JP2003347618A - Piezoelectric element, ink jet head and manufacturing method of the same, and ink jet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce variations in characteristic of a piezoelectric element and to improve breakdown voltage and reliability by forming a piezoelectric layer consisting of a perovskite type oxide having excellent crystallinity and degree of (001) face crystal orientation in the piezoelectric element. <P>SOLUTION: A first electrode layer 14 made of a noble metal containing a titanium or titanic oxide is formed on a substrate 11. An orientation- controlling layer 15 made of a perovskite type oxide (strontium titanate, etc.), containing a strontium of a cubic or tetragonal system is formed on the layer 14. The layer 15 is preferentially oriented to a (100) face or (001) face, and a piezoelectric layer 16 made of a perovskite type oxide (PTZ, etc.), of a rhombohedral or tetragonal system is formed on the layer 15. The layer 16 is preferentially oriented to the (001) face. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric element having an electromechanical conversion function, an ink-jet head using the piezoelectric element, a method of manufacturing the same, and an ink-jet recording apparatus having the ink-jet head as printing means. Belongs to the field.

[0002]

2. Description of the Related Art In general, a piezoelectric material is a material that converts mechanical energy into electrical energy or converts electrical energy into mechanical energy. A typical example of this piezoelectric material is lead zirconate titanate (Pb (Zr, Ti) O ₃ ) having a perovskite crystal structure.
(Hereinafter referred to as PZT). The direction in which the largest piezoelectric displacement is obtained in this PZT is the <001> direction (c-axis direction) in the case of the tetragonal system, and is the <111> direction in the case of the rhombohedral system. However, since many piezoelectric materials are polycrystals composed of aggregates of crystal particles, the crystal axes of the crystal particles are oriented in random directions. Therefore, the spontaneous polarizations Ps are also randomly arranged.

[0003] With the recent miniaturization of electronic equipment, miniaturization of piezoelectric elements using piezoelectric materials has been strongly demanded. In order to satisfy this demand, piezoelectric elements are being used in the form of a thin film whose volume can be significantly reduced as compared with a sintered body that has been used more frequently than before. R & D is becoming active. For example, in the case of tetragonal PZT, the spontaneous polarization Ps is oriented in the c-axis direction. Therefore, in order to realize high piezoelectric characteristics even when the film is made thin, the c-axis of the crystal constituting the PZT thin film is set with respect to the substrate surface. Must be aligned vertically. In order to realize this, conventionally, a single crystal substrate made of magnesium oxide (MgO) having a Nacl-type crystal structure cut out so that the (100) plane is exposed on the surface by using a sputtering method, On this substrate, (10
0) A PtT thin film oriented on the plane is formed, and PZT oriented c-axis perpendicular to the surface thereof is formed on the Pt electrode.
A thin film was formed at a temperature of 600 to 700 ° C. (for example, J. Appl. Phys. Vol. 65, No. 4 (15 Feb. 1989) pp. 1666-16).
70, see JP-A-10-209517). In this case, before forming the PZT thin film, PbTiO ₃ or (Pb, La) T without Zr is used as an underlayer of the PZT thin film.
A 0.1 μm-thick piezoelectric layer made of iO _{3 is}
If a PZT thin film having a thickness of 2.5 μm is formed on the Pt electrode oriented in the 0) plane by a sputtering method, a low crystallinity layer made of Zr oxide is formed at the beginning of the PZT thin film formation. Are difficult to form, and the higher crystalline P
A ZT thin film is obtained. That is, the (001) plane orientation degree (α
A (100%) (001)) PZT thin film is obtained.

Here, α (001) is defined as α (001) = I (001) / ΣI (hkl). ΣI (hkl) is the sum of the diffraction peak intensities from each crystal plane in the PZT of the perovskite type crystal structure at 2θ of 10 to 70 ° when Cu-Kα ray is used in the X-ray diffraction method. Since the (002) plane and the (200) plane are equivalent to the (001) plane and the (100) plane, they are not included in ΔI (hkl).

However, in the above method, since the MgO single crystal substrate is used as the base substrate, the piezoelectric element becomes expensive, and there is a problem that the ink jet head using this piezoelectric element also becomes expensive. Further, there is a disadvantage that the substrate material is also limited to one kind of MgO single crystal.

Therefore, P is placed on an inexpensive substrate such as silicon.
Various methods have been devised as a method of forming a (001) plane or (100) plane crystal orientation film of a perovskite type piezoelectric material such as ZT. For example, Japanese Patent No. 30221930 discloses that a PZ electrode on a (111) plane is
Before applying a precursor solution of PZT containing T or lanthanum and crystallizing this precursor solution, first, 450-
Pyrolysis at 550 ° C, followed by heat treatment at 550 to 800 ° C to crystallize (sol-gel method)
It is shown that a (100) plane preferential orientation film of a ZT film can be formed.

Japanese Patent Application Laid-Open No. 2001-88294 discloses that by forming an extremely thin titanium layer on an iridium lower electrode, the crystal orientation of a PZT film formed thereon can be controlled. . In this method, an underlayer containing zirconium oxide as a main component is formed on a substrate such as silicon, a lower electrode containing iridium is formed on the underlayer, and an extremely thin titanium layer is laminated on the lower electrode. Then, on this titanium layer, an amorphous piezoelectric precursor thin film containing a metal element and an oxygen element, which constitutes a ferroelectric substance having piezoelectric characteristics, is formed, and the amorphous thin film is heat-treated at a high temperature. This is a manufacturing method in which a perovskite-type piezoelectric thin film is changed by crystallization by a method (sol-gel method). In this manufacturing method, the crystal orientation of the piezoelectric thin film such as PZT can be controlled by the thickness of the titanium layer. When the thickness of the titanium layer is 2 to 10 nm, a (100) plane oriented film can be obtained.

Further, Japanese Patent Application Laid-Open No. 11-191646 discloses that a piezoelectric thin film is formed by using a sol-gel method.
By forming a titanium layer of 4 to 6 nm on a (111) plane oriented Pt electrode and using titanium oxide obtained by oxidizing titanium of the titanium layer as a nucleus, a (100) plane oriented PZT film can be obtained. It has been disclosed.

[0009]

However, although any of the above methods is excellent as a method not using an expensive MgO single crystal substrate, it is difficult to form a piezoelectric thin film by a sol-gel method. As in the case where a piezoelectric thin film is formed on a single crystal substrate, it is difficult to obtain a film with good crystallinity that is crystallographically oriented during film formation. For this reason, an amorphous piezoelectric thin film is first formed, and the laminated film including the piezoelectric thin film is heat-treated together with the substrate so that the crystal axes are preferentially oriented in a suitable direction.

In the sol-gel method, when a piezoelectric element is mass-produced, cracks due to a volume change are apt to occur in an amorphous piezoelectric precursor thin film in a degreasing step for removing organic substances. Even in the step of heating the precursor thin film at a high temperature for crystallization, cracks and film peeling from the lower electrode are likely to occur due to the crystal change.

As a method for solving these problems in the sol-gel method, Japanese Patent Application Laid-Open No. 200-255254
JP-A-10-81016 and JP-A-10-81016 show that it is effective to add titanium or titanium oxide to the lower electrode. In particular, JP-A-10-81016 discloses that a PZT film having a (100) plane orientation can be obtained even when a sputtering method is used. However, a perovskite-type PZT film is not directly obtained on the lower electrode, but a PZT film having an amorphous or pyrochlore-type crystal structure is first formed at a low temperature of 200 ° C. or lower, and then 500 to 700 ° C. in an oxygen atmosphere. Crystallization is performed by heat treatment at a high temperature, as in the case of the sol-gel method, and has the disadvantage that cracks and peeling from the lower electrode are likely to occur due to crystal changes in the step of crystallization by heating at a high temperature. Further, the (001) plane orientation degree or (100) plane orientation of the PZT film formed by the sol-gel method or the sputtering method described above.
The degree of plane orientation is 85% or less in any of the methods.

Further, in the sol-gel method, since the thickness of the PZT film formed in one process (application of the precursor solution and subsequent heat treatment) is at most about 100 nm, the required 1 μm In order to obtain the above film thickness, it is necessary to repeat the above-mentioned steps 10 times or more, which causes a problem that the yield is lowered.

On the other hand, according to the above-mentioned Japanese Patent Application Laid-Open No. 2001-88294, a sol-gel method (MOD) is a method in which an amorphous thin film is formed once, and is converted into a crystalline thin film by post-treatment such as heat treatment to synthesize. Method, ie, a method of forming a crystalline thin film directly without a crystallization step by heat treatment, such as a sputtering method, a laser ablation method, or a CVD method, was used to form an ultrathin titanium layer on the surface. Attempt to control the PZT orientation on the Ir base electrode
No alignment film was obtained except by the gel method. The reason is that in the sol-gel method, the crystallization of the PZT film gradually progresses from the lower electrode side to the upper electrode side, whereas in the CVD method, the sputtering method, etc., the crystallization of the PZT film proceeds randomly. The lack of regularity in crystallization makes it difficult to control the orientation.

Further, on the (111) plane oriented Pt electrode layer,
When a titanium oxide layer having a thickness of 12 nm or less is formed, and a lead titanate film or a PZT film having a perovskite crystal structure is formed by a direct sputtering method, each film shows (111) plane orientation and (100) plane. Alternatively, a (001) plane oriented film cannot be obtained (see J. Appl. Phys. Vol. 83, No. 7 (1998) 3835).

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a low-cost, highly reliable piezoelectric element having excellent piezoelectric characteristics. .

[0016]

In order to achieve the above object, according to the present invention, the electrode layer is made of a noble metal containing titanium or titanium oxide, and a cubic or Forming an orientation control layer made of a perovskite-type oxide containing tetragonal strontium, and preferentially orienting the orientation control layer to the (100) plane or the (001) plane;
On this orientation control layer, a piezoelectric layer made of a rhombohedral or tetragonal perovskite oxide was formed, and the piezoelectric layer was preferentially oriented to the (001) plane.

Specifically, according to the first aspect of the present invention, a first electrode layer provided on a substrate, an alignment control layer provided on the first electrode layer, The present invention is directed to a piezoelectric element including a provided piezoelectric layer and a second electrode layer provided on the piezoelectric layer.

The first electrode layer is made of a noble metal containing titanium or titanium oxide, and the orientation control layer is made of a cubic or tetragonal (100) plane or a (00) plane.
1) It is made of a perovskite-type oxide containing strontium preferentially oriented in the plane, and the piezoelectric layer is made of a perovskite-type oxide preferentially oriented in the rhombohedral or tetragonal (001) plane. .

