JP2008246789A - Method of manufacturing liquid discharge head, image forming device, and method of manufacturing piezoelectric element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To permit high precision and high density of a piezoelectric element to be realized. <P>SOLUTION: The method of manufacturing a liquid discharge head which pressurizes a liquid in a pressure chamber by using the displacement of the piezoelectric element and discharges droplets from nozzles communicating with the pressure chamber, has the process of sequentially laminating a first electrode layer, a piezoelectric material layer, and a second electrode layer which are to be the piezoelectric element on a structure in which a space portion equivalent to the pressure chamber is formed, the process of forming a mask layer on the second electrode layer and patterning the mask layer so as to leave a mask in an area smaller than the inside area of a projection space portion in which the space portion is projected at the side where the mask layer is formed, and the process of patterning at least the second electrode layer and the piezoelectric material layer by dry etching through the mask layer after the patterning. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a liquid discharge head, an image forming apparatus, and a method for manufacturing a piezoelectric element, and more particularly to a technique for manufacturing a liquid discharge head that discharges ink by using displacement of a piezoelectric element.

  An ink jet recording apparatus performs recording by ejecting ink droplets from a plurality of nozzles formed on an ink jet head. The noise during the recording operation is low, the running cost is low, and a wide variety of recording media are used. It is widely used because it can record high-quality images. As an ink discharge method, there are a piezoelectric method using displacement of a piezoelectric element and a thermal method using thermal energy generated by a heating element.

  In general, a piezoelectric inkjet head includes a plurality of nozzles, a pressure chamber communicating with each nozzle, a diaphragm constituting a wall surface of each pressure chamber, and a piezoelectric element corresponding to each pressure chamber. By deforming the diaphragm according to the displacement of the ink, the ink in the pressure chamber is pressurized and ink droplets are ejected from the nozzles.

  Conventionally, a method of directly forming a piezoelectric element on a vibration plate is known as a method for manufacturing an inkjet head. For example, in Patent Document 1, a diaphragm is bonded to a substrate having an opening corresponding to a pressure chamber (liquid chamber), and a lower electrode layer, a piezoelectric layer, and an upper electrode layer are sequentially stacked on the diaphragm. Thereafter, the upper electrode layer and the piezoelectric layer are sequentially patterned to form piezoelectric elements at positions corresponding to the openings.

In semiconductor devices such as FeRAM, electrode materials such as ferroelectrics, high dielectrics, and platinum are called difficult-to-etch materials and are difficult to process. In general, dry etching is often used for processing difficult-to-etch materials. However, in dry etching of a difficult-to-etch material, for example, as shown in FIG. 14A, a resist 904 is formed on the surface of the platinum layer 902 on the substrate 900, and the platinum layer 902 is formed by dry etching using the resist 904 as a mask. When the patterning is to be performed, a difference corresponding to the shape of the resist 904 as shown in FIG. 14B is caused due to the influence of platinum or resist components generated during the etching on the sidewalls of the resist 904 or the platinum layer 902. It cannot be patterned into a rectangular shape (a shape having a side wall surface perpendicular to the etching surface), and is patterned into a tapered shape as shown in FIG. There is a problem (see Non-Patent Document 1, for example).
JP 2005-349713 A Axakaichi, Section 7 “High Dielectric / Electrode Material Etching Technology”, 2004 Semiconductor Technology Encyclopedia, Electronic Journal, p.334

  In the manufacturing method described in Patent Document 1, the upper electrode layer is patterned by dry etching and the piezoelectric layer is patterned by wet etching at positions corresponding to the respective openings. However, in the wet etching, there is a problem that the side surface of the piezoelectric body that is individualized by patterning is not anisotropic but tapered, and the surface thereof is not flat and rattles.

  On the other hand, as described above, dry etching cannot be patterned into an anisotropic shape due to the influence of the adhesion of the sidewall adhesion film (sidewall deposition film), and there is a problem that high accuracy is difficult. In addition, since the etching rate and the resist selection ratio are in a trade-off relationship, the etching rate of the piezoelectric body and the electrode cannot be increased in consideration of the selection ratio with the resist. As a countermeasure, a method using a hard mask is conceivable. However, a process for forming a hard mask is required, and in addition, a process device is required to peel off the hard mask that is no longer necessary after etching. There is also a problem that the manufacturing cost increases due to the complexity.

  As described above, in the conventional manufacturing method, when the piezoelectric element is formed on the diaphragm constituting the wall surface of the pressure chamber, the dimensional controllability of the piezoelectric body and the electrode to be the piezoelectric element is poor, and the piezoelectric element has high accuracy and high performance. There is a problem that densification is difficult.

  The present invention has been made in view of such circumstances, and it is possible to improve the dimensional controllability of piezoelectric bodies and electrodes to be piezoelectric elements, and to manufacture a liquid discharge head that enables higher precision and higher density of the piezoelectric elements. It is an object to provide a method, an image forming apparatus, and a method for manufacturing a piezoelectric element.

  In order to achieve the object, the invention according to claim 1 is a liquid ejection head that pressurizes liquid in a pressure chamber using displacement of a piezoelectric element and ejects liquid droplets from a nozzle communicating with the pressure chamber. A method of manufacturing, wherein a first electrode layer, a piezoelectric layer, and a second electrode layer to be the piezoelectric element are sequentially stacked on a structure in which a space corresponding to the pressure chamber is formed; A mask layer is formed on the second electrode layer, and the mask layer is patterned so that the mask remains in a region smaller than the inner region of the projection space portion where the space portion is projected with respect to the surface on which the mask layer is formed. And a method of patterning at least the second electrode layer and the piezoelectric layer by dry etching through the mask layer after the patterning. .

  According to the present invention, the region corresponding to the inner side of the space corresponding to the pressure chamber has a smaller etching amount than the region corresponding to the outer side (pressure chamber partition wall portion). Can be patterned in an anisotropic shape, and the dimensional controllability of these can be improved, so that it is possible to achieve higher precision and higher density of the piezoelectric element.

  A second aspect of the present invention is the method of manufacturing a liquid ejection head according to the first aspect, wherein the mask layer formed on the second electrode layer is directly patterned by dry etching without using another mask. It is characterized by doing.

  According to the second aspect of the present invention, the mask layer can be patterned by dry etching without performing a photolithography process such as exposure or development, so that the cost can be reduced by reducing the number of processes. In addition, since alignment is not required, the accuracy of the piezoelectric element can be improved.

  According to a third aspect of the present invention, there is provided the method for manufacturing a liquid ejection head according to the first or second aspect, wherein the structure is provided on a flow path substrate on which a space corresponding to the pressure chamber is formed. The diaphragm is arranged, and the first electrode layer, the piezoelectric layer, and the second electrode layer are sequentially laminated on the diaphragm.

