JP2016054286A - Piezoelectric element utilization device and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric element utilization device which enables a piezoelectric film to be easily deformed and makes peeling of an upper electrode less likely to be peeled.SOLUTION: An ink jet print head 1 includes: a pressure chamber (cavity) 5; a movable film formation layer 10 including a movable film 10A defining the pressure chamber 5; and a piezoelectric element 6 disposed on the movable film 10A. The piezoelectric element 6 includes: a lower electrode 7 formed on the movable film formation layer 10; a piezoelectric film 8 formed on the lower electrode 7; and an upper electrode 9 formed on the piezoelectric film 8. A surface of the piezoelectric element 6 is covered by a hydrogen barrier film 13. An interlayer insulator 14 is laminated on the hydrogen barrier film 13. An opening 17 is formed in an upper surface center part of the upper electrode 9 on the hydrogen barrier film 13 and the interlayer insulator 14.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a piezoelectric element utilization apparatus using a piezoelectric element and a manufacturing method thereof.

An ink jet print head is known as a piezoelectric element utilizing apparatus using a piezoelectric element. An example of such an ink jet print head is disclosed in Patent Document 1. An ink jet print head disclosed in Patent Document 1 is bonded to a silicon substrate having a pressurizing chamber, a movable film (vibrating film) supported by the silicon substrate so as to face the pressurizing chamber, and the movable film. And a piezoelectric element. The piezoelectric element is configured by laminating a lower electrode, a piezoelectric film, and an upper electrode from the movable film side. The upper surface and side surfaces of the piezoelectric element are covered with a hydrogen barrier film made of Al ₂ O ₃ (alumina). An interlayer insulating film made of SiO ₂ is formed on the hydrogen barrier film, and a surface protective film (passivation film) made of SiN is formed on the interlayer insulating film.

JP 2013-119182 A

  If the piezoelectric film is easily deformed, the amount of displacement of the movable film can be increased. In order to easily deform the piezoelectric film, it is preferable that only the minimum necessary film is provided around the piezoelectric element and no other film is provided. An alumina film as a hydrogen barrier film is essential for protecting the piezoelectric film. Therefore, the present inventor forms an interlayer insulating film and a passivation film only in a region around the piezoelectric element where a wiring connected to the upper electrode is provided, and only a hydrogen barrier film is formed in other regions. A prototype was constructed.

  That is, the hydrogen barrier film is formed by sputtering so as to cover the surface of the movable film and the piezoelectric element. Next, an interlayer insulating film is formed on the entire surface of the hydrogen barrier film. Next, a wiring film is formed on the interlayer insulating film and patterned to form a wiring connected to the upper electrode. Next, a passivation film that covers the surface of the interlayer insulating film and the surface of the wiring is formed. Next, by patterning (etching) the passivation film by photolithography, the passivation film other than the portion covering the wiring is removed. Thereafter, the interlayer insulating film is patterned (etched) by photolithography to remove portions other than the region where the wiring exists. As a result, almost the entire side surface and upper surface of the piezoelectric element are covered with only the hydrogen barrier film.

  It has been found that the configuration made by the present inventor may cause the upper electrode to peel off. The reason why the upper electrode peels is considered as follows. Since the hydrogen barrier film formed by sputtering is thin on the side surface of the piezoelectric element, it cannot be said that the coverage is necessarily sufficient. Further, the hydrogen barrier film is damaged when the interlayer insulating film under the wiring connected to the upper electrode is patterned. Therefore, in the patterning process of the interlayer insulating film, the alkaline processing liquid used for organic substance removal after resist stripping (ashing) penetrates into the upper electrode and causes a chemical reaction (battery reaction). Causes peeling.

  An object of the present invention is to provide a piezoelectric element utilizing apparatus that can easily deform a piezoelectric film and that does not cause peeling of an upper electrode, and a manufacturing method thereof.

  The piezoelectric element utilization apparatus according to the present invention includes a lower electrode, a piezoelectric film formed on the lower electrode, a piezoelectric element having an upper electrode formed on the piezoelectric film, and an entire side surface of the upper electrode and the piezoelectric film. A hydrogen barrier film that covers the upper electrode, and an interlayer that has an opening at the center of the upper surface of the upper electrode, is stacked on the hydrogen barrier film, and faces the entire side surface of the upper electrode and the piezoelectric film through the hydrogen barrier film An insulating film.

  In this configuration, the entire side surfaces of the upper electrode and the piezoelectric film are covered with the hydrogen barrier film and the interlayer insulating film laminated on the hydrogen barrier film. Therefore, in this configuration, there is no patterning step for removing the interlayer insulating film covering the side surfaces of the upper electrode and the piezoelectric film during the manufacture of the piezoelectric element utilizing apparatus. In other words, in this configuration, there is no process that causes peeling of the upper electrode during the manufacture of the piezoelectric element utilizing apparatus, and therefore peeling of the upper electrode does not occur.

In this configuration, since the interlayer insulating film has an opening at the center of the upper surface of the upper electrode, the piezoelectric film is easily deformed when the piezoelectric element is driven.
In one embodiment of the present invention, the substrate further includes a substrate having a cavity and a movable film held on the substrate so as to face the cavity, and the piezoelectric element is provided on the movable film.

In one embodiment of the present invention, a metal barrier film is interposed between the movable film and the piezoelectric element. With this configuration, it is possible to prevent the metal element from escaping from the piezoelectric film. Thereby, the piezoelectric characteristics of the piezoelectric film can be kept good, and metal can be prevented from diffusing into the movable film when the piezoelectric film is formed.
In one embodiment of the present invention, the metal barrier film is an Al ₂ O ₃ film.

In one embodiment of the present invention, a contact hole exposing a part of the upper electrode is formed in the interlayer insulating film on the piezoelectric element, and one end of the contact hole is formed in the contact hole on the interlayer insulating film. A wiring is formed which is connected to the upper electrode through the other end and is drawn out to the outside of the piezoelectric element.
In one embodiment of the present invention, the semiconductor device further includes a passivation film that is formed only in a region where the wiring is present on the interlayer insulating film and covers the wiring. In this configuration, the displacement of the movable film can be increased as compared with the case where the passivation film is formed over the entire area of the interlayer insulating film.

  In one embodiment of the present invention, the cavity is formed in a rectangular shape in a plan view when viewed from a normal direction with respect to a main surface of the movable film, and the movable film is aligned with a cavity edge in the plan view. The piezoelectric film is a rectangle having a width shorter than the width of the movable film in the short direction and a length shorter than the length of the movable film in the longitudinal direction in the plan view. The both end edges and both side edges of the movable film recede to the inside of the movable film than the both end edges and both side edges of the movable film, respectively, and the upper electrode has a short direction of the movable film in the plan view. A rectangle having a width shorter than the width of the movable film and a length shorter than the length in the longitudinal direction of the movable film, and both end edges and both side edges of the movable film are more inward of the movable film than both end edges and both side edges of the movable film. Each retreating .

In this configuration, since the piezoelectric film and the upper electrode are not disposed on the peripheral edge of the movable film, the displacement of the movable film can be increased.
In one embodiment of the present invention, the hydrogen barrier film is an Al ₂ O ₃ film.
In one embodiment of the present invention, the interlayer insulating film is a SiO film.
In one embodiment of the present invention, the passivation film is a SiN film.

In one embodiment of the present invention, the upper electrode, and Ir0 ₂ film formed on the piezoelectric film, and a laminated film of a Ir film formed on the Ir0 ₂ film.
According to a method of manufacturing a piezoelectric element utilization apparatus according to the present invention, a piezoelectric element including a lower electrode, a piezoelectric film formed on the lower electrode, and an upper electrode formed on the piezoelectric film is formed on a movable film. In the first step, the second step of forming a hydrogen barrier film covering the surfaces of the movable film and the piezoelectric element, the third step of forming an interlayer insulating film on the hydrogen barrier film, and the piezoelectric element, A fourth step of forming a contact hole exposing a part of the upper electrode in the hydrogen barrier film and the interlayer insulating film; and one end of the contact hole on the interlayer insulating film via the contact hole. A fifth step of forming a wiring in contact with the other end of the piezoelectric element, and a passivation film for covering the wiring in a region where the wiring is present on the interlayer insulating film. 6 And degree, the upper central portion of the hydrogen barrier film and the interlayer insulating film definitive the piezoelectric element, and a seventh step of forming an opening.

In this manufacturing method, a piezoelectric element utilization apparatus having the configuration of the piezoelectric element utilization apparatus according to the present invention can be obtained. Therefore, it is possible to manufacture a piezoelectric element utilizing apparatus in which the piezoelectric film is easily deformed and the upper electrode is not peeled off.
In one embodiment of the present invention, the fifth step includes a step of forming a wiring film on the interlayer insulating film including the inside of the contact hole, and patterning the wiring film, so that one end portion forms the contact hole. Forming a wiring that is in contact with the upper electrode through the other end and led to the outside of the piezoelectric element.

  In one embodiment of the present invention, the sixth step includes a step of forming a passivation film covering the surface of the interlayer insulating film and the surface of the wiring on the interlayer insulating film; and And patterning into a pattern consisting of only the covering portion.

FIG. 1A is a schematic plan view of an inkjet print head to which the first invention is applied, in which a hydrogen barrier film, an interlayer insulating film, and a passivation film are omitted. FIG. 1B is a schematic plan view for illustrating a region where a passivation film is formed. FIG. 1C is a schematic plan view for showing a region where a passivation film is not formed on the surface of the interlayer insulating film. FIG. 2 is a schematic enlarged sectional view taken along line II-II in FIG. FIG. 3 is a schematic enlarged sectional view taken along line III-III in FIG. FIG. 4 is a schematic perspective view of the ink jet print head. FIG. 5 is a plan view showing a planar shape of the lower electrode formed on the movable film forming layer by removing the configuration other than the lower electrode formed on the movable film forming layer. FIG. 6A is a cross-sectional view illustrating an example of the manufacturing process of the inkjet print head. FIG. 6B is a cross-sectional view showing a step subsequent to FIG. 6A. FIG. 6C is a cross-sectional view showing a step subsequent to FIG. 6B. FIG. 6D is a cross-sectional view showing a step subsequent to FIG. 6C. FIG. 6E is a cross-sectional view showing a step subsequent to FIG. 6D. FIG. 6F is a cross-sectional view showing a step subsequent to FIG. 6E. FIG. 6G is a cross-sectional view showing a step subsequent to FIG. 6F. 6H is a cross-sectional view showing a step subsequent to FIG. 6G. FIG. 6I is a cross-sectional view showing a step subsequent to FIG. 6H. FIG. 6J is a cross-sectional view showing a step subsequent to FIG. 6I. FIG. 6K is a cross-sectional view showing a step subsequent to FIG. 6J. 6L is a cross-sectional view showing a step subsequent to FIG. 6K. FIG. 6M is a cross-sectional view showing a step subsequent to FIG. 11L. FIG. 6N is a cross-sectional view showing a step subsequent to FIG. 11M. FIG. 6O is a cross-sectional view showing a step subsequent to FIG. 11N. FIG. 6P is a cross-sectional view showing a step subsequent to FIG. 11O. FIG. 7A is a cross-sectional view illustrating an example of a manufacturing process in a comparative example. FIG. 7B is a cross-sectional view showing a step subsequent to FIG. 7A. FIG. 7C is a cross-sectional view showing a step subsequent to FIG. 7B. FIG. 7D is a cross-sectional view showing a step subsequent to FIG. 7C. FIG. 7E is a cross-sectional view showing a state where the Ir film of the upper electrode is peeled off from the IrO ₂ film after the step of FIG. 7D. FIG. 8 is an enlarged cross-sectional view showing a modification of the hydrogen barrier film. FIG. 9 is a schematic plan view of an ink jet print head to which the second invention is applied. FIG. 10 is a schematic enlarged sectional view taken along line XX in FIG. FIG. 11 is a schematic enlarged sectional view taken along line XI-XI in FIG. FIG. 12 is a schematic perspective view of the ink jet print head. FIG. 13 is a plan view showing a planar shape of the lower electrode formed on the movable film forming layer by removing the configuration other than the lower electrode formed on the movable film forming layer. FIG. 14 is an enlarged cross-sectional view showing the structure of the upper electrode and the structure of the hydrogen barrier film. FIG. 15A is a cross-sectional view showing an example of the manufacturing process of the inkjet print head. FIG. 15B is a cross-sectional view showing a step subsequent to FIG. 15A. FIG. 15C is a cross-sectional view showing a step subsequent to FIG. 15B. FIG. 15D is a cross-sectional view showing a step subsequent to FIG. 15C. FIG. 15E is a cross-sectional view showing a step subsequent to FIG. 15D. FIG. 15F is a cross-sectional view showing a step subsequent to FIG. 15E. FIG. 15G is a cross-sectional view showing a step subsequent to FIG. 15F. FIG. 15H is a cross-sectional view showing a step subsequent to FIG. 15G. FIG. 15I is a cross-sectional view showing a step subsequent to FIG. 15H. FIG. 15J is a cross-sectional view showing a step subsequent to FIG. 15I. FIG. 15K is a cross-sectional view showing a step subsequent to FIG. 15J. FIG. 15L is a cross-sectional view showing a step subsequent to FIG. 15K. FIG. 15M is a cross-sectional view showing a step subsequent to FIG. 19L. FIG. 16 is an enlarged cross-sectional view showing a modification of the hydrogen barrier film. FIG. 17 is an enlarged cross-sectional view showing another modification of the hydrogen barrier film. FIG. 18 is a schematic plan view showing a pyroelectric infrared image sensor. 19 is a cross-sectional view taken along line XIX-XIX in FIG. FIG. 20A is an enlarged cross-sectional view showing the structure of the hydrogen barrier film. FIG. 20B is an enlarged cross-sectional view showing a modification of the hydrogen barrier film. FIG. 20C is an enlarged cross-sectional view showing another modification of the hydrogen barrier film. FIG. 21 is a schematic plan view showing an ink jet print head to which the third and fourth inventions are applied. FIG. 22 is a schematic enlarged sectional view taken along line XXII-XXII in FIG. FIG. 23 is a schematic enlarged sectional view taken along line XXIII-XXIII in FIG. FIG. 24 is a schematic perspective view of the ink jet print head. FIG. 25 is a plan view showing a planar shape of the lower electrode formed on the movable film forming layer by removing the configuration other than the lower electrode formed on the movable film forming layer. FIG. 26 is an enlarged perspective view showing the structure of the upper electrode. FIG. 27 is an enlarged perspective view showing a first modification of the upper electrode. FIG. 28 is an enlarged perspective view showing a second modification of the upper electrode. FIG. 29 is an enlarged perspective view showing a third modification of the upper electrode. FIG. 30 is an enlarged perspective view showing a fourth modification of the upper electrode. FIG. 31 is an enlarged perspective view showing a fifth modification of the upper electrode. FIG. 32 is an enlarged perspective view showing a sixth modification of the upper electrode. FIG. 33 is an enlarged perspective view showing a seventh modification of the upper electrode. FIG. 34 is an enlarged perspective view showing an eighth modification of the upper electrode. FIG. 35 is an enlarged perspective view showing a ninth modification of the upper electrode. FIG. 36 is an enlarged perspective view showing a tenth modification of the upper electrode. FIG. 37 is an enlarged perspective view showing an eleventh modification of the upper electrode. FIG. 38 is an enlarged perspective view showing a twelfth modification of the upper electrode. FIG. 39 is an enlarged perspective view showing a thirteenth modification of the upper electrode. FIG. 40 is an enlarged perspective view showing a fourteenth modification of the upper electrode. FIG. 41 is an enlarged perspective view showing a fifteenth modification of the upper electrode. FIG. 42 is an enlarged perspective view showing a sixteenth modification of the upper electrode. FIG. 43 is an enlarged perspective view showing a seventeenth modification of the upper electrode. FIG. 44 is a schematic plan view showing another example of an ink jet print head to which the third and fourth inventions are applied. 45 is a schematic enlarged sectional view taken along line LXV-LXV in FIG. 46 is a schematic enlarged sectional view taken along line LXVI-LXVI in FIG. FIG. 47 is a schematic perspective view of an ink jet print head. FIG. 48 is a plan view showing a planar shape of the lower electrode formed on the movable film forming layer by removing the configuration other than the lower electrode formed on the movable film forming layer. FIG. 49 is a schematic plan view showing still another example of the ink jet print head to which the third and fourth inventions are applied. FIG. 50 is a schematic enlarged sectional view taken along line LL in FIG. 51 is a schematic enlarged cross-sectional view taken along the line LI-LI in FIG. FIG. 52 is a schematic perspective view of an ink jet print head. FIG. 53 is a plan view showing a planar shape of the lower electrode formed on the movable film forming layer by removing the configuration other than the lower electrode formed on the movable film forming layer. FIG. 54 is a plan view showing another example of the metal film embedded in the movable film forming body. FIG. 55 is a schematic plan view showing another example of a pyroelectric infrared image sensor to which the fourth invention is applied. 56 is a cross-sectional view taken along line LVI-LVI of FIG.

Hereinafter, embodiments of the first to fourth inventions will be described in detail with reference to the accompanying drawings.
[1] Regarding the First Invention FIG. 1A is a schematic plan view of an ink jet print head to which the first invention is applied. FIG. 1B is a schematic plan view for illustrating a region where a passivation film is formed. FIG. 1B is a schematic plan view for showing a region where a passivation film is not formed on the surface of the interlayer insulating film. FIG. 2 is a schematic enlarged sectional view taken along line II-II in FIG. FIG. 3 is a schematic enlarged sectional view taken along line III-III in FIG. FIG. 4 is a schematic perspective view of the ink jet print head. However, in FIG. 1A and FIG. 4, the hydrogen barrier film | membrane shown by the code | symbol 13 in FIG. 2 and FIG. 3 and the insulating film shown by the code | symbol 14 are abbreviate | omitted. FIG. 5 is a plan view showing a planar shape of the lower electrode formed on the movable film forming layer by removing the configuration other than the lower electrode formed on the movable film forming layer.

  Referring to FIG. 2, the ink jet print head 1 includes a silicon substrate 2 and a nozzle substrate 3 having an ejection port 3a for ejecting ink. A movable film forming layer 10 is laminated on the silicon substrate 2. In the laminated body of the silicon substrate 2 and the movable film forming layer 10, a pressure chamber (cavity) 5 as an ink flow path (ink reservoir) is formed. The pressure chamber 5 is formed in the space portion 5A formed in the silicon substrate 2 and penetrating the silicon substrate 2 in the thickness direction, and formed on the back surface (surface on the silicon substrate 2 side) of the movable film forming layer 10 and in the space portion 5A. It is comprised from the continuous recessed part 5B.