With the above structure, by adding titanium or titanium oxide to the noble metal film as the first electrode layer, the adhesion between the substrate and the first electrode layer can be improved, and the piezoelectric element In addition to preventing film peeling during the manufacture of the first electrode layer, if an orientation control layer is formed on the first electrode layer by a sputtering method or the like, the first electrode layer becomes (11)
1) Even when the orientation control layer is (100)
It is easy to be oriented to a plane or a (001) plane (in the case of a cubic system, the (100) plane and the (001) plane are the same). That is, on the surface of the first electrode layer, titanium or titanium oxide is scattered in an island shape, and the orientation control layer is formed on the nucleus of the titanium or titanium oxide scattered in the island shape as a nucleus. A crystal grows, whereby the crystal is easily oriented on a (100) plane or a (001) plane on titanium or titanium oxide. Further, since the titanium or titanium oxide is contained in the first electrode layer, it hardly protrudes from the surface of the first electrode layer (if it does, the protruding amount is smaller than 2 nm). From this, the orientation control layer is (10
It is easy to be oriented to the (0) plane or the (001) plane. In particular, a perovskite-type oxide containing strontium can be formed at a lower temperature than PZT or the like, and a thin film with good orientation and crystallinity can be easily obtained. On the other hand, when a substrate made of silicon or the like is used, the first electrode layer usually has a (111) plane orientation. Therefore, in the orientation control layer, titanium or oxide on the surface portion of the first electrode layer is used. In the region above the portion where titanium does not exist, the surface orientation (for example, the (111) surface orientation) other than the (100) and (001) planes or the amorphous state occurs. However, such (10
The region not in the (0) plane or the (001) plane orientation exists only in the vicinity of the surface of the orientation control layer on the first electrode layer side (a range from the surface to at most about 20 nm). That is, (100) on the above titanium or titanium oxide
Since the plane or (001) -oriented region expands as the crystal grows, the area of the region in the cross section perpendicular to the layer thickness direction increases from the first electrode layer side to the opposite side (piezoelectric layer side). Toward the (100) plane or (0) plane.
The region which is not in the (01) plane orientation becomes small, and when the thickness of the orientation control layer becomes about 20 nm, substantially the entire surface becomes the (100) plane or (001) plane oriented region. When a piezoelectric layer is formed on the orientation control layer thus formed, the orientation control layer causes the piezoelectric layer to be oriented in the (001) plane (in the case of a rhombohedral system, the (100) plane and the (001) plane are aligned). Is the same, so that the (100) plane orientation of the rhombohedral system is included). By providing such an orientation control layer, strontium capable of improving crystallinity and orientation can be used for the orientation control layer while using a piezoelectric material having good piezoelectric properties for the piezoelectric layer. A perovskite-type oxide can be used, and as a result, the degree of (001) orientation of the piezoelectric layer can be 90% or more. In the orientation control layer, the (100) plane and the (0
The region that is not oriented in the (01) plane may exist not only in the vicinity of the surface of the first electrode layer but also on the surface on the piezoelectric layer side. Even in such a case, if the thickness of the orientation control layer is 0.01 μm or more, most of the surface on the side of the piezoelectric layer becomes a region of (100) plane or (001) plane orientation, The (001) plane orientation of the layer can be 90% or more.

Therefore, other than the sol-gel method, a film forming method (sputtering or C
Even by the VD method or the like, a piezoelectric layer having good orientation can be obtained, whereby the variation in piezoelectric characteristics can be suppressed low and the reliability can be improved.
That is, since this piezoelectric element is used by applying an electric field in a direction perpendicular to the surface of the film of the piezoelectric layer, particularly in the tetragonal perovskite type PZT film, (00)
1) By the plane orientation, the direction of the electric field is parallel to the <001> polarization axis direction, and a large piezoelectric characteristic is obtained. In addition, since rotation of polarization due to the application of an electric field does not occur, variation in piezoelectric characteristics can be suppressed low, and reliability can be improved. On the other hand, in the rhombohedral perovskite-type PZT film, since the polarization axis is in the <111> direction, an angle of about 54 ° occurs between the electric field direction and the polarization axis direction due to the (100) plane orientation. By improving the (100) plane orientation, the polarization can always be maintained at a constant angle with respect to the application of an electric field. In this case as well, the rotation of the polarization due to the application of the electric field does not occur. And the reliability can be improved (for example, non-oriented PZT).
In the case of a membrane, the polarization is oriented in various directions,
When an electric field is applied, the polarization axis tends to be oriented in a direction parallel to the electric field, so that the piezoelectric characteristics have a voltage dependence and thus vary greatly, or a change with time occurs to cause a problem in reliability.)

Further, since a piezoelectric layer having good orientation can be easily obtained without using an expensive MgO single crystal substrate, an inexpensive glass substrate, metal substrate, ceramic substrate, Si substrate or the like should be used. Thereby, the manufacturing cost can be reduced.

Further, even when the thickness of the piezoelectric layer is 1 μm or more, the same step is not required to be repeated many times as in the sol-gel method, and the piezoelectric layer can be easily formed by sputtering or the like. And a decrease in yield can be suppressed.

According to a second aspect of the present invention, in the first aspect of the present invention, the orientation control layer contains strontium titanate.

Thus, the orientation control layer (100)
The plane or (001) plane orientation and crystallinity can be reliably improved, and thus the orientation of the piezoelectric layer can be improved.

According to a third aspect of the present invention, in the second aspect of the present invention, the content of strontium titanate in the orientation control layer is from 5 mol% to 100 mol%.

That is, when strontium titanate is contained in an amount of 5 mol% or more, the orientation and crystallinity of the orientation control layer can be surely improved. In this case, the orientation control layer may be composed only of strontium titanate (containing 100 mol%), and may be composed of strontium titanate, lead titanate or lead lanthanum zirconate titanate (PL).
ZT), a solid solution with barium titanate or the like. Further, if the orientation control layer does not contain zirconium, or if the zirconium content is 20 mol% or less, a layer having low crystallinity made of Zr oxide is difficult to be formed, and the withstand voltage of the piezoelectric element is reduced. Can be improved.

According to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, the first electrode layer is made of at least one noble metal selected from the group consisting of platinum, iridium, palladium and ruthenium. The content of titanium or titanium oxide contained in the noble metal is more than 0 and 30 mol% or less.

Thus, it is possible to sufficiently endure the temperature when each film of the piezoelectric element is formed by a sputtering method or the like, and to use a material suitable for an electrode. If the content of titanium or titanium oxide exceeds 30 mol%, the crystallinity and orientation of the orientation control layer (and hence the piezoelectric layer) decrease, so that the content should be 30 mol% or less. Good.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects of the present invention, the piezoelectric layer is made of a piezoelectric material containing lead zirconate titanate as a main component.

By doing so, a piezoelectric material having good piezoelectric characteristics can be obtained, and a high-performance piezoelectric element can be obtained.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects of the present invention, an adhesion between the substrate and the first electrode layer is provided to enhance the adhesion between the substrate and the first electrode layer. It is assumed that a layer is provided.

Thus, the adhesion between the substrate and the first electrode layer can be further improved, and film peeling during the manufacture of the piezoelectric element can be reliably prevented.

According to a seventh aspect of the present invention, there is provided a piezoelectric element in which a first electrode layer, an orientation control layer, a piezoelectric layer, and a second electrode layer are sequentially laminated, and a second electrode layer side of the piezoelectric element. A vibrating layer provided on the surface of the piezoelectric element, and a pressure chamber member having a pressure chamber for accommodating ink, which is joined to the surface of the vibrating layer opposite to the piezoelectric element. According to another aspect of the invention, there is provided an ink jet head configured to discharge ink in the pressure chamber by displacing the vibration layer in a layer thickness direction by an effect.

In the present invention, the first electrode layer of the piezoelectric element is made of a noble metal containing titanium or titanium oxide, and the orientation control layer is made of a cubic or tetragonal (100) plane or The piezoelectric layer is made of a perovskite-type oxide containing strontium preferentially oriented on the (001) plane, and the piezoelectric layer is made of a perovskite-type oxide preferentially oriented on a rhombohedral or tetragonal (001) plane. I do.

According to the present invention, a first electrode layer, an orientation control layer, a piezoelectric layer, a second electrode layer, and a vibration layer are sequentially formed on a substrate by sputtering or the like, and a pressure chamber member is formed on the vibration layer. If the substrate is removed after bonding
An ink jet head having a piezoelectric element having the same configuration as that of the first aspect of the present invention is obtained, and the degree of (001) orientation of the piezoelectric layer of the piezoelectric element can be 90% or more.
Therefore, an ink jet head having excellent durability can be obtained with little variation in ink ejection performance.

According to the eighth aspect of the present invention, there is provided a piezoelectric element in which a first electrode layer, an orientation control layer, a piezoelectric layer, and a second electrode layer are sequentially laminated, and a first electrode layer side of the piezoelectric element. A vibrating layer provided on the surface of the piezoelectric element, and a pressure chamber member having a pressure chamber for accommodating ink, which is joined to the surface of the vibrating layer opposite to the piezoelectric element. The present invention is directed to an inkjet head configured to discharge the ink in the pressure chamber by displacing the vibrating layer in a layer thickness direction by an effect.

The first electrode layer of the piezoelectric element is
The orientation control layer is made of a noble metal containing titanium or titanium oxide, and the orientation control layer is made of a perovskite-type oxide containing strontium, which is preferentially oriented in a cubic or tetragonal (100) plane or a (001) plane. The piezoelectric layer is made of a perovskite-type oxide preferentially oriented on a rhombohedral or tetragonal (001) plane.

Thus, the vibration layer, the first electrode layer, the orientation control layer, the piezoelectric layer, and the second electrode layer are sequentially formed on the pressure chamber member as a substrate by a sputtering method or the like. Then, an ink jet head having the same operation and effect as the seventh aspect of the invention can be obtained.

According to a ninth aspect of the present invention, there is provided a method of manufacturing a piezoelectric element. In this invention, a step of forming a first electrode layer made of a noble metal containing titanium or titanium oxide on a substrate by a sputtering method. And an orientation control layer formed of a perovskite-type oxide containing strontium, which is preferentially oriented on a cubic or tetragonal (100) plane or a (001) plane, on the first electrode layer by a sputtering method. Forming a piezoelectric layer composed of a perovskite oxide preferentially oriented on a rhombohedral or tetragonal (001) plane on the orientation control layer by sputtering.
Forming a second electrode layer on the piezoelectric layer.

According to the present invention, a piezoelectric element having the same function and effect as the first aspect of the present invention can be easily manufactured.

According to a tenth aspect of the present invention, there is provided a piezoelectric element in which a first electrode layer, an orientation control layer, a piezoelectric layer, and a second electrode layer are sequentially laminated, and the piezoelectric layer of the piezoelectric element has a piezoelectric element. This is an invention of a method of manufacturing an ink jet head configured to discharge ink in a pressure chamber by displacing a vibration layer in a layer thickness direction by an effect.

According to the present invention, a step of forming a first electrode layer made of a noble metal containing titanium or titanium oxide on a substrate by a sputtering method, and a step of forming a cubic or Tetragonal (100) plane or (00)
1) A step of forming an orientation control layer made of a perovskite-type oxide containing strontium preferentially oriented on a plane by a sputtering method, and forming a rhombohedral or tetragonal (001) plane on the orientation control layer. Forming a piezoelectric layer made of a perovskite-type oxide with preferential orientation by sputtering, forming a second electrode layer on the piezoelectric layer, and forming a vibration layer on the second electrode layer. Forming,
The method includes a step of joining a pressure chamber member for forming a pressure chamber to a surface of the vibration layer opposite to the second electrode layer, and a step of removing the substrate after the joining step.

Thus, an ink jet head having the same functions and effects as the seventh aspect of the present invention can be easily manufactured.

