JP2006286925A - Method for manufacturing multilayer film, method for manufacturing actuator, actuator, liquid jet head, and liquid jet device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a multilayer film which method enables the free growth of a separate film on a film showing strong crystal orientation without allowing an epitaxial relation between the films, a method for manufacturing an actuator, the actuator, a liquid jet head, and a liquid jet device. <P>SOLUTION: A growth layer 70 is formed on a substrate layer 60 having crystal orientation, the growth layer 70 being made of a material that is different from that of the substrate layer 60 and is capable of epitaxial growth, to manufacture the multilayer film. In the manufacturing process, the material of the growth layer 70 is determined to be such a material that has the same crystal surface in a plane and the same atomic sequence in the crystal surface as the material of the substrate layer 60. When a difference in inter-atomic distance in a plane between both materials is 5% or smaller, a difference in inter-atomic distance between both materials at the interface between both layers 60, 70 is determined to be 5% or smaller upon film formation. When the difference in inter-atomic distance is 5% or larger, a buffer layer 65 is formed directly on the substrate layer 60 in a continuous process, and the material of the growth layer 70 is allowed to grow freely on the buffer layer 65 to form the oriented growth layer 70. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a laminated film manufacturing method, an actuator device manufacturing method, an actuator device, a liquid jet head, and a liquid jet device.

  The piezoelectric element is an element in which a piezoelectric film made of a piezoelectric material exhibiting an electromechanical conversion function is sandwiched between two electrodes, and the piezoelectric film is made of, for example, crystallized piezoelectric ceramics.

  In addition, as a liquid ejecting head using such a piezoelectric element, for example, a part of a pressure generation chamber communicating with a nozzle opening for ejecting ink droplets is configured by a diaphragm, and the diaphragm is deformed by the piezoelectric element. There is an ink jet recording head that pressurizes ink in a pressure generating chamber and ejects ink droplets from nozzle openings. Two types of ink jet recording heads have been put into practical use: those using a longitudinal vibration mode piezoelectric actuator that extends and contracts in the axial direction of the piezoelectric element, and those using a flexural vibration mode piezoelectric actuator. As an actuator using a flexural vibration mode actuator, for example, a uniform piezoelectric film is formed by a film forming technique over the entire surface of the diaphragm, and this piezoelectric layer is applied to the pressure generation chamber by a lithography method. A device in which a piezoelectric element is formed so as to be independent for each pressure generating chamber by dividing into shapes is known.

  As the piezoelectric layer (piezoelectric thin film), for example, a ferroelectric such as lead zirconate titanate (PZT) is used. Such a piezoelectric thin film is formed, for example, by forming a titanium crystal on the lower electrode by sputtering or the like, and forming a piezoelectric precursor film on the titanium crystal by a sol-gel method. It is formed by baking (for example, refer patent document 1).

  As a result, the piezoelectric layer grows freely without being affected by the lower electrode due to the underlying titanium, and the crystal plane orientation is mostly (100) oriented, so that the piezoelectric characteristics can be improved.

  However, in order to form titanium on the lower electrode and form the piezoelectric layer with (100) orientation, strict process control is required, so that the manufacturing process becomes complicated and the manufacturing efficiency is poor. is there.

  Such a problem does not occur only in an actuator device mounted on a liquid ejecting head such as an ink jet recording head, and similarly occurs in an actuator device mounted on another device.

JP 2001-274472 A (page 5)

  In view of such circumstances, the present invention provides a method of manufacturing a laminated film, a method of manufacturing an actuator device, and an actuator device capable of allowing other films to grow freely without breaking an epitaxial relationship into a film having a strong crystal orientation. An object is to provide a liquid ejecting head and a liquid ejecting apparatus.

The first aspect of the present invention that solves the above problems is to produce a laminated film by forming a growth layer made of a material different from the material of the underlayer and capable of epitaxial growth on the underlayer having crystal orientation. In this case, if the material constituting the underlayer and the crystal plane in the plane and the material in which the atomic arrangement in the crystal plane is the same are used, and the difference in the interatomic distance in the plane between the two materials is 5% or less, the film is formed. When the difference in the interatomic distance between the two at the interface is 5% or more, or when the difference in the interatomic distance between the two materials is 5% or more, the buffer layer is formed on the base layer as it is. A method for producing a laminated film is characterized in that a film is formed in a state where the orientation is not fixed, and an oriented growth layer is formed by freely growing the material of the growth layer on the buffer layer.
In such a first aspect, a material having the same crystal plane in the plane as the material constituting the underlayer and a material having the same atomic arrangement in the crystal plane is used on the base layer having a strong crystal orientation. When the difference in interatomic distance is 5% or less, when the difference in interatomic distance between the two at the interface during film formation is 5% or more, or when the difference in interatomic distance between both materials is 5% or more Since the buffer layer is formed in a continuous process as it is, the buffer layer is formed in a state in which the orientation is not fixed. As a result, the growth film formed on this buffer layer has an epitaxial relationship with the underlying layer. Therefore, the film grows freely, so that the film has a crystal plane oriented without requiring strict process control.

According to a second aspect of the present invention, in the first aspect, when the difference in interatomic distance between the planes of the two materials is 5% or less, a tensile or compressive stress is present inside the underlayer. The difference in the distance between the atoms at the interface during film formation is 5% or more.
In the second aspect, when the buffer layer is formed, a tensile or compressive stress is present inside the underlayer so that the difference in distance between the atoms at the interface during film formation is 5% or more. Thus, the buffer layer is formed in a state where the orientation is not determined.