  The nozzle substrate 3 is made of, for example, a silicon plate, and is bonded to the back surface of the silicon substrate 2 to partition the pressure chamber 5 together with the silicon substrate 2 and the movable film forming layer 10. The nozzle substrate 3 has a recess 3b facing the pressure chamber 5, and an ink discharge passage 3c is formed on the bottom surface of the recess 3b. The ink discharge passage 3 c passes through the nozzle substrate 3 and has a discharge port 3 a on the side opposite to the pressure chamber 5. Therefore, when the volume change of the pressure chamber 5 occurs, the ink stored in the pressure chamber 5 passes through the ink discharge passage 3c and is discharged from the discharge port 3a.

  The pressure chamber 5 is formed by digging the silicon substrate 2 and the movable film forming layer 10 from the back side of the silicon substrate 2. The silicon substrate 2 and the movable film forming layer 10 are further formed with an ink supply path 4 (refer to FIG. 1A and FIG. 3 together) communicating with the pressure chamber 5. The ink supply path 4 communicates with the pressure chamber 5 and is formed to guide ink from an ink tank (for example, an ink cartridge) that is an ink supply source to the pressure chamber 5. The pressure chamber 5 is formed to be elongated along the ink flow direction 21 which is the left-right direction in FIG.

The top wall portion of the pressure chamber 5 in the movable film forming layer 10 constitutes a movable film (membrane) 10A. The movable film 10A (movable film forming layer 10) is made of, for example, a silicon oxide (SiO ₂ ) film formed on the silicon substrate 2. The movable film 10A (movable film forming layer 10) is formed on, for example, a silicon (Si) layer formed on the silicon substrate 2, a silicon oxide (SiO ₂ ) layer formed on the silicon layer, and a silicon oxide layer. It may be composed of a laminated body with a silicon nitride (SiN) layer formed. In this specification, the movable film 10 </ b> A means the top wall portion that defines the pressure chamber 5 in the movable film forming layer 10. Therefore, portions of the movable film forming layer 10 other than the top wall portion of the pressure chamber 5 do not constitute the movable film 10A.

  The thickness of the movable film 10A is, for example, 0.4 μm to 2 μm. When the movable film 10A is made of a silicon oxide film, the thickness of the silicon oxide film may be about 1.2 μm. When the movable film 10A is composed of a stacked body of a silicon layer, a silicon oxide layer, and a silicon nitride layer, the thicknesses of the silicon layer, the silicon oxide layer, and the silicon nitride layer are about 0.4 μm, respectively. Also good.

  The pressure chamber 5 is partitioned by the movable film 10A, the silicon substrate 2, and the nozzle substrate 3, and is formed in a substantially rectangular parallelepiped shape in this embodiment. For example, the pressure chamber 5 may have a length of about 800 μm and a width of about 55 μm. The ink supply path 4 is formed so as to communicate with one end in the longitudinal direction of the pressure chamber 5 (in this embodiment, the end located on the side opposite to the ejection port 3a). In this embodiment, the discharge port 3a of the nozzle substrate 3 is disposed near the other end of the pressure chamber 5 in the longitudinal direction.

A metal barrier film 11 is formed on the surface of the movable film forming layer 10. The metal barrier film 11 is made of, for example, an Al ₂ O ₃ (alumina) film. The metal barrier film 11 may be an MgO film or ZrO ₂ . On the surface of the metal barrier film 11, the piezoelectric element 6 is disposed at a position above the movable film 10A. The piezoelectric element 6 includes a lower electrode 7 formed on the metal barrier film 11, a piezoelectric film 8 formed on the lower electrode 7, and an upper electrode 9 formed on the piezoelectric film 8. . In other words, the piezoelectric element 6 is configured by sandwiching the piezoelectric film 8 between the upper electrode 9 and the lower electrode 7 from above and below.

  The lower electrode 7 has, for example, a two-layer structure in which a Ti (titanium) layer and a Pt (platinum) layer are sequentially stacked from the movable film 10A side. In addition, the lower electrode 7 can be formed of a single film such as an Au (gold) film, a Cr (chromium) layer, or a Ni (nickel) layer. The lower electrode 7 has a main electrode portion 7A in contact with the lower surface of the piezoelectric film 8, and an extension portion 7B (see also FIGS. 1A, 4 and 5) extending to an outer region of the piezoelectric film 8. doing.

As the piezoelectric film 8, for example, a PZT (PbZr _x Ti _1-x O ₃ : lead zirconate titanate) film formed by a sol-gel method or a sputtering method can be applied. Such a piezoelectric film 8 is made of a sintered body of metal oxide crystals. The thickness of the piezoelectric film 8 is preferably 1 μm to 5 μm. The total thickness of the movable film 10A is preferably about the same as the thickness of the piezoelectric film 8 or about 2/3 of the thickness of the piezoelectric film. The metal barrier film 11 described above prevents the metal element (Pb, Zr, Ti when the piezoelectric film 8 is PZT) from escaping from the piezoelectric film 8, and improves the piezoelectric characteristics of the piezoelectric film 8. At the same time, the metal film 8A is prevented from diffusing into the movable film 10A when the piezoelectric film 8 is formed.

The upper electrode 9 is formed in substantially the same shape as the piezoelectric film 8 in plan view. In this embodiment, the upper electrode 9 has a two-layer structure in which an IrO ₂ (iridium oxide) film 31 and an Ir (iridium) film 32 are sequentially laminated from the piezoelectric film 8 side.
The surface of the metal barrier film 11, the surface of the piezoelectric element 6, and the surface of the extended portion of the lower electrode 7 are covered with the hydrogen barrier film 13. The hydrogen barrier film 13 is made of, for example, Al ₂ O ₃ (alumina). Thereby, characteristic deterioration due to hydrogen reduction of the piezoelectric film 8 can be prevented. An interlayer insulating film 14 is laminated on the entire surface of the hydrogen barrier film 13. The interlayer insulating film 14 is made of, for example, SiO ₂ . A wiring 15 is formed on the interlayer insulating film 14. The wiring 15 is made of a metal material containing Al (aluminum).

  One end of the wiring 15 is disposed above one end of the upper electrode 9. A through hole (contact hole) 16 is formed between the wiring 15 and the upper electrode 9 so as to continuously penetrate the hydrogen barrier film 13 and the interlayer insulating film 14. One end of the wiring 15 enters the through hole 16 and is connected to the upper electrode 9 in the through hole 16. Further, in the hydrogen barrier film 13 and the interlayer insulating film 14, an opening 17 having a rectangular shape in plan view is formed at the center of the upper surface of the upper electrode 9 (the portion surrounded by the peripheral edge on the upper surface of the upper electrode 9).

  In addition, an opening 18 that continuously penetrates the hydrogen barrier film 13 and the interlayer insulating film 14 is formed at a position corresponding to a predetermined region on the extension 7B of the lower electrode 7, and the surface of the lower electrode 7 is opened. 18 is exposed. This exposed portion constitutes a pad portion 7d for connecting the lower electrode 7 to the outside. A passivation film 25 that covers the wiring 15 is formed on the interlayer insulating film 14.

  The piezoelectric element 6 is formed at a position facing the pressure chamber 5 with the movable film 10A and the metal barrier film 11 interposed therebetween. That is, the piezoelectric element 6 is formed so as to contact the surface of the metal barrier film 11 opposite to the pressure chamber 5. The pressure chamber 5 is filled with ink supplied from an ink tank (not shown) through the ink supply path 4. The movable film 10 </ b> A partitions the top surface portion of the pressure chamber 5 and faces the pressure chamber 5. The movable film 10A is supported by a portion around the pressure chamber 5 in the stacked body of the movable film forming layer 10 and the silicon substrate 2, and faces the pressure chamber 5 (in other words, the thickness direction of the movable film 10A). ) Is deformable and flexible.

  The wiring 15 and the pad portion 7 d of the lower electrode 7 are connected to the drive circuit 20. The drive circuit 20 may be formed in a region different from the pressure chamber 5 of the silicon substrate 2 or may be formed outside the silicon substrate 2. When a drive voltage is applied from the drive circuit 20 to the piezoelectric element 6, the piezoelectric film 8 is deformed by the inverse piezoelectric effect. As a result, the movable film 10A is deformed together with the piezoelectric element 6, whereby the volume of the pressure chamber 5 is changed, and the ink in the pressure chamber 5 is pressurized. The pressurized ink is discharged as fine droplets from the discharge port 3a through the ink discharge passage 3c.

  Referring to FIGS. 1A to 5, a plurality of pressure chambers 5 are formed in a stripe shape in a stacked body of a silicon substrate 2 and a movable film forming layer 10 so as to extend in parallel with each other. The plurality of pressure chambers 5 are formed at equal intervals with a minute interval (for example, about 30 μm to 350 μm) in the width direction thereof. Each of the pressure chambers 5 has a rectangular shape that is elongated along the ink flow direction 21 from the ink supply path 4 toward the discharge path 3c in plan view. That is, the top surface portion of the pressure chamber 5 has two side edges 5 c and 5 d along the ink circulation direction 21 and two end edges 5 a and 5 b along a direction orthogonal to the ink circulation direction 21. The ink supply path 4 is divided into two paths at one end of the pressure chamber 5 and communicates with the common ink path 19. The common ink passage 19 communicates with the ink supply paths 4 corresponding to the plurality of pressure chambers 5 and is formed to supply ink from the ink tanks to these ink supply paths 4.

  The piezoelectric element 6 is formed such that the length in the ink distribution direction 21 (the same direction as the longitudinal direction of the movable film 10A) is shorter than the length in the longitudinal direction of the movable film 10A, and has a rectangular shape in plan view. . As shown in FIG. 1A, both end edges 6a and 6b along the short direction of the piezoelectric element 6 have a predetermined distance d1 (for example, 5 μm) from the corresponding both end edges 10Aa and 10Ab of the movable film 10A. Is placed inside. In addition, the piezoelectric element 6 has a width in the short direction (direction parallel to the main surface of the silicon substrate 2) perpendicular to the longitudinal direction of the movable film 10A, and the short width of the movable film 10A (the top surface portion of the pressure chamber 5). It is formed narrower than the width in the direction. Then, both side edges 6c and 6d along the longitudinal direction of the piezoelectric element 6 are arranged on the inner side with a predetermined distance d2 (for example, 5 μm) with respect to the corresponding side edges 10Ac and 10Ad of the movable film 10A.

  As shown in FIGS. 1A and 5, the lower electrode 7 has a predetermined width in a direction along the ink flow direction 21 and a plurality of pressure chambers 5 in a direction perpendicular to the ink flow direction 21 in plan view. Is a common electrode shared by a plurality of piezoelectric elements 6. The first side 7a along the direction orthogonal to the ink flow direction 21 of the lower electrode 7 is aligned with a line connecting one end edges 6a of the plurality of piezoelectric elements 6 in plan view. The second side 7b facing the first side 7a of the lower electrode 7 is outside the edge 10Ab of the movable film 10A corresponding to the other edge 6b of the plurality of piezoelectric elements 6 (downstream in the ink flow direction 21). Side).

  The lower electrode 7 is a main electrode portion 7A having a rectangular shape in plan view that constitutes the piezoelectric element 6, and is drawn out from the main electrode portion 7A in a direction along the surface of the movable film forming layer 10, and the top surface portion of the pressure chamber 5 (movable film) 10A) and an extension portion 7B extending outward from the periphery of the top surface of the pressure chamber 5 across the periphery. The main electrode portion 7A is formed to be shorter than the movable film 10A along the longitudinal direction of the movable film 10A, and both end edges of the main electrode part 7A are predetermined with respect to the corresponding both end edges 10Aa and 10Ab of the movable film 10A. It arrange | positions inside the space | interval d1. Further, the main electrode portion 7A is formed such that the width along the short direction of the movable film 10A is narrower than the width of the movable film 10A in the short direction, and both end edges thereof correspond to both sides corresponding to the movable film 10A. With respect to the edges 10Ac, 10Ad, the gap d2 is provided at an inner side.

  The extension portion 7B extends from the side edges of the main electrode portion 7A to the corresponding side edges 5c and 5d of the top surface portion of the pressure chamber 5 in plan view, and extends outside the side edges 5c and 5d of the top surface portion of the pressure chamber 5. It extends toward. The extension portion 7B is a region excluding the main electrode portion 7A in the entire region of the lower electrode 7. In the extension part 7B, a cut-out part 7c having a rectangular shape in plan view that penetrates the lower electrode 7 is formed on the downstream side of the ink flowing direction 21 of each piezoelectric element 6. Each cut portion 7 c has two side edges (short sides) along the ink circulation direction 21 and two end edges (long sides) along a direction orthogonal to the ink circulation direction 21 in plan view. . One edge of the cut portion 7c is arranged at a position aligned with the edge 6b of the piezoelectric element 6 (the edge on the downstream side of the main electrode portion 7A) with respect to the ink flow direction 21, and the other edge of the cut portion 7c is the movable film 10A. It is arranged outside the end edge 10Ab (on the downstream side in the ink circulation direction 21). One side edge of the cut portion 7c is disposed outside the one side edge 10Ac of the movable film 10A, and the other side edge of the cut portion 7c is disposed outside the other side edge 10Ad of the movable film 10A. Yes. Therefore, in a plan view, the end of the movable film 10A on the side of the end edge 10Ab is disposed inside the cut portion 7c. In a region between the second side 7b of the lower electrode 7 and the plurality of cut portions 7c, a rectangular pad portion 7d that is elongated in a direction orthogonal to the ink circulation direction 21 is formed.

  Referring to FIGS. 1A to 4, upper electrode 9 is formed in a rectangular shape having the same pattern as main electrode portion 7 </ b> A of lower electrode 7 in plan view. That is, the upper electrode 9 is formed to be shorter than the movable film 10A along the longitudinal direction of the movable film 10A, and both end edges of the upper electrode 9 are predetermined with respect to the corresponding both end edges 10Aa and 10Ab of the movable film 10A. The space d1 is arranged inside with a gap d1. Further, the upper electrode 9 is formed so that the width along the short direction of the movable film 10A is narrower than the width of the movable film 10A in the short direction, and both end edges thereof correspond to both side edges corresponding to the movable film 10A. With respect to 10Ac and 10Ad, it arrange | positions inside the said space | interval d2.

  The piezoelectric film 8 is formed in a rectangular shape having the same pattern as that of the upper electrode 9 in plan view. That is, the piezoelectric film 8 is formed to be shorter than the movable film 10A along the longitudinal direction of the movable film 10A, and both end edges thereof are predetermined with respect to the corresponding both end edges 10Aa and 10Ab of the movable film 10A. Are arranged inside with a gap d1. In addition, the piezoelectric film 8 is formed such that the width along the short direction of the movable film 10A is narrower than the width of the movable film 10A in the short direction, and both end edges thereof correspond to both sides corresponding to the movable film 10A. With respect to the edges 10Ac, 10Ad, the gap d2 is provided at an inner side. The lower surface of the piezoelectric film 8 is in contact with the upper surface of the portion constituting the piezoelectric element 6 in the lower electrode 7, and the upper surface of the piezoelectric film 8 is in contact with the lower surface of the upper electrode 9.

  The wiring 15 has one end portion connected to one end portion of the upper electrode 9 (the end portion on the one end edge 6a side of the piezoelectric element 6) and a lead portion 15A extending in a direction opposite to the ink flow direction 21 in a plan view; The pad portion 15B is integrated with the lead portion 15A and connected to the tip of the lead portion 15A and has a rectangular shape in plan view. The pad portion 15 </ b> B is disposed upstream of the one edge 6 a of the piezoelectric element 6 in the ink circulation direction 21. The lead portion 15A extends from the upper surface of one end portion of the piezoelectric element 6 (the end portion on the one end edge 6a side of the piezoelectric element 6) along the end face of the piezoelectric element 6 connected thereto, and further on the movable film forming layer 10 on the surface. And extends to the pad portion 15B. The passivation film 25 is formed only in a region where the wiring 15 is present, and covers the upper surface and side surfaces of the wiring 15. An opening 26 is formed in the passivation film 25 to expose the central portion of the surface of the pad portion 15B.

6A to 6P are cross-sectional views showing an example of the manufacturing process of the inkjet print head 1, and show a cut surface corresponding to FIG.
First, as shown in FIG. 6A, the movable film forming layer 10 is formed on the surface of the silicon substrate 2. However, the silicon substrate 2 is thicker than the final silicon substrate 2. Specifically, a silicon oxide layer (for example, 1.2 μm thick) is formed on the surface of the silicon substrate 2. In the case where the movable film forming layer 10 is composed of a laminated body of a silicon layer, a silicon oxide layer, and a silicon nitride layer, a silicon layer (for example, 0.4 μm thick) is formed on the surface of the silicon substrate 2, and the silicon layer A silicon oxide layer (for example, 0.4 μm thickness) is formed thereon, and a silicon nitride layer (for example, 0.4 μm thickness) is formed on the silicon oxide layer.

Next, as shown in FIG. 6B, a metal barrier film 11 made of, for example, Al ₂ O ₃ is formed on the surface of the movable film forming layer 10. The metal barrier film 11 prevents escape of metal atoms (for example, Pb, Zr, Ti) from the piezoelectric film 8 to be formed later. If metal electrons escape, the piezoelectric characteristics of the piezoelectric film 8 may deteriorate. Further, when the escaped metal atoms are mixed into the silicon layer constituting the movable film 10A, the durability of the movable film 10A may be deteriorated.

Next, as shown in FIG. 6C, a lower electrode film 57 that is a material layer of the lower electrode 7 is formed on the metal barrier film 11. The lower electrode film 57 is made of, for example, a Pt / Ti laminated film having a Ti film (for example, 10 nm to 40 nm thickness) as a lower layer and a Pt film (for example, 10 nm to 400 nm thickness) as an upper layer. Such a lower electrode film 57 may be formed by sputtering.
Next, as shown in FIG. 6D, a material film (piezoelectric material film) 58 of the piezoelectric film 8 is formed on the entire surface of the lower electrode film 57. Specifically, for example, a PZT film having a thickness of 1 μm to 5 μm is formed by a sol-gel method. Such a PZT film is made of a sintered body of metal oxide crystal grains.

Next, as shown in FIG. 6E, an upper electrode film 59 that is a material of the upper electrode 9 is formed on the entire surface of the piezoelectric material film 58. The upper electrode film 59 is an IrO ₂ / Ir laminated film having an IrO ₂ film 31 (for example, 40 nm to 160 nm thickness) as a lower layer and an Ir film 32 (for example, 40 nm to 160 nm thickness) as an upper layer. Such an upper electrode film 59 may be formed by sputtering.

  Next, as shown in FIGS. 6F and 6G, the upper electrode film 59, the piezoelectric material film 58, and the lower electrode film 57 are patterned. First, as shown in FIG. 6F, a resist mask having a pattern of the lower electrode 7 is formed by photolithography, and the upper electrode film 59, the piezoelectric material film 58, and the lower electrode film 57 have the same pattern using the resist mask as a mask. As a result, the lower electrode film 57 having a predetermined pattern is formed. More specifically, the upper electrode film 59 is patterned by dry etching, the piezoelectric material film 58 is patterned by wet etching, and the lower electrode film 57 is patterned by dry etching. Thus, the lower electrode 7 is formed. The etchant used for wet etching of the piezoelectric material film 58 may be an acid mainly composed of hydrochloric acid.