  According to a fourth aspect of the present invention, in the method for manufacturing a liquid ejection head according to any one of the first to third aspects, the structure includes a first silicon substrate, a silicon oxide film, and It is characterized by comprising an SOI substrate on which a second silicon substrate is sequentially laminated and an insulating layer formed on the surface of the second silicon substrate of the SOI substrate.

  Invention of Claim 5 is a manufacturing method of the liquid discharge head of Claim 4, Comprising: The space part corresponded to the said pressure chamber is an opening part formed in the said 1st silicon substrate, The diaphragm includes the silicon oxide film, the second silicon substrate, and the insulating layer.

  In order to achieve the above object, the invention described in claim 6 includes a liquid discharge head manufactured by the method of manufacturing a liquid discharge head described in any one of claims 1 to 5. An image forming apparatus is provided.

  The image quality can be improved by the liquid discharge head in which the piezoelectric elements are densified.

  In order to achieve the above object, the invention according to claim 7 is directed to an electrode layer on a surface opposite to the opening side of the opening on the conductive substrate having a dielectric layer and having the opening formed thereon, A step of sequentially laminating piezoelectric layers, a mask layer is formed on the piezoelectric layer, and a mask is formed in a region smaller than an inner region of a projected opening obtained by projecting the opening with respect to a surface on which the mask layer is formed A step of patterning the mask layer so as to remain, and a step of patterning the electrode layer and the piezoelectric layer by dry etching through the patterned mask layer. Provide a method.

  According to the present invention, the region corresponding to the inner side of the space corresponding to the pressure chamber has a smaller etching amount than the region corresponding to the outer side (pressure chamber partition wall portion). Can be patterned in an anisotropic shape, and the dimensional controllability of these can be improved, so that it is possible to achieve higher precision and higher density of the piezoelectric element.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[Inkjet head]
First, the configuration of an ink jet head which is an embodiment of a liquid discharge head according to the present invention will be described.

  FIG. 1 is a cross-sectional view showing the main configuration of the ink jet head of this embodiment. As shown in FIG. 1, the inkjet head 10 of this embodiment includes a nozzle plate 12, a flow path substrate 14, and a piezoelectric actuator 16, and the nozzle plate 12 is bonded to the lower surface of the flow path substrate 14. At the same time, the piezoelectric actuator 16 is formed on the upper surface of the flow path substrate 14.

  The nozzle plate 12 may be made of, for example, glass such as Si, quartz, and Pyrex (registered trademark), a metal material such as SUS and Ni, or a non-metallic material such as polyimide. It may be configured. In implementing the present invention, the constituent material of the nozzle plate 12 is not particularly limited.

  The nozzle plate 12 has nozzles (nozzle holes) 20 serving as ink discharge ports. In the illustrated example, the nozzle hole 20 has a cylindrical shape (straight shape). The shape of the nozzle hole 20 is not limited to this example, and may be, for example, a tapered shape or a trumpet shape. Although not shown, the nozzle plate 12 is provided with a plurality of nozzle holes 20 arranged two-dimensionally.

  The flow path substrate 14 is composed of a silicon substrate (Si substrate), and a plurality of pressure chambers 22 are formed. The side wall portion of the pressure chamber 22 is constituted by the flow path substrate 14, the lower surface of the pressure chamber 22 is constituted by the nozzle plate 12, and the upper surface of the pressure chamber 22 is constituted by the diaphragm 18 constituting a part of the piezoelectric actuator 16. Is done.

  Each pressure chamber 22 is provided corresponding to each nozzle hole 20 of the nozzle plate 12, and the corresponding pressure chamber 22 and nozzle hole 20 communicate with each other. The pressure chamber 22 is a space that is filled with ink to be ejected from the nozzle 20. The inkjet head 10 is provided with a common flow path (not shown) communicating with the plurality of pressure chambers 22, and ink is distributed and supplied from the common flow path to each pressure chamber 22.

The piezoelectric actuator 16 includes a vibration plate 18 and a plurality of piezoelectric elements 24 provided corresponding to the respective pressure chambers 22. The vibration plate 18 includes a silicon substrate (Si substrate) 26 and silicon oxide films (SiO ₂ films) 28 and 30 disposed on both sides thereof. The silicon oxide film 28 on the lower surface side of the silicon substrate 26 is a Box layer ( The silicon oxide film 30 on the upper surface side functions as an insulating layer. The diaphragm 18 is formed over a region extending over the plurality of pressure chambers 22 and constitutes one wall surface (upper surface) of each pressure chamber 22.

  On the vibration plate 18 (insulating layer 30 side), piezoelectric elements 24 are arranged at positions facing the respective pressure chambers 22. The piezoelectric element 24 includes a lower electrode 32, a piezoelectric body 34, and an upper electrode 36. That is, the piezoelectric element 24 has a structure in which the piezoelectric body 34 is sandwiched between the lower electrode 32 and the upper electrode 36. The piezoelectric body 34 is made of lead zirconate titanate (PZT), and the electrodes 32 and 36 are made of platinum (Pt) or iridium (Ir).

  In implementing the present invention, the piezoelectric material constituting the piezoelectric element 24 is not limited to this example, and other piezoelectric materials such as barium titanate can also be applied. Further, the electrode material constituting each of the electrodes 32 and 36 is not limited to this example. For example, tungsten (W), gold (Au), silver (Ag), copper (Cu), titanium (Ti) Etc. can also be applied.

  One of the lower electrode 32 and the upper electrode 36 can be an individual electrode (address electrode), and the other electrode can be a common electrode (ground electrode). Depending on the polarization direction (orientation direction) of the piezoelectric body 34 disposed between the upper electrode 36 and the lower electrode 32, an electric field in the same direction as the polarization direction is applied even if a positive voltage is applied to the individual electrodes. It is preferable to configure. Thereby, cost reduction of a drive IC and a power supply can be aimed at.

  In particular, when the piezoelectric body 34 is formed by the sputtering method, the direction from the lower electrode 32 to the upper electrode 36 is the polarization direction of the piezoelectric body, and therefore, an embodiment in which the lower electrode 32 is an individual electrode is preferable.

An insulating layer 30 composed of a silicon oxide film (SiO ₂ film) is disposed between the silicon substrate 26 and the lower electrode 32. The insulating layer 30 may be composed of a silicon carbonitride film (SiCN film), a zirconium oxide film (ZrO ₂ film), a silicon oxynitride film (SiON film), or the like. Among these, the insulating layer 30 is preferably a silicon oxide film (SiO ₂ film) obtained by thermally oxidizing the silicon substrate 26 because it is inexpensive and easy to process. By disposing the insulating layer 30 between the silicon substrate 26 and the lower electrode 32 in this way, current leakage between the plurality of lower electrodes 32 can be suppressed, and electrical crosstalk and increase in power consumption can be prevented. be able to.