According to the eleventh aspect of the present invention, there is provided a piezoelectric element in which a first electrode layer, an orientation control layer, a piezoelectric layer, and a second electrode layer are sequentially laminated, and the piezoelectric layer of the piezoelectric element has a piezoelectric layer. The present invention is directed to a method of manufacturing an ink jet head configured to discharge ink in a pressure chamber by displacing a vibration layer in a layer thickness direction by an effect.

Then, a step of forming a vibration layer on the pressure chamber substrate for forming the pressure chamber, and forming a first electrode layer made of a noble metal containing titanium or titanium oxide on the vibration layer by sputtering. And an orientation control layer composed of a strontium-containing perovskite-type oxide preferentially oriented in a cubic or tetragonal (100) plane or a (001) plane on the first electrode layer. Forming a piezoelectric layer made of a perovskite-type oxide preferentially oriented on a rhombohedral or tetragonal (001) plane on the orientation control layer by a sputtering method; The method includes a step of forming a second electrode layer on the piezoelectric layer and a step of forming a pressure chamber on the pressure chamber substrate.

Thus, it is possible to easily manufacture an ink jet head having the same functions and effects as the eighth aspect of the present invention.

According to a twelfth aspect of the present invention, there is provided an ink jet recording apparatus. In the present invention, the ink jet head according to the seventh or eighth aspect and a relative moving means for relatively moving the ink jet head and a recording medium are provided. When the ink jet head is relatively moving with respect to the recording medium by the relative moving means, the ink in the pressure chamber is ejected to the recording medium from a nozzle hole provided in the ink jet head so as to communicate with the pressure chamber. Recording.

According to the present invention, a recording apparatus having extremely good printing performance and durability can be easily obtained.

[0049]

(Embodiment 1) FIG. 1 shows a piezoelectric element according to an embodiment of the present invention.
It is a substrate made of a φ4 inch silicon (Si) wafer having a thickness of 0.3 mm.
An adhesion layer 12 having a thickness of 02 μm and made of titanium (Ti) is formed. The substrate 11 is not limited to Si, but may be a glass substrate, a metal substrate, a ceramic substrate, or the like.

The thickness of the adhesive layer 12 is 0.22 μm.
m and platinum (Pt) doped with 2.3 mol% of Ti
The first electrode layer 14 is formed. This first
Has a (111) plane orientation.

On the first electrode layer 14, an orientation control layer 15 made of strontium titanate (SrTiO ₃ ) having a cubic perovskite crystal structure is formed. The orientation control layer 15 has a (100) plane or (0) plane.
01) plane, with a film thickness of 0.01 μm
It is.

On the orientation control layer 15, a thickness of 3.1
A piezoelectric layer 16 made of PZT having a diameter of μm and having a rhombohedral or tetragonal perovskite crystal structure is formed. The piezoelectric layer 16 is preferentially oriented to the (001) plane. The composition of PZT is a composition (Zr) near the boundary between tetragonal crystal and rhombohedral crystal (boundary of morphotropic phase).
/ Ti = 53/47). The Zr / Ti composition in the piezoelectric layer 16 is not limited to Zr / Ti = 53/47, but may be Zr / Ti = 30/70 to 70/30. The constituent material of the piezoelectric layer 16 is Sr in PZT,
PZ such as those containing additives such as Nb and Al
Any piezoelectric material containing T as a main component may be used, such as PMN or PZ.
It may be N. Further, the film thickness is 0.5 to 5.0 μm.
It may be in the range of m.

The piezoelectric layer 16 has a thickness of 0.2 μm.
A second electrode layer 17 of m and Pt is formed. The material of the second electrode layer 17 is not limited to Pt, but may be a conductive material, and the film thickness may be in the range of 0.1 to 0.4 μm.

The piezoelectric element is provided on the substrate 11 with an adhesion layer 12, a first electrode layer 14, an orientation control layer 15,
The piezoelectric layer 16 and the second electrode layer 17 are sequentially formed and laminated by a sputtering method. Note that the film formation method is not limited to the sputtering method, and may be any film formation method (for example, a CVD method or the like) that directly forms a crystalline thin film without a crystallization step by heat treatment. Further, the method of forming the adhesion layer 12 and the second electrode layer 17 may be a sol-gel method or the like.

The adhesion layer 12 is for improving the adhesion between the substrate 11 and the first electrode layer 14,
Not limited to i, it may be composed of tantalum, iron, cobalt, nickel or chromium, or a compound thereof (including Ti). The thickness may be in the range of 0.005 to 1 μm. The adhesion layer 12 is not always necessary, and even if the first electrode layer 14 is directly formed on the substrate 11, the first electrode layer 14 contains Ti. Adhesion with the first electrode layer 14 is considerably improved.

The first electrode layer 14 not only has a role as an electrode but also has a role of preferentially orienting the orientation control layer 15 to the (100) plane or the (001) plane by adding Ti. And titanium oxide may be added instead of this Ti. The added amount of titanium or titanium oxide is preferably more than 0 and 30 mol% or less. Further, the material of the first electrode layer 14 may be at least one noble metal selected from the group consisting of Pt, iridium, palladium, and ruthenium.
The range may be 2 μm. The titanium or titanium oxide located on the surface of the first electrode layer 14 on the orientation control layer 15 side is contained in the first electrode layer 14,
Since it is not provided positively above the first electrode layer 14, it hardly projects from the surface on the orientation control layer 15 side, and even if it does, the amount of projection is smaller than 2 nm.

The orientation control layer 15 is formed of the piezoelectric layer 16
And (001) plane orientation. Therefore, strontium titanate is used. The material constituting the orientation control layer 15 may be a perovskite-type oxide containing strontium, and particularly preferably contains strontium titanate as in this embodiment. The content of the strontium titanate may be 5 mol% or more and 100 mol% or less, and only strontium titanate may be contained (containing 100 mol%) as in this embodiment.
In addition to strontium titanate, lead titanate, lead lanthanum zirconate titanate (PLZT), barium titanate and the like may be contained to form a solid solution with strontium titanate. These solid solutions may be cubic or tetragonal. Furthermore, the orientation control layer 15 may be made of a material containing zirconium, such as PZT to which strontium titanate is added, but in this case, a layer having low crystallinity made of Zr oxide is formed. In order to make it difficult, the zirconium content is preferably set to 20 mol% or less. The thickness of the orientation control layer 15 may be in the range of 0.01 to 0.2 μm.

Then, the first in the orientation control layer 15
As shown in FIG. 2, a portion near the surface on the side of the electrode layer 14 of FIG.
The region (15a) of the (100) plane or (001) plane orientation is titanium located on the surface of the first electrode layer 14 on the orientation control layer 15 side (when the first electrode layer 14 contains titanium oxide, Although it is titanium oxide, even if it contains titanium, it may be oxidized to titanium oxide), and the area of the region 15 a in the cross section perpendicular to the layer thickness direction is larger than that of the first electrode layer 14. From the top to the piezoelectric layer 16 side. On the other hand, the first electrode layer 1
4 has the (111) orientation, the upper region 15b of the orientation control layer 15 where titanium or titanium oxide does not exist on the surface of the first electrode layer 14 has (10)
It is not oriented on the (0) plane or (001) plane.
It has a (111) plane orientation (depending on the material of the first electrode layer 14, the first electrode layer 14 may have an orientation other than the (111) plane or become amorphous). Such a region 15b that is not oriented in the (100) plane or the (001) plane is at most 20 μm from the surface of the orientation control layer 15 on the first electrode layer 14 side.
When the thickness of the orientation control layer 15 is 0.02 μm or more, substantially the entire surface of the orientation control layer 15 on the piezoelectric layer 16 side is the (100) plane or the (00) plane.
1) The region 15a has a plane orientation.

The piezoelectric layer 16 is formed of the orientation control layer 15
As a result, the (001) plane is preferentially oriented, and the (001) plane orientation degree α is 90% or more.

It is not necessary that the entire surface of the orientation control layer 15 on the side of the piezoelectric layer 16 be the region 15a. If the film thickness is as small as 0.01 μm, (10
There is a possibility that the region 15b not oriented in the (0) plane and the (001) plane partially exists. However, even in such a case, if the thickness of the orientation control layer 15 is 0.01 μm or more, most of the surface on the piezoelectric layer 16 side is (10 μm).
(0) plane or (001) plane oriented region.
No. 6 (001) plane orientation degree can be 90% or more.

Next, a method of manufacturing the above piezoelectric element will be described.

That is, the adhesion layer 1 is formed on the Si substrate 11.
2, first electrode layer 14, orientation control layer 15, piezoelectric layer 16
Then, the second electrode layer 17 is sequentially formed by a sputtering method.

The adhesion layer 12 is obtained by applying a high frequency power of 100 W while heating the substrate 11 to 400 ° C. using a Ti target, and forming the substrate 11 in a 1 Pa argon gas for 1 minute.

The first electrode layer 14 is formed by using a multi-source sputtering apparatus, using a Ti target and a Pt target, and heating the substrate 11 to 425 ° C. in a 1 Pa argon gas with high frequency power of 85 W and 200 W. 1
Obtained by forming for 2 minutes. This obtained first
On the surface of the electrode layer 14 opposite to the adhesion layer 12, titanium is scattered in an island shape.

The orientation control layer 15 is formed by using a sintered target of strontium titanate.
C. in a mixed atmosphere of argon and oxygen (gas volume ratio A
r: O ₂ = 39: 1), the degree of vacuum is 0.98 Pa,
It can be obtained by forming for 12 minutes under the condition of high frequency power of 280 W.

In this way, the orientation control layer 15 grows crystallographically with the titanium scattered on the surface of the first electrode layer 14 on the orientation control layer 15 side as a nucleus. It is easy to be oriented to (100) plane or (001) plane. Further, since this titanium hardly protrudes from the surface of the first electrode layer 14 as described above (the protruding amount is smaller than 2 nm even if it protrudes), the orientation control layer 15
Is more easily oriented by the (100) plane or the (001) plane. On the other hand, since the first electrode layer 14 has a (111) plane orientation, in the orientation control layer 15, in the region above the portion of the surface of the first electrode layer 14 where titanium does not exist, the (100) plane or the It does not have the (001) plane orientation (here, the (111) plane orientation). This region becomes smaller as the crystal grows, while the (100) or (001) oriented region expands. As a result, the vicinity of the surface of the orientation control layer 15 on the first electrode layer 14 side is:
As described above, the orientation control layer 15 in the first electrode layer 14
A region (15a) of (100) plane or (001) plane orientation present on titanium located on the side surface portion, and the first electrode layer 1
4 has a region 15b which is present above the portion where titanium does not exist and which is not oriented in the (100) plane or the (001) plane, and has the (100) plane or the (001) plane orientation. Region 15a is the first electrode layer 14
From the side to the opposite side (the piezoelectric layer 16 side), the surface of the orientation control layer 15 on the side of the piezoelectric layer 16 becomes a region (15a) of (100) plane or (001) plane orientation. .

The piezoelectric layer 16 is made of PZT (Zr / Ti
= 53/47) in a mixed atmosphere of argon and oxygen (gas volume ratio Ar: O ₂ = 19: 1) at a temperature of the substrate 11 of 600 ° C.
It can be obtained by forming for 3 hours under the conditions of 25 Pa and high frequency power of 240 W. The piezoelectric layer 16 has a (001) plane orientation because the surface of the orientation control layer 15 on the piezoelectric layer 16 side has a (100) plane or a (001) plane orientation (here, Zr / Since Ti = 53/47, a rhombohedral system is obtained. In the case of this rhombohedral system,
Since the (100) plane and the (001) plane are the same, the (100) plane orientation of the rhombohedral system is included), and the (001) plane
90% plane orientation (rhombohedral (100) plane orientation)
That is all. Further, since the crystallinity of the orientation control layer 15 is good, the crystallinity of the piezoelectric layer 16 is also good.

