JP6410027B2 - Manufacturing method of piezoelectric element utilizing apparatus - Google Patents

Description

This invention relates to a method for manufacturing a piezoelectric device utilizing equipment utilizing a piezoelectric element.

Patent Document 1 discloses an ink jet print head using a piezoelectric element. The ink jet print head of Patent Document 1 includes an actuator substrate having a pressure chamber (cavity), a movable film supported by the actuator substrate so as to face the pressure chamber, and a piezoelectric element bonded to the movable film. . The piezoelectric element is configured by laminating a lower electrode, a piezoelectric film, and an upper electrode from the movable film side. The entire upper surface and side surfaces of the piezoelectric element are covered with a hydrogen barrier film made of Al ₂ O ₃ (alumina). Insulating film made of Si0 ₂ in the hydrogen barrier film (interlayer insulating film) is formed.

  A wiring connected to the upper electrode is formed on the insulating film. One end of the wiring is arranged above one end of the upper electrode. A contact hole that continuously penetrates the hydrogen barrier film and the insulating film is formed between the wiring and the upper electrode. One end of the wiring enters the contact hole and is connected to the upper electrode in the contact hole. The wiring extends from above the upper electrode to the outside of the pressure chamber across the outer edge of the pressure chamber. On the insulating film, a passivation film (surface protective film) made of SiN covering the upper wiring is formed.

JP 2013-119182 A

  In the ink jet print head disclosed in Patent Document 1, a passivation film made of SiN is formed on an insulating film to cover a wiring. Such a passivation film is often formed by plasma CVD (Chemical Vapor Deposition). When a passivation film made of SiN is formed by plasma CVD, hydrogen is generated by a chemical reaction as shown below.

3SiH ₄ + 4NH ₃ → Si ₃ N ₄ + 12H ₂
When forming a passivation film, almost the entire surface of the piezoelectric element is covered with a hydrogen barrier film and an insulating film. However, the portion of the surface of the piezoelectric element in which contact holes are formed in the hydrogen barrier film and the insulating film is not covered with the hydrogen barrier film. For this reason, hydrogen generated during the formation of the passivation film passes through the wiring, the contact hole and the upper electrode and reaches the piezoelectric film. Thereby, the piezoelectric film is reduced by hydrogen. As a result, there is a risk that the breakdown voltage of the piezoelectric film may be deteriorated, or the hysteresis (polarization) characteristics of the piezoelectric film may be deteriorated.

The purpose of this invention, in forming the passivation film is to provide a method for manufacturing a piezoelectric element utilizing equipment capable of preventing the piezoelectric film is hydrogen reduction.

  According to a first aspect of the present invention, there is provided a first method for manufacturing a device using a piezoelectric element, comprising: a lower electrode; a piezoelectric film formed on the lower electrode; and a piezoelectric element comprising an upper electrode formed on the piezoelectric film on a movable film. Forming a first hydrogen barrier film covering the piezoelectric element on the movable film, and exposing a part of the upper electrode to the first hydrogen barrier film on the piezoelectric element. A step of forming a contact hole, and a wiring having one end contacting the upper electrode through the contact hole and the other end extending outside the piezoelectric element on the first hydrogen barrier film A step of forming a second hydrogen barrier film covering the wiring on the first hydrogen barrier film, and a step of forming a passivation film on the second hydrogen barrier film.

  In this method of manufacturing a piezoelectric element utilizing device, during the passivation film forming step, the region other than the portion where the contact hole is formed on the surface of the piezoelectric element is covered with the first hydrogen barrier film, and the wiring is not 2 Covered by a hydrogen barrier film. Therefore, it is possible to prevent hydrogen generated during the formation process of the passivation film from passing through the wiring, the contact hole, and the upper electrode and reaching the piezoelectric film. Thereby, it is possible to prevent the piezoelectric film from being reduced by hydrogen during the formation process of the passivation film. Thereby, characteristic deterioration due to hydrogen reduction of the piezoelectric film can be prevented.

  According to a second aspect of the present invention, there is provided a second method for manufacturing a device using a piezoelectric element comprising: a lower electrode; a piezoelectric film formed on the lower electrode; and a piezoelectric element comprising an upper electrode formed on the piezoelectric film on a movable film. Forming a first hydrogen barrier film covering the piezoelectric element on the movable film, forming an insulating film on the first hydrogen barrier film, and on the piezoelectric element, Forming a contact hole exposing a part of the upper electrode in the insulating film and the first hydrogen barrier film; and one end of the contact hole contacting the upper electrode via the contact hole on the insulating film. A step of forming a wiring having the other end drawn to the outside of the piezoelectric element, a fifth step of forming a second hydrogen barrier film covering the wiring on the insulating film, and the second hydrogen barrier film Form a passivation film And a sixth step of.

  In this method for manufacturing a piezoelectric element utilization apparatus, the same effect as that of the first method for manufacturing a piezoelectric element utilization apparatus can be obtained.

FIG. 1A is an illustrative plan view for explaining the configuration of an ink jet print head according to an embodiment of the present invention. 1B is an enlarged plan view of the main part of FIG. 2A is a schematic cross-sectional view taken along the line IIA-IIA in FIG. 1A. 2B is an enlarged cross-sectional view of a main part of FIG. 2A. FIG. 3 is an enlarged cross-sectional view schematically showing a part of the cut surface along the line III-III in FIG. 1A. FIG. 4 is a schematic enlarged sectional view taken along the line IV-IV in FIG. 2B. FIG. 5 is a schematic plan view showing a pattern example of the lower electrode of the inkjet print head. FIG. 6 is a schematic plan view showing a pattern example of the first hydrogen barrier film of the inkjet print head. FIG. 7 is a schematic plan view showing a pattern example of an interlayer insulating film of the ink jet print head. FIG. 8 is a schematic plan view showing a pattern example of the second hydrogen barrier film and the passivation film of the ink jet print head. FIG. 9A is a cross-sectional view showing an example of the manufacturing process of the inkjet print head. FIG. 9B is a cross-sectional view showing a step subsequent to FIG. 9A. FIG. 9C is a cross-sectional view showing a step subsequent to FIG. 9B. FIG. 9D is a cross-sectional view showing a step subsequent to FIG. 9C. FIG. 9E is a cross-sectional view showing a step subsequent to FIG. 9D. FIG. 9F is a cross-sectional view showing a step subsequent to FIG. 9E. FIG. 9G is a cross-sectional view showing a step subsequent to FIG. 9F. FIG. 9H is a cross-sectional view showing a step subsequent to FIG. 9G. FIG. 9I is a cross-sectional view showing a step subsequent to FIG. 9H. FIG. 9J is a cross-sectional view showing a step subsequent to FIG. 9I. FIG. 9K is a cross-sectional view showing a step subsequent to FIG. 9J. FIG. 9L is a cross-sectional view showing a step subsequent to FIG. 9K. FIG. 9M is a cross-sectional view showing a step subsequent to FIG. 9L. FIG. 9N is a cross-sectional view showing a step subsequent to FIG. 9M. FIG. 9O is a cross-sectional view showing a step subsequent to FIG. 9N. FIG. 10 is an illustrative enlarged sectional view for explaining another example of the restriction flow path of the inkjet print head. FIG. 11 is a plan view schematically showing another example of the pattern of the piezoelectric film. FIG. 12 is a plan view schematically showing still another example of the pattern of the piezoelectric film.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1A is an illustrative plan view for explaining the configuration of an ink jet print head according to an embodiment of the present invention. 1B is an enlarged plan view of the main part of FIG. 2A is a schematic cross-sectional view taken along the line IIA-IIA in FIG. 1A. 2B is an enlarged cross-sectional view of a main part of FIG. 2A. FIG. 3 is an enlarged cross-sectional view schematically showing a part of the cut surface along the line III-III in FIG. 1A. 4 is an illustrative enlarged cross-sectional view taken along line IV-IV in FIG. 2B. FIG. 5 is a schematic plan view showing a pattern example of the lower electrode of the inkjet head.