  With this configuration, when a predetermined electric field is applied to the piezoelectric body 34 sandwiched between the lower electrode 32 and the upper electrode 36, the vibration plate 18 is deformed according to the displacement of the piezoelectric body 34, and the ink in the pressure chamber 22 is discharged. An ink droplet is ejected from the nozzle 20 that is pressurized and communicates with the pressure chamber 22.

  Next, the manufacturing method of the inkjet head 10 is demonstrated as an example of the manufacturing method of the liquid discharge head which concerns on this invention.

  FIG. 2 is a process diagram showing an example (first manufacturing method) of the method for manufacturing the inkjet head 10.

First, as shown in FIG. 2A, an SOI substrate 50 having an insulating layer 58 formed on the surface is prepared. The SOI substrate 50 includes a support 52 constituted by a silicon substrate (Si substrate), a Box layer 54 constituted by a silicon oxide film (SiO ₂ film), and an active layer 56 constituted by a silicon substrate (Si substrate). A multilayer substrate. The insulating layer 58 is preferably a silicon oxide film (SiO ₂ film) and has a thickness of about 100 nm to 1 μm (for example, 300 nm). The silicon oxide film can be formed by a method such as thermal oxidation, sputtering, or CVD.

  Next, as shown in FIG. 2B, an opening 60 corresponding to the pressure chamber 22 is formed in the support body 52 of the SOI substrate 50. A specific method for forming the opening 60 is as follows.

First, resist coating, pre-baking, exposure, development, and post-baking processes are sequentially performed on the entire surface of the support (Si substrate) 52. Each process condition may be determined according to the type of resist and the film thickness. The resist thickness may be determined from the etching depth and plasma resistance. For example, when silicon is etched by 300 μm, the resist may be formed with a thickness of 5 μm to 50 μm. It is preferable to determine the resist film thickness in accordance with the selection ratio of silicon etching to be performed next. A hard mask such as an oxide film, a nitride film, or a metal may be used instead of the resist. The resist is patterned so that an opening region is formed in a portion corresponding to the pressure chamber 22. Subsequently, using the resist patterned as described above as a mask, the support (Si substrate) 52 is dry-etched to form an opening 60 corresponding to the pressure chamber 22. As a dry etching method, for example, a method of deeply processing silicon while repeatedly performing etching and protective film formation, fluorine gas is used as an etching gas, and oxygen or CF fluorine gas is added for forming a protective film. There are ways to do it. At this time, since the Box layer (SiO ₂ film) 54 functions as an etching stop layer, only the region of the support (Si substrate) 52 not covered with the resist (that is, the region corresponding to the pressure chamber 22) is etched. Then, an opening 60 having the Box layer 54 as a bottom surface is formed in the support body 52. After the opening 60 is thus formed in the support 52, the resist is removed using ashing using oxygen plasma or a special resist stripping solution.

In this way, as shown in FIG. 2B, an SOI substrate 50 in which the insulating layer 58 is formed on the surface of the active layer 56 and the opening 60 is formed in the support 52 can be obtained. In the method for forming the opening 60 described above, a resist mask is used for etching silicon. However, a material having higher selectivity than the resist may be used as a mask material. For example, a hard mask of an oxide film (SiO ₂ film), a nitride film (SiN film), or a metal (aluminum, chromium, titanium, etc.) may be used.

  In the present manufacturing method, the opening 60 corresponding to the pressure chamber 22 is formed in the support 52 of the SOI substrate 50 with the insulating layer 58. However, the present invention is not limited to this example. Absent. For example, an opening (through hole) 60 that becomes the pressure chamber 22 is formed in the silicon substrate 52, and silicon oxide films 54 and 58 are formed on both surfaces of the other silicon substrate 56, so that the silicon substrate 56 and the silicon oxide film are formed. The diaphragm 18 (see FIG. 1) composed of 54 and 56 may be bonded onto the silicon substrate 52.

  Further, in the illustrated example, the opening 60 formed in the support body 52 is formed so that the entire region is opened on the surface opposite to the surface on which the insulating layer 58 of the SOI substrate 50 is formed. However, the embodiment of the present invention is not limited to this example. For example, a hollow structure in which a hollow portion is formed in the support 52 or a structure in which a part of the hollow portion is open may be used. That is, it is sufficient that a space corresponding to the pressure chamber 22 is formed at least on the SOI substrate 50.

  Next, as shown in FIG. 2C, a lower electrode layer 62, a piezoelectric layer 64, and an upper electrode layer 66 are sequentially formed on the entire surface of the insulating layer 58 formed on the SOI substrate 50. The electrode layers 62 and 66 can be formed by sputtering, vapor deposition, or the like of electrode materials such as platinum (Pt), iridium (Ir), tungsten (W), gold (Au), silver (Ag), and copper (Cu). The film may be formed by this method. In particular, in the present invention, platinum or iridium is suitable as the electrode material. As a method for forming the piezoelectric layer 64, a piezoelectric material such as lead zirconate titanate (PZT) may be formed by a method such as sputtering, vapor deposition, CVD, or sol-gel method.

  Next, as shown in FIG. 2D, a resist layer 68 is formed on the upper electrode layer 66. Subsequently, as shown in FIG. 2E, a surface on which the resist layer 68 is formed (upper electrode) The resist layer 68 is patterned so that the resist remains in a region smaller than the inner region of the projection opening where the opening 60 is projected onto the surface of the layer 66. A specific patterning method is shown below.

  FIG. 3 is a detailed view showing the patterning process of the resist layer 68. As shown in FIG. 3A, a resist layer 68 is formed by applying a resist to the entire surface of the upper electrode layer 66, and after pre-baking, as shown in FIG. Then, the resist layer 68 is exposed. Thereafter, the resist layer 68 is developed and post-baked. Thus, as shown in FIG. 3C, a resist 68 ′ is formed at a position facing the opening 60. Each process condition of resist coating, pre-baking, exposure, development, and post-baking may be determined according to the type and film thickness of the resist. The thickness (film thickness) of the resist layer 68 may be about 1 μm to 30 μm. Specifically, the thickness may be determined from the thicknesses of the electrode layers 62 and 66 and the piezoelectric layer 64. For example, when only the electrode layer 62 (or 68) is etched, when the thickness of the electrode layer 62 is about 100 to 500 nm, the thickness of the resist layer 68 may be set to 1 to 3 μm. More specifically, when the thickness of the electrode layer 62 is 200 nm, the thickness of the resist layer 68 may be 2 μm. When the piezoelectric layer 64 and the electrode layer 62 (or 68) are etched together (continuously or collectively), the thickness of the electrode layer 62 is sufficiently thinner than the piezoelectric layer 64. For example, when the thickness of the piezoelectric layer 64 is 3 μm, the thickness of the resist layer 68 may be about 10 μm.