The second electrode layer 17 is formed by using a Pt target at room temperature in argon gas of 1 Pa.
It is obtained by forming with high frequency power of W for 10 minutes.

Therefore, in the above embodiment, the expensive M
Even if a gO single crystal substrate is not used, a piezoelectric layer 16 having good crystallinity and orientation can be obtained by forming a film on an inexpensive silicon substrate 11 by a sputtering method. Variations in the piezoelectric characteristics of the piezoelectric element can be suppressed low, and reliability can be improved. In addition, since the orientation control layer 15 does not contain zirconium, it is difficult to form a layer made of a Zr oxide having low crystallinity, thereby improving the withstand voltage of the piezoelectric element.

Next, a specific embodiment will be described. In each of the following Examples 1 to 4, the configuration in which an adhesion layer, a first electrode layer, an orientation control layer, a piezoelectric layer, and a second electrode layer were sequentially formed on a substrate was the same as in the above embodiment. Is the same.

Example 1 In Example 1, the materials, thicknesses, manufacturing methods, and the like of the respective films were the same as those described in the above embodiment. No crack or film peeling was observed in each film of the piezoelectric element of Example 1.

The crystal orientation and the film composition of the piezoelectric layer before the formation of the second electrode layer were examined. That is, from the analysis by the X-ray diffraction method, the piezoelectric layer showed a rhombohedral perovskite crystal structure with a (100) plane orientation, and the degree of (100) plane orientation was α = 98%. The composition of the PZT film was the same as the target composition as a result of composition analysis using an X-ray microanalyzer, and the Zr / Ti ratio was 53/4.
It was 7.

Subsequently, the crystal orientation and the film composition of the first electrode layer before forming the orientation control layer were examined. That is, X
As a result of analysis by the X-ray diffraction method, the Pt film was (111)
It showed plane orientation. X-ray photoelectron spectroscopy (XPS)
As a result of performing composition analysis at a depth of 5 nm from the surface at
The i amount was 2.3 mol%.

Next, the crystal orientation and the film composition of the orientation control layer before forming the piezoelectric layer were examined. This film is (10
0) It showed a plane-oriented perovskite crystal structure.
A (111) -oriented portion was observed on the first electrode layer side of the orientation control layer. It is considered that the (111) -oriented portion exists above the portion where titanium does not exist on the surface of the first electrode layer.

Next, 100 cantilevers cut out to 15 mm × 2 mm by dicing were prepared using the state before the second electrode layer was formed, and the second electrode layer having a thickness of 0.2 μm was sputtered. Then, the piezoelectric constant d31 was measured (for a method of measuring the piezoelectric constant d31, see, for example, JP-A-2001-21052). The average value of the piezoelectric constants of these 100 cantilevers was -124 pC / N, and the variation was σ = 4.0%.

Subsequently, the second electrode layer of the piezoelectric element is
As a 1 mm square, 0.2 μm thick Pt film, 65 were formed at 10 mm intervals using a metal mask by a sputtering method,
A voltage was applied between each of the second electrode layers and the first electrode layer, and the withstand voltage was measured. Note that the withstand voltage value was a value at which the current value by applying a voltage was 1 μA. As a result, the average of the withstand voltage value was 128 V, and the variation was σ = 4.1%.
Met.

(Embodiment 2) In this embodiment 2, the substrate is
Φ4 inch stainless steel 0.25 mm thick (SUS30
4), a tantalum (Ta) film having a thickness of 0.01 μm is formed on the adhesion layer, and a 0.24 μm film is formed on the first electrode layer.
And a PZT film having a thickness of 0.06 μm and containing 30 mol% of strontium (Zr / Ti = 20) is used as the orientation control layer.
/ 80), the piezoelectric layer has a P thickness of 2.8 μm.
A ZT film (Zr / Ti = 40/60) was used, and a Pt film having a thickness of 0.1 μm was used for the second electrode layer.

The adhesion layer is formed by using a Ta target.
A high-frequency power of 100 W was applied while heating the substrate to 500 ° C., and the substrate was formed in an argon gas of 1 Pa for one minute.

The first electrode layer is formed by using a Ti target and a Pt target by using a multi-source sputtering apparatus.
In a mixed atmosphere of 1 Pa of argon and oxygen while heating the substrate to 420 ° C. (gas volume ratio Ar: O ₂ = 15: 1)
In this case, it was obtained by forming with high frequency power of 120 W and 200 W for 12 minutes.

The orientation control layer is made of PZT (Zr / Ti =
20/80), a sintering target prepared by adding 31 mol% of strontium, and a substrate temperature of 600 ° C.
In a mixed atmosphere of argon and oxygen (gas volume ratio Ar: O
₂ = 19: 1), and obtained by forming for 15 minutes under the conditions of a degree of vacuum of 0.9 Pa and a high frequency power of 310 W.

The piezoelectric layer is made of PZT (Zr / Ti = 4
0/60) sintered substrate target and a substrate temperature of 580
C. in a mixed atmosphere of argon and oxygen (gas volume ratio A
(r: O ₂ = 19: 1), and obtained by forming for 3 hours under the conditions of a vacuum degree of 0.3 Pa and a high-frequency power of 290 W.

The second electrode layer was obtained by using a Pt target and forming it at a room temperature with a high-frequency power of 200 W in an argon gas of 1 Pa at room temperature.

No crack or film peeling was observed in each film of the piezoelectric element of Example 2.

When the crystal orientation and the film composition of the piezoelectric layer before forming the second electrode layer were examined in the same manner as in Example 1, the piezoelectric layer was found to have a (001) plane orientation square. A crystalline perovskite crystal structure was exhibited, and the degree of (001) orientation was α = 95%. The composition of the PZT film was the same as the target composition, and the Zr / Ti ratio was 40/60.

Subsequently, when the crystal orientation and the film composition of the first electrode layer before forming the orientation control layer were examined, the Pt film showed (111) plane orientation. The amount of titanium oxide was 7 mol%.

Next, when the crystal orientation and the film composition of the orientation control layer before forming the piezoelectric layer were examined, the film showed a (001) -oriented perovskite crystal structure. A (111) -oriented portion was observed on the first electrode layer side of the orientation control layer. It is considered that the portion having the (111) plane orientation exists above the portion where the titanium oxide does not exist on the surface of the first electrode layer.

Next, in the same manner as in the first embodiment, a cantilever cut out to 15 mm × 2 mm by dicing was used by using a state before the second electrode layer was formed.
When a second electrode layer having a thickness of 0.1 μm was formed by sputtering and the piezoelectric constant d31 was measured,
The average value of the piezoelectric constant of 100 cantilevers is -122.
pC / N, and the variation was σ = 2.6%.

Subsequently, the second electrode layer of the piezoelectric element is
As a 1 mm square and 0.1 μm thick Pt film, 65 Pt films are formed at 10 mm intervals using a metal mask by a sputtering method.
When a withstand voltage was measured by applying a voltage between each of the second electrode layers and the first electrode layer, the average of the withstand voltage value was 1
19V, and the variation was σ = 4.6%.

(Embodiment 3) In this embodiment 3, the substrate is
Barium borosilicate glass (100 mm square size) having a thickness of 0.5 mm, a nickel (Ni) film having a thickness of 0.005 μm for the adhesion layer, and a thickness of 0.15 μm for the first electrode layer.
iridium (I) containing 18 mol% of titanium
r) A PLT film having a thickness of 0.1 μm containing 12 mol% of lanthanum and adding 5 mol% of strontium is used for the orientation control layer, and a PLT film having a thickness of 0.1 mol is added to the piezoelectric layer. 2.7 μm PZT film (Zr / Ti = 60/40)
And a Pt film having a thickness of 0.01 μm was used for the second electrode layer.

The adhesion layer is formed by using a Ni target.
The substrate was obtained by applying a high-frequency power of 200 W while heating the substrate to 300 ° C. and forming the substrate in an argon gas of 1 Pa for 1 minute.

The first electrode layer was formed by using a Ti target and an Ir target by using a multi-source sputtering apparatus.
The substrate was formed by heating the substrate to 600 ° C. in a 1 Pa argon gas with high frequency power of 160 W and 200 W for 10 minutes.

The orientation control layer was formed using a sintered target prepared by adding 6 mol% of strontium to PLT containing 14 mol% of lanthanum, and using a substrate temperature of 590 ° C.
In a mixed atmosphere of argon and oxygen (gas volume ratio A
(r: O ₂ = 19: 1), and was obtained by forming for 20 minutes under the conditions of a vacuum degree of 0.8 Pa and a high frequency power of 310 W.

The piezoelectric layer is made of PZT (Zr / Ti = 6).
0/40) with a substrate temperature of 580
C. in a mixed atmosphere of argon and oxygen (gas volume ratio A
r: O ₂ = 19: 1), and was obtained by forming for 3 hours under the conditions of a vacuum degree of 0.3 Pa and a high frequency power of 260 W.

The second electrode layer was obtained by using a Pt target and forming it in a 1 Pa argon gas at a high frequency of 200 W at room temperature.

No cracks or film peeling were observed in each film of the piezoelectric element of Example 3.

When the crystal orientation and the film composition of the piezoelectric layer before the formation of the second electrode layer were examined, the piezoelectric layer showed a (100) -oriented rhombohedral perovskite crystal structure. The (100) plane orientation was α = 96%. Further, the composition of the PZT film is the same as the target composition, and Zr /
The Ti ratio was 60/40.

Subsequently, when the crystal orientation and the film composition of the first electrode layer before forming the orientation control layer were examined, the Ir film showed the (111) plane orientation. The Ti content is 18
Mol%.

Next, when the crystal orientation and the film composition of the orientation control layer before forming the piezoelectric layer were examined, this film showed a (100) plane oriented perovskite crystal structure. Note that an amorphous portion was observed on the first electrode layer side of the orientation control layer. It is considered that the amorphous portion exists above the portion where titanium does not exist on the surface of the first electrode layer.

Next, 100 cantilevers cut out to 15 mm × 2 mm by dicing were prepared using the state before the formation of the second electrode layer, and 0.01 μm
When a thick second electrode layer was formed by a sputtering method and the piezoelectric constant d31 was measured, the average value of the piezoelectric constants of the 100 cantilevers was -127 pC / N, and the variation was σ = 3.5. %Met.

Subsequently, the second electrode layer of the piezoelectric element is
65 Pt films of 1 mm square and 0.01 μm thickness are formed at intervals of 10 mm using a metal mask by a sputtering method, and a voltage is applied between each second electrode layer and the first electrode layer to withstand. When the voltage was measured, the average withstand voltage value was 115 V, and the variation was σ = 5.0%.