  Next, after removing the resist mask, a resist mask having a pattern of the piezoelectric film 8 is formed by photolithography, and the upper electrode film 59 and the piezoelectric material film 58 are etched into the same pattern using this resist pattern. The More specifically, the upper electrode film 59 is patterned by dry etching, and the piezoelectric material film 58 is patterned by wet etching. Thus, as shown in FIG. 6G, the piezoelectric film 8 and the upper electrode 9 are formed. Thereby, the piezoelectric element 6 including the main electrode portion 7A of the lower electrode, the piezoelectric film 8 and the upper electrode 9 is formed.

Next, as shown in FIG. 6H, after removing the resist mask, a hydrogen barrier film 13 covering the entire surface is formed. The hydrogen barrier film 13 may be an Al ₂ O ₃ film formed by sputtering, and the film thickness may be 40 nm to 160 nm.
Next, as shown in FIG. 6I, an interlayer insulating film 14 is formed on the entire surface of the hydrogen barrier film 13. The interlayer insulating film 14 may be a SiO ₂ film, and the film thickness may be 250 nm to 1000 nm.

Next, as shown in FIG. 6J, the through hole 16 and the opening 18 are formed in both the interlayer insulating film 14 and the hydrogen barrier film 13.
Next, a wiring film constituting the wiring 15 is formed on the interlayer insulating film 14 including the inside of the through hole 16. Thereafter, the wiring film is patterned by photolithography and etching, thereby forming the wiring 15 connected to the upper electrode 9 as shown in FIG. 6K.

Next, as shown in FIG. 6L, a passivation film 25 is formed on the surface of the interlayer insulating film 14 and the surface of the wiring 15.
Next, a resist mask that covers the upper surface of the wiring 15 and a region in the vicinity thereof and has an opening corresponding to the opening 26 is formed by photolithography, and the passivation film 25 is etched using the resist mask as a mask. As a result, the region other than the region covering the wiring 15 and the region corresponding to the opening 26 in the passivation film 25 are removed. Thereby, as shown in FIG. 6M, the passivation film 25 that covers the upper surface and side surfaces of the wiring 15 and has the opening 26 remains only in the region where the wiring 15 exists. Thereafter, after the resist mask is peeled off, the organic substance is removed using an alkaline processing liquid.

  Next, as shown in FIG. 6N, an opening 17 is formed in the center of the upper surface of the upper electrode 9 in the interlayer insulating film 14 and the hydrogen barrier film 13. Specifically, first, a resist mask having an opening corresponding to the opening 17 is formed by photolithography, and the interlayer insulating film 14 is etched using the resist mask as a mask. Thereby, an opening 17 is formed in the interlayer insulating film 14. Thereafter, the hydrogen barrier film 13 is etched using the resist mask as a mask. Thereby, an opening 17 is formed in the hydrogen barrier film 13. Thereafter, after the resist mask is peeled off, the organic substance is removed using an alkaline processing liquid.

Next, as shown in FIG. 6O, back surface grinding for thinning the silicon substrate 2 is performed. By polishing the substrate 2 from the back surface, the substrate 2 is thinned. For example, the silicon substrate 2 having a thickness of about 670 μm in the initial state may be thinned to a thickness of about 300 μm.
Next, as shown in FIG. 6P, by performing etching (dry etching or wet etching) from the back surface of the silicon substrate 2 on the stacked body of the silicon substrate 2 and the movable film forming layer 10, the pressure chamber 5, The ink supply path 4 and the common ink path 19 are formed, and the movable film 10A is formed at the same time. During this etching, the metal barrier film 11 formed on the surfaces of the hydrogen barrier film 13 and the movable film forming layer 10 is such that metal elements (Pb, Zr, Ti in the case of PZT) escape from the piezoelectric film 8. And the piezoelectric characteristics of the piezoelectric film 8 are kept good. As described above, the metal barrier film 11 formed on the surface of the movable film forming layer 10 contributes to maintaining the durability of the silicon layer forming the movable film 10A.

Thereafter, although not shown in FIG. 6, the nozzle substrate 3 is bonded to the back surface of the silicon substrate 2 to obtain the ink jet print head 1 shown in FIGS. 1A to 4.
7A to 7E are cross-sectional views showing a manufacturing process of a comparative example in which the portion other than the region where the wiring exists in the interlayer insulating film 14 is removed in the inkjet print head 1.

The steps of FIGS. 6A to 6M described above are the same in this comparative example. 7A corresponds to FIG. 6 and FIG. 6L, and FIG. 7B corresponds to FIG. 6M.
In FIG. 7A, as described above, the passivation film 25 is formed on the entire surface of the interlayer insulating film 14.
Next, a resist mask that covers the upper surface of the wiring 15 and a region in the vicinity thereof and has an opening corresponding to the opening 26 is formed by photolithography, and the passivation film 25 is etched using the resist mask as a mask. As a result, the region other than the region covering the wiring 15 and the region corresponding to the opening 26 in the passivation film 25 are removed. As a result, as shown in FIG. 7B, the passivation film 25 that covers the upper surface and the side surface of the wiring 15 and has the opening 26 remains only in the region where the wiring 15 exists. Thereafter, after the resist mask is peeled off, the organic substance is removed using an alkaline processing liquid.

  Next, as shown in FIG. 7C, a resist mask that covers the passivation film 25 and the opening 26 is formed, and the interlayer insulating film 14 is etched using the resist mask as a mask. Thereby, portions of the interlayer insulating film 14 other than the region where the wiring 15 exists are removed. Thereafter, after the resist mask is peeled off, the organic substance is removed using an alkaline processing liquid.

Next, as shown in FIG. 7D, an opening 17 is formed in the center region of the upper surface of the upper electrode 9 in the hydrogen barrier film 13. Specifically, a resist mask having an opening corresponding to the opening 17 is formed by photolithography, and the hydrogen barrier film 13 is etched using the resist mask as a mask. Thereby, an opening 17 is formed in the hydrogen barrier film 13.
In such a comparative example, the Ir film 32 of the upper electrode 9 was peeled off from the IrO ₂ film 31 as shown in FIG. 7E. The entire upper electrode 9 may be peeled off from the piezoelectric film 8 in some cases.

In the comparative example, the reason why the upper electrode 9 is peeled off is considered as follows. Since the hydrogen barrier film 13 formed by the sputtering method has a thin film thickness on the side surface of the piezoelectric element 6 (piezoelectric film 8), it cannot be said that the coverage is necessarily sufficient. Further, the hydrogen barrier film 13 is damaged in a patterning step (step of FIG. 7C) for removing a portion of the interlayer insulating film 14 other than the region where the wiring 15 exists. By patterning the interlayer insulating film 14, almost the entire side surface of the piezoelectric element 6 is covered only with the thin and damaged hydrogen barrier film 13. In this state, organic removal using an alkaline processing liquid is performed after the resist is peeled off, so that the alkaline processing liquid flows from the side surface of the upper electrode 9 to the interface between the Ir film 32 and the IrO ₂ film 31 and the IrO ₂ film 31. Penetration into the interface between the piezoelectric film 8 and the piezoelectric film 8 causes a chemical reaction (battery reaction) to cause the upper electrode 9 to peel off.

  In the above-described embodiment, unlike the comparative example, there is no patterning process for removing a portion of the interlayer insulating film 14 other than the region where the wiring 15 exists. Therefore, organic substance removal using the alkaline processing liquid is not performed in a state where almost the entire side surface of the piezoelectric element 6 is covered only with the hydrogen barrier film 13. For this reason, unlike the comparative example, peeling of the upper electrode 9 does not occur.

  Further, in the above-described embodiment, the passivation film 25 is formed only on the portion where the wiring 15 exists, and most of the side surface and the upper surface of the piezoelectric element 6 are not covered with the passivation film 25. Thereby, the displacement of the movable film 10 </ b> A can be increased as compared with the conventional example described in Japanese Patent Laid-Open No. 2013-119182 in which the entire side surface and upper surface of the piezoelectric element 6 are covered with the passivation film 25. Furthermore, in the above-described embodiment, since the opening 17 is formed in the central portion of the upper surface of the piezoelectric element 6 in the hydrogen barrier film 13 and the interlayer insulating film 14, the entire upper surface of the piezoelectric element 6 is covered with the hydrogen barrier film 13 and the interlayer film. The displacement of the movable film 10A can be increased as compared with the conventional example described in JP 2013-119182 A, which is covered with the insulating film 14.

As mentioned above, although embodiment of 1st invention was described, 1st invention can also be implemented in other embodiment. In the above-described embodiment, the hydrogen barrier film 13 is composed of a sputtered film made of Al ₂ O ₃ . However, as shown in FIG. 8, the hydrogen barrier film 13 was formed by an Al ₂ O ₃ film (sputtered film) 41 formed by sputtering and an atomic layer deposition (ALD) method. An Al ₂ O ₃ film (ALD film) 42 may be laminated. FIG. 8 is an enlarged cross section corresponding to the cut surface of FIG. 8, portions corresponding to the respective portions in FIG. 3 described above are denoted by the same reference numerals as in FIG.

  The sputtered film 41 has a high barrier property against hydrogen but a low coverage. On the other hand, the ALD film 42 has high coverage but low barrier properties against hydrogen. Therefore, as shown in FIG. 8, by forming the hydrogen barrier film 13 from a laminated film of the sputtered film 41 and the ALD film 42, the hydrogen barrier film 13 having a high barrier property against hydrogen and a high covering property can be obtained. Thereby, characteristic deterioration due to hydrogen reduction of the piezoelectric film 8 can be more effectively prevented.

In the above-described embodiment, PZT is exemplified as the material of the piezoelectric film, but in addition, lead titanate (PbPO ₃ ), potassium niobate (KNbO ₃ ), notium niobate (LiNbO ₃ ), lithium tantalate A piezoelectric material made of a metal oxide typified by (LiTaO ₃ ) or the like may be applied.
In the above-described embodiment, the recess 5B that forms a part of the pressure chamber 5 is formed on the back surface of the movable film forming layer 10, but the recess 5B may not be formed. In this case, the pressure chamber 5 is composed only of the space portion 5 </ b> A formed in the silicon substrate 2.

In addition, various design changes can be made within the scope of matters described in the claims.
[2] About the second to fourth inventions [2-1] The object of the second invention is to provide an upper electrode of a piezoelectric actuator and a piezoelectric actuator including the same, which can obtain a large hydrogen barrier effect.

The second invention has the following features.
A1. An upper electrode of a piezoelectric actuator having a structure in which metal films and conductive oxide films are alternately and repeatedly laminated at least twice.
Since the conductive oxide film is reduced when hydrogen enters, it has a function of trapping or blocking hydrogen. The metal film has a high density to some extent and has a barrier performance against oxygen and hydrogen. However, since the metal film is polycrystalline, hydrogen may enter from a grain boundary. Therefore, an upper electrode having a high hydrogen barrier property can be obtained by alternately and repeatedly laminating a conductive oxide film and a metal film twice or more. That is, in the second invention, a larger hydrogen barrier effect can be obtained with a thin overall film thickness than when the upper electrode is formed thick with a single metal film.

A2. The upper electrode of the piezoelectric actuator according to “A1.”, Wherein the metal film is an Ir film and the conductive oxide film is an IrO ₂ film.
A3. The upper electrode of the piezoelectric actuator according to “A2.”, Having a structure in which metal films and conductive oxide films are alternately and repeatedly stacked twice.
A4. A substrate having a cavity; a movable film held on the substrate so as to face the cavity; and a piezoelectric element formed on a surface of the movable film opposite to the cavity; The lower electrode formed on the surface of the movable film opposite to the cavity, and any one of “A1.” To “A3.” Disposed on the opposite side of the movable film with respect to the lower electrode. A piezoelectric actuator comprising: an upper electrode; and a piezoelectric film provided between the lower electrode and the upper electrode.

With this configuration, a piezoelectric actuator including an upper electrode having a high hydrogen barrier property can be obtained. Thereby, characteristic deterioration due to hydrogen reduction of the piezoelectric film can be suppressed.
A5. The movable film is formed in a rectangular shape in a plan view when viewed from a normal direction with respect to a main surface of the movable film, and the piezoelectric film has a width in a short direction of the movable film in the plan view. It is a rectangle having a shorter width and a length shorter than the length in the longitudinal direction of the movable film, and both end edges and both side edges recede inward of the movable film from both end edges and both side edges of the movable film. The upper electrode is a rectangle having a width shorter than the width of the movable film in the short direction and a length shorter than the length of the movable film in the longitudinal direction in the plan view; The piezoelectric actuator according to “A4.”, Wherein both side edges recede toward the inside of the movable film from both side edges and both side edges of the movable film.

In this configuration, since the piezoelectric film and the upper electrode are not disposed on the peripheral edge of the movable film, the displacement of the movable film can be increased.
A6. The piezoelectric actuator according to “A4.” Or “A5.”, Including a hydrogen barrier film covering the entire side surface of the piezoelectric film. With this configuration, it is possible to further suppress the characteristic deterioration due to hydrogen reduction of the piezoelectric film.

  A7. The piezoelectric actuator according to “A6.”, Wherein the hydrogen barrier film has a structure in which at least two types of sputtered films formed under different conditions are stacked. In this configuration, the hydrogen barrier film is composed of a laminated film of at least two types of sputtered films having different characteristics, so that the hydrogen barrier property of the hydrogen barrier film can be improved. Thereby, characteristic deterioration due to hydrogen reduction of the piezoelectric film can be more effectively suppressed.

A8. The piezoelectric actuator according to “A7.”, Wherein the condition is a pressure at the time of forming the at least two types of sputtered films.
A9. Wherein at least two types of sputtered film, and the first sputter film made of Al ₂ O _3, wherein the first sputter film is composed of a second sputter film of Al ₂ O ₃ that are deposited under different conditions The piezoelectric actuator according to “A8.”.

A10. The pressure at the time of forming the first sputtered film is 0.01 Pa or more and less than 0.1 Pa, and the pressure at the time of forming the second sputtered film is 0.1 Pa or more and 3.0 Pa or less, “A9 The piezoelectric actuator described in “.”.
A11. The first sputtered film has a thickness of 10 nm to 100 nm, the second sputtered film has a thickness of 10 nm to 100 nm, and a film of the first sputtered film and the second sputtered film. The piezoelectric actuator according to “A9.” Or “A10.” Having a total thickness of 100 nm or less.

A12. The piezoelectric actuator according to “A6.”, Wherein the hydrogen barrier film has a structure in which a sputtered film and a plasma CVD film are sequentially stacked from the piezoelectric film side.
The sputtered film has a good hydrogen barrier property, but the coverage with respect to the side surface of the piezoelectric film is not so good. Further, the sputtered film tends to generate pinholes when the surface of the piezoelectric film is uneven. On the other hand, the plasma CVD film is inferior in hydrogen barrier property to the sputtered film, but easily penetrates into the side surface of the piezoelectric film and has a high ability to fill the pinhole. For this reason, in the configuration in which the sputtered film and the plasma CVD film are laminated, if the thickness of the hydrogen barrier film is the same, the hydrogen barrier effect is enhanced as compared with the case where the hydrogen barrier film is formed only by the sputtered film. be able to. Thereby, characteristic deterioration due to hydrogen reduction of the piezoelectric film can be more effectively suppressed.

A13. The piezoelectric actuator according to “A12.”, Wherein the sputtered film is made of an Al ₂ O ₃ film, and the plasma CVD film is made of a SiN film.
A14. The film thickness of the sputtered film is 10 nm or more and 100 nm or less, the film thickness of the plasma CVD film is 10 nm or more and 100 nm or less, and the total film thickness of the sputtered film and the plasma CVD film is 100 nm or less. A13. ". [2-2] An object of the third invention is to provide a piezoelectric film utilizing apparatus capable of increasing the displacement of the movable film.

The third invention has the following features.
B1. A substrate having a cavity; a movable film held on the substrate so as to face the cavity; and a piezoelectric element formed on the movable film, wherein the piezoelectric element is opposite to the cavity of the movable film A lower electrode formed on the surface on the side, an upper electrode disposed on the opposite side of the movable film with respect to the lower electrode, and a piezoelectric film provided between the lower electrode and the upper electrode, And the upper electrode has a thin film portion along the cavity edge.

In this configuration, since the thin film portion along the cavity edge is formed on the upper electrode, the upper electrode is easily bent. Accordingly, the movable film is easily warped and deformed when the piezoelectric element is driven, so that the displacement of the movable film can be increased.
B2. The upper electrode includes a first electrode film formed on the piezoelectric film and a second electrode film formed on the first electrode film and made of a material different from the first electrode film, Use of the piezoelectric element according to “B1.”, Wherein a groove along the cavity edge is formed on a surface of the two-electrode film, and a portion of the upper electrode where the groove is formed constitutes the thin film portion. apparatus.

B3. The piezoelectric element utilization apparatus according to “B2.”, Wherein the groove penetrates the second electrode film.
B4. The piezoelectric element utilization apparatus according to “B <b> 3.”, Wherein a concave portion that matches the groove is formed on a surface of the first electrode film.
B5. The piezoelectric element utilization apparatus according to “B2.”, Wherein the groove does not penetrate the second electrode film.

B6. The apparatus for using a piezoelectric element according to any one of “B2.” To “B5.”, Wherein a Young's modulus of the first electrode film is larger than a Young's modulus of the second electrode film.
B7. The piezoelectric element utilizing apparatus according to any one of “B2.” To “B6.”, Wherein the first electrode film is made of IrO ₂ and the first electrode film is made of Ir.
B8. The upper electrode is composed of a single metal film, a groove is formed along the cavity edge on the surface of the upper electrode, and a portion of the upper electrode where the groove is formed constitutes the thin film portion. The piezoelectric element utilization apparatus described in “B1.”.

B9. The piezoelectric element utilization apparatus according to “B8.”, Wherein the metal single film is an Ir film.
B10. The piezoelectric element utilization apparatus according to any one of “B2.” To “B9.”, Wherein the groove is formed in a stripe shape.
B11. The piezoelectric element utilization apparatus according to any one of “B2.” To “B9.”, Wherein the groove is formed in a mesh shape.

B12. The piezoelectric element utilization apparatus according to any one of “B2.” To “B11.”, Wherein the groove has a rectangular cross-sectional shape.
B13. The device using a piezoelectric element according to any one of “B2.” To “B11.”, Wherein a cross-sectional shape of the groove is a trapezoid.
B14. The device using a piezoelectric element according to any one of “B2.” To “B11.”, Wherein a cross-sectional shape of the groove is V-shaped.