  FIG. 4 is an explanatory view showing an example of a resist patterning method, and is a plan perspective view in which the patterned resist 68 ′ and the opening 60 are projected onto the surface (the upper electrode layer 66 surface) on which the resist layer 68 is disposed. It is.

  In the present invention, as shown in FIG. 4, without contacting the edge of the opening 60 projected on the surface on which the resist layer 68 is disposed (hereinafter referred to as “projection opening 60 ′”) It is characterized in that the patterning is performed so that the patterned resist 68 'is completely included in the inner region. In the illustrated example, the resist 68 ′ has a shape similar to the projection opening 60 ′. However, as will be described later, the embodiment is not limited to this example. In the present invention, the patterning is performed so that one side (or diameter) of the resist 68 ′ after patterning is 95% to 50%, preferably 95% to 80% from the corresponding side (or diameter) of the projection opening 60 ′. It is preferable to carry out.

  FIG. 5 is an explanatory view showing another example of a resist patterning method. FIG. 5A shows an example in which a resist 68′A patterned in a square shape is arranged in an inner region of a circular projection opening 60′A. FIG. 5B shows an example in which a resist 68′B patterned in a circular shape is disposed in an inner region of a square projection opening 60′B. FIG. 5C shows an example in which a resist 68'C patterned in a square shape is arranged in the inner region of the hexagonal projection opening 60'C. FIG. 5D shows an example in which a resist 68′D patterned in a square shape is arranged in the inner region of the parallelogram-shaped projection opening 60′D.

  As described above, in the practice of the present invention, the shape of the opening 60 (projection opening 60 ′) and the patterned resist 68 ′ is not particularly limited, and the above-described relationship, ie, the projection opening 60 ′. It suffices to pattern the resist so that the resist 68 'is completely included in the inner region. An anisotropic shape in which the side surface of the upper electrode and the piezoelectric body patterned by dry etching performed in the next step is perpendicular to the etching surface can be obtained, dimensional controllability is improved, and the piezoelectric element High precision and high density are possible.

  In this manufacturing method, UV curing may be performed to improve the heat resistance of the resist 68 '. Further, a hard mask such as an oxide film, a nitride film, aluminum, chromium, titanium, titanium nitride, or titanium oxide may be used instead of the resist mask.

  Next, dry etching is performed in the order of the upper electrode layer 66, the piezoelectric layer 64, and the lower electrode layer 62 using the resist 68 'patterned as described above as a mask. When dry etching is performed, as shown in FIG. 2F, the upper electrode 66 ', the piezoelectric body 64', and the lower electrode 62 'having an anisotropic shape corresponding to the shape of the resist 68' can be obtained. .

  When the lower electrode layer 62 is used as a common electrode, there is an aspect in which the lower electrode layer 62 is not dry-etched.

  The etching apparatus may be an inductive coupling plasma (ICP), a reactive ion etching apparatus, a magnetic field enhanced ICP, RIE, or an ECR apparatus.

  FIG. 6 is a schematic view of an etching apparatus. The etching apparatus shown in FIG. 6 includes a process gas (reaction gas) supply means 72 into the chamber 70 and an internal gas exhaust means 74 of the chamber 70, and an antenna is provided on the dielectric window 76 on the upper surface of the chamber 70. 78 is installed, and an RF power source (antenna power source) 80 for plasma generation is connected to the antenna 78. Further, an electrostatic chuck is provided on the stage 84 that holds the substrate 82 in the chamber 70, and an RF power source (bias power source) 86 for bias application is connected to the stage 84.

When etching the upper electrode layer 66 (or the lower electrode layer 62), the substrate 82 is placed on the stage 84. A mixed gas of chlorine and argon is introduced into the chamber 70 as a process gas. As the process gas, BCl ₃ , HBr, SF ₆ , or CF ₄ may be used instead of chlorine. In addition, oxygen, nitrogen, or the like may be added. Further, a mixed gas of chlorine, BCl ₃ , Ar, oxygen, or the like, or a mixture of the above gases may be used. Etching is performed by applying RF to the antenna 78 to generate plasma, and applying bias RF to the stage 84. For example, the RF power source 80 for the antenna uses 13.56 MHz, and the RF power source 86 for the bias uses a frequency band of 400 kHz. The RF for the antenna may use a high frequency band such as 27 MHz in addition to 13.56 MHz, and may further be used by pulse driving. The bias power source may be 200 kHz to 800 kHz as a low frequency power source, and may be used by pulse driving.

  Typical etching conditions are as follows. As the process gas, a mixed gas of 10% to 60% chlorine and 40% to 90% argon is used. For example, the flow rate of chlorine may be 20 sccm and the argon may be 80 sccm. The pressure of process gas shall be 0.1-1 Pa. For example, it may be 0.2 Pa. The antenna RF power is 350 to 1000 W, for example, 500 W. The substrate bias power is 50 to 500 W, for example 150 W. In the case of using a resist mask, the temperature of the stage 214 is -20 to 150 ° C, and particularly 5 ° C. When a hard mask other than the resist mask is used, it may be heated to 200 to 400 ° C.

When etching the piezoelectric layer 64, the substrate 82 is placed on the stage 84. A mixed gas of chlorine and argon is introduced into the chamber 70 as a process gas. As the process gas, BCl ₃ , HBr, SF ₆ , CF ₄ , CHF ₃ , C ₄ F ₈ may be used instead of chlorine. In addition, oxygen, nitrogen, or the like may be added. Further, a mixture of a plurality of the gases such as a mixed gas of chlorine, C ₄ F ₈ , Ar, oxygen and the like may be used. Etching is performed by applying RF to the antenna 78 to generate plasma, and applying bias RF to the stage 84. For example, 13.56 MHz is used for the RF power source 80 for the antenna, and 13.56 MHz is used for the RF power source 86 for the bias. The RF for the antenna may use a high frequency band such as 27 MHz in addition to 13.56 MHz, and may further be used by pulse driving. The bias RF power source 86 may be 200 kHz to 800 kHz as a low frequency power source, and may be used by pulse driving.

  Typical etching conditions are as follows. As the process gas, a mixed gas of 10% to 60% chlorine and 40% to 90% argon is used. For example, the flow rate of chlorine may be 20 sccm and the argon may be 80 sccm. The pressure of the process gas is 0.1 to 5 Pa. For example, it may be 1.0 Pa. The antenna RF power is 350 to 1000 W, for example, 500 W. The substrate bias power is 50 to 500 W, for example 150 W. In the case of using a resist mask, the temperature of the stage 214 is -20 to 150 ° C, and particularly 5 ° C. When a hard mask other than the resist mask is used, it may be heated to 200 to 400 ° C.

