JP6015108B2 - Thin film manufacturing apparatus and thin film manufacturing method - Google Patents

Description

The present invention relates to a thin-film deposition apparatus and a thin film fabrication how.

  2. Related Art An ink jet recording apparatus and a liquid ejection head used as an image recording apparatus or an image forming apparatus such as a printer, a facsimile machine, a copying apparatus, etc., a nozzle for ejecting ink droplets, a pressure chamber communicating with the nozzle, and ink in the pressure chamber are added. A device having an electromechanical conversion element such as a piezoelectric element for pressing is known.

  The electromechanical conversion element has, for example, a structure in which an electromechanical conversion film and an upper electrode are stacked on a lower electrode. The electromechanical conversion film which is a thin film can be produced by, for example, a sputtering method, an MOCVD method, a vacuum deposition method, an ion plating method, a sol-gel method, an aerosol deposition method, or the like.

  Here, a method for manufacturing an electromechanical conversion film using a sol-gel method will be described as an example. First, a hydrophobic film pattern is formed on the lower electrode (step 1). The portion of the lower electrode where the hydrophobic film pattern is not formed is hydrophilic. Next, a precursor coating film of the electromechanical conversion film is formed only on the hydrophilic part (the part where the hydrophobic film pattern is not formed) on the lower electrode, and heat treatment is performed (step 2). By this heat treatment, the pattern of the hydrophobic film disappears.

  Since the precursor coating film of the electromechanical conversion film is thin, it cannot be formed in a predetermined film thickness by a single treatment. Therefore, by repeating Step 1 and Step 2 as many times as necessary, the precursor coating film of the electromechanical conversion film is laminated to produce an electromechanical conversion film having a predetermined film thickness.

  By the way, in the heat treatment of step 2, there is a case where the precursor coating film of the electromechanical conversion film is crystallized by irradiating the laser beam. It was discovered that if the relationship between the irradiation time and the laser beam irradiation time is not appropriate, the entire region of the precursor coating film of the electromechanical conversion film is not crystallized and an amorphous region is formed in part. In addition, it has been found that when the entire region of the precursor coating film of the electromechanical conversion film is not crystallized and an amorphous region is partially formed, the electrical characteristics of the electromechanical conversion film deteriorate.

  The present invention has been made in view of the above points, and it is an object to provide a thin film manufacturing apparatus and a thin film manufacturing method capable of crystallizing the entire region of a precursor coating film of an electromechanical conversion film. To do.

  The thin film manufacturing apparatus includes: a liquid discharge unit that discharges a liquid onto a film formation target to form a coating film; and a first laser beam that irradiates the coating film with a first laser beam to evaporate the solvent of the coating film. Laser irradiation means, a second laser irradiation means for irradiating the coating film obtained by evaporating the solvent with a second laser beam to crystallize the coating film obtained by evaporating the solvent, and a predetermined solid content concentration When the coating film is irradiated with the second laser light for a predetermined irradiation time, the time required for crystal growth is calculated from the film thickness of the region where the coating film crystallizes, and the calculated time required for the crystal growth is calculated. Based on the solid content concentration and irradiation time storage means for calculating and storing in advance the solid content concentration and the irradiation time capable of crystallizing the entire region of the coating film, the film thickness and light absorption of the coating film From the relationship with the rate, the first laser beam and the second laser beam corresponding to the film thickness of the coating film. Laser power storage means for calculating and storing each laser power of light in advance, and the liquid ejection means obtains the value of the solid content concentration from the solid content concentration and irradiation time storage means. The coating film is formed by discharging the liquid having the solid content concentration, and the first laser irradiation unit is configured to apply a laser beam of the first laser beam corresponding to the film thickness of the coating film from the laser power storage unit. The power value is obtained, and the coating film is irradiated with the first laser beam by the laser power corresponding to the film thickness of the coating film, and the second laser irradiation means is configured to measure the solid content concentration and the irradiation time. Obtaining the value of the irradiation time from the storage means, obtaining the laser power value of the second laser light corresponding to the film thickness of the coating film from the laser power storage means, and obtaining the film thickness of the coating film With the corresponding laser power, Wherein the irradiation time only requirement that irradiating the second laser light Kinurimaku.

  ADVANTAGE OF THE INVENTION According to this invention, the thin film manufacturing apparatus and thin film manufacturing method which can crystallize the whole area | region of the precursor coating film of an electromechanical conversion film can be provided.

FIG. 6 is a cross-sectional view illustrating a liquid discharge head using an electromechanical conversion element (part 1); FIG. 6 is a cross-sectional view (part 2) illustrating a liquid discharge head using an electromechanical conversion element. It is a perspective view which illustrates the thin film manufacturing apparatus concerning a 1st embodiment. It is FIG. (The 1) which illustrates the thin film manufacturing process which concerns on this Embodiment. It is a figure (the 2) which illustrates the thin film manufacturing process which concerns on this Embodiment. It is FIG. (The 3) which illustrates the thin film manufacturing process which concerns on this Embodiment. It is FIG. (The 4) which illustrates the thin film manufacturing process which concerns on this Embodiment. It is a figure which shows typically the cross section of a functional ink film. It is explanatory drawing regarding a light absorptivity and a film thickness. It is an example of the flowchart which shows the specific procedure of the 1st and 2nd prior examination item. It is a figure which shows an example of the information obtained by step S112 of FIG. It is a figure which shows an example of the information obtained by step S113 of FIG. It is the figure which plotted the film thickness information obtained in FIG. 11 in FIG. It is a perspective view which illustrates an inkjet recording device. It is a side view which illustrates the mechanism part of an inkjet recording device. It is a SEM photograph which shows the cross section of a functional ink film. 6 is a graph showing the results of X-ray diffraction measured in Example 2. 6 is a graph showing a PE hysteresis curve measured in Example 2. FIG. It is the photograph which measured the contact angle of water in the SAM film formation site. It is the photograph which measured the contact angle of water in the SAM film removal site | part. 6 is a graph showing a PE hysteresis curve of an electromechanical transducer produced in Example 3. FIG.

  Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant description may be omitted.

<First Embodiment>
[Thin film]
First, an electromechanical conversion film constituting an electromechanical conversion element will be described as an example of a thin film manufactured by the thin film manufacturing apparatus and the thin film manufacturing method according to the first embodiment. Needless to say, the thin film that can be manufactured by the thin film manufacturing apparatus and the thin film manufacturing method according to the first embodiment is not limited to the electromechanical conversion film.

  The electromechanical transducer is used, for example, as a component part of a liquid discharge head used in an ink jet recording apparatus. FIG. 1 is a cross-sectional view illustrating a liquid discharge head using an electromechanical transducer.

  Referring to FIG. 1, the droplet discharge head 1 includes a nozzle plate 10, a pressure chamber substrate 20, a vibration plate 30, and an electromechanical conversion element 40. The nozzle plate 10 is formed with nozzles 11 that eject ink droplets. The nozzle plate 10, the pressure chamber substrate 20, and the vibration plate 30 may be referred to as a pressure chamber 21 (an ink channel, a pressurized liquid chamber, a pressurized chamber, a discharge chamber, a liquid chamber, or the like) that communicates with the nozzle 11. ) Is formed. The diaphragm 30 forms part of the wall surface of the ink flow path.