With reference to FIGS. 2A and 2B, the configuration of the init print head 1 will be schematically described.
The init print head 1 includes an actuator substrate 2, a nozzle substrate 3, and a protective substrate 4. A movable film forming layer 10 is laminated on the surface of the actuator substrate 2. The actuator substrate 2 has a pressure chamber (cavity) 5 as an ink flow path (ink reservoir). In this embodiment, the pressure chamber 5 is formed through the actuator substrate 2.

  The nozzle substrate 3 is made of, for example, a silicon substrate. The nozzle substrate 3 is bonded to the back surface 2 b of the actuator substrate 2. The nozzle substrate 3 defines the pressure chamber 5 together with the actuator substrate 2 and the movable film forming layer 10. More specifically, the nozzle substrate 3 defines a bottom surface portion of the pressure chamber 5. The nozzle substrate 3 has a recess 3a facing the pressure chamber 5, and an ink discharge passage 3b is formed on the bottom surface of the recess 3a. The ink discharge passage 3 b penetrates the nozzle substrate 3 and has a discharge port 3 c 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 3b and is discharged from the discharge port 3c.

The actuator substrate 2 further includes a restriction channel 6 (refer to FIGS. 1A, 1B, and 4) that communicates with the pressure chamber 5 and an ink inflow portion 7 that communicates with the restriction channel 6. Yes. The pressure chamber 5 is formed to be elongated along the ink flow direction 41 which is the left-right direction in FIGS. 2A and 2B.
The top wall portion of the pressure chamber 5 in the movable film forming layer 10 constitutes the movable film 10A. The movable film 10A (movable film forming layer 10) is made of, for example, a silicon oxide (SiO ₂ ) film formed on the actuator substrate 2. The movable film 10A (movable film forming layer 10) includes, for example, a silicon (Si) film formed on the actuator substrate 2, a silicon oxide (SiO ₂ ) film formed on the silicon film, and a silicon oxide film. You may be comprised from the laminated film with the silicon nitride (SiN) film | membrane formed. In this specification, the movable film 10 </ b> A means a top wall portion that partitions the top surface portion of 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 laminated film of a silicon film, a silicon oxide film, and a silicon nitride film, the thicknesses of the silicon film, the silicon oxide film, and the silicon nitride film are about 0.4 μm, respectively. Also good.

  The pressure chamber 5 is partitioned by the movable film 10A, the actuator substrate 2, and the nozzle substrate 3, and in this embodiment, is formed in a substantially rectangular parallelepiped shape. For example, the pressure chamber 5 may have a length of about 800 μm and a width of about 55 μm. The restriction channel 6 communicates with one end portion in the longitudinal direction of the pressure chamber 5 (in this embodiment, the end portion on the upstream side in the ink circulation direction 41). The ink inflow portion 7 communicates with one end portion of the restriction flow path 6 (in this embodiment, the upstream end portion in the ink circulation direction 41).

  A piezoelectric element 9 is disposed on the surface of the movable film 10A. The piezoelectric element 9 includes a lower electrode 11 formed on the movable film forming layer 10, a piezoelectric film 12 formed on the lower electrode 11, and an upper electrode 13 formed on the piezoelectric film 12. Yes. In other words, the piezoelectric element 9 is configured by sandwiching the piezoelectric film 12 from above and below by the upper electrode 13 and the lower electrode 11.

The upper electrode 13 may be a single film of platinum (Pt), for example, a conductive oxide film (for example, IrO ₂ (iridium oxide) film) and a metal film (for example, Ir (iridium) film) are laminated. You may have the laminated structure made. The thickness of the upper electrode 13 may be, for example, about 0.2 μm.
As the piezoelectric film 12, 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 12 is made of a sintered body of metal oxide crystals. The piezoelectric film 12 includes an active part 12A in contact with the lower surface of the upper electrode 13 and an inactive part 12B extending from a part of the peripheral wall of the active part 12A to the outside of the periphery of the pressure chamber 5. The active portion 12A is formed in the same shape as the upper electrode 13 in plan view.

The thickness of the active part 12A is about 1 μm to 5 μm. The thickness of the inactive portion 12B may be about ½ of the thickness of the active portion 12A. The total thickness of the movable film 10A is preferably about the same as the thickness of the active part 12A or about 2/3 of the thickness of the active part 12A.
The lower electrode 11 has, for example, a two-layer structure in which a Ti (titanium) film and a Pt (platinum) film are sequentially stacked from the movable film forming layer 10 side. In addition, the lower electrode 11 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 11 has a main electrode portion 11A that is in contact with the lower surface of the active portion 12A of the piezoelectric film 12, and an extension portion 11B that extends to a region outside the active portion 12A. The thickness of the lower electrode 11 may be about 0.2 μm, for example.

