JP2003110158A - Piezoelectric thin film element, method of manufacturing the same, and ink jet recording head and ink jet printer using the same - Google Patents

Abstract

(57) [Problem] To provide a piezoelectric thin film element having excellent characteristics by appropriately controlling the distribution of stress applied to the inside of a barrier layer, and a method of manufacturing the same. SOLUTION: A substrate 20 and Zr provided on the substrate are provided.
_{1-x M x O y (} 0.01 ≦ x ≦ 0.15, y = 2.
0 ± α, α is a stoichiometrically acceptable value, and M is a value in the periodic table.
A barrier layer 32 having a composition represented by a group IIA element, a group IIIA element, or a group IIIB element), a lower electrode 42 provided on the barrier layer, and a piezoelectric material provided on the lower electrode. A piezoelectric thin film element comprising a thin film 43 and an upper electrode 44 provided on the piezoelectric thin film, wherein x is continuous or stepwise in the thickness direction of the barrier layer 32 toward the lower electrode. It has a gradually increased gradient composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric thin film element and a method for manufacturing the same, and an ink jet recording head and an ink jet printer using the same, and in particular, a piezoelectric thin film element having a barrier layer having a predetermined gradient composition. Regarding

[0002]

2. Description of the Related Art A piezoelectric thin film element using a piezoelectric thin film typified by lead zirconate titanate has functions such as spontaneous polarization, high dielectric constant, electro-optical effect, piezoelectric effect, and pyroelectric effect. , Has been applied to a wide range of device development.

The piezoelectric thin film element is composed of a substrate, a vibration plate, a lower electrode, a piezoelectric thin film and an upper electrode, which are sequentially laminated, and the vibration plate has a barrier layer made of a ZrO ₂ film. This barrier layer plays a role of preventing mutual diffusion of atoms between the piezoelectric thin film and the substrate.

[0004]

However, ZrO
₂ has many crystal structures, and the crystal state becomes unstable depending on the crystallization conditions.
There is a possibility that cracks may occur in the rO ₂ film. Moreover, the cracks in the ZrO ₂ film, a crack in the entire diaphragm sometimes occurs with the ZrO ₂ film as a barrier layer. It is considered that this is because the toughness of the ZrO ₂ film cannot be sufficiently obtained when the stabilization of the crystal structure is insufficient.

In addition, lead atoms are transferred from the piezoelectric thin film to the lower electrode,
There is also a problem that the adhesion between the ZrO ₂ film and the lower electrode is reduced due to diffusion into the ZrO ₂ film (barrier layer) or the substrate.

Regarding the improvement of the mechanical strength of the ZrO ₂ film and the improvement of the adhesiveness with the lower electrode, JP-A-11-204849.
Japanese Patent Publication discloses a piezoelectric actuator having a partially stabilized or completely stabilized zirconium oxide film containing an oxide such as yttrium.

However, even when the zirconium oxide film is partially stabilized or completely made safe, the toughness of the barrier layer is not sufficient and cracks occur in the barrier layer and the entire diaphragm, and the barrier layer and the lower part are also damaged. Adhesion with the electrode is not sufficient.

Therefore, according to the present invention, a predetermined gradient composition is formed in the barrier layer to appropriately control the distribution of stress applied to the inside of the barrier layer to prevent cracks from occurring in the entire barrier layer and the diaphragm. It is an object of the present invention to provide a piezoelectric thin film element having excellent characteristics, a method for manufacturing the same, and an inkjet recording head and an inkjet printer using the same.

[0009]

As a result of earnest research, the present inventor has made it possible to appropriately control the distribution of stress applied to the inside of the barrier layer by providing the barrier layer made of a ZrO ₂ film with a predetermined gradient composition. The inventors have found that an excellent piezoelectric thin film element can be obtained, and have completed the present invention.

A piezoelectric thin film element according to the present invention comprises a substrate,
Zr provided on the substrate_1-xM_x O_y(0.01 ≦ x
≤0.15, y = 2.0 ± α, α is stoichiometrically acceptable
Value, M is the IIA group element, IIIA group element, or III of the periodic table
A barrier layer having a composition represented by a group B element)
A lower electrode provided on the barrier layer, and on the lower electrode
Piezoelectric thin film provided, and provided on the piezoelectric thin film
A piezoelectric thin film element comprising an upper electrode,
In the rear layer, x is continuous in the thickness direction toward the lower electrode side.
Characterized by having a gradient composition that increases gradually or stepwise
To do.