According to a third aspect of the present invention, in the first or second aspect, the underlayer and the buffer layer are formed by a sputtering method, and both are continuously stacked without being released from vacuum. A layered film manufacturing method is characterized in that the layer is formed in a state where the orientation is not determined.
In the third aspect, the base layer and the buffer layer are formed by sputtering, and both are continuously laminated without being released from the vacuum. The film is formed in a continuous process without contacting any other gas, and as a result, the buffer layer is formed in a state where the orientation is not determined.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the foundation layer is made of platinum (Pt) or iridium (Ir) having a crystal plane orientation of (111), and the buffer layer is The method of manufacturing a laminated film is characterized in that it is made of a hexagonal material, and the growth layer is a ferroelectric material having a (100) crystal plane orientation.
In the fourth aspect, a buffer layer made of a hexagonal material is formed on an underlayer made of platinum (Pt) or iridium (Ir) with a crystal plane orientation of (111) orientation in a state where the orientation is not fixed. A growth layer made of a ferroelectric material such as lead zirconate titanate (PZT) having a (100) crystal plane orientation is freely grown thereon.

According to a fifth aspect of the present invention, in the fourth aspect, the hexagonal material is one selected from the group consisting of titanium (Ti), tellurium (Te), and iridosmine (an alloy of Os and Ir). It is in the manufacturing method of the laminated film characterized by being.
In the fifth aspect, titanium (Ti), tellurium (Te), and iridosmin (Os and Ir) are formed on a base layer made of platinum (Pt) or iridium (Ir) with a crystal plane orientation of (111). A ferroelectric layer such as lead zirconate titanate (PZT) having a crystal plane orientation of (100) orientation is formed on an underlayer made of one kind selected from the group consisting of (alloys). A growth layer made of a material grows freely.

According to a sixth aspect of the present invention, in any one of the first to third aspects, the underlayer is zirconium oxide (ZrO ₂ ) having a crystal plane orientation of (111) or yttrium having a crystal plane orientation of (100). (Y) or FSZ added with calcium (Ca), the buffer layer is made of magnesium oxide (MgO), and the growth layer is platinum (Pt) or iridium (Ir) with a crystal plane orientation of (111). It is in the manufacturing method of the laminated film characterized by being.
In the sixth aspect, zirconium oxide (ZrO ₂ ) having a crystal plane orientation of (111), or FSZ added with yttrium (Y) or calcium (Ca) having a crystal plane orientation of (100) is formed on the base layer. A buffer layer made of magnesium oxide (MgO) is formed in a state where the orientation is not fixed, and a growth layer made of platinum (Pt) or iridium (Ir) having a crystal plane orientation of (111) is freely grown thereon.

According to a seventh aspect of the present invention, there is provided a diaphragm provided on one surface side of a substrate and a bottom provided on the diaphragm using the method for manufacturing a laminated film according to any one of the first to third aspects. An actuator device comprising a piezoelectric element comprising an electrode, a piezoelectric layer, and an upper electrode is manufactured.
In the seventh aspect, a growth layer is formed on a base layer having a strong crystal orientation through a predetermined buffer layer, so that the growth layer is free-grown without an epitaxial relationship with the base layer.

According to an eighth aspect of the present invention, in the seventh aspect, the method for producing the laminated film includes a hexagonal crystal formed on a lower electrode made of platinum (Pt) or iridium (Ir) having a (100) crystal plane orientation. Ferroelectric material whose crystal plane orientation is (100) oriented through a buffer layer made of one kind selected from the group consisting of titanium-based titanium (Ti), tellurium (Te), and iridosmine (an alloy of Os and Ir) The method of manufacturing an actuator device is characterized by being applied to a step of forming a piezoelectric layer comprising:
In the eighth aspect, hexagonal titanium (Ti), tellurium (Te), and iridosmine (Os) are formed on a lower electrode made of platinum (Pt) or iridium (Ir) having a crystal plane orientation of (100). And a piezoelectric layer made of a ferroelectric material such as lead zirconate titanate (PZT) having a crystal plane orientation of (100) orientation through a buffer layer selected from the group consisting of an alloy of Since the film is formed, the piezoelectric layer is formed without the epitaxial relationship with the lower electrode by the buffer layer, grows freely, and is formed with the crystal plane oriented.

According to a ninth aspect of the present invention, in the seventh or eighth aspect, the method for producing the laminated film is performed by using zirconium oxide (ZrO ₂ ) having a crystal plane orientation of (111) or yttrium having a crystal plane orientation of (100). From a platinum (Pt) or iridium (Ir) crystal plane orientation (111) on a diaphragm made of FSZ to which (Y) or calcium (Ca) is added via a buffer layer made of magnesium oxide (MgO) The actuator device manufacturing method is characterized by being applied to a step of forming a lower electrode.
In the ninth aspect, on a diaphragm made of zirconium oxide (ZrO ₂ ) having a crystal plane orientation of (111) or FSZ added with yttrium (Y) or calcium (Ca) having a crystal plane orientation of (100). Since the lower electrode made of platinum (Pt) or iridium (Ir) having a crystal plane orientation of (111) is formed through the buffer layer made of magnesium oxide (MgO), the lower electrode is vibrated by the buffer layer. The film is formed by breaking the epitaxial relationship with the plate, grows freely, and is formed with the crystal plane oriented.

According to a tenth aspect of the present invention, there is provided an actuator device comprising: a diaphragm provided on one surface side of a substrate; and a piezoelectric element comprising a lower electrode, a piezoelectric layer, and an upper electrode provided on the diaphragm. The lower electrode is made of platinum (Pt) or iridium (Ir) having a crystal plane orientation of (100), and the piezoelectric layer is made of a ferroelectric material having a crystal plane orientation of (100). The piezoelectric layer is a film made of one kind selected from the group consisting of hexagonal titanium (Ti), tellurium (Te), and iridosmin (an alloy of Os and Ir) formed on the lower electrode. The actuator device is characterized in that the film is freely grown and formed through the film.
In the tenth aspect, hexagonal titanium (Ti), tellurium (Te), and iridosmine (Os) are formed on a lower electrode made of platinum (Pt) or iridium (Ir) with a crystal plane orientation of (100). Ferroelectric material such as lead zirconate titanate (PZT) having a crystal plane orientation of (100) is formed through a film made of one kind selected from the group consisting of (Al and Ir alloys). The piezoelectric layer grows freely and becomes an actuator device with excellent piezoelectric characteristics.