  B15. The cavity is formed in a rectangular shape in a plan view as viewed from the normal direction with respect to the main surface of the movable film, and the movable film is formed in a rectangular shape that matches the cavity edge in the plan view. The piezoelectric film is a rectangle having a width shorter than the width of the movable film in the short direction and a length shorter than the length of the movable film in the longitudinal direction in the plan view, and both end edges and both side edges thereof Are retracted inwardly of the movable film from both side edges and both side edges of the movable film, and the upper electrode has a width shorter than the width in the short direction of the movable film in the plan view, A rectangular shape having a length shorter than the length in the longitudinal direction of the movable film, and both end edges and both side edges of the movable film recede inward of the movable film from both end edges and both side edges of the movable film, and the groove Of the movable membrane Along the edges are formed, "B2." ~ Piezoelectric element using apparatus according to any one of the "B14.".

In this configuration, when the piezoelectric element is driven, the movable film is easily warped and deformed in the short direction, so that the displacement of the movable film is increased.
[2-3] An object of the fourth invention is to provide a piezoelectric film utilizing apparatus capable of increasing the displacement of the movable film.
C1. A substrate having a cavity; a membrane held on the substrate so as to face the cavity; a piezoelectric / pyroelectric element formed on the membrane and functioning as a piezoelectric element or a pyroelectric element; and at least the piezoelectric / pyroelectric element A piezoelectric / pyroelectric device utilizing device including a metal line formed on the membrane in a region between the device and the cavity edge.

  Membranes are generally made of hard and brittle materials and are therefore susceptible to cracking. In this configuration, a metal line formed on the membrane is provided at least in a region between the piezoelectric / pyroelectric element and the cavity edge. Since the metal line is formed at a high temperature and then cooled to normal temperature and contracts, the metal line has a tensile stress. That is, the metal line exerts a force in the direction of contraction on the membrane, so that the membrane is difficult to break.

C2. The piezoelectric / pyroelectric element includes a lower electrode formed on a surface of the membrane opposite to the cavity, an upper electrode disposed on the opposite side of the membrane with respect to the lower electrode, and the lower electrode And a piezoelectric / pyroelectric film provided between the upper electrode and the upper electrode,
The apparatus for using a piezoelectric / pyroelectric element according to “C1.”, Wherein the metal line is formed in the same layer as the lower electrode and constitutes a part of the lower electrode. In this configuration, the metal line can be formed in the step of forming the lower electrode.

C3. The apparatus for using a piezoelectric / pyroelectric element according to “C1.”, Wherein the metal line is formed in a layer different from the lower electrode.
C4. The apparatus for using a piezoelectric / pyroelectric element according to “C3.”, Wherein the metal line is embedded in the membrane.
C5. The piezoelectric / pyroelectric element utilizing apparatus according to any one of "C1." To "C4.", Wherein the metal lines are formed in a stripe shape.

C6. The piezoelectric / pyroelectric element utilizing apparatus according to any one of "C1." To "C4.", Wherein the metal line is formed in a mesh shape.
C7. The membrane is a movable film, the piezoelectric / pyroelectric element is a piezoelectric element, the piezoelectric / pyroelectric film is a piezoelectric film, and the piezoelectric / pyroelectric element utilization device is an inkjet printhead. C1. ”To“ C5. ”The piezoelectric / pyroelectric element utilizing device according to any one of the above. With this configuration, an ink jet print head having a movable film that is difficult to break can be obtained.

  C8. The cavity is formed in a rectangular shape in a plan view as viewed from the normal direction with respect to the main surface of the movable film, and the movable film is formed in a rectangular shape that matches the cavity edge in the plan view. The piezoelectric film is a rectangle having a width shorter than the width of the movable film in the short direction and a length shorter than the length of the movable film in the longitudinal direction in the plan view, and both end edges and both side edges thereof Are retracted inwardly of the movable film from both side edges and both side edges of the movable film, and the upper electrode has a width shorter than the width in the short direction of the movable film in the plan view, A rectangular shape having a length shorter than the length in the longitudinal direction of the movable film, and both end edges and both side edges thereof recede from the both end edges and both side edges of the movable film to the inside of the movable film. . " Pyroelectric utilization device.

In this configuration, since the piezoelectric film and the upper electrode are not disposed on the peripheral edge of the movable film, the displacement of the movable film can be increased.
C9. The membrane is a heat insulating film, the piezoelectric / pyroelectric element is a pyroelectric element, the piezoelectric / pyroelectric film is a pyroelectric film, and the piezoelectric / pyroelectric element utilizing device is an infrared image sensor. , "C1." Or "C4." With this configuration, an infrared image sensor having a heat insulating film that is difficult to break can be obtained.

C10. The cavity is formed in a circular shape in a plan view as viewed from the normal direction to the main surface of the heat insulating film, the metal line is embedded in the heat insulating film, and the metal line is The piezoelectric / pyroelectric device utilizing apparatus according to “C9.”, Which is formed in an annular stripe shape concentric with the cavity.
The second to fourth embodiments will be described in detail with reference to FIGS. The reference numerals in FIGS. 9 to 56 are irrelevant to the reference numerals in FIGS. 1A to 9 used in the description of the first invention.

  FIG. 9 is a schematic plan view of an ink jet print head to which the second invention is applied. FIG. 10 is a schematic enlarged sectional view taken along line XX in FIG. FIG. 11 is a schematic enlarged sectional view taken along line XI-XI in FIG. FIG. 12 is a schematic perspective view of the ink jet print head. However, in FIGS. 9 and 12, the hydrogen barrier film indicated by reference numeral 13 in FIGS. 10 and 11 and the insulating film indicated by reference numeral 14 are omitted. FIG. 13 is a plan view showing a planar shape of the lower electrode formed on the movable film forming layer by removing the configuration other than the lower electrode formed on the movable film forming layer.

  Referring to FIG. 10, the inkjet print head 1 includes a silicon substrate 2 and a nozzle substrate 3 having an ejection port 3a for ejecting ink. A movable film forming layer 10 is laminated on the silicon substrate 2. In the laminated body of the silicon substrate 2 and the movable film forming layer 10, a pressure chamber (cavity) 5 as an ink flow path (ink reservoir) is formed. The pressure chamber 5 is formed in the space portion 5A formed in the silicon substrate 2 and penetrating the silicon substrate 2 in the thickness direction, and formed on the back surface (surface on the silicon substrate 2 side) of the movable film forming layer 10 and in the space portion 5A. It is comprised from the continuous recessed part 5B.

  The nozzle substrate 3 is made of, for example, a silicon plate, and is bonded to the back surface of the silicon substrate 2 to partition the pressure chamber 5 together with the silicon substrate 2 and the movable film forming layer 10. The nozzle substrate 3 has a recess 3b facing the pressure chamber 5, and an ink discharge passage 3c is formed on the bottom surface of the recess 3b. The ink discharge passage 3 c passes through the nozzle substrate 3 and has a discharge port 3 a on the side opposite to the pressure chamber 5. Therefore, when the volume change of the pressure chamber 5 occurs, the ink stored in the pressure chamber 5 passes through the ink discharge passage 3c and is discharged from the discharge port 3a.

  The pressure chamber 5 is formed by digging the silicon substrate 2 and the movable film forming layer 10 from the back side of the silicon substrate 2. The silicon substrate 2 and the movable film forming layer 10 are further formed with an ink supply path 4 (see also FIGS. 9 and 11) communicating with the pressure chamber 5. The ink supply path 4 communicates with the pressure chamber 5 and is formed to guide ink from an ink tank (for example, an ink cartridge) that is an ink supply source to the pressure chamber 5.

The pressure chamber 5 is formed to be elongated along the ink flow direction 21 which is the left-right direction in FIG. The top wall portion of the pressure chamber 5 in the movable film forming layer 10 constitutes a movable film (membrane) 10A. The movable film 10A (movable film forming layer 10) is made of, for example, a silicon oxide (SiO ₂ ) film formed on the silicon substrate 2. The movable film 10A (movable film forming layer 10) is formed on, for example, a silicon (Si) layer formed on the silicon substrate 2, a silicon oxide (SiO ₂ ) layer formed on the silicon layer, and a silicon oxide layer. It may be composed of a laminated body with a silicon nitride (SiN) layer formed. In this specification, the movable film 10 </ b> A means the top wall portion that defines the pressure chamber 5 in the movable film forming layer 10. Therefore, portions of the movable film forming layer 10 other than the top wall portion of the pressure chamber 5 do not constitute the movable film 10A.

  The thickness of the movable film 10A is, for example, 0.4 μm to 2 μm. When the movable film 10A is made of a silicon oxide film, the thickness of the silicon oxide film may be about 1.2 μm. When the movable film 10A is composed of a stacked body of a silicon layer, a silicon oxide layer, and a silicon nitride layer, the thicknesses of the silicon layer, the silicon oxide layer, and the silicon nitride layer are about 0.4 μm, respectively. Also good.

  The pressure chamber 5 is partitioned by the movable film 10A, the silicon substrate 2, and the nozzle substrate 3, and is formed in a substantially rectangular parallelepiped shape in this embodiment. For example, the pressure chamber 5 may have a length of about 800 μm and a width of about 55 μm. The ink supply path 4 is formed so as to communicate with one end in the longitudinal direction of the pressure chamber 5 (in this embodiment, the end located on the side opposite to the ejection port 3a). In this embodiment, the discharge port 3a of the nozzle substrate 3 is disposed near the other end of the pressure chamber 5 in the longitudinal direction.

  A piezoelectric element 6 is disposed on the surface of the movable film 10A. The silicon substrate 2, the movable film 10A, and the piezoelectric element 6 constitute a piezoelectric actuator. The piezoelectric element 6 includes a lower electrode 7 formed on the movable film forming layer 10, a piezoelectric film 8 formed on the lower electrode 7, and an upper electrode 9 formed on the piezoelectric film 8. Yes. In other words, the piezoelectric element 6 is configured by sandwiching the piezoelectric film 8 between the upper electrode 9 and the lower electrode 7 from above and below.

  The lower electrode 7 has, for example, a two-layer structure in which a Ti (titanium) layer and a Pt (platinum) layer are sequentially stacked from the movable film 10A side. In addition, the lower electrode 7 can be formed of a single film such as an Au (gold) film, a Cr (chromium) layer, or a Ni (nickel) layer. The lower electrode 7 has a main electrode portion 7A in contact with the lower surface of the piezoelectric film 8 and an extension portion 7B (see also FIGS. 9 and 11 to 13) extending to an outer region of the piezoelectric film 8. doing.

As the piezoelectric film 8, for example, a PZT (PbZr _x Ti _1-x O ₃ : lead zirconate titanate) film formed by a sol-gel method or a sputtering method can be applied. Such a piezoelectric film 8 is made of a sintered body of metal oxide crystals. The thickness of the piezoelectric film 8 is preferably 1 μm to 5 μm. The total thickness of the movable film 10A is preferably about the same as the thickness of the piezoelectric film 8 or about 2/3 of the thickness of the piezoelectric film.

The upper electrode 9 is formed in substantially the same shape as the piezoelectric film 8 in plan view. In this embodiment, the upper electrode 9 has a four-layer structure in which a conductive oxide film (for example, an IrO ₂ (iridium oxide) film) and a metal film (for example, an IrO ₂ (iridium oxide) film) are alternately and repeatedly stacked twice. It has a structure.
The surface of the movable film forming layer 10, the surface of the piezoelectric element 6, and the surface of the extension 7 </ b> B of the lower electrode 7 are covered with the hydrogen barrier film 13. The hydrogen barrier film 13 is made of, for example, Al ₂ O ₃ (alumina). Thereby, characteristic deterioration due to hydrogen reduction of the piezoelectric film 8 can be prevented. An insulating film 14 is stacked on the hydrogen barrier film 13. Insulating film 14 is made of, for example, of SiO _2. A wiring 15 is formed on the insulating film 14. The wiring 15 is made of a metal material containing Al (aluminum).

  One end of the wiring 15 is disposed above one end of the upper electrode 9. Between the wiring 15 and the upper electrode 9, a through hole (contact hole) 16 that continuously penetrates the hydrogen barrier film 13 and the insulating film 14 is formed. One end of the wiring 15 enters the through hole 16 and is connected to the upper electrode 9 in the through hole 16. Further, in the hydrogen barrier film 13 and the insulating film 14, an opening 17 having a rectangular shape in plan view is formed in a region corresponding to the center portion of the surface of the upper electrode 9 (the portion surrounded by the peripheral edge portion on the surface of the upper electrode 9). Has been.

  In addition, an opening 18 that continuously penetrates the hydrogen barrier film 13 and the insulating film 14 is formed at a position corresponding to a predetermined region on the extended portion 7B of the lower electrode 7, and the surface of the lower electrode 7 is opened to the opening 18. Is exposed through. This exposed portion constitutes a pad portion 7d for connecting the lower electrode 7 to the outside. On the surface of the movable film forming layer 10, the hydrogen barrier film 13 and the insulating film 14 are only in a region near the upstream end of the piezoelectric element 6 on the upstream side of the upstream end in the ink flow direction 21 of the piezoelectric element 6. The hydrogen barrier film 13 and the insulating film 14 are not formed on the upstream side.

  The piezoelectric element 6 is formed at a position facing the pressure chamber 5 across the movable film 10A. That is, the piezoelectric element 6 is formed so as to be in contact with the surface of the movable film 10 </ b> A opposite to the pressure chamber 5. The pressure chamber 5 is filled with ink supplied from an ink tank (not shown) through the ink supply path 4. The movable film 10 </ b> A partitions the top surface portion of the pressure chamber 5 and faces the pressure chamber 5. The movable film 10A is supported by a portion around the pressure chamber 5 in the stacked body of the movable film forming layer 10 and the silicon substrate 2, and faces the pressure chamber 5 (in other words, the thickness direction of the movable film 10A). ) Is deformable and flexible.

  The wiring 15 and the pad portion 7 d of the lower electrode 7 are connected to the drive circuit 20. The drive circuit 20 may be formed in a region different from the pressure chamber 5 of the silicon substrate 2 or may be formed outside the silicon substrate 2. When a drive voltage is applied from the drive circuit 20 to the piezoelectric element 6, the piezoelectric film 8 is deformed by the inverse piezoelectric effect. As a result, the movable film 10A is deformed together with the piezoelectric element 6, whereby the volume of the pressure chamber 5 is changed, and the ink in the pressure chamber 5 is pressurized. The pressurized ink is discharged as fine droplets from the discharge port 3a through the ink discharge passage 3c.

  Referring to FIGS. 9 to 13, a plurality of pressure chambers 5 are formed in a stripe shape in the stacked body of silicon substrate 2 and movable film forming layer 10 so as to extend in parallel to each other. The plurality of pressure chambers 5 are formed at equal intervals with a minute interval (for example, about 30 μm to 350 μm) in the width direction thereof. Each of the pressure chambers 5 has a rectangular shape that is elongated along the ink flow direction 21 from the ink supply path 4 toward the discharge path 3c in plan view. That is, the top surface portion of the pressure chamber 5 has two side edges 5 c and 5 d along the ink circulation direction 21 and two end edges 5 a and 5 b along a direction orthogonal to the ink circulation direction 21. The ink supply path 4 is divided into two paths at one end of the pressure chamber 5 and communicates with the common ink path 19. The common ink passage 19 communicates with the ink supply paths 4 corresponding to the plurality of pressure chambers 5 and is formed to supply ink from the ink tanks to these ink supply paths 4.

  The piezoelectric element 6 is formed such that the length in the ink distribution direction 21 (the same direction as the longitudinal direction of the movable film 10A) is shorter than the length in the longitudinal direction of the movable film 10A, and has a rectangular shape in plan view. . As shown in FIG. 9, both end edges 6a and 6b along the short direction of the piezoelectric element 6 are spaced a predetermined distance d1 (for example, 5 μm) from the corresponding both end edges 10Aa and 10Ab of the movable film 10A. Is placed inside. In addition, the piezoelectric element 6 has a width in the short direction (direction parallel to the main surface of the silicon substrate 2) perpendicular to the longitudinal direction of the movable film 10A, and the short width of the movable film 10A (the top surface portion of the pressure chamber 5). It is formed narrower than the width in the direction. Then, both side edges 6c and 6d along the longitudinal direction of the piezoelectric element 6 are arranged on the inner side with a predetermined distance d2 (for example, 5 μm) with respect to the corresponding side edges 10Ac and 10Ad of the movable film 10A.

  As shown in FIGS. 9 and 13, the lower electrode 7 has a predetermined width in a direction along the ink flow direction 21 and a plurality of pressure chambers 5 in a direction perpendicular to the ink flow direction 21 in plan view. Is a common electrode shared by a plurality of piezoelectric elements 6. The first side 7a along the direction orthogonal to the ink flow direction 21 of the lower electrode 7 is aligned with a line connecting one end edges 6a of the plurality of piezoelectric elements 6 in plan view. The second side 7b facing the first side 7a of the lower electrode 7 is outside the edge 10Ab of the movable film 10A corresponding to the other edge 6b of the plurality of piezoelectric elements 6 (downstream in the ink flow direction 21). Side).

  The lower electrode 7 is a main electrode portion 7A having a rectangular shape in plan view that constitutes the piezoelectric element 6, and is drawn out from the main electrode portion 7A in a direction along the surface of the movable film forming layer 10, and the top surface portion of the pressure chamber 5 (movable film) 10A) and an extension portion 7B extending outward from the periphery of the top surface of the pressure chamber 5 across the periphery. The main electrode portion 7A is formed to be shorter than the movable film 10A along the longitudinal direction of the movable film 10A, and both end edges of the main electrode part 7A are predetermined with respect to the corresponding both end edges 10Aa and 10Ab of the movable film 10A. It arrange | positions inside the space | interval d1. Further, the main electrode portion 7A is formed such that the width along the short direction of the movable film 10A is narrower than the width of the movable film 10A in the short direction, and both end edges thereof correspond to both sides corresponding to the movable film 10A. With respect to the edges 10Ac, 10Ad, the gap d2 is provided at an inner side.

The extension portion 7B extends from the side edges of the main electrode portion 7A to the corresponding side edges 5c and 5d of the top surface portion of the pressure chamber 5 in plan view, and extends outside the side edges 5c and 5d of the top surface portion of the pressure chamber 5. It extends toward. The extension portion 7B is a region excluding the main electrode portion 7A in the entire region of the lower electrode 7.
In the extension part 7B, a cut-out part 7c having a rectangular shape in plan view that penetrates the lower electrode 7 is formed on the downstream side of the ink flowing direction 21 of each piezoelectric element 6. Each cut portion 7 c has two side edges (short sides) along the ink circulation direction 21 and two end edges (long sides) along a direction orthogonal to the ink circulation direction 21 in plan view. . One edge of the cut portion 7c is arranged at a position aligned with the edge 6b of the piezoelectric element 6 (the edge on the downstream side of the main electrode portion 7A) with respect to the ink flow direction 21, and the other edge of the cut portion 7c is the movable film 10A. It is arranged outside the end edge 10Ab (on the downstream side in the ink circulation direction 21). One side edge of the cut portion 7c is disposed outside the one side edge 10Ac of the movable film 10A, and the other side edge of the cut portion 7c is disposed outside the other side edge 10Ad of the movable film 10A. Yes. Therefore, in a plan view, the end of the movable film 10A on the side of the end edge 10Ab is disposed inside the cut portion 7c. In a region between the second side 7b of the lower electrode 7 and the plurality of cut portions 7c, a rectangular pad portion 7d that is elongated in a direction orthogonal to the ink circulation direction 21 is formed.