By increasing the amount (x) of M in the barrier layer in the thickness direction of the barrier layer toward the lower electrode side, it is possible to prevent cracks in the barrier layer and the diaphragm as a whole and to improve the piezoelectric characteristics. An excellent piezoelectric thin film element can be obtained.

The amount (x) of M may be continuously or stepwise increased within the range of 0.01 or more and 0.15 or less in the thickness direction of the barrier layer toward the lower electrode side. . Alternatively, the barrier layer may be composed of a plurality of laminated bodies, and x of the layer on the lower electrode side may be increased stepwise.

The amount (x) of M is 0.01 ≦ x ≦ 0.15
From the viewpoints of preventing cracks and improving piezoelectric properties, it is preferable.

It is preferable that y is 2.0 ± α (α is a stoichiometrically acceptable value) from the viewpoint of preventing cracks and improving piezoelectric characteristics.

M is a IIA group element, a IIIA group element of the periodic table,
Or a Group IIIB element, for example, Y (yttrium),
Examples thereof include Ca (calcium), Mg (magnesium), Ce (cerium), and Al (aluminum). In particular, Y (yttrium) or Ca (calcium) is more preferable from the viewpoint of preventing cracks from occurring and improving piezoelectric characteristics.

The barrier layer is preferably formed on a SiO ₂ film.

The thickness of the barrier layer is 0.1 μm or more,
It is preferably 1.0 μm or less.

The piezoelectric thin film is preferably a solid solution of lead titanate and lead zirconate or a solid solution of lead titanate, lead zirconate and lead magnesium niobate.

An ink jet recording head according to the present invention comprises the above piezoelectric thin film element as a piezoelectric actuator for ejecting ink.

The ink jet printer according to the present invention comprises:
The inkjet recording head is provided as a printing unit.

In the method of manufacturing a piezoelectric thin film element according to the present invention, after a SiO ₂ film is formed on a substrate, Zr _1-x M _x O _y (0.01 ≦ x ≦ 0 is formed on the SiO ₂ film. .15,
y = 2.0 ± α, α is a stoichiometrically allowable value, M is a IIA group element, IIIA group element, or IIIB group element of the periodic table) A method of manufacturing a piezoelectric thin film element by sequentially performing a film forming step of firing and then forming a barrier layer, and then sequentially forming a lower electrode, a piezoelectric thin film, and an upper electrode. In the step, the sol used in the step of forming the layer on the lower electrode side has a larger x than the sol used in the step of forming the layer on the SiO ₂ film side.

The sol-gel method is used to sequentially form films using a sol in which the amount (x) of M as a stabilizer is changed to form a barrier layer having a graded composition, thereby forming a barrier layer. It is possible to prevent the occurrence of cracks in the entire diaphragm and the piezoelectric thin film element having excellent piezoelectric characteristics.

The method of manufacturing a piezoelectric thin film element according to the present invention, after forming the SiO ₂ film on the substrate, on top of the SiO ₂ film Zr and (zirconium) or ZrO ₂ (zirconium oxide) M (M is A group IIA element, a group IIIA element, or a group IIIB element in the periodic table) is simultaneously sputtered to form a barrier layer, and then a lower electrode, a piezoelectric thin film, and an upper electrode are sequentially formed to form a piezoelectric body. A method of manufacturing a thin film element, wherein the target power of M is Zr or ZrO in the step of forming the barrier layer.
It is characterized in that it is changed so as to be relatively large with respect to the target power of ₂ , or the target power of M is changed so as to be absolutely large.

By using a sputtering method to form a barrier layer having a graded composition in which the amount of the stabilizer M is changed stepwise or continuously, cracks in the barrier layer and the entire diaphragm are generated. This can be prevented, and a piezoelectric thin film element having excellent piezoelectric characteristics can be manufactured.

The method of manufacturing a piezoelectric thin film element according to the present invention comprises an ion implantation method after forming a SiO ₂ film on a substrate and then forming a layer made of ZrO ₂ (zirconium oxide) on the SiO ₂ film. To inject M ions (M is a group IIA element, a group IIIA element, or a group IIIB element of the periodic table) to form a barrier layer, and then sequentially form a lower electrode, a piezoelectric thin film, and an upper electrode. A method of manufacturing a piezoelectric thin film element, comprising forming a gradient composition in which M ions are continuously or stepwise increased toward a lower electrode side in a thickness direction of the barrier layer by the step of forming the barrier layer. Characterize.