The electromechanical conversion element 40 includes an adhesion layer 41, a lower electrode 42, an electromechanical conversion film 43, and an upper electrode 44, and has a function of pressurizing ink in the pressure chamber 21. The adhesion layer 41 is a layer made of, for example, Ti, TiO ₂ , TiN, Ta, Ta ₂ O ₅ , Ta ₃ N ₅ or the like, and has a function of improving the adhesion between the lower electrode 42 and the diaphragm 30. However, the adhesion layer 41 is not an essential component of the electromechanical conversion element 40.

  In the electromechanical conversion element 40, when a voltage is applied between the lower electrode 42 and the upper electrode 44, the electromechanical conversion film 43 is mechanically displaced. Along with the mechanical displacement of the electromechanical conversion film 43, the vibration plate 30 is deformed and displaced, for example, in the lateral direction (d31 direction), and pressurizes the ink in the pressure chamber 21. Thereby, ink droplets can be ejected from the nozzle 11.

  As shown in FIG. 2, a plurality of droplet discharge heads 1 can be arranged in parallel to form the droplet discharge head 2.

As a material of the electromechanical conversion film 43, for example, PZT can be used. PZT is a solid solution of lead zirconate (PbZrO ₃ ) and lead titanate (PbTiO ₃ ). For example, the ratio of PbZrO ₃ and PbTiO ₃ is 53:47, and the chemical formula indicates Pb (Zr _0.53 , Ti _0.47 ) O ₃ , PZT generally indicated as PZT (53/47), etc. Can be used. The characteristics of PZT vary depending on the ratio of PbZrO ₃ and PbTiO ₃ .

When PZT is used as the electromechanical conversion film 43, lead acetate, a zirconium alkoxide compound, and a titanium alkoxide compound are used as starting materials, and dissolved in methoxyethanol as a common solvent to prepare a PZT precursor solution. The mixing amount of the lead acetate, zirconium alkoxide compound, and titanium alkoxide compound can be appropriately selected by those skilled in the art depending on the desired composition of PZT (ratio of PbZrO ₃ and PbTiO ₃ ).

  Note that the metal alkoxide compound is easily decomposed by moisture in the atmosphere. Therefore, stabilizers such as acetylacetone, acetic acid and diethanolamine may be added to the PZT precursor solution as stabilizers.

  As a material of the electromechanical conversion film 43, for example, barium titanate or the like may be used. In this case, it is possible to prepare a barium titanate precursor solution by using barium alkoxide and a titanium alkoxide compound as starting materials and dissolving them in a common solvent.

These materials are described by the general formula ABO ₃ and correspond to composite oxides containing A = Pb, Ba, Sr B = Ti, Zr, Sn, Ni, Zn, Mg, and Nb as main components. The specific description is expressed as (Pb _1-x , Ba) (Zr, Ti) O ₃ , (Pb _1-x , Sr) (Zr, Ti) O ₃ , which is the same as Pb of the A site. This is a case where the part Ba or Sr is substituted. Such substitution is possible with a divalent element, and the effect thereof has an effect of reducing characteristic deterioration due to evaporation of lead during heat treatment.

  As the material of the lower electrode 42, a metal having high heat resistance and forming a SAM film by reaction with alkanethiol shown below can be used. Specifically, platinum group metals such as ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir) and platinum (Pt) having low reactivity, and these platinum group metals An alloy material containing can be used.

Moreover, after producing these metal layers, it is also possible to use by laminating a conductive oxide layer. As the conductive oxide, specifically, there is a composite oxide described by the chemical formula ABO ₃ and having A = Sr, Ba, Ca, La, B = Ru, Co, Ni as main components, and SrRuO ₃ And CaRuO ₃ , (Sr _1-x Ca _x ) O ₃ which is a solid solution thereof, LaNiO ₃ and SrCoO ₃ , and further, (La, Sr) (Ni _1-y Co _y ) O ₃ which is a solid solution thereof. (Y may be 1). Other oxide materials include IrO ₂ and RuO ₂ .

  The lower electrode 42 can be produced by a method such as a vacuum film forming method such as sputtering or vacuum deposition. Since the lower electrode 42 is electrically connected as a common electrode when a signal is input to the electromechanical transducer 40, the diaphragm 30 under the lower electrode 42 can use an insulator or a conductor whose surface is insulated.

  As a specific material of the diaphragm 30, for example, silicon can be used. In addition, as a specific material for insulating the surface of the vibration plate 30, for example, a silicon oxide film, a silicon nitride film, a silicon oxynitride film having a thickness of about several hundred nm to several μm or a stack of these films is laminated. A film or the like can be used. In consideration of the difference in thermal expansion, a ceramic film such as an aluminum oxide film or a zirconia film may be used. The silicon-based insulating film that insulates the surface of the diaphragm 30 can be formed by a CVD method, a thermal oxidation process of silicon, or the like. Further, a metal oxide film such as an aluminum oxide film for insulating the surface of the vibration plate 30 can be formed by a sputtering method or the like.

[Thin film manufacturing equipment]
Next, the structure of the thin film manufacturing apparatus according to the first embodiment will be described. FIG. 3 is a perspective view illustrating the thin film manufacturing apparatus according to the first embodiment. Referring to FIG. 3, in the thin film manufacturing apparatus 3, Y-axis driving means 61 is installed on the gantry 60. On the Y-axis driving means 61, a stage 62 on which the substrate 5 is mounted is installed so as to be driven in the Y-axis direction.

  The stage 62 is usually accompanied by a suction means (not shown) using vacuum or static electricity, so that the substrate 5 can be fixed. In addition, a driving means (not shown) that rotates about the Z axis is mounted on the stage 62 to correct the relative inclination between the inkjet head 67, the continuous irradiation laser device 71, the pulse irradiation laser device 72, and the substrate 5, which will be described later. It is good also as a structure which can be performed.

  An X-axis support member 64 for supporting the X-axis drive means 63 is installed on the gantry 60. The X-axis drive means 63 is provided with a Z-axis drive means 65, and a head base 66 is mounted on the Z-axis drive means 65 so as to be movable in the X-axis and Z-axis directions.

  The Z-axis drive unit 65 can control the distance between an inkjet head 67 and a substrate 5 described later. On the head base 66, an ink jet head 67 that discharges functional ink (for example, PZT precursor solution) is mounted. Functional ink is supplied to the inkjet head 67 from each ink tank 68 via an ink supply pipe (not shown).

  Another Z-axis drive unit 69 is attached to the X-axis drive unit 63, and a laser support member 70 is attached to the Z-axis drive unit 69. A continuous irradiation laser device 71 and a pulse irradiation laser device 72 are attached to the laser support member 70. The Z-axis driving unit 69 can control the distance between the continuous irradiation laser device 71 and the pulse irradiation laser device 72 and the substrate 5.