  9 to 12, the upper electrode 9 is formed in a rectangular shape having the same pattern as the main electrode portion 7A of the lower electrode 7 in plan view. That is, the upper electrode 9 is formed to be shorter than the movable film 10A along the longitudinal direction of the movable film 10A, and both end edges of the upper electrode 9 are predetermined with respect to the corresponding both end edges 10Aa and 10Ab of the movable film 10A. The space d1 is arranged inside with a gap d1. Further, the upper electrode 9 is formed so that the width along the short direction of the movable film 10A is narrower than the width of the movable film 10A in the short direction, and both end edges thereof correspond to both side edges corresponding to the movable film 10A. With respect to 10Ac and 10Ad, it arrange | positions inside the said space | interval d2.

  The piezoelectric film 8 is formed in a rectangular shape having the same pattern as that of the upper electrode 9 in plan view. That is, the piezoelectric film 8 is formed to be shorter than the movable film 10A along the longitudinal direction of the movable film 10A, and both end edges thereof are predetermined with respect to the corresponding both end edges 10Aa and 10Ab of the movable film 10A. Are arranged inside with a gap d1. In addition, the piezoelectric film 8 is formed such that the width along the short direction of the movable film 10A is narrower than the width of the movable film 10A in the short direction, and both end edges thereof correspond to both sides corresponding to the movable film 10A. With respect to the edges 10Ac, 10Ad, the gap d2 is provided at an inner side. The lower surface of the piezoelectric film 8 is in contact with the upper surface of the main electrode portion 7 A of the lower electrode 7, and the upper surface of the piezoelectric film 8 is in contact with the lower surface of the upper electrode 9.

  The wiring 15 has one end connected to one end of the upper electrode 9 (the end on the one end edge 6a side of the piezoelectric element 6) and a lead portion 15A extending in a direction opposite to the ink flow direction 21 in plan view. The pad portion 15B is integrated with the lead portion 15A and connected to the tip of the lead portion 15A. The pad portion 15B is formed on the surface of the movable film forming layer 10 where the hydrogen barrier film 13 and the insulating film 14 are not formed, upstream of the one edge 6a of the piezoelectric element 6 in the ink flow direction 21. Yes. The lead portion 15A is an insulating material that covers one end portion of the upper surface of the piezoelectric element 6 (the end portion on the one end edge 6a side of the piezoelectric element 6), the end surface of the piezoelectric element 6 connected thereto, and the surface of the movable film forming layer 10 connected thereto. It has the 1st part formed on the film | membrane 14, and the 2nd part from the 1st part to the pad part 15B. The second portion is formed on the surface of the movable film forming layer 10 where the hydrogen barrier film 13 and the insulating film 14 are not formed.

FIG. 14 is an enlarged cross-sectional view showing the structure of the upper electrode 9 and the structure of the hydrogen barrier film 13, and corresponds to the cut surface of FIG.
The upper electrode 9 has a structure in which an IrO ₂ (iridium oxide) film 31 that is a conductive oxide film and an Ir (iridium) film 32 that is a metal film are alternately and repeatedly stacked twice. Specifically, the upper electrode 9 has a four-layer structure in which an IrO ₂ film 31, an Ir film 32, an IrO ₂ film 31, and an Ir film 32 are sequentially stacked from the piezoelectric film 8 side. The film thickness of each IrO ₂ film 31 is, for example, 20 nm, and the film thickness of each Ir film 32 is, for example, 10 nm.

The hydrogen barrier film 13 includes two types of sputtered films 41 and 42 formed under different conditions. Specifically, the hydrogen barrier film 13 has a two-layer structure in which a first sputter film 41 on the lower layer side and a second sputter film 42 on the upper layer side are laminated. In this embodiment, the first sputtered film 41 and the second sputtered film 42 are both made of a sputtered film of Al ₂ O ₃ (alumina). The first sputtered film 41 and the second sputtered film 42 may be a TiO film (titanium dioxide film) or a SiN film (silicon nitride film).

  The first sputtered film 41 is formed, for example, under a low pressure condition of 0.01 Pa or more and less than 0.1 Pa, and the second sputtered film 42 is formed, for example, under a high pressure condition of 0.1 Pa or more and 3.0 Pa or less. Is done. The film thickness of the first sputtered film 41 may be 10 nm or more and 100 nm or less. The film thickness of the second sputtered film 42 may be 10 nm or more and 100 nm or less. The total film thickness of the first sputtered film 41 and the second sputtered film 42 may be 100 nm or less. For example, the film thickness of the first sputtered film 41 may be 30 nm, and the film thickness of the second sputtered film 42 may be 30 nm.

The hydrogen barrier film 13 may be composed of three or more types of sputtered films formed under different conditions.
Although the insulating film 14 is formed after the piezoelectric element 6 is formed, hydrogen may enter the piezoelectric film 8 in the process of forming the insulating film 14 and the piezoelectric characteristics may be deteriorated.
In the above-described inkjet printhead 1, the upper electrode 9 has a four-layer structure in which the IrO ₂ film 31, the Ir film 32, the IrO ₂ film 31 and the Ir film 32 are stacked in this order from the piezoelectric film 8 side. A larger hydrogen barrier effect can be obtained with a thin overall film thickness than when the upper electrode is formed thick with a single metal film such as Ir. Thereby, characteristic deterioration due to hydrogen reduction of the piezoelectric film 8 can be suppressed. The reason for this will be described. The IrO ₂ film, which is a conductive oxide film, is sacrificed when hydrogen enters and changes to Ir. Thereby, it has a function of trapping or blocking hydrogen. The Ir film, which is a metal film, has a high density to some extent and has a barrier performance against oxygen and hydrogen. However, since it is polycrystalline, hydrogen may enter from a grain boundary. Therefore, an upper electrode having a high hydrogen barrier property can be obtained by alternately and repeatedly laminating an IrO ₂ film as a conductive oxide film and an Ir film as a metal film twice or more.

For example, an SrRuO ₃ (strontium ruthenate) film may be used as the conductive oxide film instead of the IrO ₂ film. Further, as the metal film, for example, Pt, Au or the like may be used instead of the Ir film.
As will be described later, in the process of forming the insulating film 14, the surface and side surfaces of the piezoelectric element 6 are covered with the hydrogen barrier film 13, and the hydrogen barrier film 13 also deteriorates the characteristics of the piezoelectric film 8 due to hydrogen reduction. Is suppressed. In particular, in the inkjet print head 1, the hydrogen barrier film 13 has a two-layer structure in which a first sputtered film 41 and a second sputtered film 42 formed under different conditions are stacked. Since the first sputtered film 41 and the second sputtered film 42 are formed under different conditions, they have different characteristics. That is, since the hydrogen barrier film 13 is composed of a laminated film of two types of sputtered films 41 and 42 having different characteristics, the hydrogen barrier property of the hydrogen barrier film 13 can be improved. Thereby, characteristic deterioration due to hydrogen reduction of the piezoelectric film 8 can be more effectively suppressed.

15A to 15M are cross-sectional views showing an example of the manufacturing process of the inkjet print head 1, and show a cut surface corresponding to FIG.
First, as shown in FIG. 15A, the movable film forming layer 10 is formed on the surface of the silicon substrate 2. However, the silicon substrate 2 is thicker than the final silicon substrate 2. Specifically, a silicon oxide layer (for example, 1.2 μm thick) is formed on the surface of the silicon substrate 2. In the case where the movable film forming layer 10 is composed of a laminated body of a silicon layer, a silicon oxide layer, and a silicon nitride layer, a silicon layer (for example, 0.4 μm thick) is formed on the surface of the silicon substrate 2, and the silicon layer A silicon oxide layer (for example, 0.4 μm thickness) is formed thereon, and a silicon nitride layer (for example, 0.4 μm thickness) is formed on the silicon oxide layer. A base oxide film such as Al ₂ O ₃ , MgO, ZrO ₂ may be formed on the surface of the movable film forming layer 10. These base oxide films prevent escape of metal atoms (for example, Pb) from the piezoelectric film 8 to be formed later. If metal electrons escape, the piezoelectric characteristics of the piezoelectric film 8 may deteriorate. Further, when the escaped metal atoms are mixed into the silicon layer constituting the movable film 10A, the durability of the movable film 10A may be deteriorated.

  Next, as shown in FIG. 15B, a lower electrode film that is a material layer of the lower electrode 7 is formed on the movable film forming layer 10 (on the base oxide film when the base oxide film is formed). 57 is formed. The lower electrode film 57 is made of, for example, a Pt / Ti laminated film having a Ti film (for example, 10 nm to 40 nm thickness) as a lower layer and a Pt film (for example, 10 nm to 400 nm thickness) as an upper layer. Such a lower electrode film 57 may be formed by sputtering.

Next, as shown in FIG. 15C, a material film (piezoelectric material film) 58 of the piezoelectric film 8 is formed on the entire surface of the lower electrode film 57. Specifically, for example, a PZT film having a thickness of 1 μm to 5 μm is formed by a sol-gel method. Such a PZT film is made of a sintered body of metal oxide crystal grains.
Next, as shown in FIG. 15D, an upper electrode film 59 that is a material of the upper electrode 9 is formed on the entire surface of the piezoelectric material film 58. As shown in FIG. 14, the upper electrode film 59 is made of an IrO ₂ film (for example, 20 nm thick), an Ir film (for example, 10 nm thick), an IrO ₂ film (for example, 20 nm thick), and an Ir film (for example, 10 nm thick) as a piezoelectric material. It consists of an Ir0 ₂ / Ir / Ir0 ₂ / Ir laminated film laminated in order from the film 58 side. Such an upper electrode film 59 may be formed by sputtering.

  Next, as shown in FIGS. 15E and 15F, the upper electrode film 59, the piezoelectric material film 58, and the lower electrode film 57 are patterned. First, as shown in FIG. 15E, a resist mask having a pattern of the lower electrode 7 is formed by photolithography, and the upper electrode film 59, the piezoelectric material film 58, and the lower electrode film 57 have the same pattern using the resist mask as a mask. As a result, the lower electrode film 57 having a predetermined pattern is formed. More specifically, the upper electrode film 59 is patterned by dry etching, the piezoelectric material film 58 is patterned by wet etching, and the lower electrode film 57 is patterned by dry etching. Thus, the lower electrode 7 is formed. The etchant used for wet etching of the piezoelectric material film 58 may be an acid mainly composed of hydrochloric acid.

  Next, after removing the resist mask, a resist mask having a pattern of the piezoelectric film 8 is formed by photolithography, and the upper electrode film 59 and the piezoelectric material film 58 are etched into the same pattern using this resist pattern. The More specifically, the upper electrode film 59 is patterned by dry etching, and the piezoelectric material film 58 is patterned by wet etching. Thereby, as shown in FIG. 15F, the piezoelectric film 8 and the upper electrode 9 are formed. Thereby, the piezoelectric element 6 including the main electrode portion 7A of the lower electrode, the piezoelectric film 8 and the upper electrode 9 is formed.

Next, as shown in FIG. 15G, after removing the resist mask, a hydrogen barrier film 13 covering the entire surface is formed. As shown in FIG. 14, the hydrogen barrier film 13 is a laminated film having the first sputtered film 41 as a lower layer and the second sputtered film 42 as an upper layer. The first sputtered film 41 is formed, for example, under a low pressure condition of 0.01 Pa or more and less than 0.1 Pa, and the second sputtered film 42 is formed, for example, under a high pressure condition of 0.1 Pa or more and 3.0 Pa or less. Is done. The first sputtered film 41 is, for example, an Al ₂ O ₃ film, and the film thickness may be 10 nm or more and 100 nm or less. The second sputtered film 42 is, for example, an Al ₂ O ₃ film, and the film thickness may be 10 nm or more and 100 nm or less.

Next, as shown in FIG. 15H, an insulating film 14 is formed on the entire surface of the hydrogen barrier film 13. The insulating film 14 may be a SiO ₂ film, and the film thickness may be 250 nm to 1000 nm.
Next, as shown in FIG. 15I, the piezoelectric element in the portion of the insulating film 14 and the hydrogen barrier film 13 that is upstream of the upstream edge of the ink flow direction 21 (see FIG. 10) of the piezoelectric element 6. A portion excluding the vicinity of 6 is removed. At the same time, the through hole 16 and the opening 18 are formed in both the insulating film 14 and the hydrogen barrier film 13.

Next, a wiring film constituting the wiring 15 is formed on the insulating film 14 including the inside of the through hole 16. Thereafter, the wiring film is patterned by photolithography and etching to form the wiring 15 connected to the upper electrode 9 as shown in FIG. 15J.
Next, as shown in FIG. 15K, an opening 17 is formed in the central region of the upper surface of the upper electrode 9 in the insulating film 14 and the hydrogen barrier film 13.

Next, as shown in FIG. 15L, back surface grinding for thinning the silicon substrate 2 is performed. By polishing the substrate 2 from the back surface, the substrate 2 is thinned. For example, the silicon substrate 2 having a thickness of about 670 μm in the initial state may be thinned to a thickness of about 300 μm.
Next, as shown in FIG. 15M, by performing etching (dry etching or wet etching) from the back surface of the silicon substrate 2 on the stacked body of the silicon substrate 2 and the movable film forming layer 10, the pressure chamber 5, The ink supply path 4 and the common ink path 19 are formed, and the movable film 10A is formed at the same time. During this etching, the base oxide film formed on the surfaces of the hydrogen barrier film 13 and the movable film forming layer 10 prevents the metal element (Pb, Zr, Ti in the case of PZT) from escaping from the piezoelectric film 8. In addition, the piezoelectric characteristics of the piezoelectric film 8 are kept good. Further, as described above, the base oxide film formed on the surface of the movable film forming layer 10 contributes to maintaining the durability of the silicon layer forming the movable film 10A.

Thereafter, although not shown in FIG. 15, the nozzle substrate 3 is bonded to the back surface of the silicon substrate 2 to obtain the ink jet print head 1 shown in FIGS. 9 to 12.
FIG. 16 is an enlarged cross-sectional view showing a modification of the hydrogen barrier film 13. FIG. 16 shows a cut surface corresponding to FIG. 16, portions corresponding to the respective portions in FIG. 14 described above are denoted by the same reference numerals as in FIG.

The hydrogen barrier film 13 is composed of a laminated film in which a lower-side sputtering film 43 formed by a sputtering method and an upper-layer plasma CVD film 44 formed by a plasma CVD (Chemical Vapor Deposition) method are laminated. ing. The sputtered film 43 is made of an Al ₂ O ₃ film formed by a sputtering method. The plasma CVD film 44 is made of a SiN film (silicon nitride film) formed by a plasma CVD method.

  The sputtered film 43 has a good hydrogen barrier property, but the coverage with respect to the side surface of the piezoelectric element 6 (side surface of the piezoelectric film 8) is not so good. Further, the sputtered film 43 easily generates pinholes when the surface of the piezoelectric film 8 is uneven. On the other hand, the plasma CVD film 44 is inferior to the sputtered film 43 in hydrogen barrier property, but easily penetrates into the side surface of the piezoelectric element 6 and has a high ability to fill a pinhole. For this reason, when the thickness of the hydrogen barrier film is the same, when the hydrogen barrier film is formed of a laminated film of a sputtered film and a plasma CVD film, compared to the case where the hydrogen barrier film is formed of only the sputtered film. This can enhance the hydrogen barrier effect.

In other words, when the hydrogen barrier film is formed of a laminated film of a sputtered film and a plasma CVD film, the hydrogen barrier film can be made thinner even if the hydrogen barrier film is made thinner than when the hydrogen barrier film is formed of only the sputtered film. Sex can be maintained. Therefore, since the hydrogen barrier film can be thinned, the displacement of the movable film 10A can be increased.
The film thickness of the sputtered film 43 may be 10 nm or more and 100 nm or less. The film thickness of the plasma CVD film 44 may be 10 nm or more and 100 nm or less. The total film thickness of the sputtered film 43 and the plasma CVD film 44 may be 100 nm or less. For example, the film thickness of the sputtered film 43 may be 30 nm, and the film thickness of the plasma CVD film 44 may be 30 nm. In order to reduce the thickness of the hydrogen barrier film 13, the film thickness of the sputtered film 43 may be made thinner than the film thickness of the plasma CVD film 44.

FIG. 17 is an enlarged cross-sectional view showing another modification of the hydrogen barrier film 13. FIG. 17 shows a cut surface corresponding to FIG. 17, portions corresponding to the respective portions in FIG. 14 are denoted by the same reference numerals as in FIG.
The hydrogen barrier film 13 includes a lowermost first sputtered film 45, an intermediate second sputtered film 46 formed under different conditions from the first sputtered film 45, and an uppermost plasma CVD film 47. It is comprised from the laminated film laminated | stacked. The first sputtered film 45 may be an Al ₂ O ₃ film formed under the same conditions as the first sputtered film 41 in FIG. The second sputtered film 46 may be an Al ₂ O ₃ film formed under the same conditions as the second sputtered film 42 in FIG. The plasma CVD film 47 is made of a SiN film formed by the plasma CVD method, like the plasma CVD film 44 of FIG.

  The film thickness of the first sputtered film 45 and the second sputtered film 46 may be 10 nm or more and 100 nm or less, respectively. The film thickness of the plasma CVD film 47 may be 10 nm or more and 100 nm or less. The total film thickness of the first sputtered film 45, the second sputtered film 46, and the plasma CVD film 47 may be 100 nm or less. For example, the thicknesses of the first sputtered film 45, the second sputtered film 46, and the plasma CVD film 47 may be 20 nm, respectively.

FIG. 18 is a schematic plan view showing a pyroelectric infrared image sensor. 19 is a cross-sectional view taken along line XIX-XIX in FIG.
The pyroelectric infrared image sensor 101 detects the amount of infrared rays by utilizing the fact that the surface charge of the pyroelectric material changes due to temperature changes caused by infrared rays. The pyroelectric infrared image sensor 101 includes a silicon substrate 102, a heat insulating film (membrane) 103 formed on the silicon substrate 102, and a pyroelectric element 104 formed on the heat insulating film 103.

In the silicon substrate 102, a cavity 105 for preventing heat transfer from the pyroelectric element 104 to the silicon substrate 102 is formed. The cavity 105 is formed by digging the silicon substrate 102 from the back side of the silicon substrate 102. The cavity 105 has a circular shape in plan view. The top surface of the cavity 105 is partitioned by a heat insulating film 103. The heat insulating film 103 is formed to cover the entire top surface of the cavity 105 and further extend to the periphery thereof. The heat insulating film 103 is composed of a silicon oxide (SiO ₂ ) film.