By forming a barrier layer having a graded composition by using the ion implantation method, it is possible to prevent cracks in the barrier layer and the entire diaphragm from being generated, and to manufacture a piezoelectric thin film element having excellent piezoelectric characteristics. be able to.

The M is Y (yttrium) or Ca
(Calcium) is more preferable.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(Overall Structure of Inkjet Printer) FIG. 1 is a perspective view of the inkjet printer. In the printer, a main body 2 is provided with a tray 3, an outlet 4, and operation buttons 9.

The main body 2 is the housing of the printer, and the paper 5
The paper feed mechanism 6 is provided at a position where the paper can be fed from the tray 3, and the ink jet recording head 1 is arranged so as to print on the paper 5. A control circuit 8 is provided inside the main body 2.

The tray 3 supplies the paper 5 before printing to a supply mechanism 6
The discharge port 4 is a discharge port for discharging the printed sheet 5.

The ink jet recording head 1 is provided with the piezoelectric thin film element according to the present invention, and is constructed so that ink can be ejected from the nozzles in response to the signal Sh output from the control circuit 8.

The paper feed mechanism 6 includes a motor 600 and rollers 60.
1, 602 are provided. The motor 600 rotates in response to the signal Sh output from the control circuit 8, and this rotational force is transmitted to the rollers 601, 602, and the rollers 601, 60
The rotation of 2 draws in the paper 5 set in the tray 3, and the head 1 supplies the paper 5 in a printable manner.

The control circuit 8 includes a CPU, RO (not shown).
M, RAM, interface circuit, etc. are provided.
The control circuit 8 outputs a signal to the paper feed mechanism 6 or the drive mechanism of the head 1 in accordance with print information supplied from the computer via a connector (not shown).

(Structure of Inkjet Recording Head) FIG. 2
FIG. 3 is an exploded perspective view of the piezoelectric thin film element according to the present invention.

The head comprises the nozzle plate 10 and the pressure chamber substrate 2
0, diaphragm 30, lower electrode 42, piezoelectric thin film 43, and upper electrode 44.

The pressure chamber substrate 20 includes a pressure chamber 21 and a side wall 2.
2, a reservoir 23 and a supply port 24. The pressure chamber 21 is formed as a space for storing ink for ejecting ink by etching a substrate such as silicon. The side wall 22 is formed so as to partition the pressure chamber 21. The reservoir 23 serves as a channel for commonly filling the pressure chambers 21 with ink. The supply port 24 is formed so that ink can be introduced from the reservoir 23 into each pressure chamber 21.

The nozzle plate 10 has nozzle holes 1 at positions corresponding to the respective pressure chambers 21 provided in the pressure chamber substrate 20.
1 is attached to one surface of the pressure chamber substrate 20.

The pressure chambers 21 and the nozzle holes 11 are arranged continuously at a constant pitch. The pitch between these nozzles can be changed in time according to the printing accuracy.
For example, they are arranged so as to be 400 dpi (dot per inch).

A lower electrode 42, a piezoelectric thin film 43 and an upper electrode 44 are provided on the vibration plate 30 at positions corresponding to the respective pressure chambers 21, and these functions as a piezoelectric actuator. The vibrating plate 30 has an ink tank port 3
5 is provided so that the ink stored in the ink tank (not shown) can be supplied into the pressure chamber substrate 20.

(Layer Structure) FIG. 3 shows a sectional view of a piezoelectric thin film element. As shown in FIG. 3, the piezoelectric thin film element 100
The vibration plate 30 is laminated on the pressure chamber substrate 20 having the nozzle plate 10, and the lower electrode 42 and the seed Ti film 4 are formed on the vibration plate 30.
5, the piezoelectric thin film 43, and the upper electrode 44 are sequentially laminated.

The pressure chamber substrate 20 has a thickness of 220 μm.
A silicon monocrystalline substrate of the order of magnitude is preferred.