  After obtaining the upper electrode 66 ', the piezoelectric body 64', and the lower electrode 62 'patterned by dry etching using the etching apparatus as described above (see FIG. 2 (f)), the resist is removed using ashing or stripping solution. 68 'is removed. If necessary, the resist residue may be removed using a polymer removing solution or the like.

  Thus, as shown in FIG. 2G, the lower electrode 62 ′, the piezoelectric body 64 ′, and the upper electrode 66 that form the piezoelectric element 24 are formed at positions facing the opening 60 corresponding to the pressure chamber 22. it can.

  Finally, as shown in FIG. 2H, a nozzle plate 12 separately manufactured is bonded to the lower surface side of the SOI substrate 50. As a bonding method, anodic bonding, eutectic bonding, room temperature bonding, bonding, and the like are possible. In this way, the inkjet head 10 of this embodiment is completed.

  FIG. 7 is an explanatory diagram for explaining the principle of the present invention. FIG. 7A is a schematic diagram showing a part of the etching apparatus shown in FIG. 6, in which dry etching is performed by drawing ions in plasma to the SOI substrate 50 side installed on the stage 84. Is shown. In order to simplify the description, in FIG. 7A, the insulating layer 58, the lower electrode layer 62, the piezoelectric layer 64, the upper electrode layer 66, and the resist layer 68 formed on the SOI substrate 50 are not shown. (See FIG. 2).

FIG. 7B is an equivalent circuit diagram shown in FIG. FIGS. 7C and 7D are graphs showing the distribution of the ion current value and the etching amount, respectively. The horizontal axis of these graphs is as shown by the broken line in FIG. 7B. This corresponds to the horizontal position of the silicon substrate 52 shown in the equivalent circuit diagram. As shown in FIG. 7B, since the Box layer (SiO ₂ film) 54 formed on the SOI substrate 50 is a dielectric layer, it functions as a capacitor at each position of the SOI substrate 50 and is formed on the SOI substrate 50. The opening 60 formed functions as a capacitor. Therefore, the position corresponding to the inner region P of the opening 60 is a high impedance portion, and the position corresponding to the outer region (partition wall portion) Q of the opening 60 is a low impedance portion. For this reason, as shown in FIG. 7C, a phenomenon occurs in which the ion current value is lower in the position corresponding to the inner region P of the opening 60 than in the position corresponding to the outer region Q of the opening 60. As described above, during etching, ions in the plasma are drawn into the SOI substrate 50 side and etching is performed, so that the etching amount varies depending on the value of the ion current value. That is, as shown in FIG. 7D, the etching amount is smaller at the position corresponding to the inner region P of the opening 60 than at the position corresponding to the outer region Q of the opening 60.

  FIG. 8 is an explanatory diagram for explaining the effect of the present invention. FIGS. 8A and 8B each show a diaphragm 204 (silicon oxide films (dielectric layers) formed on both surfaces of a silicon substrate) on a flow path substrate (silicon substrate) 202 in which an opening 200 is formed. ) Are joined on the structure 206 (ie, on the diaphragm 204), and a resist 210 having a predetermined shape is formed on the electrode layer 208 at a position corresponding to the opening 200. Represents.

  In FIG. 8A, when the width of the resist 210 is formed larger than the width of the opening 200, specifically, the opening 200 is formed with respect to the surface (surface of the electrode layer 208) on which the resist 210 is disposed. The case where the side edge part (left and right edge part in Fig.8 (a)) of the resist 210 has protruded to the outer area | region of the projected opening part (not shown) projected is represented. As described above, the position corresponding to the outer region of the opening 200 is the low impedance portion, and an ionic current value equivalent to that of the region where the resist 210 is not formed flows. As a result, the etching amount increases. Therefore, the side edge of the resist 210 is easily affected by the adhesion of the sidewall deposition film as in the case shown in FIG. 14, and the shape after etching is anisotropic as shown in the right figure of FIG. It becomes a taper shape without becoming a natural shape.

  In FIG. 8B, when the width of the resist 210 is formed smaller than the width of the opening 200, specifically, the opening 200 is formed with respect to the surface (surface of the electrode layer 208) on which the resist 210 is disposed. This represents a case where the resist 210 is included in the inner area of the projected opening (not shown) without contacting the edge. As described above, the position corresponding to the inner region of the opening 200 is a high impedance portion, and the ion current value is lower and the etching amount is smaller than the position corresponding to the outer region of the opening 200. For this reason, the side end portions (left and right end portions in FIG. 8B) of the resist 210 existing at the position corresponding to the inner region of the opening 200 are not easily etched, and as a result, the right view of FIG. As shown, the electrode layer 208 can be patterned into an anisotropic shape corresponding to the shape of the resist 210.

  Although illustration is omitted, when the opening 200 and the resist 210 have the same width, specifically, a projection in which the opening 200 is projected onto the surface on which the resist 210 is disposed (the surface of the electrode layer 208). When the opening (not shown) and the resist 210 completely coincide with each other, as can be seen from FIG. 7C, the opening 200 is formed at the edge of the opening 200 (60) that coincides with the side end of the resist 210. Since the ionic current value equivalent to the position corresponding to the outer region of FIG. 8 flows, it is easy to be etched in a tapered shape as shown in the right diagram of FIG. Therefore, it is preferable that the resist 210 be formed so as not to completely coincide with the projected opening obtained by projecting the opening 200 with respect to the surface on which the resist 210 is disposed (the surface of the electrode layer 208).

  In this manufacturing method, by using the above-described principle, dry etching is performed through a mask pattern smaller than a space (opening) corresponding to a pressure chamber, so that an electrode or a piezoelectric body serving as a piezoelectric element is different. It can be etched into an isotropic shape. Therefore, the dimensional controllability is high, and the piezoelectric element can be made highly accurate and dense.

  FIG. 9 is a process diagram illustrating another example (second manufacturing method) of the method for manufacturing the inkjet head 10 of the present embodiment. 9, parts that are the same as those in FIG. 2 are given the same numbers.

First, an insulating layer (SiO ₂ film) 58 is formed on the surface of the active layer 56 of the SOI substrate 50 (FIG. 9A), and an opening 60 corresponding to the pressure chamber 22 is formed in the support 52 (FIG. 9 ( b)), a lower electrode layer 62, a piezoelectric layer 64, and an upper electrode layer 66 are sequentially formed on the entire surface of the insulating layer 58 (FIG. 9C), and a resist layer 68 is formed on the entire surface of the upper electrode layer 66. Since the steps from applying to the baking are the same as those in the first manufacturing method described above (see FIGS. 2A to 2C), description thereof is omitted.