(Embodiment 4) In this embodiment 4, the substrate is
A φ4 inch silicon wafer having a thickness of 0.5 mm was formed. A titanium film having a thickness of 0.01 μm was formed on the adhesion layer, and a titanium oxide having a thickness of 0.25 μm and 5 mol% of titanium oxide was formed on the first electrode layer.
The thickness of the Ir film contained in the alignment control layer was set to 0.02 μm.
m, a film made of a solid solution of strontium titanate and barium titanate (strontium titanate content: 78 mol%), and a piezoelectric layer having a thickness of 3.1 μm
The PZT film (Zr / Ti = 52/48) was used, and the Pt film having a thickness of 0.01 μm was used for the second electrode layer.

The adhesion layer is formed by using a Ti target.
A high-frequency power of 100 W was applied while heating the substrate to 500 ° C., and the substrate was formed in an argon gas of 1 Pa for one minute.

The first electrode layer was formed using a Ti target and an Ir target by using a multi-source sputtering apparatus.
In a mixed atmosphere of 1 Pa of argon and oxygen while heating the substrate to 400 ° C. (gas volume ratio Ar: O ₂ = 10: 1)
In this case, it was obtained by forming for 12 minutes with high frequency power of 90 W and 200 W.

The orientation control layer is made of strontium titanate.
Solid solution of titanium and barium titanate (strontium titanate)
Sintering target consisting of
At a substrate temperature of 500 ° C. in a mixed atmosphere of argon and oxygen.
In ambient (gas volume ratio Ar: O _Two= 29: 1)
20 minutes under the conditions of vacuum degree 0.8 Pa and high frequency power 300 W
It was obtained by forming during.

The piezoelectric layer is made of PZT (Zr / Ti = 5).
2/48) using a sintered target and a substrate temperature of 620
C. in a mixed atmosphere of argon and oxygen (gas volume ratio A
r: O ₂ = 19: 1), and formed by forming for 3 hours under the conditions of a vacuum degree of 0.4 Pa and a high frequency power of 270 W.

The second electrode layer was obtained by using a Pt target and forming it at room temperature with high-frequency power of 200 W in 1 Pa of argon gas.

No crack or film peeling was observed in each film of the piezoelectric element of Example 4.

When the crystal orientation and the film composition of the piezoelectric layer before the formation of the second electrode layer were examined, the piezoelectric layer showed a (100) -oriented rhombohedral perovskite crystal structure. The (100) plane orientation was α = 98%. Further, the composition of the PZT film is the same as the target composition, and Zr /
The Ti ratio was 52/48.

Subsequently, when the crystal orientation and the film composition of the first electrode layer before forming the orientation control layer were examined, the Ir film showed the (111) plane orientation. The amount of titanium oxide was 5 mol%.

Next, when the crystal orientation and the film composition of the orientation control layer before the formation of the piezoelectric layer were examined, the film showed a (100) -oriented perovskite crystal structure. Note that an amorphous portion was observed on the first electrode layer side of the orientation control layer. It is considered that the amorphous portion exists above the portion where the titanium oxide does not exist on the surface of the first electrode layer.

Next, 100 cantilevers cut out to a size of 15 mm × 2 mm by dicing were manufactured by using the state before the formation of the second electrode layer, and 0.01 μm
When a thick second electrode layer was formed by sputtering and the piezoelectric constant d31 was measured, the average value of the piezoelectric constants of the 100 cantilevers was -140 pC / N, and the variation was σ = 2.3. %Met.

Subsequently, the second electrode layer of the piezoelectric element is
65 Pt films of 1 mm square and 0.01 μm thickness are formed at intervals of 10 mm using a metal mask by a sputtering method, and a voltage is applied between each second electrode layer and the first electrode layer to withstand. When the voltage was measured, the average of the withstand voltage value was 121 V, and the variation was σ = 4.6%.

(Comparative Example) This comparative example is different from Example 1 in that the orientation control layer is not provided and the thickness of the piezoelectric layer is different. layer,
In this configuration, a first electrode layer, a piezoelectric layer, and a second electrode layer are sequentially formed. The thickness of the piezoelectric layer is 3 μm, and the conditions for forming the piezoelectric layer are the same as those in the first embodiment except that the degree of vacuum is 0.3 Pa and the high-frequency power is 250 W.

The piezoelectric layer in the piezoelectric element of this comparative example had a (100) plane oriented rhombohedral perovskite crystal structure, and the degree of (100) plane orientation was α = 38%.

When the piezoelectric constant d31 was measured in the same manner as in Example 1, the average value of the piezoelectric constant was -7.
It was 5 pC / N, and the variation was σ = 12.2%.

Further, when the withstand voltage was measured in the same manner as in Example 1, the average withstand voltage was 64 V, and the variation was σ = 14.6%.

Therefore, it is understood that the crystallinity and orientation of the piezoelectric layer can be improved only by providing the orientation control layer as in the first embodiment, and the piezoelectric characteristics and withstand voltage of the piezoelectric element can be improved.

(Embodiment 2) FIG. 3 shows an overall configuration of an ink jet head according to an embodiment of the present invention, and FIG. 4 shows a configuration of a main part thereof. In FIGS. 3 and 4, A is
The pressure chamber member A is formed with a pressure chamber opening 101 penetrating in the thickness direction (vertical direction) of the pressure chamber member A. B is an actuator portion disposed so as to cover the upper end opening of the pressure chamber opening portion 101;
Is an ink flow path member arranged to cover the lower end opening of the pressure chamber opening 101. The pressure chamber opening 101 of the pressure chamber member A is formed as a pressure chamber 102 by being closed by the actuator section B and the ink flow path member C located above and below the pressure chamber opening 101, respectively.

The actuator section B has a first electrode layer 103 (individual electrode) located almost directly above each of the pressure chambers 102, and the pressure chamber 102 and the first electrode layer 10
3 are arranged in a staggered pattern as can be seen from FIG.

The ink flow path member C has a common liquid chamber 105 shared by the pressure chambers 102 arranged in the ink supply direction, and a supply port 106 for supplying the ink of the common liquid chamber 105 to the pressure chamber 102. And an ink flow path 107 for discharging the ink in the pressure chamber 102.

D is a nozzle plate, and this nozzle plate D
Is provided with a nozzle hole 108 communicating with the ink flow path 107.
Are formed. E denotes an IC chip, and a voltage is supplied from the IC chip to each of the individual electrodes 103 via a bonding wire BW.

Next, the structure of the actuator section B will be described with reference to FIG. FIG. 5 is a cross-sectional view in a direction orthogonal to the ink supply direction shown in FIG. In the drawing, a pressure chamber member A having four pressure chambers 102 arranged in the orthogonal direction is illustrated for reference. The actuator section B includes a first electrode layer 103 located substantially directly above each pressure chamber 102 and a first electrode layer 1
03 (on the lower side in the figure)
And a second piezoelectric layer 110 provided on (lower side of) the orientation control layer 104 and a second common layer provided on (lower side of) the piezoelectric layer 110 and common to all the piezoelectric layers 110. Electrode layer 1
12 (common electrode); a vibrating layer 111 provided on (the lower side of) the second electrode layer 112 and displaced and vibrated in the layer thickness direction by the piezoelectric effect of the piezoelectric layer 110; An intermediate layer 11 provided on the upper side (the lower side) and located above a partition wall 102a that partitions each pressure chamber 102 from each other.
3 (vertical wall), and the first electrode layer 103,
Orientation control layer 104, piezoelectric layer 110, and second electrode layer 1
Numeral 12 constitutes a piezoelectric element in which these are sequentially laminated. The vibration layer 111 is provided on the surface of the piezoelectric element on the side of the second electrode layer 112.

In FIG. 5, reference numeral 114 denotes an adhesive for adhering the pressure chamber member A and the actuator section B. The intermediate layers 113 are partially adhered when the adhesive 114 is used. Even when the agent 114 protrudes outside the partition wall 102a, the upper surface of the pressure chamber 102 is vibrated so that the adhesive 114 does not adhere to the vibration layer 111 and the vibration layer 111 causes the expected displacement and vibration. It has a role of increasing the distance from the lower surface of the layer 111. As described above, the pressure chamber member A is preferably bonded to the side surface of the vibration layer 111 of the actuator section B opposite to the second electrode layer 112 via the intermediate layer 113. The pressure chamber member A may be directly joined to the opposite side.

The first electrode layer 103 and the orientation control layer 10
4. The constituent materials of the piezoelectric layer 110 and the second electrode layer 112 include the first electrode layer 14, the orientation control layer 15, the piezoelectric layer 16 and the second electrode layer 17 described in the first embodiment. Each is the same. The structures of the orientation control layer 104 and the piezoelectric layer 110 are the same as those of the orientation control layer 15 and the piezoelectric layer 16, respectively. The portion of the orientation control layer 104 near the surface on the first electrode layer 103 side is (100) ) Face or (0
01) A plane orientation region exists on titanium located on the surface of the first electrode layer 103 on the orientation control layer 104 side, and the area of the region in a cross section perpendicular to the layer thickness direction is the first electrode layer. It has a structure that increases from the 103 side toward the piezoelectric layer 110 side.

Next, a method of manufacturing an ink jet head excluding the IC chip E shown in FIG. 3, that is, an ink jet head including the pressure chamber member A, the actuator section B, the ink flow path member C and the nozzle plate D shown in FIG. 6 to 10
It will be described based on FIG.

As shown in FIG. 6A, an adhesion layer 121, a first electrode layer 103, an orientation control layer 104, a piezoelectric layer 110, a second electrode layer 112, a vibration layer 111, the intermediate layer 113 is formed by a sputtering method and laminated. The adhesion layer 121 is similar to the adhesion layer 12 described in the first embodiment, and
Substrate 1 to improve the adhesion between the substrate 1 and the first electrode layer 103.
The first electrode layer 103 is formed between the first electrode layer 20 and the first electrode layer 103 (the adhesion layer 121 need not always be formed). This adhesion layer 12
1 is removed similarly to the substrate 120 as described later. Further, Cr is used for the material of the vibration layer 111 and Ti is used for the intermediate layer 113.

As the substrate 120, a Si substrate cut into an 18 mm square is used. The substrate 120 is not limited to Si, and may be a glass substrate, a metal substrate, or a ceramic substrate. Further, the substrate size is not limited to an 18 mm square, and a Si substrate having a diameter of 2 to 10 inches may be used.

The adhesion layer 121 is obtained by applying a high-frequency power of 100 W while heating the substrate 120 to 400 ° C. using a Ti target, and forming the same in an argon gas of 1 Pa for one minute. The thickness of the adhesion layer 121 is 0.02 μm. The material of the adhesion layer 121 is
Not limited to Ti, tantalum, iron, cobalt, nickel or chromium, or a compound thereof (including Ti) may be used. The thickness may be in the range of 0.005 to 0.2 μm.

The first electrode layer 103 is formed by using a multi-source sputtering apparatus, using a Ti target and a Pt target, and heating the substrate 120 to 425 ° C. in a 1 Pa argon gas at a high frequency power of 85 W and 200 W. Obtained by forming for 12 minutes. The first electrode layer 103 has a thickness of 0.22 μm and is oriented in the (111) plane. The content of Ti is 2.3 mol%. Similarly to the first electrode layer 14 of the first embodiment, the first electrode layer 103 is formed by adding titanium or titanium oxide to at least one noble metal selected from the group consisting of Pt, iridium, palladium, and ruthenium. (Addition amount is preferably more than 0 and 30 mol% or less)
The thickness may be in the range of 0.05 to 2 μm.