According to an eleventh aspect of the present invention, in the tenth aspect, zirconium oxide (ZrO ₂ ) having a crystal plane orientation of (111) acting as the diaphragm, yttrium (Y) having a crystal plane orientation of (100), or An actuator device having a film made of FSZ added with calcium (Ca), and the lower electrode is formed through a magnesium oxide (MgO) film formed on the film. .
In the eleventh aspect, zirconium oxide (ZrO ₂ ) having a crystal plane orientation of (111) acting as a diaphragm, or FSZ added with yttrium (Y) or calcium (Ca) having a crystal plane orientation of (100) is used. Since the lower electrode is formed on the resulting film via the magnesium oxide (MgO) film, the lower electrode is a film in which the crystal planes grown freely are oriented.

According to a twelfth aspect of the present invention, the actuator device according to the tenth or eleventh aspect is provided in a region facing the pressure generation chamber formed on the substrate, and the liquid in the pressure generation chamber is discharged from the nozzle opening. The liquid ejecting head is configured as pressure generating means for generating pressure.
In the twelfth aspect, the liquid ejecting head includes an actuator device having excellent piezoelectric characteristics as pressure generating means.

A thirteenth aspect of the present invention is a liquid ejecting apparatus including the liquid ejecting head according to the twelfth aspect.
In the thirteenth aspect, the liquid ejecting apparatus includes the liquid ejecting head including the actuator device having excellent piezoelectric characteristics as the pressure generating unit.

  Hereinafter, the present invention will be described in detail based on embodiments. In the following embodiments, an ink jet recording head as an example of a liquid ejecting head is given as a specific example of the actuator device of the present invention, and a method for manufacturing a laminated film and a method of manufacturing an actuator device of the present invention are also described.

(Embodiment 1)
FIG. 1 is an exploded perspective view showing an ink jet recording head according to Embodiment 1 of the present invention, and FIG. 2 is a plan view and a cross-sectional view of FIG. As shown in the drawing, the flow path forming substrate 10 is made of a silicon single crystal substrate having a plane orientation (110) in this embodiment, and one surface thereof is made of silicon dioxide previously formed by thermal oxidation. An elastic film 50 of 5 to 2 μm is formed. A plurality of pressure generating chambers 12 are arranged in parallel in the width direction of the flow path forming substrate 10. In addition, a communication portion 13 is formed in a region outside the longitudinal direction of the pressure generation chamber 12 of the flow path forming substrate 10, and the communication portion 13 and each pressure generation chamber 12 are provided for each pressure generation chamber 12. Communication is made via a supply path 14. The communication part 13 constitutes a part of a reservoir that communicates with a reservoir part of a protective substrate, which will be described later, and serves as a common ink chamber for the pressure generating chambers 12. The ink supply path 14 is formed with a narrower width than the pressure generation chamber 12, and maintains a constant flow path resistance of ink flowing into the pressure generation chamber 12 from the communication portion 13.

Further, a nozzle plate 20 having a nozzle opening 21 communicating with the vicinity of the end portion of each pressure generating chamber 12 on the side opposite to the ink supply path 14 on the opening surface side of the flow path forming substrate 10 will be described later. It is fixed by an adhesive, a heat welding film or the like through a mask film. The nozzle plate 20 has a thickness of, for example, 0.01 to 1 mm, a linear expansion coefficient of 300 ° C. or less, for example, 2.5 to 4.5 [× 10 ⁻⁶ / ° C.], glass ceramics, silicon It consists of a single crystal substrate or non-rust steel.

On the other hand, as described above, the elastic film 50 made of silicon dioxide (SiO ₂ ) having a thickness of, for example, about 1.0 μm is formed on the side opposite to the opening surface of the flow path forming substrate 10. . On the elastic film 50, a lower electrode film 60 having a thickness of, for example, about 0.1 to 0.2 μm, a piezoelectric layer 70 having a thickness of, for example, about 1.0 μm, and a thickness of, for example, The upper electrode film 80 of about 0.05 μm is laminated and formed by a process described later to constitute the piezoelectric element 300. Here, the piezoelectric element 300 refers to a portion including the lower electrode film 60, the piezoelectric layer 70, and the upper electrode film 80. In general, one electrode of the piezoelectric element 300 is used as a common electrode, and the other electrode and the piezoelectric layer 70 are patterned for each pressure generating chamber 12. In addition, here, a portion that is configured by any one of the patterned electrodes and the piezoelectric layer 70 and in which piezoelectric distortion is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion. In this embodiment, the lower electrode film 60 is a common electrode of the piezoelectric element 300, and the upper electrode film 80 is an individual electrode of the piezoelectric element 300. However, there is no problem even if this is reversed for the convenience of the drive circuit and wiring. In either case, a piezoelectric active part is formed for each pressure generating chamber. Further, here, the piezoelectric element 300 and the vibration plate that is displaced by driving the piezoelectric element 300 are collectively referred to as a piezoelectric actuator. In this embodiment, the elastic film and the lower electrode film act as a diaphragm, but of course, only the elastic film may act as a diaphragm.

  The upper electrode film 80 of each piezoelectric element 300 is connected to a lead electrode 90 made of, for example, gold (Au) or the like, and a voltage is selectively applied to each piezoelectric element 300 via the lead electrode 90. Is applied.