  As shown in FIG. 9D, the present manufacturing method is characterized in that after the resist layer 68 is applied to the entire surface of the upper electrode layer 66 and baked, the resist layer 68 is directly subjected to dry etching. It is said. That is, it differs from the first manufacturing method in that the photolithography process such as exposure and development as shown in FIG. 3 is not performed. As described with reference to FIG. 7, the first manufacturing method uses the phenomenon that the etching amount is smaller at the position corresponding to the inner region of the opening 60 than at the position corresponding to the outer region of the opening 60. As shown in FIG. 9E, a position corresponding to the inner region of the opening 60 can be obtained by directly performing dry etching on the resist layer 68 without going through the photolithography process as described above (see FIG. 3). A resist 68 'can be formed.

  The subsequent steps are the same as those in the first manufacturing method (see FIGS. 2F to 2H). The upper electrode layer 66, the piezoelectric layer 64, and the lower electrode layer 62 are formed using the patterned resist 68 ′ as a mask. The dry etching is sequentially performed (FIG. 9 (f)), the resist 68 'is peeled off (FIG. 9 (g)), and the nozzle plate 12 prepared separately is joined (FIG. 9 (h)). In this way, the inkjet head 10 of this embodiment is completed.

  According to this manufacturing method, the resist layer 68 can be patterned by dry etching without performing a photolithographic process such as exposure or development, so that the cost can be reduced by reducing the number of processes. Further, since alignment (positioning) is not required, the piezoelectric element 24 can be highly accurate.

[Inkjet recording device]
Next, an ink jet recording apparatus as an embodiment of the image forming apparatus according to the present invention will be described.

  FIG. 10 is an overall configuration diagram showing an outline of the ink jet recording apparatus. As shown in FIG. 10, the inkjet recording apparatus 100 includes a printing unit 112 having a plurality of recording heads 112K, 112C, 112M, and 112Y provided for each ink color, and the recording heads 112K, 112C, 112M, and 112Y. An ink storage / loading unit 114 that stores ink to be supplied to the printer, a paper feeding unit 118 that supplies recording paper 116, a decurling unit 120 that removes curling of the recording paper 116, and a nozzle surface of the printing unit 112 A suction belt conveyance unit 122 that is arranged opposite to the (ink ejection surface) and conveys the recording paper 116 while maintaining the flatness of the recording paper 116; a print detection unit 124 that reads a printing result by the printing unit 112; And a paper discharge unit 126 that discharges printed recording paper (printed matter) to the outside. Each of the recording heads 112K, 112C, 112M, and 112Y corresponds to the inkjet head 10 shown in FIG.

  In FIG. 10, a magazine for rolled paper (continuous paper) is shown as an example of the paper supply unit 118, but a plurality of magazines having different paper widths, paper quality, and the like may be provided side by side. Further, instead of the roll paper magazine or in combination therewith, the paper may be supplied by a cassette in which cut papers are stacked and loaded.

  In the case of an apparatus configuration using roll paper, a cutter 128 is provided as shown in FIG. 10, and the roll paper is cut into a desired size by the cutter 128. The cutter 128 includes a fixed blade 128A having a length equal to or larger than the conveyance path width of the recording paper 116, and a round blade 128B that moves along the fixed blade 128A. The fixed blade 128A is provided on the back side of the print. The round blade 128B is arranged on the printing surface side with the conveyance path interposed therebetween. Note that the cutter 128 is not necessary when cut paper is used.

  When multiple types of recording paper are used, an information recording body such as a barcode or wireless tag that records paper type information is attached to the magazine, and the information on the information recording body is read by a predetermined reader. Therefore, it is preferable to automatically determine the type of paper to be used and perform ink ejection control so as to realize appropriate ink ejection according to the type of paper.

  The recording paper 116 delivered from the paper supply unit 118 retains curl due to having been loaded in the magazine. In order to remove this curl, the decurling unit 120 applies heat to the recording paper 116 by the heating drum 130 in the direction opposite to the curl direction of the magazine. At this time, it is more preferable to control the heating temperature so that the printed surface is slightly curled outward.

  After the decurling process, the cut recording paper 116 is sent to the suction belt conveyance unit 122. The suction belt conveyance unit 122 has a structure in which an endless belt 133 is wound between rollers 131 and 132, and at least a portion facing the nozzle surface of the printing unit 112 and the sensor surface of the printing detection unit 124 is flat. It is configured to make.

  The belt 133 has a width that is wider than the width of the recording paper 116, and a plurality of suction holes (not shown) are formed on the belt surface. As shown in FIG. 10, an adsorption chamber 134 is provided at a position facing the nozzle surface of the printing unit 112 and the sensor surface of the printing detection unit 124 inside the belt 133 spanned between the rollers 131 and 132. The suction chamber 134 is sucked by the fan 135 to make a negative pressure, whereby the recording paper 116 on the belt 133 is sucked and held.

  The power of a motor (not shown) is transmitted to at least one of the rollers 131 and 132 around which the belt 133 is wound, so that the belt 133 is driven in the clockwise direction in FIG. 10 and held on the belt 133. The recording paper 116 is conveyed from left to right in FIG.

  Since ink adheres to the belt 133 when a borderless print or the like is printed, the belt cleaning unit 136 is provided at a predetermined position outside the belt 133 (an appropriate position other than the print region). Although details of the configuration of the belt cleaning unit 136 are not shown, for example, there are a method of niping a brush roll, a water absorption roll, etc., an air blowing method of blowing clean air, or a combination thereof. In the case where the cleaning roll is nipped, the cleaning effect is great if the belt linear velocity and the roller linear velocity are changed.

  Although a mode using a roller / nip conveyance mechanism instead of the suction belt conveyance unit 122 is also conceivable, if the roller / nip conveyance is performed in the printing area, the roller comes into contact with the printing surface of the paper immediately after printing, so that the image blurs. There is a problem that it is easy. Therefore, as in this example, suction belt conveyance that does not contact the image surface in the printing region is preferable.

  A heating fan 140 is provided on the upstream side of the printing unit 112 on the paper conveyance path formed by the suction belt conveyance unit 122. The heating fan 140 heats the recording paper 116 by blowing heated air onto the recording paper 116 before printing. Heating the recording paper 116 immediately before printing makes it easier for the ink to dry after landing.

  The printing unit 112 is a so-called full-line type head in which a line-type head having a length corresponding to the maximum paper width is arranged in a direction (main scanning direction) orthogonal to the paper transport direction (sub-scanning direction). Each of the recording heads 112K, 112C, 112M, and 112Y constituting the printing unit 112 has a plurality of ink discharge ports (nozzles) arranged over a length exceeding at least one side of the maximum size recording paper 116 targeted by the inkjet recording apparatus 100. The line type head is constructed (see FIG. 11).