A first hydrogen barrier film 14 is formed on the extension 11 </ b> B of the lower electrode 11 and the piezoelectric element 9. The first hydrogen barrier film 14 is made of, for example, Al ₂ O ₃ (alumina). The thickness of the first hydrogen barrier film 14 is about 50 nm to 100 nm. The first hydrogen barrier film 14 is provided in order to prevent characteristic deterioration due to hydrogen reduction of the piezoelectric film 12.
An insulating film 15 is stacked on the first hydrogen barrier film 14. The insulating film 15 is made of, for example, SiO ₂ , low hydrogen SiN, or the like. The thickness of the insulating film 15 is about 200 nm to 300 nm. On the insulating film 15, an upper wiring 17, a lower wiring 18, and a dummy wiring 19 are formed. These wirings 17, 18, and 19 may be made of a metal material containing Al (aluminum). The thickness of these wirings 17, 18, and 19 is, for example, about 1000 nm.

  One end of the upper wiring 17 is disposed above one end of the upper electrode 13. A contact hole 33 that continuously penetrates the first hydrogen barrier film 14 and the insulating film 15 is formed between the upper wiring 17 and the upper electrode 13. One end of the upper wiring 17 enters the contact hole 33 and is connected to the upper electrode 13 in the contact hole 33. The upper wiring 17 extends from above the upper electrode 13 to the outside of the pressure chamber 5 across the outer edge of the pressure chamber 5.

  The lower wiring 18 faces the extension 11 </ b> B of the lower electrode 11 in the outer region of the pressure chamber 5. A contact 34 is formed between the lower wiring 18 and the extension 11B of the lower electrode 11 so as to penetrate the first hydrogen barrier film 14 and the insulating film 15 continuously. The lower wiring 18 enters the contact hole 34 and is connected to the extension 11 </ b> B of the lower electrode 11 in the contact 34.

The dummy wiring 19 is an electrically insulated wiring that is not electrically connected to any of the upper wiring 17 and the lower wiring 18.
A second hydrogen barrier film 20 that covers the wirings 17, 18, 19 and the insulating film 15 is formed on the insulating film 15. The second hydrogen barrier film 20 is made of, for example, Al ₂ O ₃ (alumina). The second hydrogen barrier film 20 may be made of SiTaOx, SiZrOx, or the like. The second hydrogen barrier film 20 may be formed by sputtering or ALD (Atomic Layer Deposition). The thickness of the second hydrogen barrier film 20 is about 50 nm to 100 nm.

  A passivation film 21 is formed on the second hydrogen barrier film 20. As will be described in detail later, the second hydrogen barrier film 20 is provided in order to prevent characteristic deterioration due to hydrogen reduction of the piezoelectric film 12 during the formation process of the passivation film 21. The passivation film 21 is made of, for example, SiN (silicon nitride). The thickness of the passivation film 21 may be about 850 nm, for example.

Pad openings 35 and 36 are formed in the second hydrogen barrier film 20 and the passivation film 21 to expose portions of the upper wiring 17 and the lower wiring 18 as pads. The pad opening 35 is formed in an outer region of the pressure chamber 5, and is formed, for example, at the tip end portion of the upper wiring 17 (the end portion on the opposite side of the contact portion to the upper electrode 13).
An ink supply path 22 that penetrates the passivation film 21, the second hydrogen barrier film 20, the insulating film 15, the first hydrogen barrier film 14, and the lower electrode 11 is formed at a position corresponding to the ink inflow portion 7. The lower electrode 11 includes an ink supply path 22, and a through hole 23 larger than the ink supply path 22 is formed. The first hydrogen barrier film 14 enters the gap between the through hole 23 of the lower electrode 11 and the ink supply path 22. An ink circulation hole 24 is formed in the movable film forming layer 10 between the ink supply path 22 and the ink inflow portion 7. The ink supply path 22 and the ink inflow portion 7 communicate with each other through the ink circulation hole 24.

  The protective substrate 4 is made of, for example, a silicon substrate. The protective substrate 4 is disposed on the actuator substrate 2 so as to cover the piezoelectric element 9. The protective substrate 4 is bonded to the passivation film 21 via an adhesive 50. The protective substrate 4 has an accommodation recess 52 in an opposing surface 51 that faces the surface 2 a of the actuator substrate 2. The piezoelectric element 9 is housed in the housing recess 52. Further, the protective substrate 4 is formed with a wiring through hole 53 for exposing the pad of the upper wiring 17 and a wiring through hole 54 for exposing the pad of the lower wiring 18.

An ink tank (not shown) that stores ink is disposed on the protective substrate 4. In the protective substrate 4, an ink supply path 55 communicating with the ink supply path 22 is formed between the accommodation recess 52 and the wiring through hole 54. The ink supply path 55 passes through the protective substrate 4.
The piezoelectric element 9 is formed at a position facing the pressure chamber 5 across the movable film 10A. That is, the piezoelectric element 9 is formed so as to be in contact with the surface of the movable film 10 </ b> A opposite to the pressure chamber 5. By supplying ink from the ink tank to the pressure chamber 5 through the ink supply path 55, the ink supply path 22, the ink circulation hole 24, the ink inflow portion 7 and the restriction flow path 6, the pressure chamber 5 is filled with ink. The 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 of the actuator substrate 2 around the pressure chamber 5, and has flexibility capable of being deformed in a direction facing the pressure chamber 5 (in other words, the thickness direction of the movable film 10A). doing.

  The upper wiring 17 and the lower wiring 18 are connected to a drive circuit (not shown). Specifically, the pad of the upper wiring 17 and the drive circuit are connected via a connection metal member (not shown) that passes through the connection wiring through hole 53 of the protective substrate 4. Similarly, the pad of the lower wiring 18 and the drive circuit are connected via a connection metal member (not shown) passing through the wiring through hole 54 of the protective substrate 4. When a drive voltage is applied to the piezoelectric element 9 from the drive circuit, the piezoelectric film 12 is deformed by the inverse piezoelectric effect. As a result, the movable film 10A is deformed together with the piezoelectric element 9, whereby the volume of the pressure chamber 5 is changed, and the ink in the pressure chamber 5 is pressurized. The pressurized ink passes through the ink discharge passage 3b and is discharged as fine droplets from the discharge port 3c.

The configuration of the inkjet print head 1 will be described in more detail with reference to FIGS. 1A to 5.
On the actuator substrate 2, a plurality of pressure chambers 5 are formed in stripes extending in parallel to each other. A restriction channel 6 and an ink inflow portion 7 are provided for each of the plurality of pressure chambers 5. A piezoelectric element 9 is disposed for each of the plurality of pressure chambers 5. 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 41 from the restriction channel 6 toward the discharge passage 3b in plan view. That is, the top surface portion of the pressure chamber 5 has two side edges 5c and 5d along the ink circulation direction 41 and two end edges 5a and 5b along a direction orthogonal to the ink circulation direction 41 (FIG. 1B).