  Further, a protective substrate 30 having a piezoelectric element holding portion 31 is bonded to a surface facing the piezoelectric element 300 on the surface of the flow path forming substrate 10 on the piezoelectric element 300 side. Since the piezoelectric element 300 is formed in the piezoelectric element holding part 31, it is protected in a state hardly affected by the external environment. Further, the protective substrate 30 is provided with a reservoir portion 32 in a region corresponding to the communication portion 13 of the flow path forming substrate 10. In this embodiment, the reservoir portion 32 is provided along the direction in which the pressure generating chambers 12 are arranged so as to penetrate the protective substrate 30 in the thickness direction, and as described above, the communication portion of the flow path forming substrate 10. The reservoir 100 is connected to the pressure generation chamber 12 and serves as a common ink chamber for the pressure generation chambers 12.

  In addition, a through hole 33 that penetrates the protective substrate 30 in the thickness direction is provided in a region between the piezoelectric element holding portion 31 and the reservoir portion 32 of the protective substrate 30, and the lower electrode film 60 is provided in the through hole 33. A part of the lead electrode 90 and the leading end of the lead electrode 90 are exposed, and one end of a connection wiring extending from the drive IC is connected to the lower electrode film 60 and the lead electrode 90, although not shown.

  In addition, examples of the material of the protective substrate 30 include glass, ceramic material, metal, resin, and the like, but it is more preferable that the material is substantially the same as the coefficient of thermal expansion of the flow path forming substrate 10. In this embodiment, the silicon single crystal substrate made of the same material as the flow path forming substrate 10 is used.

  A compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded onto the protective substrate 30. The sealing film 41 is made of a material having low rigidity and flexibility (for example, a polyphenylene sulfide (PPS) film having a thickness of 6 μm). Yes. The fixing plate 42 is made of a hard material such as metal (for example, stainless steel (SUS) having a thickness of 30 μm). Since the region of the fixing plate 42 facing the reservoir 100 is an opening 43 that is completely removed in the thickness direction, one surface of the reservoir 100 is sealed only with a flexible sealing film 41. Has been.

  In such an ink jet recording head of this embodiment, ink is taken in from an external ink supply means (not shown), filled with ink from the reservoir 100 to the nozzle opening 21, and then in accordance with a recording signal from a drive IC (not shown). By applying a voltage between each of the lower electrode film 60 and the upper electrode film 80 corresponding to the pressure generating chamber 12 to cause the elastic film 50, the lower electrode film 60, and the piezoelectric layer 70 to bend and deform, The pressure in the generation chamber 12 increases and ink droplets are ejected from the nozzle openings 21.

  Here, a method of manufacturing such an ink jet recording head will be described with reference to FIGS. 3 to 6 are cross-sectional views of the pressure generating chamber 12 in the longitudinal direction. First, as shown in FIG. 3A, a channel forming substrate wafer 110 which is a silicon wafer is thermally oxidized in a diffusion furnace at about 1100 ° C., and a silicon dioxide film 51 constituting an elastic film 50 is formed on the surface thereof. To do. In the present embodiment, a silicon wafer having a relatively thick film thickness of about 625 μm and a high rigidity is used as the flow path forming substrate 10.

  Next, as shown in FIG. 3B, a lower electrode film 60 made of, for example, platinum or iridium is formed on the entire surface of the elastic film 50 by, for example, a sputtering method.

  Next, as shown in FIG. 3C, titanium (Ti) is formed on the lower electrode film 60 by, for example, a sputtering method to form a predetermined seed titanium layer 65. Here, the seed titanium layer 65 is formed in a continuous process from the formation of the lower electrode film 60. This continuous process means that the temperature of the substrate is not lowered and no gas other than the gas at the time of film formation comes into contact between the two film formation processes. As described above, when the film is formed by the continuous process, the seed titanium layer 65 is strongly influenced by the orientation of the underlying lower electrode film 60 as compared with the case where the film is not continuously formed.

  Here, since the lower electrode film 60 is formed on the elastic film 50 made of amorphous silicon oxide, the (111) orientation is obtained by free growth. Further, Pt or Ir constituting the lower electrode film 60 is both a face-centered cubic system, while Ti of the seed titanium layer 65 is a hexagonal system, and the crystal plane of both and the atomic arrangement in the crystal plane are Although Pt is the same, Pt has a lattice constant of 3.92Å and an interatomic distance of 2.77Å, and Ir has a lattice constant of 3.83Å and an interatomic distance of 2.71Å. On the other hand, Ti has a lattice constant of 2.92 Å and an interatomic distance of 2.92 、, and the difference in the interatomic distance between them is 7.7% and 5.4%, which is 5% or more, respectively. There is a difference. Therefore, the two are not in an epitaxial relationship, and the seed titanium layer 65 originally grows freely. However, by forming the seed titanium layer 65 by a continuous process, the seed titanium layer 65 is strongly influenced by the orientation of the lower electrode film 60 as the underlayer. The film is formed in such a state that is not determined. That is, the seed titanium layer 65 does not have the original (002) orientation but is in a non-oriented state in which the orientation is not fixed, and a buffer that blocks the influence of the orientation of the lower electrode film 60 when the piezoelectric layer 70 described later is formed. Will act as a layer. Further, by forming a film in a continuous process in this way, a thick film having no orientation can be formed as compared with a case in which a film is not formed by a continuous process. The layer 70 can be freely grown relatively easily without strictly controlling the film forming conditions such as the drying and firing conditions. However, if the seed titanium layer 65 is too thick, the original (002) orientation appears, and the piezoelectric layer formed thereon tends to become the (111) orientation, which is not preferable. Therefore, the thickness of the seed titanium layer 65 is about 1 nm to 5 nm, preferably 2 to 5 nm.

  Note that, as described above, in order to form a film in a state where the orientation is not fixed when the film is formed by a continuous process, the crystal plane and the atomic arrangement in the crystal plane are the same, and the difference in the interatomic distance in the crystal plane is 5 In the case of% or more, free growth occurs even if the difference in interatomic distance is too large. Therefore, the difference in interatomic distance is in the range of 5 to 13%, preferably in the range of 5 to 8%.