  Recording corresponding to each color ink in the order of black (K), cyan (C), magenta (M), and yellow (Y) from the upstream side (left side in FIG. 10) along the conveyance direction (paper conveyance direction) of the recording paper 116. Heads 112K, 112C, 112M, and 112Y are disposed. A color image can be formed on the recording paper 116 by ejecting the color inks from the recording heads 112K, 112C, 112M, and 112Y while conveying the recording paper 116, respectively.

  As described above, according to the printing unit 112 in which the full line head that covers the entire paper width is provided for each ink color, the recording paper 116 and the printing unit 112 are relatively moved in the paper transport direction (sub-scanning direction). It is possible to record an image on the entire surface of the recording paper 116 by performing this operation only once (that is, in one sub-scan). Thereby, high-speed printing is possible and productivity can be improved as compared with the shuttle type head in which the recording head reciprocates in the direction (main scanning direction) orthogonal to the paper transport direction.

  In this example, the configuration of KCMY standard colors (four colors) is illustrated, but the combination of ink colors and the number of colors is not limited to this embodiment, and light ink and dark ink are added as necessary. May be. For example, it is possible to add a recording head that discharges light ink such as light cyan and light magenta.

  As shown in FIG. 10, the ink storage / loading unit 114 has tanks that store inks of colors corresponding to the recording heads 112K, 112C, 112M, and 112Y, and each tank has a pipeline that is not shown. Via the recording heads 112K, 112C, 112M, and 112Y. Further, the ink storage / loading unit 114 includes notifying means (display means, warning sound generating means, etc.) for notifying when the ink remaining amount is low, and has a mechanism for preventing erroneous loading between colors. is doing.

  The print detecting unit 124 includes an image sensor (line sensor or the like) for imaging the droplet ejection result of the printing unit 112, and means for checking nozzle clogging and other ejection defects from the droplet ejection image read by the image sensor. Function as.

  The print detection unit 124 of this example is composed of a line sensor having a light receiving element array that is wider than at least the ink discharge width (image recording width) by the recording heads 112K, 112C, 112M, and 112Y. The line sensor includes an R sensor row in which photoelectric conversion elements (pixels) provided with red (R) color filters are arranged in a line, a G sensor row provided with green (G) color filters, The color separation line CCD sensor includes a B sensor array provided with a blue (B) color filter. Instead of the line sensor, an area sensor in which the light receiving elements are two-dimensionally arranged can be used.

  The print detection unit 124 reads the test pattern printed by the recording heads 112K, 112C, 112M, and 112Y for each color, and detects the ejection of each head. The ejection determination includes the presence / absence of ejection, measurement of dot size, measurement of dot landing position, and the like.

  A post-drying unit 142 is provided following the print detection unit 124. The post-drying unit 142 is means for drying the printed image surface, and for example, a heating fan is used. Since it is preferable to avoid contact with the printing surface until the ink after printing is dried, a method of blowing hot air is preferred.

  When printing on porous paper with dye-based ink, the weather resistance of the image is improved by preventing contact with ozone or other things that cause dye molecules to break by blocking the paper holes by pressurization. There is an effect to.

  A heating / pressurizing unit 144 is provided following the post-drying unit 142. The heating / pressurizing unit 144 is a means for controlling the glossiness of the image surface, and pressurizes with a pressure roller 145 having a predetermined uneven surface shape while heating the image surface, and transfers the uneven shape to the image surface. To do.

  The printed matter generated in this manner is outputted from the paper output unit 126. It is preferable that the original image to be printed (printed target image) and the test print are discharged separately. The ink jet recording apparatus 100 is provided with sorting means (not shown) for switching the paper discharge path in order to select the printed matter of the main image and the printed matter of the test print and send them to the respective discharge units 126A and 126B. ing. Note that when the main image and the test print are simultaneously formed in parallel on a large sheet, the test print portion is separated by the cutter (second cutter) 148. The cutter 148 is provided immediately before the paper discharge unit 126, and cuts the main image and the test print unit when the test print is performed on the image margin. The structure of the cutter 148 is the same as that of the first cutter 128 described above, and includes a fixed blade 148A and a round blade 148B. Although not shown, the paper output unit 126A for the target prints is provided with a sorter for collecting prints according to print orders.

  Since the structures of the recording heads 112K, 112C, 112M, and 112Y provided for each ink color are common, the recording head will be denoted by reference numeral 150 in the following.

  FIG. 12A is a perspective plan view showing a structural example of the recording head 150. As shown in FIG. 12A, the recording head 150 of this example includes a plurality of ink chamber units (one nozzle per nozzle 20) including nozzles 20 serving as ink droplet ejection ports and pressure chambers 22 corresponding to the nozzles 20. Corresponding recording element unit droplet discharge elements 160 are arranged in a zigzag matrix (two-dimensional), and thereby, along the longitudinal direction of the head (direction perpendicular to the paper feed direction). High density of substantial nozzle interval (projection nozzle pitch) projected in line is achieved.

  Note that the form in which the nozzle row having a length corresponding to the full width of the recording paper 116 is configured in the direction (main scanning direction) substantially orthogonal to the conveyance direction (sub-scanning direction) of the recording paper 116 is not limited to this example. For example, instead of the configuration of FIG. 12A, as shown in FIG. 12B, short head units 150 ′ in which a plurality of nozzles 20 are two-dimensionally arranged are arranged in a staggered manner and connected. A line head having a nozzle row having a length corresponding to the entire width of the recording paper 116 may be configured.

  The pressure chamber 22 provided corresponding to each nozzle 20 has a substantially square planar shape. The pressure chamber 22 provided corresponding to each nozzle 20 has a substantially square planar shape. The nozzles 20 are arranged at substantially central portions of the pressure chambers 22, and supply ink inlets (supply ports) 154 are provided at the corners thereof.

  The shape of the pressure chamber 22 is not limited to this example, and the planar shape may have various forms such as a quadrangle (rhombus, rectangle, etc.), a pentagon, a hexagon and other polygons, a circle, and an ellipse. Further, the arrangement of the nozzles 20 and the supply ports 154 is not limited to the arrangement shown in FIGS.

  Next, the control system of the inkjet recording apparatus 100 will be described.

  FIG. 13 is a principal block diagram showing a control system of the inkjet recording apparatus 100. The inkjet recording apparatus 100 includes a communication interface 170, a system controller 172, an image memory 174, a motor driver 176, a heater driver 178, a print control unit 180, an image buffer memory 182, a head driver 184, and the like.