  In FIG. 3, the stage 62 has a uniaxial degree of freedom in the Y direction, and the inkjet head 67, the continuous irradiation laser device 71, and the pulse irradiation laser device 72 have a uniaxial degree of freedom in the X direction. Although shown, it is not limited to this form. For example, the stage 62 may have two axes of freedom in the X and Y directions, and the inkjet head 67, the continuous irradiation laser device 71, and the pulse irradiation laser device 72 may be fixed. Further, the stage 62 may have a single axis freedom in the Y direction, and the inkjet head 67, the continuous irradiation laser device 71, and the pulse irradiation laser device 72 may be arranged in a line in the Y axis direction.

  Alternatively, the substrate 5 may be fixed, and the inkjet head 67, the continuous irradiation laser device 71, and the pulse irradiation laser device 72 may have a biaxial degree of freedom in the X and Y directions. The X axis and the Y axis need not be orthogonal as long as one plane can be expressed by the X axis and Y axis vectors. For example, the X axis vector and the Y axis vector have angles of 30 degrees, 45 degrees, and 60 degrees. You may do it.

  The thin film manufacturing apparatus 3 includes an apparatus control unit (not shown) and can control the functional ink ejection conditions of the inkjet head 67 and the laser irradiation conditions of the continuous irradiation laser apparatus 71 and the pulse irradiation laser apparatus 72.

  The device control unit includes, for example, a CPU, a ROM, a RAM, a nonvolatile memory, a main memory, and the like. Various functions of the device control unit are read by the control program recorded in the ROM and the like and executed by the CPU. It is realized by doing. However, part or all of the apparatus control unit may be realized only by hardware.

  The device control unit may be physically configured by a plurality of devices. In a recording unit such as a RAM or a non-volatile memory, it is possible to record the crystalline state of the functional ink, the optimal laser irradiation conditions, and the like. For example, the solid content concentration and irradiation time storage unit and the laser power storage unit according to the present invention can be realized by the apparatus control unit.

[Thin film manufacturing method]
Next, the thin film manufacturing method according to the first embodiment will be described. Here, the example which manufactures the electromechanical conversion film | membrane 43 shown in FIG. 1 as a thin film is shown.

[SAM film patterning]
First, as shown in FIG. 4, a SAM (Self Assembled Monolayer) film 50 having a predetermined pattern is formed on the surface of the lower electrode 42. Specifically, in the step shown in FIG. 4A, for example, a substrate to be the lower electrode 42 is prepared. As the lower electrode 42, for example, platinum (Pt) can be used.

  Next, in the step shown in FIG. 4B, the lower electrode 42 is immersed in a SAM material made of alkanethiol or the like. Thereby, the SAM material reacts on the surface of the lower electrode 42 and the SAM film 50 adheres, and the surface of the lower electrode 42 can be made water repellent. Although alkanethiol has different reactivity and hydrophobicity (water repellency) depending on the molecular chain length, it is usually prepared by dissolving a molecule having 6 to 18 carbon atoms in an organic solvent such as alcohol, acetone or toluene. Usually, the concentration of alkanethiol is about several moles / liter. After a predetermined time, the lower electrode 42 is taken out, and excess molecules are replaced with a solvent and dried.

  Next, in a step shown in FIG. 4C, a photoresist 51 having an opening 51x is formed on the SAM film 50 formed on the surface of the lower electrode 42 by a known photolithography method. Next, in the step shown in FIG. 4D, the SAM film 50 exposed in the opening 51x is removed by dry etching or the like, and the photoresist 51 is further removed. As a result, the SAM film 50 having a predetermined pattern is formed on the surface of the lower electrode 42.

  The region where the SAM film 50 is formed on the surface of the lower electrode 42 is hydrophobic. On the other hand, the region where the surface of the lower electrode 42 is exposed after the SAM film 50 is removed becomes hydrophilic. By utilizing this surface energy contrast, it becomes possible to coat the PZT precursor solution described in detail below.

  After the step shown in FIG. 4A, a photoresist 53 is formed on the surface of the lower electrode 42 as in the step shown in FIG. 5A, and the SAM treatment is performed as in the step shown in FIG. And the photoresist 53 may be removed as in the step shown in FIG. Thereby, a SAM film 50 having a predetermined pattern is formed on the surface of the lower electrode 42 as in the step shown in FIG.

  4B, after the process shown in FIG. 6A, the surface of the lower electrode 42 is irradiated with ultraviolet light, oxygen plasma, or the like through the photomask 54 having the opening 54x. The SAM film 50 in the exposed portion (in the opening 54x) may be removed as in the step shown in FIG. Thereby, a SAM film 50 having a predetermined pattern is formed on the surface of the lower electrode 42 as in the step shown in FIG.

[Formation of electromechanical conversion film]
Next, as shown in FIG. 7, an electromechanical conversion film 43 is formed on the surface of the lower electrode 42. Specifically, in the process shown in FIG. 7A, a lower electrode 42 (corresponding to the substrate 5 in FIG. 3) having a SAM film 50 of a predetermined pattern formed on the surface is provided on the stage 62 of the thin film manufacturing apparatus 3. Place. Then, the position, inclination, and the like of the lower electrode 42 are aligned using a known alignment device (CCD camera, CMOS camera, or the like).

  Then, the inkjet head 67 is driven on the X axis, the stage 62 on which the lower electrode 42 is mounted is driven on the Y axis, and the inkjet head 67 is disposed on the stage 62. Then, the functional ink 43a is ejected from the inkjet head 67 to a region (hydrophilic region) on the surface of the lower electrode 42 where the SAM film 50 does not exist. At this time, due to the contrast of the surface energy, the functional ink 43a spreads wet only in the region where the SAM film 50 does not exist (hydrophilic region).

  As described above, the functional ink 43a is formed only in the region where the SAM film 50 does not exist (hydrophilic region) by utilizing the contrast of the surface energy. In addition, the process can be simplified and the process can be simplified. As the functional ink 43a, for example, a PZT precursor solution can be used.

  Next, in the step shown in FIG. 7B, the continuous irradiation laser device 71 is driven on the X axis, and if necessary, the stage 62 on which the lower electrode 42 is mounted is driven on the Y axis. A continuous irradiation laser device 71 is arranged on the top. Then, the continuous irradiation laser device 71 irradiates the functional ink 43a wetted and spread in the step shown in FIG. The functional ink 43a irradiated with the laser light 71x is vaporized and thermally decomposed into the functional ink 43b thermally decomposed. For example, a semiconductor laser device or a YAG laser device can be used as the continuous irradiation laser device 71.

  The wavelength of the laser beam 71x is preferably 400 nm or more (for example, about 400 nm to 10000 nm), which is a region where the light absorption rate of the substrate including the lower electrode 42 is relatively high. More specifically, the functional ink 43a almost transmits laser light 71x having a wavelength of 400 nm or more and hardly absorbs it. Therefore, the functional ink 43a is not directly heated, the substrate including the lower electrode 42 (platinum or the like) on which the functional ink 43a is mounted is heated, and the functional ink 43a is indirectly heated accordingly. Therefore, it is preferable that the wavelength of the laser beam 71x is 400 nm or more, which is a region where the light absorption rate of the lower electrode 42 is relatively high.