The pyroelectric element 104 includes a lower electrode 111 formed in contact with the surface of the heat insulating film 103 opposite to the cavity 105, a pyroelectric film 112 formed on the lower electrode 111, and the pyroelectric film 112. And an upper electrode 113 formed on the substrate.
The lower electrode 111 is made of, for example, a Pt film. The pyroelectric film 112 is made of, for example, a PZT (PbZr _x Ti _1-x O ₃ : lead zirconate titanate) film. The upper electrode 113 is made of, for example, a Pt film.

The lower electrode 111 is concentric with the center of the cavity 105 in a plan view and is formed in a circular shape having a diameter smaller than the diameter of the cavity 105. The pyroelectric film 112 is formed in the same pattern as the lower electrode 111. The upper electrode 113 is formed in the same pattern as the pyroelectric film 112.
The surfaces of the heat insulating film 103 and the pyroelectric element 104 are covered with a hydrogen barrier film 114. Although not shown, an insulating film is formed on the surface of the hydrogen barrier film 114. In the process of forming this insulating film, hydrogen may enter the pyroelectric film 112 and the pyroelectric characteristics may deteriorate. Therefore, a hydrogen barrier film 114 is formed on the surfaces of the heat insulating film 103 and the pyroelectric element 104.

  When the pyroelectric element 104 is irradiated with infrared rays, the temperature of the pyroelectric film 112 changes due to the heat, and the surface charge of the pyroelectric film 112 changes. Changes in the surface charge of the pyroelectric film 112 are taken out through the lower electrode 111 and the upper electrode 113. Thereby, the amount of infrared light can be detected. In FIG. 18 and FIG. 19, for convenience of explanation, the wiring for taking out the change in the surface charge of the pyroelectric film 112 from the lower electrode 111 and the upper electrode 113 is omitted.

FIG. 20A is an enlarged cross-sectional view showing the structure of the hydrogen barrier film 114.
The hydrogen barrier film 114 includes two types of sputtered films 121 and 122 formed under different conditions. Specifically, the hydrogen barrier film 114 has a two-layer structure in which a lower first sputtering film 121 and an upper second sputtering film 122 are stacked. Both the first sputtered film 121 and the second sputtered film 122 are made of a sputtered film of Al ₂ O ₃ (alumina). The first sputtered film 121 and the second sputtered film 122 may be a TiO film (titanium dioxide film) or a SiN film (silicon nitride film).

  The first sputtered film 121 is formed, for example, under a low pressure condition of 0.01 Pa or more and less than 0.1 Pa, and the second sputtered film 122 is formed, for example, under a high pressure condition of 0.1 Pa or more and 3.0 Pa or less. Is done. The film thickness of the first sputtered film 121 may be 10 nm or more and 100 nm or less. The film thickness of the second sputtered film 122 may be 10 nm or more and 100 nm or less. The total film thickness of the first sputtered film 121 and the second sputtered film 122 may be 100 nm or less. For example, the film thickness of the first sputtered film 121 may be 30 nm, and the film thickness of the second sputtered film 122 may be 30 nm. As described above, since the hydrogen barrier film 114 is formed by stacking the two types of sputtered films 121 and 122 having different characteristics, the hydrogen barrier property of the hydrogen barrier film 114 can be improved. Thereby, the characteristic deterioration by hydrogen reduction of the pyroelectric film 112 can be suppressed more effectively.

FIG. 20B is an enlarged cross-sectional view showing a modification of the hydrogen barrier film 114.
The hydrogen barrier film 114 is composed of a laminated film in which a lower-side sputtered film 123 formed by sputtering and an upper-layer plasma CVD film 124 formed by plasma CVD are stacked. The sputtered film 123 is made of an Al ₂ O ₃ film formed by a sputtering method. The plasma CVD film 124 is made of a SiN film (silicon nitride film) formed by a plasma CVD method.

  Although the sputtered film 123 has a good hydrogen barrier property, the coverage with respect to the side surface of the pyroelectric element 104 (the outer peripheral surface of the pyroelectric film 112) is not so good. In addition, the sputtered film 123 is likely to generate pinholes when the surface of the pyroelectric film 112 is uneven. On the other hand, the plasma CVD film 124 is inferior to the sputtered film 123 in hydrogen barrier properties, but easily penetrates to the outer peripheral surface of the pyroelectric element 104 and has a high ability to fill a pinhole. For this reason, when the thickness of the hydrogen barrier film is the same, when the hydrogen barrier film is formed of a laminated film of a sputtered film and a plasma CVD film, compared to the case where the hydrogen barrier film is formed of only the sputtered film. This can enhance the hydrogen barrier effect.

  The film thickness of the sputtered film 123 may be 10 nm or more and 100 nm or less. The film thickness of the plasma CVD film 124 may be 10 nm or more and 100 nm or less. The total film thickness of the sputtered film 123 and the plasma CVD film 124 may be 100 nm or less. For example, the film thickness of the sputtered film 123 may be 30 nm, and the film thickness of the plasma CVD film 124 may be 30 nm.

FIG. 20C is an enlarged cross-sectional view showing another modification of the hydrogen barrier film 114.
The hydrogen barrier film 114 includes a lowermost first sputtered film 125, an intermediate second sputtered film 126 formed under different conditions from the first sputtered film 125, and an uppermost plasma CVD film 127. It is comprised from the laminated film laminated | stacked. The first sputtered film 125 may be an Al ₂ O ₃ film formed under the same conditions as the first sputtered film 121 of FIG. 20A. The second sputtered film 126 may be an Al ₂ O ₃ film formed under the same conditions as the second sputtered film 122 in FIG. 20A. The plasma CVD film 127 is made of a SiN film formed by the plasma CVD method, similarly to the plasma CVD film 124 of FIG. 20B.

  The film thickness of the first sputtered film 125 and the second sputtered film 126 may be 10 nm or more and 100 nm or less, respectively. The film thickness of the plasma CVD film 127 may be 10 nm or more and 100 nm or less. The total thickness of the first sputtered film 125, the second sputtered film 126, and the plasma CVD film 127 may be 100 nm or less. For example, the film thicknesses of the first sputtered film 125, the second sputtered film 126, and the plasma CVD film 127 may be 20 nm, respectively.

  FIG. 21 is a schematic plan view showing an ink jet print head to which the third and fourth inventions are applied. FIG. 22 is a schematic enlarged sectional view taken along line XXII-XXII in FIG. FIG. 23 is a schematic enlarged sectional view taken along line XXIII-XXIII in FIG. FIG. 24 is a schematic perspective view of the ink jet print head. However, in FIGS. 21 and 24, the hydrogen barrier film indicated by reference numeral 13 and the insulating film indicated by reference numeral 14 in FIGS. 22 and 23 are omitted. FIG. 25 is a plan view showing a planar shape of the lower electrode formed on the movable film forming layer by removing the configuration other than the lower electrode formed on the movable film forming layer. FIG. 26 is an enlarged perspective view showing the structure of the upper electrode.

  Referring to FIG. 22, the inkjet print head 1 </ b> A includes a silicon substrate 2 and a nozzle substrate 3 having an ejection port 3 a that ejects ink. A movable film forming layer 10 is laminated on the silicon substrate 2. In the laminated body of the silicon substrate 2 and the movable film forming layer 10, a pressure chamber (cavity) 5 as an ink flow path (ink reservoir) is formed. The pressure chamber 5 is formed in the space portion 5A formed in the silicon substrate 2 and penetrating the silicon substrate 2 in the thickness direction, and formed on the back surface (surface on the silicon substrate 2 side) of the movable film forming layer 10 and in the space portion 5A. It is comprised from the continuous recessed part 5B.

  The nozzle substrate 3 is made of, for example, a silicon plate, and is bonded to the back surface of the silicon substrate 2 to partition the pressure chamber 5 together with the silicon substrate 2 and the movable film forming layer 10. The nozzle substrate 3 has a recess 3b facing the pressure chamber 5, and an ink discharge passage 3c is formed on the bottom surface of the recess 3b. The ink discharge passage 3 c passes through the nozzle substrate 3 and has a discharge port 3 a on the side opposite to the pressure chamber 5. Therefore, when the volume change of the pressure chamber 5 occurs, the ink stored in the pressure chamber 5 passes through the ink discharge passage 3c and is discharged from the discharge port 3a.

  The pressure chamber 5 is formed by digging the silicon substrate 2 and the movable film forming layer 10 from the back side of the silicon substrate 2. The silicon substrate 2 and the movable film forming layer 10 are further formed with an ink supply path 4 (see also FIGS. 21 and 23) communicating with the pressure chamber 5. The ink supply path 4 communicates with the pressure chamber 5 and is formed to guide ink from an ink tank (for example, an ink cartridge) that is an ink supply source to the pressure chamber 5.

The pressure chamber 5 is formed to be elongated along the ink flow direction 21 which is the left-right direction in FIG. The top wall portion of the pressure chamber 5 in the movable film forming layer 10 constitutes a movable film (membrane) 10A. The movable film 10A (movable film forming layer 10) is made of, for example, a silicon oxide (SiO ₂ ) film formed on the silicon substrate 2. The movable film 10A (movable film forming layer 10) is formed on, for example, a silicon (Si) layer formed on the silicon substrate 2, a silicon oxide (SiO ₂ ) layer formed on the silicon layer, and a silicon oxide layer. It may be composed of a laminated body with a silicon nitride (SiN) layer formed. In this specification, the movable film 10 </ b> A means the top wall portion that defines the pressure chamber 5 in the movable film forming layer 10. Therefore, portions of the movable film forming layer 10 other than the top wall portion of the pressure chamber 5 do not constitute the movable film 10A.

  The thickness of the movable film 10A is, for example, 0.4 μm to 2 μm. When the movable film 10A is made of a silicon oxide film, the thickness of the silicon oxide film may be about 1.2 μm. When the movable film 10A is composed of a stacked body of a silicon layer, a silicon oxide layer, and a silicon nitride layer, the thicknesses of the silicon layer, the silicon oxide layer, and the silicon nitride layer are about 0.4 μm, respectively. Also good.

  The pressure chamber 5 is partitioned by the movable film 10A, the silicon substrate 2, and the nozzle substrate 3, and is formed in a substantially rectangular parallelepiped shape in this embodiment. For example, the pressure chamber 5 may have a length of about 800 μm and a width of about 55 μm. The ink supply path 4 is formed so as to communicate with one end in the longitudinal direction of the pressure chamber 5 (in this embodiment, the end located on the side opposite to the ejection port 3a). In this embodiment, the discharge port 3a of the nozzle substrate 3 is disposed near the other end of the pressure chamber 5 in the longitudinal direction.

  A piezoelectric element 6 is disposed on the surface of the movable film 10A. The silicon substrate 2, the movable film 10A, and the piezoelectric element 6 constitute a piezoelectric actuator. The piezoelectric element 6 includes a lower electrode 7 formed on the movable film forming layer 10, a piezoelectric film 8 formed on the lower electrode 7, and an upper electrode 9 formed on the piezoelectric film 8. Yes. In other words, the piezoelectric element 6 is configured by sandwiching the piezoelectric film 8 between the upper electrode 9 and the lower electrode 7 from above and below.

The lower electrode 7 has, for example, a two-layer structure in which a Ti (titanium) layer and a Pt (platinum) layer are sequentially stacked from the movable film 10A side. The lower electrode 7 has a main electrode portion 7A in contact with the lower surface of the piezoelectric film 8 and an extension portion 7B (see also FIGS. 21, 24, and 25) extending to an outer region of the piezoelectric film 8. doing.
As the piezoelectric film 8, for example, a PZT (PbZr _x Ti _1-x O ₃ : lead zirconate titanate) film formed by a sol-gel method or a sputtering method can be applied. Such a piezoelectric film 8 is made of a sintered body of metal oxide crystals. The thickness of the piezoelectric film 8 is preferably 1 μm to 5 μm. The total thickness of the movable film 10A is preferably about the same as the thickness of the piezoelectric film 8 or about 2/3 of the thickness of the piezoelectric film.

The upper electrode 9 is formed in substantially the same shape as the piezoelectric film 8 in plan view. In this embodiment, the upper electrode 9 has a two-layer structure in which an IrO ₂ (iridium oxide) film 61 and an Ir (iridium) film 62 are sequentially stacked from the piezoelectric film 8 side.
The surface of the movable film forming layer 10, the surface of the piezoelectric element 6, and the surface of the extension 7 </ b> B of the lower electrode 7 are covered with the hydrogen barrier film 13. The hydrogen barrier film 13 is made of, for example, Al ₂ O ₃ (alumina). Thereby, characteristic deterioration due to hydrogen reduction of the piezoelectric film 8 can be prevented. An insulating film 14 is stacked on the hydrogen barrier film 13. Insulating film 14 is made of, for example, of SiO _2. A wiring 15 is formed on the insulating film 14. The wiring 15 is made of a metal material containing Al (aluminum).

  One end of the wiring 15 is disposed above one end of the upper electrode 9. Between the wiring 15 and the upper electrode 9, a through hole (contact hole) 16 that continuously penetrates the hydrogen barrier film 13 and the insulating film 14 is formed. One end of the wiring 15 enters the through hole 16 and is connected to the upper electrode 9 in the through hole 16. Further, in the hydrogen barrier film 13 and the insulating film 14, an opening 17 having a rectangular shape in plan view is formed in a region corresponding to the center portion of the surface of the upper electrode 9 (the portion surrounded by the peripheral edge portion on the surface of the upper electrode 9). Has been.

  In addition, an opening 18 that continuously penetrates the hydrogen barrier film 13 and the insulating film 14 is formed at a position corresponding to a predetermined region on the extended portion 7B of the lower electrode 7, and the surface of the lower electrode 7 is opened to the opening 18. Is exposed through. This exposed portion constitutes a pad portion 7d for connecting the lower electrode 7 to the outside. On the surface of the movable film forming layer 10, the hydrogen barrier film 13 and the insulating film 14 are only in a region near the upstream end of the piezoelectric element 6 on the upstream side of the upstream end in the ink flow direction 21 of the piezoelectric element 6. The hydrogen barrier film 13 and the insulating film 14 are not formed on the upstream side.

  The piezoelectric element 6 is formed at a position facing the pressure chamber 5 across the movable film 10A. That is, the piezoelectric element 6 is formed so as to be in contact with the surface of the movable film 10 </ b> A opposite to the pressure chamber 5. The pressure chamber 5 is filled with ink supplied from an ink tank (not shown) through the ink supply path 4. The movable film 10 </ b> A partitions the top surface portion of the pressure chamber 5 and faces the pressure chamber 5. The movable film 10A is supported by a portion around the pressure chamber 5 in the stacked body of the movable film forming layer 10 and the silicon substrate 2, and faces the pressure chamber 5 (in other words, the thickness direction of the movable film 10A). ) Is deformable and flexible.

  The wiring 15 and the pad portion 7 d of the lower electrode 7 are connected to the drive circuit 20. The drive circuit 20 may be formed in a region different from the pressure chamber 5 of the silicon substrate 2 or may be formed outside the silicon substrate 2. When a drive voltage is applied from the drive circuit 20 to the piezoelectric element 6, the piezoelectric film 8 is deformed by the inverse piezoelectric effect. As a result, the movable film 10A is deformed together with the piezoelectric element 6, whereby the volume of the pressure chamber 5 is changed, and the ink in the pressure chamber 5 is pressurized. The pressurized ink is discharged as fine droplets from the discharge port 3a through the ink discharge passage 3c.

  Referring to FIGS. 21 to 25, a plurality of pressure chambers 5 extend in parallel to each other and are formed in a stripe shape in the stacked body of silicon substrate 2 and movable film forming layer 10. The plurality of pressure chambers 5 are formed at equal intervals with a minute interval (for example, about 30 μm to 350 μm) in the width direction thereof. Each of the pressure chambers 5 has a rectangular shape that is elongated along the ink flow direction 21 from the ink supply path 4 toward the discharge path 3c in plan view. That is, the top surface portion of the pressure chamber 5 has two side edges 5 c and 5 d along the ink circulation direction 21 and two end edges 5 a and 5 b along a direction orthogonal to the ink circulation direction 21. The ink supply path 4 is divided into two paths at one end of the pressure chamber 5 and communicates with the common ink path 19. The common ink passage 19 communicates with the ink supply paths 4 corresponding to the plurality of pressure chambers 5 and is formed to supply ink from the ink tanks to these ink supply paths 4.

  The piezoelectric element 6 is formed such that the length in the ink distribution direction 21 (the same direction as the longitudinal direction of the movable film 10A) is shorter than the length in the longitudinal direction of the movable film 10A, and has a rectangular shape in plan view. . As shown in FIG. 21, both end edges 6a and 6b along the short direction of the piezoelectric element 6 are spaced apart from the corresponding both end edges 10Aa and 10Ab of the movable film 10A by a predetermined distance d1 (for example, 5 μm). Is placed inside. In addition, the piezoelectric element 6 has a width in the short direction (direction parallel to the main surface of the silicon substrate 2) perpendicular to the longitudinal direction of the movable film 10A, and the short width of the movable film 10A (the top surface portion of the pressure chamber 5). It is formed narrower than the width in the direction. Then, both side edges 6c and 6d along the longitudinal direction of the piezoelectric element 6 are arranged on the inner side with a predetermined distance d2 (for example, 5 μm) with respect to the corresponding side edges 10Ac and 10Ad of the movable film 10A.

  The lower electrode 7 includes a main electrode portion 7A having a rectangular shape in plan view that constitutes the piezoelectric element 6, and an extension portion 7B drawn from the main electrode portion 7A in a direction along the surface of the movable film forming layer 10. The main electrode portion 7A is formed to be shorter than the movable film 10A along the longitudinal direction of the movable film 10A, and both end edges of the main electrode part 7A are predetermined with respect to the corresponding both end edges 10Aa and 10Ab of the movable film 10A. It arrange | positions inside the space | interval d1. Further, the main electrode portion 7A is formed such that the width along the short direction of the movable film 10A is narrower than the width of the movable film 10A in the short direction, and both end edges thereof correspond to both sides corresponding to the movable film 10A. With respect to the edges 10Ac, 10Ad, the gap d2 is provided at an inner side.

  The extension portion 7B is configured to draw a common electrode portion 71 that is drawn out from the side edge of the downstream end portion of the plurality of main electrode portions 7A in the ink circulation direction 21 in a direction orthogonal to the ink circulation direction 21 and also extends in the ink circulation direction 21. Have. Further, the extension portion 7B is drawn out from both side edges of each main electrode portion 7A in a direction orthogonal to the ink circulation direction 21 on the upstream side of the common electrode portion 71 in the ink circulation direction 21, and the top surface portion of the pressure chamber 5 ( A plurality of linear electrode portions (metal lines) 72 extending outward from the side edges 10Ac, 10Ad of the top surface of the pressure chamber 5 across the side edges 10Ac, 10Ad of the movable film 10A).