  The restriction channel 6 is a channel having a large liquid resistance formed between the ink inflow portion 7 and the pressure chamber 6. The restriction channel 6 is formed to prevent the ink in the pressure chamber 5 from flowing from the pressure chamber 5 toward the ink inflow portion 7 when the ink in the pressure chamber 5 is pressurized. As shown in FIG. 4, the restriction channel 6 includes a meandering channel 61 formed in a meandering shape in a plan view. The meandering flow path 61 is formed in a plan view by connecting a plurality of linear portions 61a arranged in parallel with each other at intervals in the ink circulation direction 41 and connecting these linear portions 61a. As shown in the figure, a connecting portion 61b that connects the ends of adjacent linear portions 61a is included. One end of the serpentine channel 61 is connected to the pressure chamber 5, and the other end of the serpentine channel 61 is connected to the ink inflow portion 7. In this embodiment, the depth of the restriction channel 6 is the same as the depth of the pressure chamber 5. The depth of the restriction channel 6 may be shallower than the pressure chamber 5.

Since the restriction flow path 6 includes the meandering flow path 61, the length of the restriction flow path forming region (the length between the ink inflow portion 7 and the pressure chamber 5 is larger than that of the restriction flow path of Patent Document 1. ), The fluid resistance of the entire restriction channel can be increased. Thereby, the length of the restricted flow path forming region can be shortened. Thereby, the size of the ink jet print head can be reduced.
The ink supply path 22 has a rectangular shape extending across the plurality of ink inflow portions 7 in a direction orthogonal to the ink circulation direction 41 in plan view (see in particular FIG. 1A). The ink supply path 22 is a common ink supply path shared by the plurality of ink inflow portions 7. The ink supply path 22 communicates with the plurality of ink inflow portions 7 through ink circulation holes 24 formed in the movable film forming layer 10.

  The piezoelectric element 9 is formed such that the length along the ink circulation direction 41 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. 1B, both end edges 9a and 9b along the short direction of the piezoelectric element 9 are respectively set to predetermined end edges 10Aa and 10Ab of the movable film 10A (the top surface portion of the pressure chamber 5). It arrange | positions inside the space | interval d1, d2. The piezoelectric element 9 is formed so that the width in the short direction is narrower than the width in the short direction of the movable film 10A. Both side edges 9c, 9d along the longitudinal direction of the piezoelectric element 9 are arranged on the inner side with a predetermined distance d3 with respect to the corresponding side edges 10Ac, 10Ad of the movable film 10A.

  The lower electrode 11 is formed over almost the entire surface of the movable film forming layer 10 (see particularly FIG. 5). The lower electrode 11 is a common electrode shared for the plurality of piezoelectric elements 9. The lower electrode 11 is drawn from the main electrode part 11A in a direction along the surface of the movable film forming layer 10 in a rectangular shape in plan view, which constitutes the piezoelectric element 9, and at the periphery of the top surface part of the pressure chamber 5 And an extension portion 11B extending outward.

  The main electrode portion 11A is formed shorter than the movable film 10A along the longitudinal direction of the movable film 10A. As shown in FIG. 1B, both end edges of the main electrode portion 11A are arranged on the inner side with predetermined intervals d1 and d2 with respect to the corresponding both end edges 10Aa and 10Ab of the movable film 10A. Further, the main electrode portion 11A 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. Both side edges of the main electrode portion 11A are arranged on the inner side with the gap d3 with respect to the corresponding side edges 10Ac and 10Ad of the movable film 10A. The through hole 23 formed in the extension portion 11B has a rectangular shape larger than the ink supply path 22 in plan view. The peripheral edge portion of the through hole 23 in the extension portion 11B surrounds the ink supply path 22 in plan view.

  The upper electrode 13 is formed in a rectangular shape with the same pattern as the main electrode portion 11A of the lower electrode 11 in plan view. That is, the upper electrode 13 is formed shorter than the movable film 10A along the longitudinal direction of the movable film 10A. As shown in FIG. 1B, both end edges of the upper electrode 13 are arranged on the inner side of the corresponding both end edges 10Aa and 10Ab of the movable film 10A with predetermined intervals d1 and d2, respectively. Further, the upper electrode 13 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. Both side edges of the upper electrode 13 are arranged on the inner side with the gap d3 with respect to the corresponding side edges 10Ac, 10Ad of the movable film 10A.

  As described above, the piezoelectric film 12 includes the active portion 12A and the inactive portion 12B. The active portion 12A is formed in a rectangular shape having the same pattern as that of the upper electrode 13 in plan view. That is, the active portion 12A is formed shorter than the movable film 10A along the longitudinal direction of the movable film 10A. As shown in FIG. 1B, both end edges of the active portion 12A are arranged on the inner side with predetermined intervals d1 and d2 with respect to the corresponding both end edges 10Aa and 10Ab of the movable film 10A. The active portion 12A is formed such that the width of the movable film 10A along the short direction is narrower than the width of the movable film 10A in the short direction. Both side edges of the active portion 12A are arranged on the inner side with the gap d3 with respect to the corresponding side edges 10Ac, 10Ad of the movable film 10A. The lower surface of the active portion 12A is in contact with the upper surface of the main electrode portion 11A of the lower electrode 11, and the upper surface of the active portion 12A is in contact with the lower surface of the upper electrode 12.

  The inactive portion 12B extends from the downstream end of the active portion 12A in the ink circulation direction 41 to the outside of the edge 5a of the pressure chamber 5 along the lower surface of the upper wiring 17 in plan view. In this embodiment, the width of the inactive portion 12B is substantially equal to the width of the active portion 12A. In this embodiment, the thickness of the inactive portion 12B is about ½ of the active portion 12A. The tip of the inactive portion 12B is supported by the actuator substrate 2 outside the edge 5a of the pressure chamber 5. The lower surface of the inactive portion 12B is in contact with the upper surface of the extension portion 11B of the lower electrode 11. The upper surface of the inactive portion 12B is covered with the first hydrogen barrier film 14.

  The upper wiring 17 made of metal expands and contracts to generate stress. The inactive portion 12B is provided to prevent the movable film 10A from cracking due to the stress of the upper wiring 17. This point will be described in more detail. The piezoelectric element 9 is not provided at the peripheral portion of the movable film 10A in order to increase the displacement amount of the movable film 10A. Since the stress of the upper wiring 17 is applied to the region where the upper wiring 17 passes upward in the peripheral portion of the movable film 10A, there is a possibility that a crack may occur.