  The communication interface 170 is an interface unit that receives image data sent from the host computer 186. A serial interface or a parallel interface can be applied to the communication interface 170. In this part, a buffer memory (not shown) for speeding up communication may be mounted.

  Image data sent from the host computer 186 is taken into the inkjet recording apparatus 100 via the communication interface 170 and temporarily stored in the image memory 174. The image memory 174 is a storage unit that temporarily stores an image input via the communication interface 170, and data is read and written through the system controller 172. The image memory 174 is not limited to a memory composed of semiconductor elements, and a magnetic medium such as a hard disk may be used.

  The system controller 172 is a control unit that controls the communication interface 170, the image memory 174, the motor driver 176, the heater driver 178, and the like. The system controller 172 includes a central processing unit (CPU) and its peripheral circuits, and performs communication control with the host computer 186, read / write control of the image memory 174, and the like, and a transport motor 188 and heater 189. A control signal for controlling is generated.

  The motor driver 176 is a driver (drive circuit) that drives the motor 188 in accordance with an instruction from the system controller 172. The heater driver 178 is a driver that drives the heater 189 of the post-drying unit 142 and other units in accordance with an instruction from the system controller 172.

  The print control unit 180 has a signal processing function for performing various processes such as processing and correction for generating a print control signal from the image data in the image memory 174 in accordance with the control of the system controller 172. The control unit supplies a control signal (dot data) to the head driver 184. Necessary signal processing is performed in the print control unit 180, and the ejection amount and ejection timing of the ink droplets of the recording head 150 are controlled via the head driver 184 based on the image data. Thereby, a desired dot size and dot arrangement are realized.

  The print control unit 180 includes an image buffer memory 182, and image data, parameters, and other data are temporarily stored in the image buffer memory 182 when image data is processed in the print control unit 180. In FIG. 13, the image buffer memory 182 is shown in a form associated with the print control unit 180, but it can also be used as the image memory 174. Also possible is an aspect in which the print controller 180 and the system controller 172 are integrated and configured with one processor.

  The head driver 184 generates a drive signal for driving the piezoelectric element 24 (see FIG. 1) of the recording head 150 of each color based on the dot data given from the print control unit 180, and the drive signal generated in the piezoelectric element 24. Supply. The head driver 184 may include a feedback control system for keeping the driving conditions of the recording head 150 constant.

  As described with reference to FIG. 10, the print detection unit 124 is a block including a line sensor. The print detection unit 124 reads an image printed on the recording paper 116, performs necessary signal processing, and the like to perform a print status (whether ejection is performed, droplet ejection). And the detection result is provided to the print control unit 180.

  The print control unit 180 performs various corrections on the recording head 150 based on information obtained from the print detection unit 124 as necessary.

  The liquid ejection head manufacturing method, the image forming apparatus, and the piezoelectric element manufacturing method of the present invention have been described in detail above. However, the present invention is not limited to the above examples and does not depart from the spirit of the present invention. Of course, various improvements and modifications may be made.

Cross-sectional view showing the main configuration of an inkjet head Process diagram showing an example of a method for manufacturing an inkjet head Detailed view showing resist layer patterning process Explanatory drawing showing an example of resist patterning method Explanatory drawing showing another example of resist patterning method Schematic diagram of etching equipment Explanatory drawing for explaining the principle of the present invention Explanatory drawing for demonstrating the effect of this invention Process diagram showing another example of a method of manufacturing an inkjet head Overall configuration diagram showing outline of inkjet recording apparatus Main part plan view showing the periphery of the printing unit of the ink jet recording apparatus Plane perspective view showing a structural example of an inkjet head (recording head) Main block diagram showing the system configuration of the inkjet recording apparatus Explanatory drawing showing how the platinum layer on the substrate was dry-etched

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Inkjet head, 12 ... Nozzle plate, 14 ... Flow path substrate, 16 ... Piezoelectric actuator, 18 ... Vibrating plate, 20 ... Nozzle, 22 ... Pressure chamber, 24 ... Piezoelectric element, 50 ... SOI substrate, 52 ... Silicon substrate ( Support), 54 ... Silicon oxide film (Box layer), 56 ... Silicon substrate (active layer), 58 ... Insulating layer, 60 ... Opening, 62 ... Lower electrode layer, 64 ... Piezoelectric layer, 66 ... Upper electrode layer 68: Resist layer, 100: Inkjet recording apparatus

Claims (7)

A method of manufacturing a liquid discharge head that pressurizes a liquid in a pressure chamber using displacement of a piezoelectric element and discharges droplets from a nozzle communicating with the pressure chamber,
A step of sequentially laminating a first electrode layer, a piezoelectric layer, and a second electrode layer to be the piezoelectric element on a structure in which a space corresponding to the pressure chamber is formed;
A mask layer is formed on the second electrode layer, and the mask layer is patterned so that the mask remains in a region smaller than an inner region of a projection space portion obtained by projecting the space portion with respect to a surface on which the mask layer is formed. And a process of
Patterning at least the second electrode layer and the piezoelectric layer by dry etching via the patterned mask layer;
A method of manufacturing a liquid discharge head, comprising:   The method of manufacturing a liquid discharge head according to claim 1, wherein the mask layer formed on the second electrode layer is patterned by direct dry etching without using another mask. In the structure, a diaphragm is disposed on a flow path substrate in which a space corresponding to the pressure chamber is formed,
3. The method of manufacturing a liquid ejection head according to claim 1, wherein the first electrode layer, the piezoelectric layer, and the second electrode layer are sequentially laminated on the vibration plate.   The structure includes an SOI substrate in which a first silicon substrate, a silicon oxide film, and a second silicon substrate are sequentially stacked, and an insulating layer formed on a surface of the second silicon substrate of the SOI substrate. The method of manufacturing a liquid ejection head according to claim 1, wherein the liquid ejection head is configured. The space corresponding to the pressure chamber is an opening formed in the first silicon substrate,
The method of manufacturing a liquid ejection head according to claim 4, wherein the vibration plate includes the silicon oxide film, the second silicon substrate, and the insulating layer.   An image forming apparatus comprising: a liquid discharge head manufactured by the method of manufacturing a liquid discharge head according to claim 1. A step of sequentially laminating an electrode layer and a piezoelectric layer on a surface opposite to the opening side of the opening on the conductor substrate having the dielectric layer and the opening formed;
A mask layer is formed on the piezoelectric layer, and the mask layer is patterned so that the mask remains in a region smaller than the inner region of the projected opening obtained by projecting the opening with respect to the surface on which the mask layer is formed. And a process of
Patterning the electrode layer and the piezoelectric layer through dry etching through the patterned mask layer;
A method for manufacturing a piezoelectric element, comprising:

Images