The orientation control layer 104 is formed by using a strontium titanate sintered target,
At a temperature of 80 ° C. in a mixed atmosphere of argon and oxygen (gas volume ratio Ar: O ₂ = 39: 1), the degree of vacuum is 0.98 P
a, It is obtained by forming for 12 minutes under the condition of high frequency power of 280 W. The obtained strontium titanate film has a perovskite-type crystal structure, and is oriented to (100) plane or (001) plane on titanium located on the surface of the first electrode layer 103 on the orientation control layer 104 side. The (100) plane or (001) plane oriented region expands from the first electrode layer 103 side toward the opposite side (the piezoelectric layer 110 side). On the other hand, the orientation control layer 10
4, the region above the surface of the first electrode layer 103 where titanium or titanium oxide does not exist does not have the (100) plane or the (001) plane orientation, but this region faces the piezoelectric layer 110 side. Smaller. And here,
Since the thickness of the orientation control layer 104 is 0.01 μm, almost the entire surface on the piezoelectric layer 110 side is the (100) plane or the (0) plane.
There is a possibility that the region is not oriented to the (01) plane, but as described in the first embodiment, there is no problem at all if the film thickness is about this level.

The orientation control layer 1 in the first embodiment is used.
Similarly to 5, the constituent material of the orientation control layer 104 may be a perovskite oxide containing strontium. The content of strontium titanate is 5 mol%.
The content may be not less than 100 mol%, and may contain lead titanate, lead lanthanum zirconate titanate (PLZT), barium titanate, or the like in addition to strontium titanate, and may form a solid solution with strontium titanate. Further, the thickness of the orientation control layer 104 may be in the range of 0.01 to 0.2 μm.

The piezoelectric layer 110 is made of PZT (Zr / T
i = 53/47) and a substrate 12
0 at a temperature of 600 ° C. in a mixed atmosphere of argon and oxygen (gas volume ratio Ar: O ₂ = 19: 1) under conditions of a vacuum degree of 0.25 Pa and a high frequency power of 240 W for 3 hours. . The obtained PZT film has a rhombohedral perovskite crystal structure and a (100) plane orientation. Further, the film thickness of the piezoelectric layer 110 is 3.1 μm. The Zr / Ti composition of the piezoelectric layer 110 is Zr / Ti
/ Ti = 30/70 to 70/30, and the film thickness may be in the range of 1 to 5 μm. Also, the piezoelectric layer 1
The constituent material 10 may be a piezoelectric material containing PZT as a main component, such as PZT containing an additive such as Sr, Nb, or Al, and may be PMN or PZN.

The second electrode layer 112 is formed by using a Pt target at room temperature in argon gas of 1 Pa.
It is obtained by forming with high frequency power of 0 W for 10 minutes. The thickness of the second electrode layer 112 is 0.2 μm. The material of the second electrode layer 112 is not limited to Pt, but may be a conductive material, and the film thickness may be in the range of 0.1 to 0.4 μm.

The vibrating layer 111 is obtained by forming a Cr target at room temperature in a 1 Pa argon gas with a high frequency power of 200 W for 6 hours. The thickness of the vibration layer 111 is 3 μm. This vibration layer 111
Is not limited to Cr, but may be nickel, aluminum, tantalum, tungsten, silicon, or oxides or nitrides thereof (eg, silicon dioxide, aluminum oxide, zirconium oxide, silicon nitride) and the like. The thickness of the vibration layer 111 may be 2 to 5 μm.

The intermediate layer 113 is obtained by using a Ti target at room temperature for 5 hours in a 1 Pa argon gas with a high-frequency power of 200 W. The thickness of the intermediate layer 113 is 5 μm. This intermediate layer 113
Is not limited to Ti, and may be any conductive metal such as Cr. The thickness of the intermediate layer 113 may be 3 to 10 μm.

On the other hand, as shown in FIG. 6B, a pressure chamber member A is formed. The pressure chamber member A is made of the Si substrate 1
It is formed using a silicon substrate 130 (see FIG. 11) of a size larger than 20, for example, a 4-inch wafer. Specifically, first, a plurality of pressure chamber openings 101 are patterned on the silicon substrate 130 (for pressure chamber members). In this patterning, four pressure chamber openings 101 are formed as one set as shown in FIG.
The partition wall 102b that divides each set is set to have a thickness approximately twice as large as the width of the partition wall 102a that divides the pressure chamber opening 101 in each set. Thereafter, the patterned silicon substrate 130 is processed by chemical etching, dry etching, or the like to form four pressure chamber openings 101 in each group to obtain a pressure chamber member A.

Thereafter, the silicon substrate 12 after the film formation is formed.
0 (for film formation) and the pressure chamber member A are bonded using an adhesive. The formation of this adhesive is by electrodeposition. That is, first, as shown in FIG. 3C, an adhesive 114 is applied by electrodeposition to the upper surfaces of the partition walls 102a and 102b of the pressure chamber as an adhesive surface on the pressure chamber member A side. More specifically, although not shown, on the upper surfaces of the partition walls 102a and 102b, as a base electrode film, several hundreds of Ni thin enough to transmit light is formed.
A thin film is formed by a sputtering method, and thereafter, a patterned adhesive resin agent 114 is formed on the Ni thin film. At this time, as the electrodeposition liquid, a solution obtained by adding 0 to 50 parts by weight of pure water to an acrylic resin-based aqueous dispersion and stirring and mixing well is used. The reason why the thickness of the Ni thin film is set to be thin enough to transmit light is to make it easy to visually recognize that the adhesive resin has completely adhered to the silicon substrate 130 (for pressure chamber members). According to the experiment, the electrodeposition conditions were that the liquid temperature was about 2
5 ° C., DC voltage 30 V, energization time 60 seconds are suitable,
Under these conditions, about 3 to 10 μm of an acrylic resin is formed on the Ni thin film of the silicon substrate 130 (for the pressure chamber member) by electrodeposition.

Then, as shown in FIG. 7A, the laminated Si substrate 120 (for film formation) and the pressure chamber member A are bonded using the electrodeposited adhesive 114. This bonding is performed on the intermediate layer 1 formed on the substrate 120 (for film formation).
13 is used as a substrate-side bonding surface. Also, the Si substrate 120
(For film formation) is 18 mm in size, and the Si substrate 130 forming the pressure chamber member A is as large as 4 inches, so that a plurality of (14 in FIG. 11) S
The i-substrate 120 (for film formation) is attached to one pressure chamber member A (Si substrate 130). This pasting is performed as shown in FIG.
As shown in (1), the process is performed in a state where the center of each Si substrate 120 (for film formation) is positioned at the center of the partition wall 102b having a large width of the pressure chamber member A. After this paste,
The pressure chamber member A is pressed against and brought into close contact with the Si substrate 120 (for film formation) to increase the liquid-tightness between the two. Further, the temperature of the bonded Si substrate 120 (for film formation) and the pressure chamber member A is gradually increased in a heating furnace, and the adhesive 114 is completely cured. Subsequently, a plasma treatment is performed to remove the protruding fragments from the adhesive 114.

In FIG. 7A, the Si substrate 1 after the film formation is shown.
20 (for film forming) and the pressure chamber member A are adhered, but the Si substrate 130 (for pressure chamber member) at the stage where the pressure chamber opening 101 is not formed is replaced with the Si substrate 120 (for film forming) after film formation. )
May be adhered.

Thereafter, as shown in FIG. 7 (b), the intermediate layer 113 is etched into a predetermined shape using the partition walls 102a and 102b of the pressure chamber member A as a mask. Continuous shape (vertical wall)
And). Next, as shown in FIG. 8A, the Si substrate 120 (for film formation) and the adhesion layer 121 are removed by etching.

Subsequently, as shown in FIG. 8B, the first electrode layer 103 located on the pressure chamber member A
Etching is performed using a photolithography technique, so that each pressure chamber 102 is individualized. Then, as shown in FIG. 9A, the orientation control layer 104 and the piezoelectric layer 110 are etched using a photolithography technique to separate them into the same shape as the first electrode layer 103. The first electrode layer 103, the orientation control layer 104, and the piezoelectric layer 110 after the etching are located above each of the pressure chambers 102, and the first electrode layer 103, the orientation control layer 104, and the piezoelectric layer 110 Are formed so that the center in the width direction of the pressure chamber 102 coincides with the center of the corresponding pressure chamber 102 in the width direction with high precision. After individualizing the first electrode layer 103, the orientation control layer 104, and the piezoelectric layer 110 for each pressure chamber 102 as described above, FIG.
As shown in (b), the silicon substrate 130 (for the pressure chamber member) was cut at the portion of the partition wall 102b of each thickness and fixed to the pressure chamber member A having four pressure chambers 102 and the upper surface thereof. Four sets of actuator units B are completed.

Subsequently, as shown in FIG. 10A, a common liquid chamber 105, a supply port 106 and an ink flow path 107 are formed in the ink flow path member C, and a nozzle hole 108 is formed in the nozzle plate D. . Next, as shown in FIG. 2B, the ink flow path member C and the nozzle plate D are bonded with an adhesive 10.
Adhere with 9.

Thereafter, an adhesive (not shown) is transferred to the lower end surface of the pressure chamber member A or the upper end surface of the ink flow path member C, as shown in FIG. The alignment with the road member C is adjusted, and both are adhered by the adhesive. Thus, an ink jet head having the pressure chamber member A, the actuator section B, the ink flow path member C, and the nozzle plate D is completed as shown in FIG.

By applying a predetermined voltage between the first and second electrode layers 103 and 112 of the ink jet head obtained as described above, the portion of the vibrating layer 111 corresponding to each pressure chamber 102 in the layer thickness direction is applied. When the amount of displacement was measured, the variation in the amount of displacement was σ = 1.8%. When a 20 V AC voltage having a frequency of 20 kHz was continuously applied for 10 days, there was no ink ejection failure, and no deterioration in ejection performance was observed.

On the other hand, an ink jet head which is different from the above ink jet head of the present invention only in that the orientation control layer 104 is not provided is manufactured, and a predetermined voltage is applied between the first and second electrode layers 103 and 112 of the ink jet head. When the voltage was applied to measure the amount of displacement in the layer thickness direction of the portion corresponding to each pressure chamber 102 in the vibration layer 111, the variation in the amount of displacement was σ = 7.2%. When a 20 V AC voltage having a frequency of 20 kHz was continuously applied for 10 days, about 30% of the pressure chambers 10
Ink ejection failure occurred in the portion corresponding to No. 2. This is not due to clogging of ink or the like, and thus it is considered that the durability of the actuator section B (piezoelectric element) is low.

Accordingly, it can be seen that the ink jet head of this embodiment has a small variation in ink discharge performance and is excellent in durability.

(Embodiment 3) FIG. 12 shows a main part of another ink jet head according to an embodiment of the present invention. As in the ink jet head of Embodiment 2, a substrate is formed for film formation and for a pressure chamber member. Instead of using them separately, they are used both for film formation and for pressure chamber members.

