forming a dielectric film.

As can be seen from FIG. 10, the relative permittivity is 15
When 0 to 500, the insulating property is good.

In the conventional sol-gel method, screen-printed or other ferroelectrics having a sintered body structure, the relative dielectric constant was often more than 1000 because it was difficult to control the film thickness, but the film formation technique by sputtering was used. Then, it is easy to control the film thickness. However, it is difficult to control the crystal structure of the ferroelectric film, and it is not possible to obtain predetermined characteristics by simply thinning it.

Here, by using the sputtering target of the present embodiment, a piezoelectric film having good crystallinity can be obtained. As a result, a film having a low relative dielectric constant and a high (001) orientation rate can be obtained, and a ferroelectric film having a low relative dielectric constant as described above can be obtained. Moreover, since the relative density of the target is high, the impurities contained in the ferroelectric film are reduced, and the dielectric loss that increases the relative dielectric constant is reduced. can get.

The reason why the insulation characteristic is deteriorated when the relative dielectric constant is 150 or less is that the film quality is poor and many defects are generated.

As explained above, according to the sputtering target for forming a ferroelectric film of the present embodiment, it becomes possible to obtain a ferroelectric film having high piezoelectric characteristics and insulating properties.

By forming a ferroelectric element with such a ferroelectric film, stable operation characteristics can be obtained.

Further, an actuator using the ferroelectric element as a piezoelectric element can perform a stable displacement operation, and an ink jet head using such an actuator can stably eject ink. Will be able to do. Then, according to the ink jet type recording apparatus including such an ink jet head, it is possible to perform high quality printing by stable ink ejection.

In the present embodiment, the case where the ferroelectric element formed of the ferroelectric film of the present invention is applied to an actuator used for ink ejection of an ink jet type recording apparatus has been described. The sputtering target for forming a dielectric film, the ferroelectric film, and the ferroelectric element can be applied to various other uses such as a temperature sensor utilizing its pyroelectricity.

In the present embodiment, for convenience of explanation,
Although the individual electrode is the second electrode and the common electrode is the first electrode, the individual electrode may be the first electrode and the common electrode may be the second electrode.

[0067]

As described above, according to the present invention, it is possible to obtain an effective effect that it is possible to obtain a ferroelectric film having high piezoelectric characteristics and insulating properties.

If a ferroelectric element is formed using such a ferroelectric film, an effective effect that stable operation characteristics can be obtained can be obtained.

By forming an actuator using such a ferroelectric element, an effective effect that a stable displacement operation can be performed can be obtained.

When an ink jet head is formed by using such an actuator, an effective effect that stable ink ejection can be performed can be obtained.

According to the ink jet recording apparatus having such an ink jet head, it is possible to obtain an effective effect that high quality printing can be performed by stable ink ejection.

[Brief description of drawings]

FIG. 1 is a perspective view showing an overall schematic configuration of an inkjet recording apparatus using a ferroelectric element manufactured by a sputtering target for forming a ferroelectric film according to an embodiment of the present invention.

FIG. 2 is a sectional view showing the overall configuration of an inkjet head in the inkjet recording apparatus of FIG.

FIG. 3 is a perspective view showing a main part of FIG.

FIG. 4 is a cross-sectional view showing a configuration of an actuator section of the inkjet head shown in FIG.

FIG. 5 is a graph showing a relationship between a Zr ratio and a piezoelectric characteristic in a ferroelectric film produced by a sputtering target for forming a ferroelectric film.

FIG. 6 is a graph showing the relationship between Pb / (Zr + Ti) and piezoelectric characteristics in a ferroelectric film produced by a sputtering target for forming a ferroelectric film.

FIG. 7 is a graph showing the relationship between target relative density and piezoelectric characteristics in a ferroelectric film manufactured by a sputtering target for forming a ferroelectric film.

FIG. 8 is a graph showing the relationship between the target relative density and the dielectric breakdown voltage in the ferroelectric film produced by the sputtering target for forming the ferroelectric film.

FIG. 9 is a graph showing a relationship between a film thickness and a piezoelectric characteristic of a ferroelectric film produced by a sputtering target for forming a ferroelectric film.

FIG. 10 is a graph showing the relationship between the relative dielectric constant and the dielectric breakdown voltage of a ferroelectric film produced by a sputtering target for forming a ferroelectric film.

[Explanation of symbols]

3 Individual electrodes (second electrode) 10 Ferroelectric film 11 Vibration plate and common electrode (first electrode) 41 inkjet head 40 Inkjet recording device

Front page continuation (51) Int.Cl. ⁷ identification code FI theme code (reference) H01L 41/18 H01L 41/08 U (72) Inventor Takanori Nakano 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Kazuo Nishimura 1006, Kadoma, Kadoma-shi, Osaka Prefecture F-term within Matsushita Electric Industrial Co., Ltd. (reference) 2C057 AF93 AG44 AP14 AP52 BA04 BA14 4K029 BA50 BB07 CA05 DC05 DC09 5G303 AA10 AB01 AB20 BA03 BA09 CA01 CB25 CB35 CB39

Claims (8)

[Claims] 1. A perovskite type sputtering target for forming a ferroelectric film containing Pb, Zr and Ti, wherein the relative density is 85% or more and 0.3 <Zr <0.8 (Zr +
Ti = 1), and 1.0 <Pb / (Zr + Ti) <1.
5. A sputtering target for forming a ferroelectric film, which is No. 5. 2. A perovskite type sputtering target for forming a ferroelectric film containing Pb, Zr and Ti, wherein the relative density is 95% or more and 0.3 <Zr <0.8 (Zr +
Ti = 1), and 1.0 <Pb / (Zr + Ti) <1.
5. A sputtering target for forming a ferroelectric film, which is No. 5. 3. A ferroelectric film formed by the sputtering target for forming a ferroelectric film according to claim 1. 4. The ferroelectric film has a film thickness of 1 to 10 μm.
4. The ferroelectric film according to claim 3, wherein the relative dielectric constant is 150 to 500 in m. 5. A first electrode, a ferroelectric film according to claim 3 formed on the first electrode, and a second electrode formed on the ferroelectric film. A ferroelectric element having. 6. An actuator comprising the ferroelectric element according to claim 5. 7. An ink jet head, comprising: the actuator according to claim 6; and a plurality of pressure chambers in which an ink liquid is contained and on which the displacement of the actuator acts. 8. An ink jet recording apparatus comprising the ink jet head according to claim 7.