  Further, when the difference in the interatomic distance between the crystal planes is less than 5%, the buffer layer is formed in such a state that the difference in the interatomic distance between the two materials becomes 5% or more when the buffer layer is formed. do it. As a result, as in the case where the difference in interatomic distance is 5% or more, the buffer layer is formed in a state where the orientation is not fixed, and the piezoelectric layer formed on the buffer layer grows freely (100 ) Oriented.

  In the present invention, the state where orientation is not determined or non-oriented does not mean amorphous, but is crystalline but means a non-oriented state where orientation is not determined. That is, in the above-described example, when the seed titanium layer 65 that is a buffer layer becomes amorphous, the above-described film is not transmitted to the piezoelectric layer 70 to transmit the binding force of the orientation of the lower electrode film 60 that is the base layer. A film thickness greater than the thickness is required, and if the film thickness is small, there is a problem that a different phase is formed after crystallization. Also, if the buffer layer is made of a material having the same crystal system and free growth direction as that of the piezoelectric layer as the growth layer, the orientation of the growth layer becomes random as compared with the case where the buffer layer as described above is used. There is a problem that it is easy. That is, the technique of forming a buffer layer whose orientation is not determined by the continuous process of the present invention eliminates these drawbacks.

  In addition, when the difference in the interatomic distance between the two materials is 5% or more when the buffer layer is formed, for example, a tensile or compressive stress is present inside the underlayer when the buffer layer is formed. It is to be. Here, in order to cause a tensile or compressive stress to exist inside the underlayer in this way, it can be generated by a difference in thermal expansion coefficient between the substrate and the underlayer, etc. If it cannot be generated, for example, another film may be formed on the back side of the substrate to generate stress. Needless to say, this film may be removed later.

  Thus, although the difference of interatomic distance is less than 5%, the example of the combination of the material which can be used instead of Ti of embodiment mentioned above is shown in the following Table 1. As the underlayer, Pt or Ir of the above-described embodiment is exemplified, and Te and iridosmin (OsIr) are cited as metals other than Ti that can be combined with this. Table 1 lists the crystal system, lattice constant, and interatomic distance in the crystal plane of each material, and calculates the difference in interatomic distance. In Table 1, when the interatomic distance of the underlayer is smaller (difference in interatomic distance is indicated by +), it is only necessary that compressive stress is present in the underlayer when the buffer layer is formed. In addition, when the interatomic distance of the underlayer is larger (the difference in interatomic distance is indicated by-), it is sufficient that there is a tensile stress. May be 5% or more.

  In the case of the above-described embodiment, the difference in interatomic distance between Ir of the base layer and Ti of the buffer layer is 7.6%. However, when the buffer layer is formed, the Ir layer and the silicon that is the substrate are different from each other. It is considered that a compressive stress is generated in the Ir layer due to the difference in the thermal expansion coefficient, and the difference in the interatomic distance is further increased.

  The lower electrode film 60 and the seed titanium layer 65 thus formed are patterned into a predetermined shape as shown in FIG.

  Here, the surface of the seed titanium layer 65 formed in this way is naturally oxidized to a certain depth with time, and an oxide layer (not shown) is formed on the surface of the seed titanium layer 65. If such an oxide layer is formed relatively thick on the surface layer of the seed titanium layer 65, it is not preferable because crystal growth of the piezoelectric layer 70 formed in the process described later may be hindered. For this reason, when forming the piezoelectric layer, the thickness (oxidation depth) of the surface oxide layer of the seed titanium layer 65 is preferably as thin as possible, and is preferably at least less than 2.0 nm.

The seed titanium layer 65 thus formed preferably has a film density (Ti density) as high as possible, and is preferably at least 4.5 g / cm ³ or more. This is because as the film density of the seed titanium layer 65 is higher, the thickness of the oxide layer is reduced, and the crystal of the piezoelectric layer 70 grows better. The film density of the seed titanium layer 65 is determined by the film formation conditions regardless of the thickness.

  Then, by forming the piezoelectric layer 70 made of, for example, lead zirconate titanate on the seed titanium layer 65 formed in this manner, the piezoelectric layer 70 has the influence of the orientation of the lower electrode film 60. The crystal grows freely and is uniformized by free growth. For example, in the present embodiment, a so-called sol-gel method is obtained in which a so-called sol in which a metal organic material is dissolved and dispersed in a catalyst is applied and dried to be gelled, and further baked at a high temperature to obtain a piezoelectric layer 70 made of a metal oxide. Was used to form the piezoelectric layer 70.

As a procedure for forming the piezoelectric layer 70, first, as shown in FIG. 4A, a piezoelectric precursor film 71 which is a PZT precursor film is formed on the seed titanium layer 65. That is, a sol (solution) containing a metal organic compound is applied onto the flow path forming substrate wafer 110. Next, the piezoelectric precursor film 71 is heated to a predetermined temperature and dried for a predetermined time, and the sol solvent is evaporated to dry the piezoelectric precursor film 71. Further, the piezoelectric precursor film 71 is degreased at a constant temperature for a predetermined time in an air atmosphere. Here, degreasing refers, the organic components of the sol film, for _example, is to be detached as _{NO 2, CO 2, H 2} O or the like.

  Then, by repeating such coating, drying, and degreasing processes a predetermined number of times, for example, twice in the present embodiment, the piezoelectric precursor film 71 has a predetermined thickness as shown in FIG. Then, the piezoelectric precursor film 71 is crystallized by heat treatment in a diffusion furnace to form the piezoelectric film 72. That is, by firing the piezoelectric precursor film 71, crystals grow with the seed titanium layer 65 as a nucleus to form the piezoelectric film 72. For example, in this embodiment, the piezoelectric precursor film 71 is baked by heating at about 700 ° C. for 30 minutes to form the piezoelectric film 72. Note that the piezoelectric film 72 formed in this way is free growing, and the crystals are preferentially oriented in the (100) plane.