Specifically, the vibration layer 403, the adhesion layer 404, and the first electrode layer 406 are formed on a pressure chamber substrate 401 (pressure chamber member) in which the pressure chamber 402 is formed by etching.
(Common electrode), an orientation control layer 407, a piezoelectric layer 408, and a second electrode layer 409 (individual electrode) are sequentially stacked. The first electrode layer 406, the orientation control layer 407, the piezoelectric layer 408, and the second electrode layer 409 constitute a piezoelectric element in which these are sequentially laminated. The vibration layer 403 is provided on the surface of the piezoelectric element on the side of the first electrode layer 406 via the adhesion layer 404.
The adhesion layer 404 is formed by the vibration layer 403 and the first electrode layer 40.
6 to improve the adhesiveness to the adhesive layer 6 and need not be provided like the adhesive layer 121 in the second embodiment. Adhesion layer 4
04, the first electrode layer 406, the orientation control layer 407, the piezoelectric layer 408, and the second electrode layer 409 are composed of the adhesion layer 121 and the first electrode layer 10 described in the second embodiment.
3, the same as the orientation control layer 104, the piezoelectric layer 110, and the second electrode layer 112, respectively. Further, the orientation control layer 40
7 and the piezoelectric layer 408 have the same structure as the orientation control layer 104 and the piezoelectric layer 110, respectively.
7 near the surface on the first electrode layer 406 side is (1)
The (00) plane or the (001) plane region is the first electrode layer 4
06, the area of the above-mentioned region in the section perpendicular to the layer thickness direction which is present on the titanium located on the surface portion of the orientation control layer 407 side is from the first electrode layer 406 side to the piezoelectric layer 40 side.
It has a structure that increases toward the 8th side.

As the pressure chamber substrate 401, a Si substrate having a diameter of 4 inches and a thickness of 200 μm is used. Also in this embodiment,
The substrate is not limited to Si, and may be a glass substrate, a metal substrate, or a ceramic substrate.

In the present embodiment, the vibration layer 403 is
It has a thickness of 2.8 μm and is made of silicon dioxide.
The material of the vibration layer 403 is not limited to silicon dioxide, but may be the material described in the second embodiment (a simple substance such as nickel or chromium, or an oxide or nitride thereof). The thickness of the vibration layer 111 may be 0.5 to 10 μm.

Next, a method of manufacturing the above-described ink jet head will be described with reference to FIG.

That is, first, as shown in FIG. 13A, the pressure chamber substrate 401 on which the pressure chamber 402 is not formed.
In addition, the vibration layer 403, the adhesion layer 404, and the first electrode layer 40
6. An orientation control layer 407, a piezoelectric layer 408, and a second electrode layer 409 are sequentially formed by a sputtering method.

The vibration layer 403 is formed by applying a high-frequency power of 300 W at room temperature without heating the pressure chamber substrate 401 using a silicon dioxide sintered body target at 0.4 Pa of argon and oxygen. In a mixed atmosphere (gas volume ratio Ar: O ₂ = 5: 25) for 8 hours. The method of forming the vibration layer 403 is not limited to the sputtering method, but may be a thermal CVD method, a plasma CVD method, or the like.
D method, sol-gel method, etc.
It may be a method of forming by the thermal oxidation treatment of 1.

The adhesion layer 404 is formed by heating the pressure chamber substrate 401 to 400 ° C. using a Ti target.
It is obtained by applying a high-frequency power of 00 W and heating for 1 minute in an argon gas of 1 Pa. The thickness of the adhesion layer 404 is 0.03 μm. In addition, the adhesion layer 404
Is not limited to Ti, but may be tantalum, iron, cobalt, nickel or chromium, or a compound thereof (including Ti). The thickness is 0.005 to 0.1 μm
It may be in the range of m.

The first electrode layer 406 is formed by heating the pressure chamber substrate 401 to 425 ° C. using a Ti target and a Pt target by using a multi-source sputtering apparatus.
It can be obtained by forming for 12 minutes with high frequency power of 85 W and 200 W in the argon gas of a. The thickness of the first electrode layer 406 is 0.22 μm, and (11
1) Orient to the plane. The content of Ti is 2.3 mol%.
It is. The first electrode layer 406 is also made of Pt, iridium, or Pt, similarly to the first electrode layer 14 in the first embodiment.
It is sufficient that titanium or titanium oxide is added to at least one noble metal selected from the group of palladium and ruthenium (the addition amount is preferably more than 0 and 30 mol% or less). It may be in the range of 0.05 to 2 μm.

The orientation control layer 407 is formed using a sintered target of strontium titanate at a temperature of 580 ° C. of the pressure chamber substrate 401 in a mixed atmosphere of argon and oxygen (gas volume ratio Ar: O ₂ = 39: 1). )).
It can be obtained by forming at 98 Pa and high frequency power of 280 W for 12 minutes. The obtained strontium titanate film is the same as the alignment control layer 104 in the second embodiment.
Is the same as

Note that the orientation control layer 1 in the first embodiment is used.
Similarly to 5, the constituent material of the orientation control layer 407 may be a perovskite oxide containing strontium. The content of strontium titanate is 5 mol%.
The content may be not less than 100 mol%, and may contain lead titanate, lead lanthanum zirconate titanate (PLZT), barium titanate, or the like in addition to strontium titanate, and may form a solid solution with strontium titanate. Further, the thickness of the orientation control layer 104 may be in the range of 0.01 to 0.2 μm.

The piezoelectric layer 408 is made of PZT (Zr / T
i = 53/47) in a mixed atmosphere of argon and oxygen (gas volume ratio Ar: O ₂ = 19: 1) at a temperature of the pressure chamber substrate 401 of 600 ° C.
It can be obtained by forming for 3 hours under the conditions of a vacuum degree of 0.25 Pa and a high frequency power of 240 W. The obtained PZT film is the same as the piezoelectric layer 110 in the second embodiment. The Zr / Ti composition of the piezoelectric layer 408 is Zr / T
i = 30/70 to 70/30, and the film thickness is 1
It may be in the range of up to 5 μm. The constituent material of the piezoelectric layer 408 may be a piezoelectric material containing PZT as a main component, such as PZT containing an additive such as Sr, Nb, or Al, and may be PMN or PZN. Is also good.

The second electrode layer 409 is formed by using a Pt target at room temperature in argon gas of 1 Pa.
It is obtained by forming with high frequency power of 0 W for 10 minutes. The thickness of the second electrode layer 409 is 0.2 μm. The material of the second electrode layer 409 is not limited to Pt, but may be a conductive material, and the film thickness may be in the range of 0.1 to 0.4 μm.

Next, a resist is applied on the second electrode layer 409 by spin coating, and patterning is performed by exposing and developing to a position where the pressure chamber 402 is to be formed. Then, the second electrode layer 409 and the piezoelectric layer 4
08 and the orientation control layer 407 are etched and individualized. This etching is performed by dry etching using a mixed gas of argon and an organic gas containing a fluorine element.

Subsequently, as shown in FIG. 13B, a pressure chamber 402 is formed in the pressure chamber substrate 401. This pressure chamber 4
02 is formed by anisotropic dry etching using a sulfur hexafluoride gas, an organic gas containing elemental fluorine, or a mixed gas thereof. That is, an etching mask is formed on a portion of the pressure chamber substrate 401 that is to be the side wall 413 on a surface opposite to the surface on which the above-described films are formed, and the pressure chamber 402 is formed by anisotropic dry etching.

Then, the nozzle plate 412 in which the nozzle holes 410 are formed in advance is bonded to the surface of the pressure chamber substrate 401 on the side opposite to the surface on which the above-mentioned films are formed by using an adhesive, whereby the ink jet head is completed. I do. Nozzle hole 4
Reference numeral 10 denotes an opening at a predetermined position of the nozzle plate 412 by a lithography method, a laser processing method, an electric discharge processing method or the like. Then, when joining the nozzle plate 412 to the pressure chamber substrate 401, alignment is performed so that each nozzle hole 410 is arranged corresponding to the pressure chamber 402.

By applying a predetermined voltage between the first and second electrode layers 406 and 409 of the ink jet head obtained as described above, the portion of the vibrating layer 403 corresponding to each pressure chamber 402 in the layer thickness direction is applied. When the amount of displacement was measured, the variation in the amount of displacement was σ = 1.8%. When a 20 V AC voltage having a frequency of 20 kHz was continuously applied for 10 days, there was no ink ejection failure, and no deterioration in ejection performance was observed.

On the other hand, an ink jet head which is different from the above ink jet head of the present invention only in that the orientation control layer 407 is not provided is manufactured, and a predetermined voltage is applied between the first and second electrode layers 406 and 409 of the ink jet head. When the voltage was applied and the displacement in the layer thickness direction of the portion corresponding to each pressure chamber 402 in the vibration layer 403 was measured, the variation in the displacement was σ = 5.8%. When a 20 V AC voltage having a frequency of 20 kHz was continuously applied for 10 days, about 25% of the pressure
Ink ejection failure occurred in the portion corresponding to No. 2. This is not due to clogging of ink or the like, and it is considered that the durability of the actuator section (piezoelectric element) is low.

Accordingly, it can be seen that the ink jet head of this embodiment has a small variation in ink discharge performance and is excellent in durability, similarly to the ink jet head of the second embodiment.

(Embodiment 4) FIG. 14 shows an ink jet recording apparatus 27 according to an embodiment of the present invention.
An ink jet head 28 similar to that described above is provided. In the ink jet head 28, the pressure chamber (the pressure chamber 102 in the second embodiment or the third embodiment)
The ink in the pressure chamber is ejected onto the recording medium 29 (recording paper or the like) from nozzle holes (the nozzle hole 108 in the second embodiment or the nozzle hole 410 in the third embodiment) provided so as to communicate with the pressure chamber 402 in the first embodiment. It is configured to perform recording.

The ink-jet head 28 is mounted on a carriage 31 provided on a carriage shaft 30 extending in the main scanning direction X. The carriage 31 reciprocates along the carriage shaft 30 in the main scanning direction. X
It is configured to reciprocate. This allows the carriage 31 to move between the inkjet head 28 and the recording medium 2.
9 in the main scanning direction X.

The ink jet recording apparatus 27
Is provided with a plurality of rollers 32 for moving the recording medium 29 in a sub-scanning direction Y substantially perpendicular to the main scanning direction X (width direction) of the inkjet head 28. With this,
The plurality of rollers 32 constitute a relative moving unit that relatively moves the inkjet head 28 and the recording medium 29 in the sub-scanning direction Y. In FIG. 14, Z is the vertical direction.

When the ink jet head 28 is moving in the main scanning direction X by the carriage 31,
Ink is ejected from the nozzle holes of the inkjet head 28 onto the recording medium 29, and when this one-scan recording is completed,
The recording medium 29 is moved by a predetermined amount by the roller 32, and the recording of the next one scan is performed.

Therefore, since the ink jet recording apparatus 27 includes the same ink jet head 28 as in the second or third embodiment, it has good printing performance and durability.

In the above embodiment, the piezoelectric element of the present invention is applied to an ink jet head and an ink jet recording apparatus. However, other than this, a thin film capacitor, a charge storage capacitor of a nonvolatile memory element, various actuators, Outside sensor, ultrasonic sensor, pressure sensor, acceleration sensor, flow sensor, shock sensor, piezoelectric transformer, piezoelectric ignition element, piezoelectric speaker, piezoelectric microphone, piezoelectric filter, piezoelectric pickup,
The present invention is also applicable to a tuning fork oscillator, a delay line, and the like. In particular, in a head support mechanism in which a head for recording or reproducing information on a disk that is driven to rotate in a disk device (used as a storage device of a computer) is provided on the substrate. A thin film piezoelectric actuator for a disk drive that displaces the head by deforming a substrate using a thin film piezoelectric element (for example,
1-333241). That is,
The thin-film piezoelectric element has a structure in which a first electrode layer, an orientation control layer, a piezoelectric layer, and a second electrode layer having the same configuration as those described in the above embodiment are sequentially laminated. An electrode layer is bonded to the substrate.