  If the direct heating method is used, temperature unevenness may occur in the irradiated portion due to unevenness of the beam profile of the laser beam. However, by using the indirect heating method, the functional ink 43a is uniformly distributed within the irradiation surface. Can be heated.

  In the above description, the functional ink 43a is formed on the lower electrode 42, but the adhesion layer 41 made of titanium or the like and the lower electrode 42 made of platinum or the like are laminated on the vibration plate 30 made of silicon. In some cases, the functional ink 43 a is formed on the formed lower electrode 42. Even in such a case, it is preferable that the wavelength of the laser beam 71x is 400 nm or more, which is a region where the light absorption rate of silicon, titanium, and platinum is relatively high.

  Silicon is highly reliable because it has low in-plane unevenness in thickness, crystal characteristics, and thermal characteristics, and is suitable as a substrate (diaphragm 30) used in this embodiment.

  The moving speed of the lower electrode 42 can be about 10 mm / s to 1000 mm / s, and the power of the laser light 71x can be about several watts to several tens of watts. The beam diameter of the laser beam 71x can be about several tens of μm to several hundreds of μm, and the beam profile can be a general Gaussian profile.

  The laser beam 71x is also applied to the SAM film 50, and the SAM film 50 is also heated. The SAM film 50 may disappear when the temperature is 500 ° C. or higher. However, when the laser light 71x is set as the above setting condition, the temperature of the lower electrode 42 remains at 500 ° C. or lower, so the SAM film 50 disappears. do not do.

  Next, in the step shown in FIG. 7C, the pulse irradiation laser device 72 is driven on the X axis, and if necessary, the stage 62 on which the lower electrode 42 is placed is driven on the Y axis, and the stage 62 is driven. A pulse irradiation laser device 72 is arranged on the top. Then, in the pulse irradiation laser device 72, only the functional ink 43b thermally decomposed in the process shown in FIG. That is, if the SAM film 50 is irradiated with the laser beam 72x, the temperature of the lower electrode 42 may be 500 ° C. or more, and the SAM film 50 may disappear. Therefore, the SAM film 50 is not irradiated with the laser beam 72x.

  The functional ink 43b irradiated with the laser beam 72x is crystallized to become the functional ink 43c (for example, PZT thin film), and the SAM film 50 remains without disappearing. As the pulse irradiation laser device 72, for example, a semiconductor fiber coupling laser device, a semiconductor laser stack device, or the like can be used.

  The power of the laser beam 72x can be set to several W to several tens of W, and the irradiation time of the laser beam 72x can be set to several μs to several 100 μs. The emission frequency of the laser beam 72x is preferably adjusted by the pattern of the functional ink 43b and the moving speed of the stage 62. For example, when the pattern interval is 100 μm and the moving speed of the stage 62 is 100 mm / s, the laser beam 72x The emission frequency can be 1 kHz.

  In addition, when the stage 62 moves while the laser beam 72x is emitted, the range in which the laser beam 72x is irradiated is expanded. For example, when the irradiation time is 100 μs and the moving speed of the stage 62 is 100 mm / s, the stage 62 moves while the laser light 72x is emitting, thereby expanding the range of irradiation with the laser light 72x by about 10 μm.

  Therefore, in order to irradiate only the functional ink 43b with the laser beam 72x and not to irradiate the SAM film 50, the laser beam is irradiated at an irradiation timing suitable for the pattern shape of the functional ink 43b in consideration of the irradiation range of the laser beam 72x. 72x needs to emit light.

  The film thickness of the functional ink 43c (for example, PZT thin film) crystallized in the process shown in FIG. 7C is about several tens of nm. Since this film thickness is insufficient, after the step shown in FIG. 7C, the steps shown in FIGS. 7A to 7C are repeated as many times as necessary. Thereby, the functional ink 43c is laminated, and the functional ink film crystallized with an arbitrary pattern and thickness (for example, about several μm), that is, the electromechanical conversion film 43 is formed on the lower electrode.

  As described above, in the first embodiment, the continuous ink laser device 71 irradiates the functional ink 43a with the laser beam 71x and heats the functional ink 43a at a temperature at which the SAM film 50 does not disappear. The functional ink 43b is produced by evaporating the solvent and performing thermal decomposition. Then, the functional ink 43b is irradiated with a laser beam 72x (pulse), heated, and crystallized to produce the functional ink 43c. At this time, in the pulse irradiation laser device 72, since the SAM film 50 is not irradiated with the laser beam 72x, the SAM film 50 remains without disappearing.

  Accordingly, it is not necessary to repeat the steps shown in FIGS. 4 to 6, and the functional ink 43 c can be stacked by repeating only the steps shown in FIGS. 7A to 7C as many times as necessary. That is, a thin film such as an electromechanical conversion film can be manufactured by a simple process.

  As described above, it has been described that it is preferable to irradiate the laser beam in the step shown in FIG. 7C. However, the functional ink 43b is crystallized by continuously irradiating the laser beam in the step shown in FIG. It is also possible to produce the functional ink 43c. However, when the SAM film 50 disappears due to continuous irradiation with laser light, it is necessary to repeat the steps shown in FIGS. 4 to 7C when laminating the functional ink 43c.

  By the way, in order to form the functional ink 43c by completely crystallizing the functional ink 43b in the step shown in FIG. 7C through the steps shown in FIG. 7A and FIG. There are items to be considered (hereinafter referred to as pre-review items). The first prior examination items are the film thickness of the functional ink 43a applied in the step shown in FIG. 7A and the laser light (pulse irradiation or continuous irradiation) irradiated in the step shown in FIG. It is the relationship with the irradiation time. Here, since the film thickness of the functional ink 43a is determined by the solid content concentration of the functional ink to be applied (for example, PZT), the relationship between the solid content concentration of the functional ink to be applied and the irradiation time of the laser beam is expressed as follows. It will be examined in advance.

  For example, if the relationship between the solid content concentration of the functional ink to be applied and the irradiation time of the laser beam is not appropriate, a functional ink 43c as shown in FIG. 8 is formed. FIG. 8 is a diagram schematically showing a cross section of the functional ink 43c after the step shown in FIG. 7C, where the relationship between the solid content concentration of the applied functional ink and the irradiation time of the laser beam is not appropriate. An example is shown.

8, functional ink 43c has a crystal region 43c _1, and the amorphous region 43c _2. The functional ink 43c transmits almost no laser light having a wavelength of 400 nm or more and hardly absorbs it. Therefore, if the wavelength of the laser light is, for example, 980 nm, the laser light passes through the functional ink 43c and heats the substrate including the lower electrode 42 (platinum or the like). Along with this, the functional ink 43c is indirectly heated. Thereby, the functional ink 43c is crystallized from the lower electrode 42 side.

If the irradiation time of the relationship between applied to functional ink solids concentration and the laser beam is not appropriate, as shown in FIG. 8, the lower electrode 42 side of the functional ink 43c crystal region 43c ₁ is crystallized form but it is the part of a region opposite to the amorphous region 43c ₂ without being crystallized to form the lower electrode 42.