The vibration plate 30 is formed on the pressure chamber substrate 20.
Silicon dioxide (SiO_Two) Consisting of SiO_TwoMembrane 3
1 and the SiO_TwoZr formed on the film 31_1-x
M_x O_y(0.01 ≦ x ≦ 0.15, y = 2.0 ± α,
α is a stoichiometrically acceptable value, M is the IIA group element of the periodic table
Element, group IIIA element, or group IIIB element)
And a barrier layer 32 made of a laminated material. M is Y,
They are Ca, Mg, Be, Ce and the like. The barrier layer 32 is below
X toward the electrode side is continuous or stepwise in the thickness direction
With an increased gradient composition. This allows the barrier layer
It is possible to properly control the stress and the adhesion force with the lower electrode.
Form a diaphragm that is thin and prevents the occurrence of cracks.
be able to. The thickness of the barrier layer 32 is 0.1 μm or more.
It is preferably 1.0 μm or less.

The lower electrode 42 is composed of a single layer film of iridium, or is arranged from the diaphragm 30 side to the iridium layer /
It is preferable to have a laminated structure such as a platinum layer, a platinum layer / iridium layer, and an iridium layer / platinum layer / iridium layer. Alternatively, a film made of an alloy of iridium and platinum may be used.

A seed Ti film 45 is formed on the lower electrode 42. By forming the seed Ti film 45, the orientation of the piezoelectric thin film 43 formed thereon can be controlled. The seed Ti film 45 preferably has a film thickness of 3 nm to 10 n.
m, and more preferably 5 nm. The seed Ti film may have an island shape in addition to being formed with a uniform thickness.

An appropriate buffer layer such as an ultrathin titanium thin film or chromium thin film may be interposed between the diaphragm 30 and the lower electrode 42 in order to further improve the adhesion between them. The thickness of the titanium thin film is 10 nm or more and 20 n
It is preferably less than m.

The piezoelectric thin film 43 is made of lead titanate (PbTi).
O_Three), Lead zirconate (PbZrO _Three), Zirconate
Lead titanate (Pb (Zr, Ti) O_Three), Lead orchid titanate
Tan ((Pb, La) TiO_Three), Niomagnesate
Lead bumate (Pb (Mg, Nb) O_Three), Titanium zirconate
Lanthanum leadate ((Pb, La) (Zr, Ti) O_Three),
Or lead magnesium niobate zirconium titanate
(Pb (Zr, Ti) (Mg, Nb) O_Three) Etc.
It is preferable. In particular, lead titanate (PbTiO 3 _Three)When
Lead zirconate (PbZrO_Three) Solid solution with
Lead niobate (Pb (Mg, Nb) O)_Three) And Zirco
Lead acidate (PbZrO_Three) And lead titanate (PbTiO_Three)
It is preferable to consist of a solid solution of Of the piezoelectric thin film 43
The film thickness is preferably 0.8 μm or more and 2.0 μm or less
Good

The upper electrode 44 is not particularly limited as long as it is a conductive material that can be used as a normal electrode. For example, a single layer film of Pt, RuO ₂ , Ir, IrO ₂ or Pt / Ti, Pt / Ti / TiN, Pt / Ti
N / Pt, Ti / Pt / Ti, TiN / Pt / TiN,
Pt / Ti / TiN / Ti, RuO ₂ / TiN, IrO
_It may be a laminated film of two or more layers such as ₂ / Ir or IrO ₂ / TiN.

(Printing Operation) The printing operation of the ink jet recording head will be described below. When the drive signal is output from the control circuit, the supply mechanism operates and the sheet is conveyed by the head to a printable position. When the ejection signal is not supplied from the control circuit and the voltage is not applied between the lower electrode and the upper electrode of the piezoelectric element, the piezoelectric thin film layer does not change. No pressure change occurs in the pressure chamber provided with the piezoelectric element to which the ejection signal is not supplied, and the ink droplet is not ejected from the nozzle hole.

On the other hand, when a discharge signal is supplied from the control circuit and a constant voltage is applied between the lower electrode and the upper electrode of the piezoelectric element, the piezoelectric thin film layer is deformed. In the pressure chamber provided with the piezoelectric element to which the ejection signal is supplied, the vibrating plate flexes greatly. Therefore, the pressure in the pressure chamber is momentarily increased, and ink droplets are ejected from the nozzle holes. Arbitrary characters and figures can be printed by individually supplying the ejection signals to the piezoelectric element at the position where printing is desired in the head.

(Manufacturing Method) Next, the manufacturing process of the piezoelectric thin film element will be described with reference to FIGS.

[Film Forming Step of Vibrating Plate] First, as shown in FIG. 4A, a film thickness of about 5 is formed on the pressure chamber substrate 20 made of silicon by using a film forming method such as thermal oxidation or a CVD method. 1 μm S
The iO ₂ film 31 is formed.