  Further, by repeating the above-described coating, drying, degreasing, and firing steps a plurality of times, as shown in FIG. 4C, a predetermined thickness composed of a plurality of layers, in this embodiment, five layers of piezoelectric films 72. The piezoelectric layer 70 is formed. For example, when the film thickness per sol application is about 0.1 μm, the entire film thickness of the piezoelectric layer 70 is about 1 μm.

  As described above, in this embodiment, the seed titanium layer 65 is formed in a continuous process with the lower electrode film 60, so that the seed titanium layer 65 becomes non-oriented even when the seed titanium layer 65 is thickened. As a result, the seed titanium layer 65 is formed on this. The piezoelectric layer 70 grows freely in a wide temperature range and becomes a (100) oriented film.

As a material of the piezoelectric layer 70, for example, a relaxor ferroelectric material obtained by adding a metal such as niobium, nickel, magnesium, bismuth or yttrium to a ferroelectric piezoelectric material such as lead zirconate titanate (PZT). Etc. may be used. The composition may be appropriately selected in consideration of the characteristics and application of the piezoelectric element. For example, PbTiO ₃ (PT), PbZrO ₃ (PZ), Pb (Zr _x Ti _1-x ) O ₃ (PZT) , Pb (Mg _1/3 Nb _2/3 ) O ₃ -PbTiO ₃ (PMN-PT), Pb (Zn _1/3 Nb _2/3 ) O ₃ -PbTiO ₃ (PZN-PT), Pb (Ni _{1 / 3 Nb 2/3) O 3 -PbTiO 3} (PNN-PT), Pb (In 1/2 Nb 1/2) O 3 -PbTiO 3 (PIN-PT), Pb (Sc 1/3 Ta 2/3) O ₃ -PbTiO ₃ (PST-PT), Pb (Sc _1/3 Nb _2/3 ) O ₃ -PbTiO ₃ (PSN-PT), BiScO ₃ -PbTiO ₃ (BS-PT), BiYbO ₃ -PbTiO ₃ ( BY-PT Etc. The. The method for manufacturing the piezoelectric layer 70 is not limited to the sol-gel method, and for example, a MOD (Metal-Organic Decomposition) method or the like may be used.

(Test example)
Here, in an example in which the seed titanium layer 65 was formed with a thickness of 4.5 nm by a sputtering process of a continuous process, and a comparative example in which the seed titanium layer was not continuously formed but with a thickness of 1.5 nm. The relationship with the orientation of the piezoelectric layer 70 when the temperature treatment range of the drying process described above was changed was observed.

  Each piezoelectric layer according to these examples and comparative examples was measured by the X-ray diffraction wide angle method, and the diffraction intensity (peak intensity) (vertical axis: I_100 (cps)) corresponding to the (100) plane at that time and the drying treatment The relationship with temperature is shown in FIG.

  As shown in FIG. 7, in the case of the comparative example, the peak intensity exceeds 140 cps within a very narrow range of the processing temperature of 180 to 190 ° C., but the example has a very wide temperature of 150 to 230 ° C. A peak intensity of 140 cps or more was shown in the range. This is because the example in which the continuous process is applied is in a non-oriented state even though the seed titanium layer is as thick as 4.5 nm. In the comparative example which is not applied, the (002) orientation of Ti appeared despite the thin state of 1.5 nm, and therefore the piezoelectric layer on the Ti tends to become (111) orientation. As a result, (100 ) It is considered that the strength of the orientation is decreased over a wide range of processing temperatures.

  After the piezoelectric layer 70 is formed in this way, as shown in FIG. 5A, for example, an upper electrode film 80 made of iridium is formed on the entire surface of the flow path forming substrate wafer 110. Next, as shown in FIG. 5B, the piezoelectric layer 300 and the upper electrode film 80 are patterned in a region facing each pressure generating chamber 12 to form the piezoelectric element 300. Next, the lead electrode 90 is formed. Specifically, as shown in FIG. 5C, a metal layer 91 made of, for example, gold (Au) or the like is formed over the entire surface of the flow path forming substrate wafer 110. Thereafter, for example, the lead electrode 90 is formed by patterning the metal layer 91 for each piezoelectric element 300 through a mask pattern (not shown) made of a resist or the like.

  Next, as shown in FIG. 5D, a protective substrate wafer 130 that is a silicon wafer and serves as a plurality of protective substrates 30 is bonded to the piezoelectric element 300 side of the flow path forming substrate wafer 110. Since the protective substrate wafer 130 has a thickness of, for example, about 400 μm, the rigidity of the flow path forming substrate wafer 110 is remarkably improved by bonding the protective substrate wafer 130.

  Next, as shown in FIG. 6A, after the flow path forming substrate wafer 110 is polished to a certain thickness, the flow path forming substrate wafer 110 is further etched to a predetermined thickness by wet etching with hydrofluoric acid. To. For example, in this embodiment, the flow path forming substrate wafer 110 is etched so as to have a thickness of about 70 μm. Next, as shown in FIG. 6B, a mask film 52 made of, for example, silicon nitride (SiN) is newly formed on the flow path forming substrate wafer 110 and patterned into a predetermined shape. Then, the flow path forming substrate wafer 110 is anisotropically etched through the mask film 52, whereby, as shown in FIG. 13 and the ink supply path 14 are formed.

  After that, unnecessary portions of the outer peripheral edge portions of the flow path forming substrate wafer 110 and the protective substrate wafer 130 are removed by cutting, for example, by dicing. The nozzle plate 20 having the nozzle openings 21 formed on the surface of the flow path forming substrate wafer 110 opposite to the protective substrate wafer 130 is bonded, and the compliance substrate 40 is bonded to the protective substrate wafer 130. By dividing the flow path forming substrate wafer 110 and the like into the flow path forming substrate 10 and the like of one chip size as shown in FIG. 1, the ink jet recording head of this embodiment is obtained.