  In this embodiment, an inactive portion 12B of the piezoelectric film 12 is interposed between a region directly below the upper wiring 17 and the upper wiring 17 in the peripheral portion of the movable film 10A. The tip of the inactive portion 12 </ b> B of the piezoelectric film 12 is supported on the peripheral wall of the pressure chamber 5 in the actuator substrate 2. Accordingly, the stress generated in the upper wiring 17 and applied to the movable film 10 </ b> A is relieved by the inactive portion 12 </ b> B of the piezoelectric film 12. Thereby, generation | occurrence | production of the crack of 10 A of movable films | membranes by the stress of the upper wiring 17 can be prevented.

  The upper wiring 17 has one end portion connected to one end portion of the upper electrode 12 (the end portion on the one end edge 9a side of the piezoelectric element 9) and extending along the ink circulation direction 41 in a plan view; The pad portion 17B is integrated with the drawer portion 17A and connected to the tip of the drawer portion 17A and has a rectangular shape in plan view. The pad portion 17 </ b> B is disposed outside the one end edge 5 a of the pressure chamber 5. The lead portion 17A extends from the upper surface of one end portion of the piezoelectric element 9 along the end surface of the piezoelectric element 9 connected thereto, and further along the surfaces of the inactive portion 12B and the lower electrode 11 of the piezoelectric film 12 to the pad portion 17B. It extends. The passivation film 21 is formed with a pad opening 35 that exposes the central portion of the surface of the pad portion 17B.

The lower wiring 18 has a rectangular shape that is long in a direction orthogonal to the ink circulation direction 41 in plan view. In this embodiment, one contact hole 34 is formed as an extension of each pressure chamber 5. The lower wiring 18 enters the plurality of contact holes 34 and is connected to the extension 11 </ b> B of the lower electrode 11 in the contact holes 34.
The accommodation recess 52 of the protective substrate 4 has a rectangular shape extending across the plurality of pressure chambers 5 in a direction orthogonal to the ink flow direction 41 in plan view. A plurality of piezoelectric elements 9 respectively corresponding to the plurality of pressure chambers 5 are housed in the housing recesses 52. The wiring through-hole 53 of the protective substrate 4 has a rectangular shape extending across the plurality of pad portions 17B in a direction orthogonal to the ink circulation direction 41 in plan view. A plurality of pad portions 17 </ b> B are exposed through the pad openings 35 in the wiring through holes 53. The wiring through hole 54 of the protective substrate 4 has a rectangular shape extending along the lower wiring 18 in a plan view. The lower wiring 18 is exposed through the pad opening 36 in the wiring through hole 54. The ink supply path 55 of the protection substrate 4 has a rectangular shape with the same pattern as the ink supply path 22 on the actuator substrate 2 side in plan view. The ink supply path 55 is aligned with the ink supply path 22 in plan view.

  In this embodiment, the dummy wiring 19 is, in plan view, the virtual line along the side edge on the piezoelectric element 9 side of the wiring through hole 53 and the virtual line along the side edge on the piezoelectric element 9 side of the wiring through hole 54. Are formed in a predetermined pattern in a region excluding the housing recess 52 and the ink supply path 22 (hereinafter referred to as “dummy wiring region”). The dummy wiring 19 includes a rectangular annular wiring that surrounds the ink supply path 22 in plan view. This rectangular annular wiring has an inner peripheral edge at a position away from the ink supply path 22 by a certain distance. The dummy wiring 19 is also formed in an area outside the rectangular annular wiring in the dummy wiring area, excluding the vicinity of the rectangular annular wiring, the upper wiring 17 and the vicinity thereof.

FIG. 6 is a schematic plan view showing a pattern example of the first hydrogen barrier film 14.
In this embodiment, the first hydrogen barrier film 14 is formed on the actuator substrate 2 over substantially the entire outer region of each pressure chamber 5 in plan view. However, in this region, the ink supply path 22 and the contact hole 34 are formed in the first hydrogen barrier film 14.
In the inner region of each pressure chamber 5, the first hydrogen barrier is formed on the entire side surfaces of the piezoelectric film 12 and the upper electrode 13, the upper surface of the inactive portion 12 </ b> B of the piezoelectric film 12, and the upper peripheral edge of the upper electrode 13. A film 14 is formed. That is, the first hydrogen barrier film 14 has an opening 31 having a rectangular shape in plan view at the center of the upper surface of the upper electrode 13. In other words, the first hydrogen barrier film 14 is not formed at the center of the upper surface of the upper electrode 13.

  The first hydrogen barrier film 14 has an end-like annular opening 32 in a region between the peripheral edge of the pressure chamber 5 and the first hydrogen barrier film 14 formed on the side surface of the piezoelectric film 12 in plan view. Is formed. In other words, there is a region where the first hydrogen barrier film 14 is not formed between the peripheral edge of the pressure chamber 5 and the first hydrogen barrier film 14 formed on the side surface of the piezoelectric film 12 in plan view.

FIG. 7 is a schematic plan view showing a pattern example of the insulating film 15. FIG. 8 is a schematic plan view showing a pattern example of the second hydrogen barrier film 20 and the passivation film 21.
In this embodiment, the insulating film 15, the second hydrogen barrier film 20, and the passivation film 21 are formed on almost the entire region of the outer region of the housing recess 52 of the protective substrate 4 in plan view on the actuator substrate 2. However, in this region, the ink supply path 22 and the contact hole 34 are formed in the insulating film 15. In this region, an ink supply path 22 and pad openings 35 and 36 are formed in the second hydrogen barrier film 20 and the passivation film 21.

  In the inner region of the accommodation recess 52 of the protective substrate 4, the insulating film 15, the second hydrogen barrier film 20, and the passivation film 21 are formed only in the upper wiring region where the upper wiring 17 exists. In this region, the second hydrogen barrier film 20 and the passivation film 21 are formed so as to cover the upper surface and side surfaces of the upper wiring 17 on the insulating film 15. In other words, in the insulating film 15, the second hydrogen barrier film 20, and the passivation film 21, the opening 37 is formed in a region excluding the upper wiring region in the inner region of the housing recess 52 in plan view. . A contact hole 33 is further formed in the insulating film 15.

  In this embodiment, the insulating film 15, the second hydrogen barrier film 20, and the passivation film 21 are formed only in the upper wiring region where the upper wiring 17 exists in the inner region around the periphery of the pressure chamber 5 in plan view. Therefore, most of the side surfaces and the upper surface of the piezoelectric element 9 are not covered with the insulating film 15, the second hydrogen barrier film 20, and the passivation film 21. Accordingly, the displacement of the movable film 10A can be increased as compared with the conventional example described in Patent Document 1 in which the entire side surface and upper surface of the piezoelectric element 9 are covered with the insulating film and the passivation film.