Next, as shown in FIG. 4B, SiO ₂
A barrier layer 32 made of a ZrO ₂ film is formed on the film 31. The barrier layer 32 is formed by a sol-gel method, a sputtering method, or an ion implantation method.

The sol-gel method is a method in which a hydrated complex (sol) of a metal hydroxide is dehydrated to give a gel, and the gel is heated and baked to form an inorganic oxide film. When forming the barrier layer 32 using the sol-gel method, first, Zr _1-x
M _x O _y (M is, for example, Y or Ca) is hydrolyzed with an acid or the like to prepare a sol, and then the prepared sol is mixed with S
It is applied on the iO ₂ film 31. At the time of coating, a method such as spin coating is used. After applying the sol, it is dried at a constant temperature for a certain period of time to evaporate the solvent of the sol. The drying temperature is preferably 120 ° C. or higher and 200 ° C. or lower, and the drying time is preferably 5 minutes or longer and 15 minutes or shorter. After drying, degreasing is further performed at a constant temperature for a predetermined time in an air atmosphere. As a degreasing method, it is preferable to bring the entire substrate into close contact with a hot plate and heat the heat from the hot plate so that the heat is conducted to the entire substrate. The degreasing temperature is preferably 300 ° C. or higher and 400 ° C. or lower, and the degreasing time is preferably 10 minutes or longer and 20 minutes or shorter. Next, this is 800 ℃ or more and 1000 ℃
Crystallization is performed by firing at the following firing temperature for 10 minutes or more and 60 minutes or less. RTA (Rapid Thermal Anneal)
ing) equipment or diffusion furnace is used. Next, Zr _1-x M
_x O _y to adjust the sol to increase the amount of M (x) in, Likewise coating, drying, degreasing and firing are performed. In this way, the barrier layer 32 is obtained by performing the film forming steps of applying the sol, drying, degreasing, and firing a plurality of times. Thereby, the barrier layer 32 in which the amount (x) of M gradually increases toward the lower electrode 42 side is obtained.

In the sputtering method, while introducing an inert gas into a vacuum, a voltage is applied between the substrate and the target to cause the ionized inert gas to collide with the target to form the repelled target material on the substrate. Is the way to do it. As a method of forming the barrier layer 32 using the sputtering method, Zr and the element M (for example, Y, Ca)
There are a reactive sputtering method in which a small amount of oxygen gas is introduced together with an inert gas as a target, and an RF sputtering method in which ZrO ₂ and the element M are targeted. In the process of performing reactive sputtering or RF sputtering, the target power of the element M is changed so as to increase gradually or stepwise. Alternatively,
The target power of Zr or ZrO ₂ may be adjusted to change the target power of the element M such that it gradually or gradually increases. Thereby, the barrier layer 32 in which the amount (x) of M increases continuously or stepwise toward the lower electrode 42 side is obtained.

Ion implantation is
It is one of the methods to add an element to a metal material.
Ionize and accelerate with voltage and use its kinetic energy
Is the way to do it. The barrier layer 32 is formed by using the ion implantation method.
When forming, first use the sol-gel method or the sputtering method.
Ri ZrO_TwoA film is formed, and then ion implantation is performed.
Ion implantation is performed by ionizing M with an ion source to produce M ions.
(For example, Y³⁺, Ca ²⁺) And add charged particles
ZrO is given energy by using a speedometer._TwoThe membrane surface
Let's puttering. As a result, M ion becomes Z
rO_TwoThe surface of the film is scraped off, and Z
rO_TwoEnergy that penetrates into the film and collides with atoms inside
Lost and still dope. Driving a charged particle accelerator
By controlling the thickness direction toward the lower electrode 42 side
Barrier in which the amount of M (x) increases continuously or stepwise
A layer 32 is obtained.

[Lower Electrode Film Forming Step] Next, referring to FIG.
As shown in (C), the lower electrode 42 is formed on the diaphragm. The lower electrode 42 is formed by using an electron beam evaporation method, a sputtering method, or the like. For example, a platinum layer having a film thickness of about 200 nm is formed, or after a platinum layer having a film thickness of about 100 nm is formed, an iridium layer having a film thickness of about 10 to 50 nm is formed thereon.