  In the embodiment described above, the lower electrode film 60 is provided on the elastic film 50 made of silicon oxide. However, a layer made of zirconium oxide may be provided on the elastic film 50, and the lower electrode film 60 may be provided thereon. .

  In this case, zirconium oxide varies depending on the sputtering conditions, and has a (111) orientation or a (100) orientation, but by sputtering under the (111) orientation conditions, the lower electrode film 60 is (111) oriented as described above. It can be oriented. Zirconium oxide may be sputtered by itself, or may be oxidized to zirconium oxide after sputtering. Note that the thickness of such zirconium oxide is, for example, about 0.4 μm.

(Embodiment 2)
The method for forming a laminated film by the continuous process described in the first embodiment can also be applied when providing the lower electrode film after providing zirconium oxide on the elastic film 50 as described above.

  Hereinafter, the manufacturing method in this case will be described. In this example as well, the ink jet recording head as an example of the liquid ejecting head is described as a specific example of the actuator device of the present invention as in the above-described embodiment, and the description overlapping with the first embodiment is omitted. .

  Also in this embodiment, after the elastic film is formed on the flow path forming substrate wafer by the above-described procedure, the insulator film that acts as a vibration plate is composed of zirconium oxide, and a buffer layer is formed thereon. A lower electrode film is formed, and a piezoelectric layer and an upper electrode are further formed thereon.

  Here, the manufacturing method of the laminated film of the present invention is applied to the production of a laminated film of zirconium oxide, a buffer layer, and a lower electrode film.

  Specifically, as shown in FIG. 8, an insulator film 55 made of zirconium oxide is formed by sputtering on the elastic film 50 formed on the flow path forming substrate 110 in a (111) orientation. At this time, in order to obtain the (111) orientation, it is necessary to appropriately set sputtering conditions, particularly temperature conditions. Next, a magnesium oxide layer 56 as a buffer layer is formed by sputtering in a continuous process. Next, the lower electrode film 60 is formed by sputtering.

  Here, zirconium oxide is monoclinic and has a lattice constant of 5.31 Å and an interatomic distance of 3.75 結晶, whereas magnesium oxide is hexagonal and has a lattice constant of 4.21 Å. The interatomic distance is 4.21 mm. Therefore, it satisfies the point that the crystal plane and the atomic arrangement in the crystal plane are the same as the conditions of the method for manufacturing the laminated film of the present invention, and the difference in interatomic distance is 5% or more. In particular, if a continuous process is performed without generating stress, the magnesium oxide layer 56 does not have the original (100) orientation, but becomes an unoriented state in which the orientation is not determined. Therefore, the lower electrode film 60 formed thereon grows freely and has a (111) orientation.

  In such an embodiment, the adhesion between the diaphragm and the lower electrode film 60 can be improved by providing the insulator film 55 made of zirconium oxide on the elastic film 50 made of silicon oxide. Compared with the case where the lower electrode film 60 is provided directly on the insulator layer 55, the orientation is random when Ir or Pt is freely grown through a buffer layer made of non-oriented magnesium oxide whose orientation is not fixed. Therefore, the lower electrode film 60 is aligned with the (111) orientation.

  Note that, when the piezoelectric layer 70 is formed on the lower electrode film 60, it is not always necessary to apply the method for manufacturing a laminated film of the present invention as in the above-described embodiment. The scope of the embodiment.

  Of course, when the piezoelectric layer 70 is formed on the lower electrode film 60, the piezoelectric layer 70 is formed on the lower electrode film 60 via the seed titanium layer 65 serving as a buffer layer, as in the above-described embodiment. When the film is formed, the same effect as in the first embodiment can be obtained, and this is also an embodiment of the present invention.

(Other embodiments)
Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment.

  Further, such a liquid ejecting head of the present invention constitutes a part of a recording head unit including an ink flow path communicating with an ink cartridge or the like, and is mounted on the liquid ejecting apparatus. FIG. 9 is a schematic diagram illustrating an example of the liquid ejecting apparatus.

  As shown in FIG. 9, in the recording head units 1A and 1B having the liquid ejecting head, cartridges 2A and 2B constituting the ink supply means are detachably provided, and the carriage 3 on which the recording head units 1A and 1B are mounted is provided. A carriage shaft 5 attached to the apparatus main body 4 is provided so as to be movable in the axial direction. The recording head units 1A and 1B, for example, are configured to eject a black ink composition and a color ink composition, respectively.

  The driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears and timing belt 7 (not shown), so that the carriage 3 on which the recording head units 1A and 1B are mounted is moved along the carriage shaft 5. The On the other hand, the apparatus body 4 is provided with a platen 8 along the carriage shaft 5, and a recording sheet S which is a recording medium such as paper fed by a paper feed roller (not shown) is conveyed onto the platen 8. It is like that.

  Here, in the above-described embodiment, the liquid ejecting head has been described as an example of the liquid ejecting head of the present invention, but the basic configuration of the liquid ejecting head is not limited to the above-described configuration. The present invention is intended for a wide range of liquid ejecting heads, for example, various recording heads used in image recording apparatuses such as printers, color material ejecting heads used in the manufacture of color filters such as liquid crystal displays, The present invention can also be applied to electrode material ejecting heads used for forming electrodes such as organic EL displays and FEDs (surface emitting displays), bioorganic matter ejecting heads used for biochip manufacturing, and the like.

  Needless to say, a liquid ejecting apparatus including such a liquid ejecting head is not particularly limited.

  Furthermore, the present invention can be applied not only to an actuator device mounted as pressure generating means on such a liquid jet head but also to an actuator device mounted on any device. For example, the actuator device can be applied to a sensor or the like in addition to the head described above.