  Furthermore, in this embodiment, the first hydrogen barrier film 14 has an opening 31 formed at the center of the upper surface of the piezoelectric element 9. Thereby, since the piezoelectric film 12 is easily deformed, the displacement of the movable film 10A is further reduced as compared with the conventional example described in Patent Document 1 in which the entire upper surface of the piezoelectric element 9 is covered with the hydrogen barrier film and the insulating film. Can be bigger. Further, in this embodiment, the first hydrogen barrier film 14 has an annular opening 32 having an end in the region between the peripheral edge of the pressure chamber 5 and the first hydrogen barrier film 14 on the side surface of the piezoelectric film 12 in plan view. Is formed. Thereby, the displacement of the movable film 10A can be further increased.

9A to 9O are cross-sectional views showing an example of the manufacturing process of the ink jet print head 1, and show a cut surface corresponding to FIG. 2A.
First, as shown in FIG. 9A, the movable film forming layer 10 is formed on the surface 2 a of the actuator substrate 2. However, the actuator substrate 2 is thicker than the final thickness of the actuator substrate 2. Specifically, a silicon oxide film (for example, 1.2 μm thick) is formed on the surface of actuator substrate 2. When the movable film forming layer 10 is composed of a laminated film of a silicon film, a silicon oxide film, and a silicon nitride film, a silicon film (for example, 0.4 μm thick) is formed on the surface of the actuator substrate 2, and the silicon film A silicon oxide film (for example, 0.4 μm thickness) is formed thereon, and a silicon nitride film (for example, 0.4 μm thickness) is formed on the silicon oxide film.

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 from the piezoelectric film 12 to be formed later. If metal electrons escape, the piezoelectric characteristics of the piezoelectric film 12 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. 9B, a lower electrode film that is a material layer of the lower electrode 11 is formed on the movable film forming layer 10 (on the base oxide film when the base oxide film is formed). 71 is formed. The lower electrode film 71 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 71 may be formed by sputtering.

Next, a material film (piezoelectric material film) 72 of the piezoelectric film 12 is formed on the entire surface of the lower electrode film 71. Specifically, for example, the piezoelectric material film 72 having a thickness of 1 μm to 5 μm is formed by a sol-gel method. Such a piezoelectric material film 72 is made of a sintered body of metal oxide crystal grains.
Next, an upper electrode film 73 that is a material of the upper electrode 13 is formed on the entire surface of the piezoelectric material film 72. The upper electrode film 73 may be a single film of platinum (Pt), for example. Upper electrode film 73 may be, for example, an IrO ₂ / Ir laminated film having an IrO ₂ film (for example, 40 nm to 160 nm thickness) as a lower layer and an Ir film (for example, 40 nm to 160 nm thickness) as an upper layer. Such an upper electrode film 73 may be formed by sputtering.

  Next, as shown in FIGS. 9C to 9E, the upper electrode film 73, the piezoelectric material film 72, and the lower electrode film 73 are patterned. First, a resist mask having a pattern of the upper electrode 13 is formed by photolithography. Then, as shown in FIG. 9C, the upper electrode film 73 is etched using the resist mask as a mask, whereby the upper electrode 13 having a predetermined pattern is formed. Thereafter, the etching is continued and overetching is performed, so that the portion of the piezoelectric material film 72 exposed from the upper electrode 13 is thinned. As a result, the thickness of the portion of the piezoelectric material film 72 exposed from the upper electrode 13 is reduced to, for example, about ½ of the thickness of the portion covered with the upper electrode 13.

  Next, after the resist mask is peeled off, a resist mask having a pattern of the piezoelectric film 12 is formed by photolithography. Then, as shown in FIG. 9D, the piezoelectric material film 72 is etched using the resist mask as a mask, whereby the piezoelectric film 12 having a predetermined pattern is formed. As a result, the piezoelectric film 12 including the active portion 12A whose upper surface is in contact with the lower surface of the upper electrode 13 and the inactive portion 12B having a thickness smaller than that of the active portion 12A is formed.

  Next, after the resist mask is peeled off, a resist mask having a pattern of the lower electrode 11 is formed by photolithography. Then, as shown in FIG. 9E, the lower electrode film 73 is etched using the resist mask as a mask, whereby the lower electrode 11 having a predetermined pattern is formed. Thereby, the lower electrode 11 including the main electrode portion 11 </ b> A and the extension portion 11 </ b> B having the through hole 23 is formed. In this manner, the piezoelectric element 9 including the main electrode portion 11A of the lower electrode 11, the active portion 12A of the piezoelectric film 12, and the upper electrode 13 is formed.

Next, as shown in FIG. 9F, after the resist mask is peeled off, a first hydrogen barrier film 14 covering the entire surface is formed. The first hydrogen barrier film 14 may be an Al ₂ O ₃ film formed by sputtering, and the film thickness may be 50 nm to 100 nm. Thereafter, an insulating film 15 is formed on the entire surface of the first hydrogen barrier film 14. The insulating film 15 may be a SiO ₂ film, and the film thickness may be 200 nm to 300 nm. Subsequently, contact holes 33 and 34 are formed by etching the insulating film 15 and the first hydrogen barrier film 14 successively.

  Next, as shown in FIG. 9G, wiring films constituting the upper wiring 17, the lower wiring 18, and the dummy wiring 19 are formed on the insulating film 15 including the inside of the contact holes 33 and 34 by sputtering. Thereafter, the wiring film is patterned by photolithography and etching, so that the upper wiring 17, the lower wiring 18, and the dummy wiring 19 are simultaneously formed.

Next, as shown in FIG. 9H, a second hydrogen barrier film 20 that covers the wirings 17, 18, 19 is formed on the surface of the insulating film 15. The second hydrogen barrier film 20 may be an Al ₂ O ₃ film formed by sputtering, and the film thickness may be 50 nm to 100 nm. Thereafter, a passivation film 21 is formed on the entire surface of the second hydrogen barrier film 20. The passivation film 21 is made of, for example, SiN. The passivation film 21 is formed by plasma CVD, for example.

  If the passivation film 21 is formed without forming the second hydrogen barrier film 20 covering the wirings 17, 18, 19 on the surface of the insulating film 15, the following problems may occur. Hydrogen is generated when the passivation film 21 is formed. This hydrogen passes through the upper wiring 17, the contact hole 33 and the upper electrode 13 and reaches the piezoelectric film 12. Thereby, the piezoelectric film 12 is reduced by hydrogen. As a result, there is a risk that a breakdown voltage failure of the piezoelectric film 12 may occur or the hysteresis characteristics of the piezoelectric film 12 may deteriorate.