[Seed Ti Film Forming Step] Next, referring to FIG.
As shown in (D), DC magnetron sputtering method, R
The lower electrode 42 is formed by using a film forming method such as F sputtering.
A seed Ti film 45 is formed thereon. The thickness of the seed Ti film 45 is preferably in the range of 3 nm to 10 nm. The seed Ti film may have an island shape in addition to being formed with a uniform thickness.

[Piezoelectric Thin Film Forming Step] Next, referring to FIG.
As shown in (E), the sol-gel method and the MOD method (Metal Or
The piezoelectric thin film 43 is formed on the seed Ti film 45 by using the Ganic Decomposition method or the like. When the sol-gel method is used, since the PZT crystal grows in order from the seed Ti film 45 side provided on the lower electrode 42 toward the upper side, a PZT film having excellent orientation can be formed.

When the piezoelectric thin film 43 is formed by using the sol-gel method, first, an alkoxide or acetate compound such as methoxide, ethoxide, propoxide or butoxide of a metal such as titanium, zirconium, lead or zinc is hydrolyzed with an acid or the like. Disassemble to prepare sol. Next, the adjusted sol is applied on the seed Ti film 45. After applying the sol, it is dried at a constant temperature for a certain period of time to evaporate the solvent of the sol. The drying temperature is preferably 150 ° C. or higher and 200 ° C. or lower, and the drying time is preferably 5 minutes or longer and 15 minutes or shorter. After drying, degreasing is further performed for a certain period of time at a certain degreasing temperature in the air atmosphere. The degreasing temperature is preferably 300 ° C or higher and 500 ° C or lower. The degreasing time is preferably 5 minutes or more and 30 minutes or less. The degreasing dissociates the organic matter coordinated with the metal from the metal, causes an oxidative combustion reaction, and scatters into the atmosphere. Next, this is baked and crystallized to form the piezoelectric thin film 43. The firing temperature is preferably 550 ° C. or higher and 750 ° C. or lower. The firing time is preferably 5 minutes or more and 60 minutes or less. [Upper Electrode Film Forming Step] An upper electrode 44 is formed on the piezoelectric thin film 43 formed as described above, as shown in FIG. For example, iridium is formed into a film having a thickness of 20 to 100 nm by a DC sputtering method, an RF sputtering method, or the like.

[Etching Step] Next, as shown in FIG. 5A, a resist is spin-coated on the upper electrode 44, and is exposed / developed and patterned according to the position where the pressure chamber is to be formed. Using the remaining resist as a mask, the upper electrode 44, the piezoelectric thin film 43, the seed Ti film 45 and the lower electrode 42 are etched by ion milling or dry etching.

[Pressure Chamber Forming Step] Subsequently, as shown in FIG. 5B, an etching mask is provided in accordance with the position where the pressure chamber is to be formed, and active gas such as parallel plate type reactive ion etching is applied. By the dry etching used,
The pressure chamber substrate 20 is etched to a predetermined depth to form the pressure chamber 21. The portion left without being dry-etched becomes the sidewall 22.

[Nozzle Plate Bonding Step] Finally, referring to FIG.
As shown in (C), the nozzle plate 10 is attached to the pressure chamber substrate 20 using an adhesive. In this case, each nozzle 1
1 is arranged so as to correspond to each space of the pressure chambers 21. The pressure chamber substrate 20 to which the nozzle plate 10 is attached is attached to a casing (not shown) to complete the ink jet recording head.

[0064]

According to the present invention, the distribution of the stress applied to the inside of the barrier layer is appropriately controlled by giving the barrier layer a predetermined gradient composition, and cracks are generated in the barrier layer and the entire diaphragm. It is possible to obtain a highly reliable piezoelectric thin film element that prevents this, and an inkjet recording head and an inkjet printer using the same.

Further, since the distribution of the stress applied to the inside of the barrier layer can be appropriately controlled to improve the toughness of the barrier layer and the adhesion between the barrier layer and the lower electrode, it is possible to further improve the vibration plate. Can be thinned.

[Brief description of drawings]

FIG. 1 is a perspective view of an inkjet printer.

FIG. 2 is an exploded perspective view of an inkjet recording head.

FIG. 3 is a sectional view of a piezoelectric thin film element.

FIG. 4 is a cross-sectional view of a manufacturing process of a piezoelectric thin film element.

FIG. 5 is a cross-sectional view of a manufacturing process of a piezoelectric thin film element.