As shown in FIG. 8, the amorphous region 43c ₂ is formed functional ink 43c, compared with a case made of only a crystal region 43c _1, characteristics of the electromechanical transducer 40 (e.g., P-E hysteresis Curve). Therefore, it is necessary to appropriately set the relationship between the solid content concentration of the functional ink to be applied and the irradiation time of the laser beam. A specific setting procedure will be described later with reference to FIG.

  The second prior examination item is the relationship between the power of laser light (pulse irradiation or continuous irradiation) and the number of times the functional ink 43c is laminated. That is, since the film thickness is increased when the functional ink 43c is laminated, the light absorption rate of the functional ink 43c changes. Even if the laser beam with the same power is irradiated as the light absorption rate changes, the heating temperature differs. Therefore, in the steps shown in FIGS. 7B and 7C, in order to heat the functional ink 43c to a constant temperature, the functional ink 43c is laminated with the power of the laser beam irradiated to the functional ink 43c. It is preferable to set the number of times corresponding to the number of times (that is, it is preferable to set the number corresponding to the film thickness of the functional ink 43c).

  FIG. 9 is an explanatory diagram regarding the light absorption rate and the film thickness. When the functional ink 43a is applied on the lower electrode 42 and irradiated with the laser light 71x, a part of the laser light 71x is reflected by the film surface of the functional ink 43a (A) and a part of the functional ink 43a is applied. The light is transmitted and reflected on the surface of the lower electrode 42 (B), and a part is absorbed by the lower electrode 42 (C). Some may pass through the lower electrode 42. The light absorption rate of the functional ink 43a varies depending on the film thickness H of the functional ink 43a. The same applies to the functional ink 43b. Therefore, it is necessary to measure the relationship between the light absorption rate and the film thickness of the functional ink 43a.

  Here, a specific procedure of the first and second prior examination items will be described with reference to FIG. FIG. 10 is an example of a flowchart showing a specific procedure of the first and second preliminary examination items. Steps S101 to S106 relate to the first preliminary examination item, and steps S111 to S117 are the second. This relates to the items to be considered in advance. Note that FIG. 10 illustrates an example in which functional ink is crystallized by continuous irradiation with laser light.

  Referring to FIG. 10, first, in step S101, the provisional solid content concentration of the functional ink to be applied and the provisional irradiation time of the laser beam that is continuously irradiated to crystallize the functional ink are determined. Here, as an example, it is assumed that PZT is used as the functional ink, the temporary solid content concentration of the functional ink (PZT) is 5 mol / l, and the temporary irradiation time of the laser beam for continuous irradiation is determined to be 3.5 ms. I do.

  Next, in step S102, a functional ink film is formed on the substrate to be a film formation target using the functional ink having the temporary solid content concentration determined in step S101. The functional ink film can be uniformly applied and formed by, for example, an inkjet method or a spin coating method.

  Here, the purpose is to examine how long the irradiation time of the laser beam to be continuously irradiated is necessary to crystallize the functional ink having a predetermined solid content concentration. Therefore, when the laser beam is continuously irradiated for the provisional irradiation time determined in step S101, the step is performed so that the entire region does not become a crystal region but has a film thickness such that an amorphous region is partially formed. In S102, a functional ink film is formed.

  Next, in step S103, the functional ink film formed in step S102 is heated. Specifically, the functional ink film is first dried and thermally decomposed by continuously irradiating with laser light, and then further irradiated with laser light at a temperature at which crystallization is possible (with crystallization power). The ink film is crystallized (however, some regions may be amorphous). In addition, the power of the laser beam continuously irradiated is appropriately determined within a range of about 40 W to 90 W, for example.

Next, in step S104, the cross section of the functional ink film heated in step S102 is observed using, for example, SEM. By observing the cross section of the functional ink film, the film thickness of each of the crystalline region and the amorphous region of the functional ink film heated in step S102 can be measured.
As described above, the functional ink film should have been formed to a thickness that allows an amorphous region to be partially formed in step S102. However, if all the regions are crystalline regions in step S104, If it is, the thickness of the functional ink film is increased (the temporary solid content concentration of the functional ink is increased), and steps S101 to S104 are performed again.

Next, in step S105, the time required for crystal growth is calculated. For example, cross-section as schematically shown in FIG. 8 is observed in step S104, for example, crystal region 43c ₁ is 52 nm, consider the case where the amorphous region 43c ₂ was measured as 15 nm. Since the provisional irradiation time is 3.5 ms, in this case, 52 nm ÷ 3.5 ms≈15 nm / ms is the time required for crystal growth. The total thickness of the functional ink film is 52 nm + 15 nm = 67 nm.

  Next, in step S106, the solid content concentration and the irradiation time are optimized, and the optimized values are recorded in a recording unit such as a RAM or a nonvolatile memory. In step S105, it was confirmed that the time required for crystal growth was 15 nm / ms. In Steps S101 to S105, it was confirmed that when a functional ink having a temporary solid content concentration of 5 mol / l was heated, a functional ink film having a total film thickness of 67 nm was formed.

  Thus, for example, when it is desired to form a functional ink film in which the entire region is crystallized with a solid content concentration of 5 mol / l (a functional ink film in which the total region is 67 nm and the entire region is crystallized is formed. It is understood that the irradiation time may be 67 nm ÷ 15 nm / ms≈4.5 ms.

  It should be noted that the heating time seems to be any value as long as it is longer than 4.5 ms, but this is not the case. If the heating time is too long, cracks may occur in the crystallized functional ink film, so it is not preferable to make it too long. On the other hand, considering the margin, the actual heating time is preferably set slightly longer than 4.5 ms. That is, the actual heating time may be set within a predetermined range between 4.5 ms and the heating time during which the functional ink film cracks. It should be noted that the heating time during which the functional ink film cracks can be known by experiments.

  In order to form a functional ink film in which the entire region is crystallized, the solid content concentration may be changed. In steps S101 to S105, it was confirmed that the functional ink film of 52 nm was crystallized when the functional ink was heated with the provisional irradiation time of laser light of a predetermined power (continuous irradiation) being 3.5 ms.

  Accordingly, when a functional ink film having a total film thickness of 52 nm and crystallized in the entire region is formed by laser light with a predetermined power of 3.5 ms (continuous irradiation), the solid content concentration is 5 mol / It can be seen that l × (52 nm ÷ 67 nm) ≈3.9 mol / l is sufficient.

  Of course, the solid content concentration and the irradiation time may be optimized by changing both the temporary solid content concentration (5 mol / l) and the temporary irradiation time (3.5 ms). For example, when the solid content concentration is 6 mol / l, a functional ink film having a film thickness of 67 nm × (6 mol / l ÷ 5 mol / l) ≈80 nm can be formed. In this case, if the irradiation time is set to 80 nm ÷ 15 nm / ms≈5.3 ms, the entire region having a thickness of 80 nm can be crystallized.

  The film thickness of the functional ink film can be determined in consideration of productivity. For example, when it is desired to form a functional ink film having a total thickness of 2 μm, it cannot be formed at one time. For example, it is necessary to form a functional ink film having a film thickness of 50 nm by stacking 40 times. Here, if the film thickness is thicker than 50 nm, the number of laminations is reduced, but the total irradiation time of the laser light is increased. On the other hand, if the film thickness is made thinner than 50 nm, the number of lamination increases, but the total irradiation time of the laser light decreases. Therefore, considering the increase / decrease in the number of laminations and the increase / decrease in the total irradiation time of the laser light, the thickness of the functional ink film formed at a time may be set to an appropriate value.