  In this embodiment, a passivation film 21 is formed on the second hydrogen barrier film 20 after the second hydrogen barrier film 20 covering the wirings 17, 18, 19 is formed on the surface of the insulating film 15. Therefore, when forming the passivation film 21, the upper wiring 17 is covered with the second hydrogen barrier film 20. Therefore, hydrogen generated when forming the passivation film 21 can be prevented from passing through the upper wiring 17, the contact hole 33 and the upper electrode 13 and reaching the piezoelectric film 12. Accordingly, it is possible to prevent deterioration of characteristics due to hydrogen reduction of the piezoelectric film 12 during the formation process of the passivation film 21.

Next, a resist mask having openings corresponding to the pad openings 35 and 36 is formed by photolithography, and the second hydrogen barrier film 20 and the passivation film 21 are etched using the resist mask as a mask. Thus, pad openings 35 and 36 are formed in the second hydrogen barrier film 20 and the passivation film 21 as shown in FIG. 9I.
Next, the resist mask is peeled off. Then, a resist mask having openings 37 and openings corresponding to the ink supply paths 22 is formed by photolithography, and the passivation film 21, the second hydrogen barrier film 20, and the insulating film 15 are continuously etched using the resist mask as a mask. Is done. As a result, as shown in FIG. 9J, the opening 37 and the ink supply path 22 are formed in the passivation film 21, the second hydrogen barrier film 20, and the insulating film 15.

  Next, the resist mask is peeled off. Then, a resist mask having openings corresponding to the openings 31 and 32 and the ink supply path 22 is formed by photolithography, and the first hydrogen barrier film 14 is patterned using the resist mask as a mask. As a result, the openings 31 and 32 and the ink supply path 22 are formed in the first hydrogen barrier film 14 as shown in FIG. 9K.

Next, the resist mask is peeled off. Then, as shown in FIG. 9L, ink circulation holes 24 are formed in the movable film forming layer 10 by photography and etching.
Next, as shown in FIG. 9M, the adhesive 50 is applied to the facing surface 51 of the protective substrate 4, and the protective substrate 4 is fixed to the actuator substrate 2 so that the ink supply path 55 and the ink supply path 22 coincide with each other. Is done.

  Next, as shown in FIG. 9N, back surface grinding for thinning the actuator substrate 2 is performed. The actuator substrate 2 is polished from the back surface 2b, whereby the actuator substrate 2 is thinned. For example, the actuator substrate 2 having a thickness of about 670 μm in the initial state may be thinned to a thickness of about 300 μm. Next, etching (dry etching or wet etching) is performed on the actuator substrate 2 from the back surface of the actuator substrate 2, thereby forming the pressure chamber 5, the restriction channel 6, and the ink inflow portion 7.

During this etching, the base oxide film formed on the surface of the movable film forming layer 10 prevents the metal element (Pb, Zr, Ti in the case of PZT) from escaping from the piezoelectric film 12, and the piezoelectric film 12 piezoelectric characteristics 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, as shown in FIG. 9O, the nozzle substrate 3 is bonded to the back surface of the actuator substrate 2, whereby the ink jet print head 1 is obtained.

  As mentioned above, although embodiment of this invention was described, this invention can also be implemented in another embodiment. In the above-described embodiment, the restriction channel 6 has a form as shown in FIG. 4, but may have a form as shown in FIG. The restriction channel 6 includes a meandering channel 62 formed in a meandering shape in plan view. The serpentine flow path 62 is connected to the plurality of linear portions 62a arranged in parallel with each other in a direction orthogonal to the ink flow direction 41 in a plan view, and connects the linear portions 62a to each other. It includes a connecting portion 62b that connects the ends of the adjacent linear portions 62a so that a flow path is formed. One end of the serpentine channel 62 is connected to the pressure chamber 5, and the other end of the serpentine channel 62 is connected to the ink inflow portion 7. The depth of the restriction channel 6 may be the same as the depth of the pressure chamber 5 or may be shallower than the pressure chamber 5.

  In the above-described embodiment, the piezoelectric film 12 includes the active portion 12A and the inactive portion 12B. However, the piezoelectric film 12 may not include the inactive portion 12B. That is, as shown in FIG. 11, the piezoelectric film 12 may be formed in a rectangular shape having the same pattern as the upper electrode 13 in plan view. In this case, each of the upper electrode 13 and the piezoelectric film 12 has a peripheral edge that recedes inward of the pressure chamber 5 with respect to the movable film 10A in plan view.

Further, as shown in FIG. 12, the piezoelectric film 12 has a pattern having a peripheral edge that is located outward from the peripheral edge of the upper electrode and recedes inward of the pressure chamber 5 from the movable film 10A in plan view. It may be formed in a rectangular shape.
In the above-described embodiment, the insulating film 15 is formed on a part of the surface of the first hydrogen barrier film 14, but the insulating film 15 may be formed on the entire surface of the first hydrogen barrier film 14. Good.

In the above-described embodiment, the insulating film 15 is formed on a part of the surface of the first hydrogen barrier film 14, but the insulating film 15 may not be provided.
In the embodiment described above, the openings 31 and 32 are formed in the first hydrogen barrier film 14, but the openings 31 and 32 may not be formed in the first hydrogen barrier film 14.
In the above-described embodiment, the restriction channel 6 includes the meandering channels 61 and 62, but the restriction channel 6 may not include the meandering channels 61 and 62.

In the above-described embodiment, PZT is exemplified as the material for the piezoelectric film. 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.
Although the case where the present invention is applied to an ink jet print head has been described in the above-described embodiment, the present invention can also be applied to a piezoelectric microphone, a pressure sensor, and the like using a piezoelectric element.