[0172]

As described above, according to the present invention,
The electrode layer is made of a noble metal containing titanium or titanium oxide, and on this electrode layer, an orientation control layer made of a perovskite oxide containing cubic or tetragonal strontium is formed. The orientation control layer is preferentially oriented on the (100) plane or the (001) plane.
By forming a piezoelectric layer made of a rhombohedral or tetragonal perovskite oxide and orienting the piezoelectric layer preferentially in the (001) plane, the adhesion of each layer and the piezoelectric layer The crystallographic structure and preferred orientation plane can be controlled.
A piezoelectric element having good variation, withstand voltage, and reliability can be obtained, and an inkjet head and an inkjet recording apparatus using the piezoelectric element can have excellent durability with little variation in ink ejection performance. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a piezoelectric element according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view schematically showing the structure of an orientation control layer.

FIG. 3 is a perspective view illustrating an overall configuration of an inkjet head according to an embodiment of the present invention.

FIG. 4 is an exploded perspective view showing main parts of a pressure chamber member and an actuator unit in the ink jet head of FIG.

FIG. 5 is a cross-sectional view illustrating a main part of a pressure chamber member and an actuator unit in the inkjet head of FIG. 3;

6 is a diagram showing a laminating step, a step of forming an opening for a pressure chamber, and a step of attaching an adhesive in the method of manufacturing the ink jet head of FIG.

FIG. 7 is a diagram showing a bonding step between a substrate and a pressure chamber member after film formation and a vertical wall forming step in the method of manufacturing the ink jet head of FIG.

FIG. 8 is a view showing a step of removing a substrate (for film formation) and an adhesion layer and a step of individualizing a first electrode layer in the method of manufacturing the ink jet head of FIG.

FIG. 9 is a diagram showing a step of individualizing an orientation control layer and a piezoelectric layer and a step of cutting a substrate (for a pressure chamber member) in the method of manufacturing the ink jet head of FIG.

FIG. 10 shows a process for producing an ink flow channel member and a nozzle plate, a process for bonding an ink flow channel member to a nozzle plate, a process for bonding a pressure chamber member and an ink flow channel member, and a method for manufacturing the ink jet head shown in FIG. FIG. 3 is a diagram illustrating a completed inkjet head.

FIG. 11 is a plan view showing a bonding state between a formed Si substrate and a Si substrate for a pressure chamber member in the method of manufacturing the ink jet head of FIG.

FIG. 12 is a cross-sectional view illustrating a main part of a pressure chamber member and an actuator unit in another inkjet head according to an embodiment of the present invention.

13 is a diagram illustrating a laminating step and a pressure chamber forming step in the method of manufacturing the ink jet head of FIG.

FIG. 14 is a schematic perspective view showing an ink jet recording apparatus according to an embodiment of the present invention.

[Explanation of symbols]

11 Substrate 12 Adhesion layer 14 First electrode layer 15 Orientation control layer 16 Piezoelectric layer 17 Second electrode layer 27 Inkjet recording device 28 Inkjet head 29 Recording media 31 Carriage (relative moving means) 102 pressure chamber 103 first electrode layer (individual electrode) 104 Orientation control layer 108 nozzle hole 110 Piezoelectric layer 111 vibrating layer 112 second electrode layer (common electrode) 120 substrate 121 adhesion layer 401 pressure chamber substrate 402 pressure chamber 403 vibrating layer 404 adhesion layer 406 first electrode layer (common electrode) 407 Orientation control layer 408 Piezoelectric layer 409 Second electrode layer (individual electrode) 410 nozzle hole A Pressure chamber member

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 41/18 H01L 41/22 A 41/22 41/08 D 41/24 (72) Inventor Taku Hirasawa Osaka 1006 Kadoma, Kadoma, Fumonma-shi Matsushita Electric Industrial Co., Ltd. (72) Inventor Jun Tomozawa 1006 Kadoma, Kadoma, Osaka, Japan Matsushita Electric Industrial Co., Ltd. (72) Hideo Torii 1006 Kadoma, Kadoma-shi, Osaka Matsushita (72) Inventor Ryoichi Takayama 1006 Ozumado Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Co., Ltd. F-term (reference) 2C057 AF65 AF93 AG44 AG52 AG55 AP02 AP14 AP25 AP31 AP52 AQ02 BA03 BA14

Claims (12)

[Claims] A first electrode layer provided on the substrate; an orientation control layer provided on the first electrode layer; a piezoelectric layer provided on the orientation control layer; A piezoelectric element comprising: a second electrode layer provided on a body layer; wherein the first electrode layer is made of a noble metal containing titanium or titanium oxide; and the orientation control layer is made of a cubic system. Or tetragonal (100)
The piezoelectric layer is made of a perovskite-type oxide containing strontium preferentially oriented on the (001) plane or the (001) plane, and the piezoelectric layer is a rhombohedral or tetragonal (001)
A piezoelectric element comprising a perovskite oxide preferentially oriented on a plane. 2. The piezoelectric element according to claim 1, wherein the orientation control layer contains strontium titanate. 3. The piezoelectric element according to claim 2, wherein the content of strontium titanate in the orientation control layer is 5 mol% or more and 100 mol% or less. 4. The piezoelectric element according to claim 1, wherein the first electrode layer is made of at least one noble metal selected from the group consisting of platinum, iridium, palladium, and ruthenium, A piezoelectric element, wherein the content of titanium or titanium oxide contained in the noble metal is more than 0 and 30 mol% or less. 5. The piezoelectric element according to claim 1, wherein the piezoelectric layer is made of a piezoelectric material containing lead zirconate titanate as a main component. 6. The piezoelectric element according to claim 1, wherein an adhesion layer that enhances adhesion between the substrate and the first electrode layer is provided between the substrate and the first electrode layer. A piezoelectric element, which is provided. 7. A piezoelectric element in which a first electrode layer, an orientation control layer, a piezoelectric layer, and a second electrode layer are sequentially laminated, and a piezoelectric element is provided on a surface of the piezoelectric element on the second electrode layer side. A vibrating layer, and a pressure chamber member having a pressure chamber for accommodating ink, which is joined to a surface of the vibrating layer opposite to the piezoelectric element, wherein the vibrating layer is formed by a piezoelectric effect of a piezoelectric layer of the piezoelectric element. Wherein the first electrode layer of the piezoelectric element is made of a noble metal containing titanium or titanium oxide, wherein the first electrode layer is made of a noble metal containing titanium or titanium oxide. The orientation control layer is a cubic or tetragonal (100)
The piezoelectric layer is made of a perovskite-type oxide containing strontium preferentially oriented on the (001) plane or the (001) plane, and the piezoelectric layer is a rhombohedral or tetragonal (001)
An ink jet head comprising a perovskite type oxide preferentially oriented on a surface. 8. A piezoelectric element in which a first electrode layer, an orientation control layer, a piezoelectric layer, and a second electrode layer are sequentially laminated, and a piezoelectric element provided on a surface of the piezoelectric element on the first electrode layer side. A vibrating layer, and a pressure chamber member having a pressure chamber for accommodating ink, which is joined to a surface of the vibrating layer opposite to the piezoelectric element, wherein the vibrating layer is formed by a piezoelectric effect of a piezoelectric layer of the piezoelectric element. Wherein the first electrode layer of the piezoelectric element is made of a noble metal containing titanium or titanium oxide, wherein the first electrode layer is made of a noble metal containing titanium or titanium oxide. The orientation control layer is a cubic or tetragonal (100)
The piezoelectric layer is made of a perovskite-type oxide containing strontium preferentially oriented on the (001) plane or the (001) plane, and the piezoelectric layer is a rhombohedral or tetragonal (001)
An ink jet head comprising a perovskite type oxide preferentially oriented on a surface. 9. A step of forming a first electrode layer made of a noble metal containing titanium or titanium oxide on a substrate by a sputtering method; and forming a cubic or tetragonal system on the first electrode layer. (10
Forming, by sputtering, an orientation control layer made of a perovskite-type oxide containing strontium, which is preferentially oriented to the (0) plane or the (001) plane; and a rhombohedral or tetragonal system is formed on the orientation control layer. (00
1) A piezoelectric element, comprising: a step of forming a piezoelectric layer made of a perovskite oxide preferentially oriented on a surface by a sputtering method; and a step of forming a second electrode layer on the piezoelectric layer. Manufacturing method. 10. A piezoelectric element in which a first electrode layer, an orientation control layer, a piezoelectric layer, and a second electrode layer are sequentially laminated, and a vibration layer is formed by a piezoelectric effect of the piezoelectric layer of the piezoelectric element. What is claimed is: 1. A method for manufacturing an ink jet head configured to discharge ink in a pressure chamber by displacing in a layer thickness direction, wherein a first electrode layer made of a noble metal containing titanium or titanium oxide is formed on a substrate by a sputtering method. And forming a cubic or tetragonal (10) on the first electrode layer.
Forming, by sputtering, an orientation control layer made of a perovskite-type oxide containing strontium, which is preferentially oriented to the (0) plane or the (001) plane; and a rhombohedral or tetragonal system is formed on the orientation control layer. (00
1) a step of forming, by sputtering, a piezoelectric layer made of a perovskite oxide preferentially oriented on a surface; a step of forming a second electrode layer on the piezoelectric layer; and a step of forming a second electrode layer on the piezoelectric layer. Forming a vibrating layer; bonding a pressure chamber member for forming a pressure chamber to a surface of the vibrating layer opposite to the second electrode layer; And a removing step. 11. A piezoelectric element in which a first electrode layer, an orientation control layer, a piezoelectric layer, and a second electrode layer are sequentially laminated, and a vibration layer is formed by a piezoelectric effect of the piezoelectric layer of the piezoelectric element. A method for manufacturing an ink jet head configured to discharge ink in a pressure chamber by displacing in a layer thickness direction, comprising: forming a vibration layer on a pressure chamber substrate for forming a pressure chamber; Forming a first electrode layer made of a noble metal containing titanium or titanium oxide on the vibrating layer by a sputtering method; and forming a cubic or tetragonal (10) on the first electrode layer.
A step of forming, by sputtering, an orientation control layer made of a perovskite-type oxide containing strontium, which is preferentially oriented to the (0) plane or the (001) plane, and a rhombohedral or tetragonal system is formed on the orientation control layer. Forming a piezoelectric layer made of a perovskite oxide preferentially oriented on the (001) plane by sputtering, forming a second electrode layer on the piezoelectric layer, and applying pressure to the pressure chamber substrate. Forming a chamber. 12. An ink jet head according to claim 7, further comprising: a relative moving means for relatively moving the ink jet head and the recording medium, wherein the relative moving means moves the ink jet head relative to the recording medium. Wherein the ink jet recording is performed by discharging ink in the pressure chamber to a recording medium from a nozzle hole provided in the ink jet head so as to communicate with the pressure chamber. apparatus.