[Explanation of symbols]

10 ... Nozzle plate, 11 ... Nozzle hole, 20 ... Pressure chamber substrate,
30 ... Vibration plate, 31 ... SiO ₂ film, 32 ... Barrier layer, 4
2 ... Lower electrode, 43 ... Piezoelectric thin film, 44 ... Upper electrode, 4
5 ... Seed Ti film, 100 ... Piezoelectric thin film element, 1 ... Ink jet recording head, 2 ... Main body, 3 ... Tray, 4 ... Ejection port, 5 ... Paper, 6 ... Paper feeding mechanism, 8 ... Control circuit, 600 ...
Motor, 601 ... Roller, 602 ... Roller, 9 ... Operation button

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01L 41/09 H01L 41/18 101C 41/187 101D 41/22 41/22 B41J 3/04 103A

Claims (11)

[Claims] 1. A substrate and Zr _1-x provided on the substrate
M _x O _y (0.01 ≦ x ≦ 0.15, y = 2.0 ±
α and α are stoichiometrically acceptable values, M is IIA in the periodic table
Group element, IIIA group element, or IIIB group element) a barrier layer composed of a composition represented by, a lower electrode provided on the barrier layer, a piezoelectric thin film provided on the lower electrode,
A piezoelectric thin film element comprising: an upper electrode provided on the piezoelectric thin film, wherein the barrier layer has a thickness x toward a lower electrode side.
Is a piezoelectric thin film element characterized by having a gradient composition which is continuously or stepwise increased. 2. The M is Y (yttrium) or Ca.
The piezoelectric thin film element according to claim 1, which is (calcium). 3. The piezoelectric thin film element according to claim 1, wherein the barrier layer is formed on a SiO ₂ film. 4. The piezoelectric thin film element according to claim 1, wherein the film thickness of the barrier layer is 0.1 μm or more and 1.0 μm or less. 5. The piezoelectric film according to claim 1, wherein the piezoelectric thin film is a solid solution of lead titanate and lead zirconate or a solid solution of lead titanate, lead zirconate and lead niobate magnesiumate. Body thin film element. 6. An inkjet recording head comprising the piezoelectric thin film element according to claim 1 as a piezoelectric actuator for ejecting ink. 7. An ink jet printer comprising the ink jet recording head according to claim 6 as printing means. 8. SiO on the substrate_TwoAfter forming the film, the S
iO_TwoZr on the membrane _1-xM_xO_y(0.01 ≦ x ≦
0.15, y = 2.0 ± α, α is stoichiometrically acceptable
Value, M is IIA group element, IIIA group element, or IIIB of the periodic table
After applying a sol containing a composition represented by a group element)
The barrier layer is formed by performing the film-forming step of firing to multiple times,
Then, the lower electrode, the piezoelectric thin film, and the upper electrode are sequentially formed.
A method of manufacturing a piezoelectric thin film element, comprising: In the step of forming the barrier layer, the layer formation on the lower electrode side is performed.
The sol used in the film process is SiO_TwoDeposition of layer on film side
A pressure characterized in that x is larger than the sol used in the process.
Manufacturing method of electric thin film element. 9. After forming a SiO ₂ film on a substrate, the S
Zr (zirconium) or ZrO on the iO ₂ film
₂ (zirconium oxide) and M (M is a group IIA element, a group IIIA element, or a group IIIB element of the periodic table) are simultaneously sputtered to form a barrier layer,
A method of manufacturing a piezoelectric thin film element by sequentially forming a lower electrode, a piezoelectric thin film, and an upper electrode, wherein the target power of M is Zr or ZrO ₂ with respect to the target power in the step of forming the barrier layer. And a target power of M are changed so as to be absolutely larger. A method of manufacturing a piezoelectric thin film element, comprising: 10. An SiO ₂ film is formed on a substrate, a layer made of ZrO ₂ (zirconium oxide) is formed on the SiO ₂ film, and then M ions (M is a group IIA of the periodic table) are formed by an ion implantation method. Element, IIIA group element, or IIIB group element) is implanted to form a barrier layer, and then a lower electrode,
A method of manufacturing a piezoelectric thin film element by sequentially forming a piezoelectric thin film and an upper electrode, wherein M ions are continuously or stepped toward a lower electrode side in a thickness direction of the barrier layer by the barrier layer forming step. A method for manufacturing a piezoelectric thin film element, which comprises forming a gradient composition that is increased substantially. 11. The M is Y (yttrium) or C
The method for manufacturing a piezoelectric thin film element according to claim 8, wherein the piezoelectric thin film element is a (calcium).