In addition, various design changes can be made within the scope of matters described in the claims.
The following features can be further extracted from this specification.
1. The piezoelectric element utilizing apparatus according to the present invention is formed on a cavity, a movable film disposed on the cavity and defining a top surface portion of the cavity, a lower electrode formed on the movable film, and the lower electrode A piezoelectric element including a piezoelectric film and an upper electrode formed on the piezoelectric film; a first hydrogen barrier film having a contact hole that covers a surface of the piezoelectric element and exposes a part of the upper electrode; In a plan view as viewed from the normal direction with respect to the main surface of the movable film, one end of which is connected to the upper electrode through the contact hole and the other end is drawn to the outside of the piezoelectric element A piezoelectric element comprising: a second hydrogen barrier film covering at least a region including the contact hole on the surface of the wiring; and a passivation film covering the wiring and the second hydrogen barrier film. Apparatus for.
In this configuration, when the passivation film is formed, the region other than the portion where the contact hole is formed in the surface of the piezoelectric element can be covered with the first hydrogen barrier film, and at least the contact hole on the surface of the wiring The region containing can be covered with the second hydrogen barrier film. Thereby, hydrogen generated during the formation of the passivation film can be prevented from passing through the wiring, the contact hole and the upper electrode and reaching the piezoelectric film. Thereby, it is possible to prevent the piezoelectric film from being reduced by hydrogen when forming the passivation film. Thereby, characteristic deterioration due to hydrogen reduction of the piezoelectric film can be prevented.
2. And further including an insulating film interposed between the first hydrogen barrier film and the wiring and having a contact hole communicating with the contact hole of the first hydrogen barrier film, wherein one end of the wiring is formed on the insulating film. The piezoelectric element utilization apparatus according to “1.”, which is connected to the upper electrode through the contact hole and the contact hole of the first hydrogen barrier film.
3. The first hydrogen barrier film has an opening at the center of the upper surface of the upper electrode, and covers the peripheral edge of the upper electrode and the entire side surface of the upper electrode and the piezoelectric film. The piezoelectric element utilization apparatus described in “2.”.
In this configuration, since the first hydrogen barrier film has an opening at the center of the upper surface of the upper electrode, the piezoelectric film is easily deformed. Thereby, the displacement amount of the movable film can be increased.
4). In the plan view, each of the upper electrode and the piezoelectric film has a periphery that recedes inward of the cavity from the movable film, and covers the side surface of the piezoelectric film, The piezoelectric element utilizing apparatus according to any one of “1.” to “3.”, wherein a region where the first hydrogen barrier film is not formed exists in a region between the periphery of the movable film.
In this configuration, since the upper electrode and the piezoelectric film are not disposed on the peripheral edge of the movable film, the displacement of the movable film can be further increased. Further, in this configuration, since there is a region where the first hydrogen barrier film is not formed in a region between the first hydrogen barrier film covering the side surface of the piezoelectric film and the periphery of the movable film, the displacement amount of the movable film Can be further increased.
5). The cavity is formed in a rectangular shape in the plan view, the movable film is formed in a rectangular shape aligned with the periphery of the cavity in the plan view, and the piezoelectric film is formed in the plan view. A rectangular shape 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, and both end edges and both side edges of the movable film are longer than both end edges and both side edges of the movable film. And the upper electrode has 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 toward the inside of the movable film from the both end edges and both side edges of the movable film, respectively, according to any one of “1.” to “4.” The piezoelectric element utilization apparatus described
In this configuration, the upper electrode and the piezoelectric film are not arranged on the peripheral edge of the movable film, so that the displacement of the movable film can be increased.
6). In one embodiment of the present invention, the device for utilizing a piezoelectric element according to “2.” , wherein the insulating film is made of a SiO ₂ film.
7). The piezoelectric device utilizing apparatus according to any one of “1.” to “6.”, wherein the first hydrogen barrier film is made of Al ₂ O ₃ .
8). The piezoelectric device utilizing apparatus according to any one of “1.” to “7.”, wherein the second hydrogen barrier film is made of Al ₂ O ₃ .
9. The piezoelectric element utilization apparatus according to any one of “1.” to “8.”, wherein the passivation film is made of a SiN film.
10. The said passivation film is a piezoelectric element utilization apparatus in any one of "1."-"8." which consists of a SiN film formed by plasma CVD.
11. The piezoelectric element utilization apparatus according to any one of “1.” to “10.”, wherein the movable film is made of a single SiO ₂ film.
12 The movable film includes a laminated film of a Si film formed on a substrate, a SiO ₂ film formed on the Si film, and a SiN film formed on the SiO ₂ film. The piezoelectric element utilization apparatus according to any one of "10."
13. The piezoelectric element utilization apparatus according to any one of “1.” to “12.”, wherein the piezoelectric film is a PZT film.
14 The piezoelectric element utilization apparatus according to any one of “1.” to “13.”, wherein the upper electrode is made of a single Pt film.
15. The upper electrode, and Ir0 ₂ film formed on the piezoelectric film, a laminated film of Ir film formed on the Ir0 ₂ film, either "1" - "13." The piezoelectric element utilization apparatus of description.
16. The piezoelectric material according to any one of “1.” to “15.”, wherein the lower electrode includes a laminated film of a Ti film formed on the movable film side and a Pt film formed on the Ti film. Device utilization device.

DESCRIPTION OF SYMBOLS 1 Init print head 2 Actuator board | substrate 2a Front surface 2b Back surface 3 Nozzle board 3a Recessed part 3b Ink discharge path 3c Ejection port 4 Protective board 5 Pressure chamber (cavity)
6 Restricted flow path 7 Ink inflow part 9 Piezoelectric element 10 Movable film forming layer 10A Movable film 11 Lower electrode 11A Main electrode part 11B Extension part 12 Piezoelectric film 12A Active part 12B Inactive part 13 Upper electrode 14 First hydrogen barrier film 15 Insulating film 17 Upper wiring 17A Lead part 17B Pad part 18 Lower wiring 19 Dummy wiring 20 Second hydrogen barrier film 21 Passivation film 22 Ink supply path 23 Through hole (lower electrode)
24 Ink flow hole (movable film forming layer)
31 opening 32 opening 33 contact hole 34 contact hole 35 pad opening 36 pad opening 37 opening (insulating film, second hydrogen barrier film and passivation film)
41 Ink flow direction 50 Adhesive 51 Opposing surface 52 Accommodating recess 53 Wiring through hole 54 Wiring through hole 55 Ink supply path 61, 62 Serpentine flow path

Claims (2)

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;
Forming a first hydrogen barrier film covering the piezoelectric element on the movable film;
Forming a contact hole in the first hydrogen barrier film to expose a part of the upper electrode on the piezoelectric element;
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 first hydrogen barrier film;
Forming a second hydrogen barrier film covering the wiring on the first hydrogen barrier film;
Forming a passivation film on the second hydrogen barrier film . 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;
Forming a first hydrogen barrier film covering the piezoelectric element on the movable film;
Forming an insulating film on the first hydrogen barrier film;
Forming a contact hole exposing a part of the upper electrode in the insulating film and the first hydrogen barrier film on the piezoelectric element;
On the insulating film, forming a wiring having one end in contact with the upper electrode through the contact hole and the other end extending to the outside of the piezoelectric element;
Forming a second hydrogen barrier film covering the wiring on the insulating film;
Forming a passivation film on the second hydrogen barrier film.

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