  In this way, it is possible to optimize the solid content concentration of the functional ink 43a to be applied in the step shown in FIG. 7A and the irradiation time of the laser beam to be continuously irradiated for crystallization. Note that it is also possible to accumulate data by repeating steps S101 to S105 a plurality of times, and using the averaged data to obtain the optimum values of solid concentration and irradiation time in step S106, and storing the obtained optimum values in the storage unit. Good.

  The power of the laser beam (continuous irradiation) is set to a predetermined value within a range of about 40 W to 90 W, but the power of the laser beam (continuous irradiation) has an optimum value as described later. Therefore, in practice, it is necessary to obtain the optimum values of the solid content concentration and the irradiation time when the power of the laser beam (continuous irradiation) is set to the optimum values. Therefore, in steps S101 to S106, the power of the laser beam (continuous irradiation) is changed stepwise within a range of, for example, 40 W to 90 W, and the solid content concentration and the optimum irradiation time at the power of each laser beam (continuous irradiation). It is preferable that each optimum value obtained is stored in the storage unit.

  This is the end of the description of the steps relating to the first preliminary examination item. In the above description, the functional ink is crystallized by continuously irradiating laser light. However, the same applies to the case where the functional ink is crystallized by pulsed laser light irradiation. According to the procedure, the optimum values of the solid content concentration and the irradiation time at the power of the laser beam (pulse irradiation) can be obtained, and the obtained optimum values can be stored in the storage unit.

  Next, steps related to the second prior examination item will be described. First, in step S111, a functional ink film is formed by uniformly applying a functional ink, for example, by an inkjet method or a spin coating method onto a substrate that is a film formation target.

  Next, in step S112, the thickness of the functional ink film formed in step S111 is measured. The film thickness of the functional ink film can be measured using, for example, a non-contact shape measuring instrument using light or the like. More specifically, for example, an interferometer NewView series manufactured by Zygo or a shape measurement laser microscope VK series manufactured by Keyence can be used.

  Next, in step S113, the light absorption rate of the functional ink film formed in step S111 is measured. The light absorption rate of the functional ink film can be measured using, for example, FTIR, UV-VIS-NIR Spectrometry, or the like. More specifically, for example, IR series, UV series of Shimadzu Corporation, Lambda series of PerkinElmer, etc. can be used.

  Next, in step S114, the functional ink film formed in step S111 is heated. In order to heat the functional ink film, for example, an oven or RTA can be used. Further, a laser device may be used.

  Next, while determining whether there is no change in the film thickness in step S115, steps S112 to S114 are repeated to adjust the heating temperature condition and the laser power in several stages to change the phase state of the functional ink film. If it is determined in step S115 that there is no change in film thickness (in the case of YES), in step S116, information on the light absorption rate, film thickness, and state (heating temperature, laser power) of the functional ink film is recorded. .

  Next, while determining whether or not the target film thickness has been reached in step S117, steps S111 to S116 are repeated until the target film thickness is reached, and the functional ink is overcoated to absorb the light of the functional ink film. Continue recording information on rate, film thickness, and state (heating temperature, laser power). Thereby, the relationship between the light absorption rate and the film thickness of the functional ink film (functional inks 43a and 43b) is obtained.

  FIG. 11 is a diagram showing an example of information obtained in step S112 of FIG. 10, and shows the relationship between the heating temperature and the film thickness of the functional ink film. In FIG. 11, 601 is the thickness of the functional ink film when heated on a hot plate at 120 ° C. for 1 minute (about 170 nm), and 602 is the thickness of the functional ink film when heated at 300 ° C. for several minutes in an oven. 603 is the thickness of the functional ink film when heated at 500 ° C. for several minutes in an oven (about 90 nm), 604 is the function when heated at 700 ° C. for several minutes in the oven The thickness of the conductive ink film (about 75 nm). Although not shown in the present embodiment, it goes without saying that the thickness of the functional ink film at room temperature (about 25 ° C.) can be measured.

  FIG. 12 is a diagram showing an example of information obtained in step S103 of FIG. 10, and shows the relationship between the thickness of the functional ink film and the light absorption rate. In FIG. 12, the light absorptance when light with a wavelength of about 1000 nm is irradiated is plotted. In FIG. 12, the solid line is the light absorption rate of the functional ink film from 0 to 1000 μm when baked at 120 ° C. for several minutes on a hot plate, and the rough dotted line is when heated at 500 ° C. for several minutes in an oven. The light absorption rate of the functional ink film is from 0 to 1000 μm, and the fine dotted line is the light absorption rate from 0 to 1000 μm of the functional ink film when heated in an oven at 700 ° C. for several minutes.

  In actual data, the film thickness is measured at a pitch of several tens of μm, and FIG. 12 shows the result of curve fitting. The film thickness can be changed at a pitch of several tens of μm by changing the film formation conditions of the spin pin coat and the ink jet discharge conditions. The temperatures measured in this embodiment are three points of 120 ° C., 500 ° C., and 700 ° C. However, more accurate information can be obtained by acquiring data up to 25 ° C. Needless to say.

  Next, a method for calculating the optimum laser power from the results of FIGS. 11 and 12 measured in advance will be described. FIG. 13 is a diagram in which the film thickness information obtained in FIG. 11 (film thickness information when heated from 120 ° C. to 700 ° C. obtained in FIG. 11) is plotted in FIG.

  In FIG. 11, since the film thickness is about 170 nm at 120 ° C., when this is plotted on the light absorptance curve (solid line) when heated at 120 ° C. in FIG. Similarly to the above, when the film thickness information at the time of heating at 500 ° C. and 700 ° C. is plotted on each curve, 703 and 704 become points.

  FIG. 13 shows that when the functional ink film is heated from 120 ° C. to 700 ° C. by irradiating light with a wavelength of about 1000 nm, the light absorption rate changes nonlinearly from about 52% → about 58% → about 46%. Means. The second layer was coated with functional ink in the same manner (the final film thickness of the first layer was 75 nm, so the thickness of the second layer after heating at 120 ° C. is 75 nm + 170 nm = 245 nm) When the absorption rate and film thickness are measured and plotted in FIG.

  Similarly to the above, when the film thickness information during heating at 500 ° C. and 700 ° C. (about 165 μm at 500 ° C. and about 150 μm at 700 ° C.) is plotted on each curve, 803 and 804 are shown. Unlike the first layer, the change in the light absorption rate of the second layer varies nonlinearly from about 62% to about 42% to about 38%. As described above, the characteristics in which the light absorption rate varies greatly depending on the film thickness.

  Several methods for determining the optimum laser power for each layer of a laser device that irradiates laser light having a wavelength of about 1000 nm are conceivable. As an example, the center value of the light absorption rate change range can be used. From the above results, the central value of the light absorption rate of the first layer is 52%, and the central value of the light absorption rate of the second layer is 50%. Since the second layer has a slightly lower light absorption rate than the first layer, it is necessary to irradiate with a stronger laser power.