  The common electrode portion 71 has a rectangular shape that is long in a direction orthogonal to the ink circulation direction 21 in plan view. In the common electrode portion 71, a cut-out portion 7c having a rectangular shape in plan view that penetrates the lower electrode 7 is formed on the downstream side in the ink flow direction 21 in each main electrode portion 7A. Each cut portion 7 c has two side edges (short sides) along the ink circulation direction 21 and two end edges (long sides) along a direction orthogonal to the ink circulation direction 21 in plan view. . One edge of the cut portion 7c is arranged at a position aligned with the edge 6b of the piezoelectric element 6 (the edge on the downstream side of the main electrode portion 7A) with respect to the ink flow direction 21, and the other edge of the cut portion 7c is the movable film 10A. It is arranged outside the end edge 10Ab (on the downstream side in the ink circulation direction 21). One side edge of the cut portion 7c is disposed outside the one side edge 10Ac of the movable film 10A, and the other side edge of the cut portion 7c is disposed outside the other side edge 10Ad of the movable film 10A. Yes. Therefore, in a plan view, the end of the movable film 10A on the side of the end edge 10Ab is disposed inside the cut portion 7c. In a region between the downstream edge of the common ink portion 71 in the ink circulation direction 21 and the plurality of cut portions 7c, a rectangular pad portion 7d that is elongated in a direction perpendicular to the ink circulation direction 21 is formed.

  The plurality of linear electrode portions 72 b drawn from the side edges of the main electrode portion 7 </ b> A are formed at intervals in the ink circulation direction 21. A plurality of linear electrode portions 72 drawn from one side edge of the main electrode portion 7A and a plurality of linear electrodes connected to the plurality of linear electrode portions 72 drawn from the other side edge of the main electrode portion 7A The portion 72 is aligned with respect to a direction orthogonal to the ink flow direction 21. And the several linear electrode part 72 pulled out from the side edge which the adjacent main electrode part 7A opposes is mutually connected. In other words, between the adjacent main electrode portions 7A, a plurality of linear electrode portions 72 are formed so as to connect the opposing side edges of these main electrode portions 7A. That is, the lower electrode 7 has a plurality of linear electrode portions 72 formed in a stripe pattern in a region outside the piezoelectric element 6.

Referring to FIGS. 21 to 24 and FIG. 26, the upper electrode 9 was formed so as to form a flat IrO ₂ film 61 formed on the piezoelectric film 8 and a stripe pattern on the IrO ₂ film 61. It comprises a plurality of linear Ir films 62. The IrO ₂ film 61 is formed in a rectangular shape having the same pattern as that of the main electrode portion 7A of the lower electrode 7 in plan view. That is, the IrO ₂ film 61 is formed shorter than the movable film 10A along the longitudinal direction of the movable film 10A, and both end edges of the IrO ₂ film 61 are predetermined with respect to the corresponding both end edges 10Aa and 10Ab of the movable film 10A. Are arranged inside with a gap d1. Further, the IrO ₂ film 61 is formed such that the width along the short direction of the movable film 10A is narrower than the width of the movable film 10A in the short direction, and both end edges thereof correspond to both sides corresponding to the movable film 10A. With respect to the edges 10Ac, 10Ad, the gap d2 is provided at an inner side.

A plurality of linear Ir film 62 extends parallel to the longitudinal direction of the IrO ₂ film 61 is formed over the entire length of the IrO ₂ film 61. The cross section of the Ir film 62 is rectangular. The thickness (groove portion) of the upper electrode 9 where the linear Ir film 62 is not formed is thinner than the thickness of the portion where the linear Ir film 62 is formed. Therefore, the upper electrode 9 has a plurality of thin film portions (groove portions) extending in the longitudinal direction.

  The piezoelectric film 8 is formed in a rectangular shape having the same pattern as that of the upper electrode 9 in plan view. That is, the piezoelectric film 8 is formed to be shorter than the movable film 10A along the longitudinal direction of the movable film 10A, and both end edges thereof are predetermined with respect to the corresponding both end edges 10Aa and 10Ab of the movable film 10A. Are arranged inside with a gap d1. In addition, the piezoelectric film 8 is formed such that the width along the short direction of the movable film 10A is narrower than the width of the movable film 10A in the short direction, and both end edges thereof correspond to both sides corresponding to the movable film 10A. With respect to the edges 10Ac, 10Ad, the gap d2 is provided at an inner side. The lower surface of the piezoelectric film 8 is in contact with the upper surface of the main electrode portion 7 A of the lower electrode 7, and the upper surface of the piezoelectric film 8 is in contact with the lower surface of the upper electrode 9.

  The wiring 15 has one end connected to one end of the upper electrode 9 (the end on the one end edge 6a side of the piezoelectric element 6) and a lead portion 15A extending in a direction opposite to the ink flow direction 21 in plan view. The pad portion 15B is integrated with the lead portion 15A and connected to the tip of the lead portion 15A. The pad portion 15B is formed on the surface of the movable film forming layer 10 where the hydrogen barrier film 13 and the insulating film 14 are not formed, upstream of the one edge 6a of the piezoelectric element 6 in the ink flow direction 21. Yes. The lead portion 15A is an insulating material that covers one end portion of the upper surface of the piezoelectric element 6 (the end portion on the one end edge 6a side of the piezoelectric element 6), the end surface of the piezoelectric element 6 connected thereto, and the surface of the movable film forming layer 10 connected thereto. It has the 1st part formed on the film | membrane 14, and the 2nd part from the 1st part to the pad part 15B. The second portion is formed on the surface of the movable film forming layer 10 where the hydrogen barrier film 13 and the insulating film 14 are not formed.

The manufacturing process of the ink jet print head 1A shown in FIG. 21 is the same as the manufacturing process (FIGS. 15A to 15M) of the ink jet print head 1 shown in FIG.
In the movable film 10A, an annular region between the peripheral edges 10Aa to 10Ad of the movable film 10A and the peripheral edges 6a to 6d of the piezoelectric element 6 (in this embodiment, a rectangular annular area elongated in the ink flow direction 21) is the piezoelectric element 6 or This is a region that is not constrained by the peripheral wall of the pressure chamber 5, and is a main deformation region in which large deformation occurs. That is, the peripheral portion of the movable film 10A is a main deformation region where large deformation occurs. Therefore, when the piezoelectric element 6 is driven, the peripheral edge of the movable film 10A is bent so that the inner peripheral edge of the peripheral edge of the movable film 10A is displaced in the thickness direction of the pressure chamber 5 (downward in this embodiment). As a result, the entire central portion surrounded by the peripheral edge of the movable film 10A is displaced in the thickness direction of the pressure chamber 5 (downward in this embodiment). At this time, the movable film 10 </ b> A warps and deforms in the short direction so that the central portion of the width is displaced in the thickness direction of the pressure chamber 5 (downward in this embodiment).

  If the main deformation region of the movable film 10A is constituted only by the movable film 10A, the displacement of the movable film 10A can be increased. However, since the movable film 10A is a hard and brittle material such as silicon oxide, it is easily broken. Therefore, the movable film 10A can be reinforced by forming the lower electrode 7 over the entire main deformation region of the movable film 10A as in the ink jet print head 1 of FIG. 9 described above, but the displacement of the movable film 10A is small. Become.

  In the ink jet print head 1 </ b> A of FIG. 21, the lower electrode 7 has a plurality of linear electrode portions (metal lines) 72 formed in a stripe pattern in a region outside the piezoelectric element 6. Since the linear electrode portion 72 made of metal is formed at a high temperature and then cooled to normal temperature and contracts, the linear electrode portion 72 has a tensile stress. That is, since the linear electrode portion 72 exerts a force in the contracting direction on the movable film 10A, the movable film 10A is hardly broken. Further, since the linear electrode portion 72 is formed not in the entire main deformation area of the movable film 10A but in a part of the main deformation area, compared with the case where the lower electrode is formed in the entire main deformation area of the movable film 10A. The displacement of the movable film 10A does not decrease.

Note that the plurality of linear electrode portions 72 may be formed so as to form a stripe pattern or a mesh pattern between the piezoelectric element 6 and the edge of the pressure chamber 5 (periphery of the movable film 10A).
In the ink jet print head 1A shown in FIG. 21, the upper electrode 9 has a plurality of thin film portions (groove portions) extending in the longitudinal direction. Thereby, when the piezoelectric element 6 is driven, the movable film 10A is easily warped and deformed in the short direction, so that the displacement of the movable film 10A can be increased. Further, the portion (thick film portion) where the linear Ir film 62 is formed in the upper electrode 9 contributes to lowering the resistance of the upper electrode 9. Therefore, it is possible to soften the upper electrode 9 while lowering the direct current resistance of the upper electrode 9, thereby increasing the displacement of the movable film 10A and improving the operation speed (responsiveness).

FIG. 27 is an enlarged perspective view showing a first modification of the upper electrode 9.
As in the case of the upper electrode 9 shown in FIG. 26, the upper electrode 9 includes a flat IrO ₂ film 61 formed on the piezoelectric film 8 and a plurality of linear shapes formed on the IrO ₂ film 61 in stripes. An Ir film 62 is included. 26 is different from the upper electrode 9 shown in FIG. 26 in that the cross section of the projecting portion made of the IrO ₂ film 61 is trapezoidal.

FIG. 28 is an enlarged perspective view showing a second modification of the upper electrode 9.
As with the upper electrode 9 shown in FIG. 26, the upper electrode 9B includes an IrO ₂ film 61 formed on the piezoelectric film 8 and a plurality of linear Ir films formed on the IrO ₂ film 61 in a stripe shape. 62. The IrO ₂ film 61 has a plurality of linear grooves (linear recesses) 61a on the surface thereof that are aligned with the grooves between the adjacent linear Ir films 62 and the outer grooves of the linear Ir films 62 on both sides. .

FIG. 29 is an enlarged perspective view showing a third modification of the upper electrode 9.
The upper electrode 9 </ _b > C includes a flat IrO ₂ film 61 formed on the piezoelectric film 8 and an Ir film 62 formed on the IrO ₂ film 61. The Ir film 62 includes a plurality of linear portions 62A formed in the longitudinal intermediate portion of the surface of the IrO ₂ film 61, and a solid pattern portion 62B formed at both ends of the linear portions 62A. Yes. The plurality of linear portions 62 </ _b > A are formed in parallel to the longitudinal direction of the IrO ₂ film 61. That is, the plurality of linear portions 62A are formed in a stripe shape. Each solid pattern portion 62B is a portion where the Ir film 62 is formed on the entire surface of the corresponding end portion of the IrO ₂ film 61. The corresponding end portions of the plurality of linear portions 62A are connected to each solid pattern portion 62B.

FIG. 30 is an enlarged perspective view showing a fourth modification of the upper electrode 9.
In the upper electrode 9D, similarly to the upper electrode 9C of FIG. 29, the Ir film 62 includes a plurality of linear portions 62A formed in the longitudinal intermediate portion of the surface of the IrO ₂ film 61, and these linear portions 62A. And a solid pattern portion 62B formed at both ends. The plurality of linear portions 62A is different from the upper electrode 9C of FIG. 29 in that the linear portions 62A include a linear portion 62A formed in a curved shape in plan view.

FIG. 31 is an enlarged perspective view showing a fifth modification of the upper electrode 9.
The upper electrode 9E is composed of a flat IrO ₂ film 61 formed on the piezoelectric film 8 and a plurality of dot-like Ir films 62 formed on the IrO ₂ film 61. The plurality of dot-like Ir films 62 are arranged in a plurality of rows arranged in the short direction of the IrO ₂ film 61 and extending in the longitudinal direction thereof.

FIG. 32 is an enlarged perspective view showing a sixth modification of the upper electrode 9.
The upper electrode 9F is composed of a flat IrO ₂ film 61 formed on the piezoelectric film 8 and an Ir film 62 covering the surface of the IrO ₂ film 61. A plurality of linear grooves 63 extending in parallel with the longitudinal direction of the Ir film 62 are formed on the surface of the Ir film 62. That is, the plurality of linear grooves 63 are formed in a stripe shape. The groove 63 does not penetrate the Ir film 62, and the bottom of the groove 63 is also formed by the Ir film 62. The cross section of the groove 63 is rectangular. However, the two grooves 63 on both sides open upward and also open outward.

FIG. 33 is an enlarged perspective view showing a seventh modification of the upper electrode 9.
Similar to the upper electrode 9F shown in FIG. 32, the upper electrode 9G is composed of a flat IrO ₂ film 61 formed on the piezoelectric film 8 and an Ir film 62 covering the surface of the IrO ₂ film 61. Yes. A plurality of linear grooves 63 extending in parallel with the longitudinal direction of the Ir film 62 are formed on the surface of the Ir film 62. 32 is different from the upper electrode 9F shown in FIG. 32 in that the cross section of the groove 63 is trapezoidal.

FIG. 34 is an enlarged perspective view showing an eighth modification of the upper electrode 9.
Similar to the upper electrode 9F shown in FIG. 32, the upper electrode 9H is composed of a flat IrO ₂ film 61 formed on the piezoelectric film 8 and an Ir film 62 covering the surface of the IrO ₂ film 61. Yes. A plurality of linear grooves 63 extending in parallel with the longitudinal direction of the Ir film 62 are formed on the surface of the Ir film 62. 32 is different from the upper electrode 9F shown in FIG. 32 in that the cross section of the groove 63 is V-shaped.

FIG. 35 is an enlarged perspective view showing a ninth modification of the upper electrode 9.
Similar to the upper electrode 9F shown in FIG. 32, the upper electrode 9I is composed of a flat IrO ₂ film 61 formed on the piezoelectric film 8 and an Ir film 62 covering the surface of the IrO ₂ film 61. Yes. A plurality of linear grooves 64 extending in parallel with the longitudinal direction of the Ir film 62 are formed in the longitudinal middle portion of the surface of the Ir film 62. That is, the plurality of linear grooves 64 are formed in a stripe shape. The bottom of the groove 64 is also formed by the Ir film 62. The cross section of the groove 64 is rectangular. However, the two grooves 64 on both sides open upward and open outward. Both end portions of the Ir film 62 are formed in the solid pattern portion 65 where the groove 64 is not formed.

FIG. 36 is an enlarged perspective view showing a tenth modification of the upper electrode 9.
In the upper electrode 9J, similarly to the upper electrode 9H in FIG. 35, a plurality of linear grooves 64 extending in the longitudinal direction of the Ir film 62 are formed in the longitudinal middle portion of the surface of the Ir film 62. . Both end portions of the Ir film 62 are formed in the solid pattern portion 65 where the groove 64 is not formed. The plurality of grooves 64 are different from the upper electrode 9I of FIG. 35 in that they include grooves having curved portions in plan view.

FIG. 37 is an enlarged perspective view showing an eleventh modification of the upper electrode 9.
The upper electrode 9K includes a flat IrO ₂ film 61 formed on the piezoelectric film 8 and an Ir film 62 that covers the surface of the IrO ₂ film 61. Grooves 66 are formed in a lattice pattern on the surface of the Ir film 62, and a plurality of dot-shaped protrusions 67 are formed by the grooves 66. The plurality of dot-like protrusions 67 are arranged in a plurality of rows aligned in the short direction of the IrO ₂ film 61 and extending in the longitudinal direction in plan view.

FIG. 38 is an enlarged perspective view showing a twelfth modification of the upper electrode 9.
The upper electrode 9L is made of, for example, a single metal film made of an Ir film. A plurality of linear grooves 91 extending in parallel with the longitudinal direction of the upper electrode 9L are formed on the surface of the upper electrode 9L. That is, the plurality of linear grooves 91 are formed in a stripe shape. The cross section of the groove 91 is rectangular. However, the two grooves 91 on both sides open upward and open outward.

FIG. 39 is an enlarged perspective view showing a thirteenth modification of the upper electrode 9.
The upper electrode 9M is made of, for example, a single metal film made of an Ir film, similarly to the upper electrode 9L shown in FIG. A plurality of linear grooves 91 extending in parallel with the longitudinal direction of the upper electrode 9M are formed on the surface of the upper electrode 9M. It differs from the upper electrode 9L shown in FIG. 38 in that the cross section of the groove 91 is trapezoidal.

FIG. 40 is an enlarged perspective view showing a fourteenth modification of the upper electrode 9.
The upper electrode 9N is made of, for example, a single metal film made of an Ir film, similarly to the upper electrode 9L shown in FIG. A plurality of linear grooves 91 extending in the longitudinal direction of the upper electrode 9N are formed on the surface of the upper electrode 9N. It differs from the upper electrode 9L shown in FIG. 38 in that the cross section of the groove 91 is V-shaped.

FIG. 41 is an enlarged perspective view showing a fifteenth modification of the upper electrode 9.
The upper electrode 9O is composed of, for example, a single metal film made of an Ir film, similarly to the upper electrode 9L shown in FIG. A plurality of linear grooves 92 extending in parallel with the longitudinal direction of the upper electrode 9O are formed in the middle portion in the longitudinal direction of the surface of the upper electrode 9O. Both end portions of the upper electrode 9O are formed in a solid pattern portion 93 in which the groove 92 is not formed. However, the two grooves 92 on both sides open upward and also open outward.

FIG. 42 is an enlarged perspective view showing a sixteenth modification of the upper electrode 9.
In the upper electrode 9P, like the upper electrode 9O in FIG. 41, a plurality of linear grooves 92 extending in the longitudinal direction of the upper electrode 9P are formed in the middle portion in the longitudinal direction of the surface of the upper electrode 9P. . Both end portions of the upper electrode 9P are formed in a solid pattern portion 93 where the groove 92 is not formed. The plurality of grooves 92 are different from the upper electrode 9O of FIG. 41 in that they include grooves having curved portions in plan view.

FIG. 43 is an enlarged perspective view showing a seventeenth modification of the upper electrode 9.
The upper electrode 9Q is made of, for example, a single metal film made of an Ir film. Grooves 94 are formed in a lattice pattern on the surface of the upper electrode 9Q, and a plurality of dot-shaped protrusions 95 are formed by the grooves 94. The plurality of dot-like protrusions 95 are arranged in a plurality of rows aligned in the short direction of the upper electrode 9Q and extending in the longitudinal direction in plan view.

  FIG. 44 is a schematic plan view showing another example of an ink jet print head to which the third and fourth inventions are applied. 45 is a schematic enlarged sectional view taken along line LXV-LXV in FIG. 46 is a schematic enlarged sectional view taken along line LXVI-LXVI in FIG. FIG. 47 is a schematic perspective view of an ink jet print head. However, in FIGS. 44 and 47, the hydrogen barrier film indicated by reference numeral 13 and the insulating film indicated by reference numeral 14 in FIGS. 45 and 46 are omitted. FIG. 48 is a plan view showing a planar shape of the lower electrode formed on the movable film forming layer by removing the configuration other than the lower electrode formed on the movable film forming layer. 44 to 48, portions corresponding to the respective portions in FIGS. 21 to 25 described above are denoted by the same reference numerals as those in FIGS.