FIG. 3 is an exploded perspective view of the recording head according to the first embodiment. 2A and 2B are a plan view and a cross-sectional view of the recording head according to the first embodiment. 5 is a cross-sectional view illustrating a manufacturing process of the recording head according to Embodiment 1. FIG. 5 is a cross-sectional view illustrating a manufacturing process of the recording head according to Embodiment 1. FIG. 5 is a cross-sectional view illustrating a manufacturing process of the recording head according to Embodiment 1. FIG. 5 is a cross-sectional view illustrating a manufacturing process of the recording head according to Embodiment 1. FIG. It is a graph which shows the relationship between the calcination temperature of a piezoelectric material layer, and the diffraction intensity (peak intensity) equivalent to a 100) surface. 6 is a cross-sectional view showing a structure of a laminated film according to Embodiment 2. FIG. 1 is a schematic perspective view of an ink jet recording apparatus according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Flow path formation board | substrate, 12 Pressure generation chamber, 20 Nozzle plate, 21 Nozzle opening, 30 Protection board | substrate, 40 Compliance board | substrate, 50 Elastic film, 60 Lower electrode film, 65 seed titanium layer, 70 Piezoelectric film, 80 Upper electrode film 300 Piezoelectric elements

Claims (13)

When manufacturing a laminated film by forming a growth layer made of a material different from the material of the base layer and capable of epitaxial growth on the base layer having crystal orientation,
When the material constituting the underlayer and the material having the same crystal plane in the plane and the atomic arrangement in the crystal plane are the same, and the difference in interatomic distance between the planes of the two materials is 5% or less, the interface at the time of film formation The orientation of the buffer layer is determined by a continuous process on the base layer as it is in a state where the difference in distance between the two atoms is 5% or more or when the difference in atomic distance between the two materials is 5% or more. A method for producing a laminated film, characterized in that a film is formed in a non-existing state, and an oriented growth layer is formed on the buffer layer by freely growing the material of the growth layer. In Claim 1, in the case where the difference in interatomic distance in the plane of the two materials is 5% or less, the tensile stress or the compressive stress is present inside the underlayer so that both of them at the interface during film formation. A method for producing a laminated film, wherein a difference in interatomic distance is 5% or more. 3. The underlayer and the buffer layer according to claim 1 or 2, wherein the underlayer and the buffer layer are formed by a sputtering method, and the buffer layer is formed in a state in which the orientation is not fixed by continuously forming both layers without releasing from the vacuum. A method for producing a laminated film, comprising: 4. The growth according to claim 1, wherein the underlayer is made of platinum (Pt) or iridium (Ir) having a crystal plane orientation of (111), and the buffer layer is made of a hexagonal crystal material. A method for producing a laminated film, wherein the layer is a ferroelectric material having a (100) crystal plane orientation. 5. The multilayer film according to claim 4, wherein the hexagonal material is a kind selected from the group consisting of titanium (Ti), tellurium (Te), and iridosmin (an alloy of Os and Ir). Production method. 4. The base layer according to claim 1, wherein zirconium oxide (ZrO ₂ ) having a crystal plane orientation of (111) or yttrium (Y) or calcium (Ca) having a crystal plane orientation of (100) is added to the underlayer. A laminated film comprising: FSZ, wherein the buffer layer is made of magnesium oxide (MgO), and the growth layer is platinum (Pt) or iridium (Ir) having a crystal plane orientation of (111). Production method. Using the laminated film manufacturing method according to any one of claims 1 to 3, the vibration plate is provided on one side of the substrate, and the lower electrode, the piezoelectric layer, and the upper electrode provided on the vibration plate. A method of manufacturing an actuator device comprising manufacturing an actuator device including a piezoelectric element. 8. The manufacturing method of the laminated film according to claim 7, wherein a hexagonal system titanium (Ti), tellurium (Te) is formed on a lower electrode made of platinum (Pt) or iridium (Ir) having a (100) crystal plane orientation. And a piezoelectric layer made of lead zirconate titanate (PZT) having a (100) crystal plane orientation through a buffer layer made of one kind selected from the group consisting of iridosmin (an alloy of Os and Ir). A method for manufacturing an actuator device, wherein the method is applied to a forming step. 9. The method for manufacturing the laminated film according to claim 7, wherein zirconium oxide (ZrO ₂ ) having a crystal plane orientation of (111) or yttrium (Y) or calcium (Ca) having a crystal plane orientation of (100) is added. Applied to a process of forming a lower electrode made of platinum (Pt) or iridium (Ir) having a crystal plane orientation of (111) on a diaphragm made of FSZ through a buffer layer made of magnesium oxide (MgO) A method for manufacturing an actuator device, comprising: In an actuator device comprising a diaphragm provided on one side of a substrate and a piezoelectric element comprising a lower electrode, a piezoelectric layer and an upper electrode provided on the diaphragm,
The lower electrode is made of platinum (Pt) or iridium (Ir) having a crystal plane orientation of (100), and the piezoelectric layer is made of a ferroelectric material having a crystal plane orientation of (100). The piezoelectric layer is formed on the lower electrode through a film made of one type selected from the group consisting of hexagonal titanium (Ti), tellurium (Te), and iridosmine (an alloy of Os and Ir). An actuator device characterized in that the film is a film that is freely grown and formed. 11. The zirconia (ZrO ₂ ) having a crystal plane orientation of (111) acting as the diaphragm, or FSZ added with yttrium (Y) or calcium (Ca) having a crystal plane orientation of (100). An actuator device having a film, wherein the lower electrode is formed through a magnesium oxide (MgO) film formed on the film. The actuator device according to claim 10 or 11 is configured as a pressure generating unit that is provided in a region facing the pressure generating chamber formed on the substrate and generates a pressure for discharging the liquid in the pressure generating chamber from the nozzle opening. A liquid jet head characterized by that. A liquid ejecting apparatus comprising the liquid ejecting head according to claim 12.

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