  In the present embodiment, since the film thickness of each layer is constant, when calculating the optimum laser power of each layer, it can be considered in proportion to the laser power of the first layer. For example, when the optimum laser power of the first layer is 100 W (the optimum laser power as a reference needs to be evaluated in advance), the second layer is 52% / 50% of 100 W, and 104 W is the optimum laser power. Similarly, the optimum laser power can be easily calculated for the second and subsequent layers.

  In the above description, the case of heating in a single process from 120 ° C. to 700 ° C. has been described, but the heating process is divided into three stages: evaporation (120 ° C.), thermal decomposition (500 ° C.), and crystallization (700 ° C.) In this case, it is not necessary to use the center value of the light absorption rate of each state. For example, when it is desired to perform only the evaporation process in the laser device, as shown in FIG. 13, the light absorption rate at 120 ° C. of the first layer is 52% and the light absorption rate at 120 ° C. of the second layer is 62%. For example, when the optimum laser power of the first layer is 100 W (similarly, it is necessary to evaluate the optimum optimum laser power in advance), the second layer is 52% / 62% of 100 W, and about 84 W is optimum. Laser power. In the same manner as this method, thermal decomposition (500 ° C.) and crystallization (700 ° C.) processes can also be performed.

  Prior evaluation of the optimum laser power as a reference is required. In this embodiment, when the laser irradiation area is 1000 μm × 50 μm, the laser wavelength is 980 nm, the laser beam profile is top hat (flat), and the substrate scanning speed is 100 mm / s, the optimum laser power is recognized in the vicinity of 20 to 40 W. . The functional ink film produced under the above conditions had no cracks, good crystallization (confirmed with an XRD measuring machine, etc.), and the measured piezoelectric element characteristics were also good.

  Thus, in the first embodiment, the time required for crystal growth is determined from the film thickness of the region where the coating film crystallizes when the coating film having a predetermined solid content concentration is irradiated with laser light for a predetermined irradiation time. calculate. Based on the calculated time required for crystal growth, the solid content concentration and irradiation time that can crystallize the entire region of the coating film are calculated and stored in advance. Further, the laser power corresponding to the film thickness of the coating film is calculated and stored in advance from the relationship between the film thickness of the coating film and the light absorption rate.

  Then, a liquid with a solid content concentration stored in advance is ejected to form a coating film, and then the coating film is continuously irradiated with laser light with a laser power corresponding to the film thickness of the coating film stored in advance, The coating is dried and pyrolyzed. Further, the laser power corresponding to the film thickness of the coating film stored in advance is irradiated with laser light (pulse irradiation or continuous irradiation) for the irradiation time previously stored in the coating film, and the coating film is crystallized.

  Thereby, since the functional ink film in which the entire region is crystallized can be obtained, it is possible to prevent deterioration of characteristics (for example, a PE hysteresis curve) of the electromechanical conversion element.

  In the first embodiment, only one layer of the functional ink film has been discussed, but the same idea can be applied even when the number of layers is increased. This is because the process of crystallizing the functional ink film for each layer and then applying and crystallizing the functional ink to be the functional ink film of the next layer is repeated. Further, since the irradiated laser light passes through the lower functional ink film that has already been crystallized, the functional ink film (the uppermost layer) to be crystallized is not easily affected by the lower layer.

  Further, even when the coating film forming process is repeated and the coating film thickness changes, the coating film can be irradiated with laser light having an optimum laser power. That is, even when the thickness of the coating film changes, the coating film can be heated to a desired temperature. In addition, since the film thickness of a coating film can be known by the discharge amount of a liquid, etc., it is not necessary to measure the film thickness of a coating film before irradiating a laser beam.

<Second Embodiment>
In the first embodiment, the continuous irradiation laser device 71 and the pulse irradiation laser device 72 are used as separate devices. In the second embodiment, an example in which the continuous irradiation laser device 71 and the pulse irradiation laser device 72 are one laser device is shown. Specifically, for example, by using a pulse irradiation laser device such as a semiconductor fiber coupling laser device or a semiconductor laser stack device, one laser device has both functions of a pulse laser device and a continuous irradiation laser device. Can do.

  Thereby, the process from solvent evaporation, thermal decomposition, and crystallization of functional ink can be performed with one laser device. Further, for example, when the stage 62 has a single axis freedom in the Y direction and the inkjet head 67, the continuous irradiation laser device 71, and the pulse irradiation laser device 72 are arranged in a line in the Y axis direction, the stage 62 is continuous. By using the irradiation laser device 71 and the pulse irradiation laser device 72 as a single laser device, the length of the stage driving means in the Y-axis direction can be shortened. For this reason, not only the movement accuracy in the Y-axis direction is improved, but the apparatus becomes compact, so that the cost of the apparatus can be reduced.

<Third Embodiment>
Usually, the shape of the laser irradiation area by laser heating is circular, and the beam profile is Gaussian. Therefore, when functional ink is irradiated in a circular laser irradiation area, the actual irradiation time differs between the circle center region and the circle end portion. That is, the center of the circle is irradiated for a longer time, and the end of the circle is irradiated for a shorter time. For this reason, it is preferable that the laser irradiation area has the same shape as the functional ink pattern or a shape larger than that. Thereby, the functional ink patterned into a predetermined shape can be heated uniformly.

  Furthermore, for example, by making the beam profile of laser irradiation by the continuous irradiation laser device 71 and the pulse irradiation laser device 72 into a flat shape or a top hat shape in the irradiation area, the functional ink can be heated more uniformly. It becomes. The adjustment of the shape of the irradiation area and the beam profile can be mounted on either the continuous irradiation laser device 71 or the pulse irradiation laser device 72.

  For example, when the planar shape of the functional ink is rectangular, in any case of the continuous irradiation laser device 71 and the pulse irradiation laser device 72, when the direction in which the stage 62 can move simultaneously is one direction, the irradiation area is rectangular. Preferably there is. The inclination of the rectangle and the inclination of the moving direction of the stage 62 are preferably aligned. That is, it is preferable that the long side or the short side of the functional ink having a rectangular planar shape is parallel to the moving direction of the stage 62.

  With such a configuration, the irradiation time in the moving direction of the stage 62 is the same in a direction perpendicular to the moving direction of the stage 62. That is, uniform laser heating is possible, and a highly reliable functional ink film can be formed.

<Fourth embodiment>
In the fourth embodiment, laser irradiation is performed using an excimer laser before laser heating the functional ink for crystallization. Since the organic compound containing a metal component is decomposed at different temperatures depending on the metal component contained, the method for forming crystal grains differs depending on the material. Therefore, laser irradiation using an excimer laser cuts the chemical bonds of the respective metal organic compounds and unifies the crystal grain formation method.

  Thereby, when a piezoelectric element is produced from functional ink, a dense crystal film having a uniform particle diameter can be formed, and the piezoelectric element characteristics of the obtained crystal film are improved. About the chemical bond cut | disconnected by the excimer laser, it can confirm using an infrared absorption spectrum etc. Specifically, after the solvent is evaporated by the continuous irradiation laser device 71, for example, an excimer laser having a wavelength of 300 nm or less is irradiated.