The ink jet print head 1B is different in the pattern of the lower electrode 7 from the ink jet print head 1A shown in FIG. The other points are the same as those of the ink jet print head 1A of FIG.
The lower electrode 7 is a flat plate having a predetermined width in a direction along the ink circulation direction 21 and extending across the plurality of pressure chambers 5 in a direction orthogonal to the ink circulation direction 21 in a plan view. This is a common electrode shared for the piezoelectric element 6. The first side 7a along the direction orthogonal to the ink flow direction 21 of the lower electrode 7 is aligned with a line connecting one end edges 6a of the plurality of piezoelectric elements 6 in plan view. The second side 7b facing the first side 7a of the lower electrode 7 is outside the edge 10Ab of the movable film 10A corresponding to the other edge 6b of the plurality of piezoelectric elements 6 (downstream in the ink flow direction 21). Side).

  The lower electrode 7 includes a main electrode portion 7A having a rectangular shape in plan view that constitutes the piezoelectric element 6, and an extension portion 7B drawn from the main electrode portion 7A in a direction along the surface of the movable film forming layer 10. The main electrode portion 7A is formed to be shorter than the movable film 10A along the longitudinal direction of the movable film 10A, and both end edges of the main electrode part 7A are predetermined with respect to the corresponding both end edges 10Aa and 10Ab of the movable film 10A. It arrange | positions inside the space | interval d1. Further, the main electrode portion 7A is formed such that the width along the short direction of the movable film 10A is narrower than the width of the movable film 10A in the short direction, and both end edges thereof correspond to both sides corresponding to the movable film 10A. With respect to the edges 10Ac, 10Ad, the gap d2 is provided at an inner side. The extension portion 7B is a region excluding the main electrode portion 7A in the entire region of the lower electrode 7.

  In the extension part 7B, a cut-out part 7c having a rectangular shape in plan view that penetrates the lower electrode 7 is formed on the downstream side of the ink flowing direction 21 of each piezoelectric element 6. Each cut portion 7 c has two side edges (short sides) along the ink circulation direction 21 and two end edges (long sides) along a direction orthogonal to the ink circulation direction 21 in plan view. . One edge of the cut portion 7c is arranged at a position aligned with the edge 6b of the piezoelectric element 6 (the edge on the downstream side of the main electrode portion 7A) with respect to the ink flow direction 21, and the other edge of the cut portion 7c is the movable film 10A. It is arranged outside the end edge 10Ab (on the downstream side in the ink circulation direction 21). One side edge of the cut portion 7c is disposed outside the one side edge 10Ac of the movable film 10A, and the other side edge of the cut portion 7c is disposed outside the other side edge 10Ad of the movable film 10A. Yes. Therefore, in a plan view, the end of the movable film 10A on the side of the end edge 10Ab is disposed inside the cut portion 7c. In a region between the second side 7b of the lower electrode 7 and the plurality of cut portions 7c, a rectangular pad portion 7d that is elongated in a direction orthogonal to the ink circulation direction 21 is formed.

  Further, the extending portion 7B includes a plurality of cut portions 7e in the vicinity of the outside of each side edge of the main electrode portion 7A (side edges 6c and 6d of the piezoelectric element 6) along each side edge of the main electrode portion 7A. Is formed. The plurality of cut portions 7e are formed at intervals in the longitudinal direction of the main electrode portion 7A. Each cut portion 7e has a rectangular shape in plan view, and includes two side edges (long sides) along the ink circulation direction 21 and two end edges (short sides) along a direction orthogonal to the ink circulation direction 21. Have.

  One side edge of each cut portion 7c formed in the region near the outside of one side edge 6c of the piezoelectric element 6 is disposed at a position aligned with one side edge 6c of the piezoelectric element 6, and the other side edge is movable. The membrane 10A is disposed outside the side edge 10Ac. One side edge of each cut portion 7e formed in a region near the outside of the other side edge 6d of the piezoelectric element 6 is disposed at a position aligned with the other side edge 6d of the piezoelectric element 6, and the other side edge is movable. It is arranged outside the side edge 10Ad of the film 10A.

  Since such a plurality of cut portions 7e are formed in the extension portion 7B, the extension portion 7B is formed in a mesh pattern (lattice pattern) in plan view in the outer region of both side edges 6c and 6d of the piezoelectric element 6. Yes. More specifically, in the region near the outside of each side edge of the main electrode portion 7A, the extension portion 7B is drawn out from both side edges of the main electrode portion 7A in a direction perpendicular to the ink flow direction 21, and the top of the pressure chamber 5 is drawn. A plurality of linear electrode portions 73 extending outward from the top surface portion of the pressure chamber 5 across the periphery of the surface portion (movable film 10A) are provided. These linear electrode portions 73 are arranged in parallel with an interval in the ink flow direction 21. Therefore, the plurality of linear electrode portions 73 are formed in a stripe shape.

  That is, in the inkjet print head 1B of FIG. 44, the lower electrode 7 has a plurality of linear electrode portions (metal lines) 73 formed in a stripe pattern in a region near the outside of the piezoelectric element 6. Since the linear electrode portion 73 made of metal is formed at a high temperature and then cooled to normal temperature and contracts, the linear electrode portion 73 has a tensile stress. That is, the linear electrode portion 73 exerts a force in the contracting direction on the movable film 10A, so that the movable film 10A is hardly broken. Further, since the linear electrode portion 73 is formed not in the entire main deformation region of the movable film 10A but in a part of the region, compared to the case where the lower electrode is formed in the entire main deformation region of the movable film 10A. The displacement of the movable film 10A does not decrease.

The plurality of linear electrode portions 73 may be formed so as to form a stripe pattern or a mesh pattern between the piezoelectric element 6 and the edge of the pressure chamber 5 (periphery of the movable film 10A).
In the inkjet print head 1B of FIG. 44, the upper electrode 9 may have any one of the structures of the upper electrodes 9A to 9Q shown in FIGS.

  FIG. 49 is a schematic plan view showing still another example of the ink jet print head to which the third and fourth inventions are applied. FIG. 50 is a schematic enlarged sectional view taken along line LL in FIG. 51 is a schematic enlarged cross-sectional view taken along the line LI-LI in FIG. FIG. 52 is a schematic perspective view of an ink jet print head. However, in FIGS. 49 and 52, the hydrogen barrier film indicated by reference numeral 13 and the insulating film indicated by reference numeral 14 in FIGS. 50 and 51 are omitted. FIG. 53 is a plan view showing a planar shape of the lower electrode formed on the movable film forming layer by removing the configuration other than the lower electrode formed on the movable film forming layer. 49 to 53, portions corresponding to the respective portions in FIGS. 21 to 25 described above are denoted by the same reference numerals as those in FIGS.

The inkjet print head 1C is different in the structure of the movable film 10A (movable film forming layer 10) and the pattern of the lower electrode 7 from the inkjet print head 1A of FIG. The other points are the same as those of the ink jet print head 1A of FIG.
A stripe-pattern metal film 81 is embedded in the movable film forming layer 10. The stripe-patterned metal film 81 is composed of a plurality of linear metal films (metal lines) 81a parallel to a direction orthogonal to the ink flow direction 21 (width direction of the piezoelectric element 6). The metal film 81 may be, for example, a Ti film.

  The movable film forming layer 10 in which the stripe pattern metal film 81 is embedded can be formed, for example, as follows. On the substrate 2, a first silicon oxide film that is a material of the movable film forming layer 10 is formed. Next, a metal material film made of the material of the metal film 81 is formed on the surface of the first silicon oxide film, for example, by sputtering. Next, a resist mask having a stripe pattern is formed on the metal material film by photolithography. Using this resist mask as a mask, the metal material film is etched to form a stripe-pattern metal film 81. Next, a second silicon oxide film is formed on the surface of the first silicon oxide film and the surface of the metal film 81. As a result, the movable film forming layer 10 in which the stripe-pattern metal film 81 is embedded is obtained.

  The lower electrode 7 has a rectangular main electrode portion 7A in contact with the lower surface of the piezoelectric film 8 and an extension portion 7B extending to an outer region of the piezoelectric film 8. The main electrode portion 7A is formed to be shorter than the movable film 10A along the longitudinal direction of the movable film 10A, and both end edges of the main electrode part 7A are predetermined with respect to the corresponding both end edges 10Aa and 10Ab of the movable film 10A. It arrange | positions inside the space | interval d1. Further, the main electrode portion 7A is formed such that the width along the short direction of the movable film 10A is narrower than the width of the movable film 10A in the short direction, and both end edges thereof correspond to both sides corresponding to the movable film 10A. With respect to the edges 10Ac, 10Ad, the gap d2 is provided at an inner side.

  The extension portion 7B includes a lead electrode portion 74 drawn from the main electrode portion 7A and a common connection portion 75 that commonly connects the main electrode portions 7A of the plurality of piezoelectric elements 6. The common connection portion 75 extends in a direction perpendicular to the ink circulation direction 21 on the downstream side of the plurality of piezoelectric elements 6 in the ink circulation direction 21. The lead electrode portion 74 is drawn along the longitudinal direction of the piezoelectric element 6 from the vicinity of the central portion of the downstream edge 6 b of the piezoelectric element 6 in the ink flow direction 21, and is connected to the common connection portion 75. The common connection portion 75 is formed with an elongated rectangular pad portion 7 d in a direction orthogonal to the ink circulation direction 21. That is, in the inkjet print head 1C, the lower electrode 7 is not formed in the outer region of the side edges 6c and 6d of the piezoelectric element 6.

  In the ink jet print head 1C, the lower electrode 7 is not formed in the outer region of the side edges 6c and 6d of the piezoelectric element 6, but a stripe-pattern metal film 81 is embedded in the movable film forming layer 10. . That is, a plurality of linear metal films 81 a parallel to each other are embedded in the movable film forming layer 10. Since the linear metal film 81a is formed at a high temperature and is then cooled to normal temperature and contracts, the linear metal film 81a has a tensile stress. That is, the linear metal film 81a exerts a force in the contracting direction on the movable film 10A, so that the movable film 10A is difficult to break.

  The metal film 81 embedded in the movable film forming layer 10 is not limited to a stripe pattern, and may be a mesh pattern (lattice pattern). FIG. 54 shows an example in which a mesh pattern metal film 81 is embedded in the movable film forming layer 10. The mesh-patterned metal film 81 is integrated with a plurality of first linear metal films 81a parallel to a direction orthogonal to the ink flow direction 21 (width direction of the piezoelectric element 6), and these first linear metal films 81a. And a plurality of second linear metal films 81b orthogonal to the first linear metal films 81a.

In the inkjet print head 1C of FIG. 49, the upper electrode 9 may have any one of the structures of the upper electrodes 9A to 9Q shown in FIGS.
FIG. 55 is a schematic plan view showing another example of a pyroelectric infrared image sensor to which the fourth invention is applied. 56 is a cross-sectional view taken along line LVI-LVI of FIG.
The pyroelectric infrared image sensor 131 detects the amount of infrared rays by utilizing the fact that the surface charge of the pyroelectric material changes due to temperature changes caused by infrared rays. The pyroelectric infrared image sensor 131 includes a silicon substrate 132, a heat insulating film (membrane) 133 formed on the silicon substrate 132, and a pyroelectric element 134 formed on the heat insulating film 133.

A cavity 135 is formed in the silicon substrate 132 to prevent heat transfer from the pyroelectric element 134 to the silicon substrate 132. The cavity 135 is formed by digging the silicon substrate 132 from the back side of the silicon substrate 132. The cavity 135 is circular in plan view. The top surface of the cavity 135 is partitioned by a heat insulating film 133. The heat insulating film 133 covers the entire top surface of the cavity 135, and further extends around it. The heat insulating film 133 is composed of a silicon oxide (SiO ₂ ) film.

  A metal film 136 having an annular stripe pattern is embedded in the heat insulating film 133. The metal film 136 having an annular stripe pattern has a plurality of annular metal films (metal lines) 136a that are concentric with the cavity 135 and have different diameters in plan view. The metal film 136 may be a Ti film, for example. Since each annular metal film 136a is formed at a high temperature and then cooled to normal temperature and contracts, each annular metal film 136a has a tensile stress. That is, each annular metal film 136a exerts a force on the heat insulating film 133 in a contracting direction, so that the heat insulating film 133 is hardly broken.

The pyroelectric element 134 includes a lower electrode 141 formed in contact with the surface of the heat insulating film 133 opposite to the cavity 135, a pyroelectric film 142 formed on the lower electrode 141, and the pyroelectric film 142 And an upper electrode 143 formed on the substrate.
The lower electrode 141 is made of, for example, a Pt film. The pyroelectric film 142 is made of, for example, a PZT (PbZr _x Ti _1-x O ₃ : lead zirconate titanate) film. The upper electrode 143 is made of, for example, a Pt film. The lower electrode 141 is formed in a circular shape that is concentric with the center of the cavity 135 and smaller in diameter than the cavity 135 in plan view. The pyroelectric film 142 is formed in the same pattern as the lower electrode 141. The upper electrode 143 is formed in the same pattern as the pyroelectric film 142.

  When the pyroelectric element 144 is irradiated with infrared rays, the temperature of the pyroelectric film 142 changes due to the heat, and the surface charge of the pyroelectric film 142 changes. Changes in the surface charge of the pyroelectric film 142 are taken out via the lower electrode 141 and the upper electrode 143. Thereby, the amount of infrared light can be detected. In FIG. 55 and FIG. 56, for convenience of explanation, the wiring for extracting the change in surface charge of the pyroelectric film 142 from the lower electrode 141 and the upper electrode 143 is omitted.

As mentioned above, although embodiment of the 2nd-4th invention was described, the 2nd-4th invention can also be implemented in other embodiment. In the ink jet print heads 1 to 1C of FIGS. 9, 21, 44 and 49, PZT is exemplified as the material of the piezoelectric film, but in addition, lead titanate (PbPO ₃ ), potassium niobate (KNbO _3). ), A piezoelectric material made of a metal oxide typified by lithium niobate (LiNbO ₃ ), lithium tantalate (LiTaO ₃ ), or the like may be applied.

  Further, in the inkjet print heads 1 to 1C of FIGS. 9, 21, 44 and 49, the back surface of the movable film forming layer 10 is formed with a recess 5B that forms a part of the pressure chamber 5, The recess 5B may not be formed. In this case, the pressure chamber 5 is composed only of the space portion 5 </ b> A formed in the silicon substrate 2.

DESCRIPTION OF SYMBOLS 1 Inkjet print head 2 Silicon substrate 3a Ejection port 4 Ink supply path 5 Piezoelectric chamber (cavity)
5a, 5b Both ends of the top surface of the piezoelectric chamber 5c, 5d Both sides of the top of the piezoelectric chamber 6 Piezoelectric elements 6a, 6b Both ends of the piezoelectric element 6c, 6d Both edges of the piezoelectric element 7 Lower electrode 7A Main electrode section 7B Extension Part 8 Piezoelectric film 9 Upper electrode 10 Movable film forming layer 10A Movable film 10Aa, 10Ab Both ends of the movable film 10Ac, 10Ad Both edges of the movable film 11 Metal barrier film 13 Hydrogen barrier film 14 Interlayer insulating film 15 Wiring 25 Passivation film 17 Opening 31 IrO ₂ film 32 Ir film

Claims (14)

A piezoelectric element having a lower electrode, a piezoelectric film formed on the lower electrode, and an upper electrode formed on the piezoelectric film;
A hydrogen barrier film covering the entire side surface of the upper electrode and the piezoelectric film;
A piezoelectric element having an opening at the center of the upper surface of the upper electrode, and an interlayer insulating film stacked on the hydrogen barrier film and facing the entire surface of the side surface of the upper electrode and the piezoelectric film through the hydrogen barrier film. Device utilization device. A substrate having a cavity;
A movable film held on the substrate so as to face the cavity,
The piezoelectric element utilization apparatus according to claim 1, wherein the piezoelectric element is provided on a movable film.   The piezoelectric element utilization apparatus according to claim 2, wherein a metal barrier film is interposed between the movable film and the piezoelectric element. The piezoelectric element utilization apparatus according to claim ₃ , wherein the metal barrier film is an Al ₂ O ₃ film. On the piezoelectric element, a contact hole exposing a part of the upper electrode is formed in the interlayer insulating film,
5. The wiring according to claim 2, wherein one end portion is connected to the upper electrode through the contact hole and the other end portion is led out of the piezoelectric element on the interlayer insulating film. The piezoelectric element using apparatus according to claim 1.   The piezoelectric element utilization apparatus according to claim 5, further comprising a passivation film that is formed only in a region where the wiring is present on the interlayer insulating film and covers the wiring. The cavity is formed in a rectangular shape in a plan view seen from the normal direction to the main surface of the movable film,
The movable film is formed in a rectangular shape aligned with the cavity edge in the plan view;
The piezoelectric film is a rectangle having a width shorter than a width of the movable film in a short direction and a length shorter than a length of the movable film in a longitudinal direction in the plan view, and both end edges and both side edges thereof are Retreating inward of the movable film from both side edges and both side edges of the movable film,
The upper electrode is a rectangle having a width shorter than a width of the movable film in a short direction and a length shorter than a length of the movable film in a longitudinal direction in the plan view, and both end edges and both side edges of the upper electrode are The piezoelectric element utilization apparatus according to any one of claims 2 to 6, wherein the device is retracted inward of the movable film from both end edges and both side edges of the movable film. The piezoelectric element utilization apparatus according to claim 1, wherein the hydrogen barrier film is an Al ₂ O ₃ film.   The piezoelectric element utilization apparatus according to any one of claims 1 to 8, wherein the interlayer insulating film is a SiO film.   The piezoelectric element utilization apparatus according to claim 1, wherein the passivation film is a SiN film. The upper electrode, and Ir0 ₂ film formed on said piezoelectric film, wherein a stacked film of the Ir film formed on Ir0 ₂ film, any one of claims 1 to 10 The piezoelectric element utilization apparatus of description. A first step of forming a piezoelectric element comprising a lower electrode, a piezoelectric film formed on the lower electrode and an upper electrode formed on the piezoelectric film on the movable film;
A second step of forming a hydrogen barrier film covering the movable film and the surface of the piezoelectric element;
A third step of forming an interlayer insulating film on the hydrogen barrier film;
Forming a contact hole exposing a part of the upper electrode in the hydrogen barrier film and the interlayer insulating film on the piezoelectric element;
A fifth step of forming a wiring having one end in contact with the upper electrode through the contact hole and the other end led out of the piezoelectric element on the interlayer insulating film;
A sixth step of forming a passivation film covering the wiring in a region where the wiring exists on the interlayer insulating film;
And a seventh step of forming an opening in a central portion of the upper surface of the piezoelectric element in the hydrogen barrier film and the interlayer insulating film. The fifth step includes
Forming a wiring film on the interlayer insulating film including the inside of the contact hole;
And forming a wiring having one end in contact with the upper electrode through the contact hole and the other end being drawn outside the piezoelectric element by patterning the wiring film. The manufacturing method of the piezoelectric element utilization apparatus of description. The sixth step includes forming a passivation film covering the surface of the interlayer insulating film and the surface of the wiring on the interlayer insulating film;
14. The method for manufacturing a piezoelectric element utilizing apparatus according to claim 12, further comprising: patterning the passivation film into a pattern including only a portion covering the wiring.

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