More specifically, for example, by using a continuous irradiation type KrF excimer laser device, the excimer laser is irradiated under irradiation conditions of a wavelength of 230 to 280 nm and 100 mJ / cm ² or more, thereby obtaining the characteristics of the functional ink film obtained. Can be improved. The same effect can be obtained by irradiating ultraviolet rays using a UV lamp instead of the continuous irradiation type KrF excimer laser device.

<Fifth embodiment>
In the fifth embodiment, an example of an ink jet recording apparatus on which the liquid discharge head 2 (see FIG. 2) manufactured by the thin film manufacturing apparatus 3 is mounted will be described. FIG. 14 is a perspective view illustrating an ink jet recording apparatus. FIG. 15 is a side view illustrating a mechanism unit of the ink jet recording apparatus.

  Referring to FIGS. 14 and 15, the ink jet recording apparatus 4 is an ink jet recording which is an embodiment of the liquid discharge head 2 mounted on the carriage 93 that can move in the main scanning direction inside the recording apparatus main body 81. A print mechanism unit 82 including an ink cartridge 95 that supplies ink to the head 94 and the inkjet recording head 94 is accommodated.

  A paper feed cassette 84 (or a paper feed tray) on which a large number of sheets 83 can be stacked can be detachably attached to the lower portion of the recording apparatus main body 81. Further, the manual feed tray 85 for manually feeding the paper 83 can be turned over. The paper 83 fed from the paper feed cassette 84 or the manual feed tray 85 is taken in, and after a required image is recorded by the printing mechanism unit 82, the paper is discharged to a paper discharge tray 86 mounted on the rear side.

  The printing mechanism 82 holds the carriage 93 slidably in the main scanning direction with a main guide rod 91 and a sub guide rod 92 which are guide members horizontally mounted on left and right side plates (not shown). The carriage 93 has an inkjet recording head 94 that ejects ink droplets of yellow (Y), cyan (C), magenta (M), and black (Bk), and a plurality of ink ejection ports (nozzles) in the main scanning direction. They are arranged in the intersecting direction and mounted with the ink droplet ejection direction facing downward. Further, the carriage 93 is mounted with replaceable ink cartridges 95 for supplying ink of each color to the ink jet recording head 94.

  The ink cartridge 95 has an air port (not shown) that communicates with the atmosphere above, an air port (not shown) that supplies ink to the ink jet recording head 94 below, and a porous body (not shown) filled with ink inside. ing. The ink supplied to the inkjet recording head 94 is maintained at a slight negative pressure by the capillary force of the porous body. Further, although the respective color heads are used here as the ink jet recording head 94, one head having nozzles for ejecting ink droplets of each color may be used.

  The carriage 93 is slidably fitted to the main guide rod 91 on the downstream side in the paper conveyance direction, and is slidably mounted on the sub guide rod 92 on the upstream side in the paper conveyance direction. In order to move and scan the carriage 93 in the main scanning direction, a timing belt 100 is stretched between a driving pulley 98 and a driven pulley 99 that are rotationally driven by the main scanning motor 97, so that the main scanning motor 97 is forward / reverse. The carriage 93 is reciprocated by the rotation. The timing belt 100 is fixed to the carriage 93.

  Further, the ink jet recording apparatus 4 reverses and feeds the paper feed roller 101 for separating and feeding the paper 83 from the paper feed cassette 84, the friction pad 102, the guide member 103 for guiding the paper 83, and the fed paper 83. A conveyance roller 104, a conveyance roller 105 that is pressed against the circumferential surface of the conveyance roller 104, and a leading end roller 106 that defines a feeding angle of the sheet 83 from the conveyance roller 104 are provided. As a result, the paper 83 set in the paper feed cassette 84 is conveyed to the lower side of the ink jet recording head 94. The transport roller 104 is rotationally driven by a sub-scanning motor 107 through a gear train.

  The printing receiving member 109 which is a paper guide member guides the paper 83 sent out from the conveying roller 104 corresponding to the movement range of the carriage 93 in the main scanning direction on the lower side of the ink jet recording head 94. On the downstream side of the printing receiving member 109 in the sheet conveyance direction, a conveyance roller 111 and a spur 112 that are rotationally driven to send out the sheet 83 in the sheet discharge direction are provided. Further, a paper discharge roller 113 and a spur 114 for sending the paper 83 to the paper discharge tray 86, and guide members 115 and 116 for forming a paper discharge path are provided.

  During image recording, the inkjet recording head 94 is driven in accordance with the image signal while moving the carriage 93, thereby ejecting ink onto the stopped paper 83 to record one line and transporting the paper 83 by a predetermined amount. After that, the next line is recorded. Upon receiving a recording end signal or a signal that the trailing end of the paper 83 reaches the recording area, the recording operation is terminated and the paper 83 is discharged.

  A recovery device 117 for recovering defective ejection of the inkjet recording head 94 is provided at a position outside the recording area on the right end side in the movement direction of the carriage 93. The recovery device 117 includes a cap unit, a suction unit, and a cleaning unit. The carriage 93 is moved to the recovery device 117 side during printing standby, and the ink jet recording head 94 is capped by the capping unit, and the ejection port portion is kept in a wet state to prevent ejection failure due to ink drying. Further, by ejecting ink not related to recording during recording or the like, the ink viscosity of all the ejection ports is made constant, and stable ejection performance is maintained.

  When ejection failure occurs, the ejection port of the ink jet recording head 94 is sealed with a capping unit, and bubbles and the like are sucked out from the ejection port with the suction unit through the tube. Also, ink or dust adhering to the ejection port surface is removed by the cleaning means, and the ejection failure is recovered. Further, the sucked ink is discharged to a waste ink reservoir (not shown) installed at the lower part of the main body and absorbed and held by an ink absorber inside the waste ink reservoir.

  Thus, since the inkjet recording head 94 which is one embodiment of the liquid ejection head 2 manufactured by the thin film manufacturing apparatus 3 is mounted in the inkjet recording apparatus 4, there is no ink droplet ejection defect due to vibration plate drive failure. Since stable ink droplet ejection characteristics can be obtained, image quality can be improved.

[Example 1]
In Example 1, a functional ink film was examined when the relationship between the solid content concentration of the functional ink to be applied and the irradiation time of laser light (continuous irradiation) was not optimized. FIG. 16 is a SEM (scanning electron microscope) photograph showing a cross section of the functional ink, and corresponds to the cross section of the functional ink schematically shown in FIG.

  In this embodiment, PZT (functional ink) having a solid content concentration of 5 mol / l is applied on the lower electrode 42 made of a platinum film by using the thin film manufacturing apparatus 3, and dried and heated by using an oven. Decomposed. Thereafter, the dried and thermally decomposed PZT is continuously irradiated with laser light having a wavelength of 980 nm with a predetermined power in the range of 40 W to 90 W for an irradiation time of 3.5 ms (scanning speed 100 mm / s), and the functional ink 43c shown in FIG. (PZT film) was obtained. The estimated heating temperature at this time is about 700 ° C. The laser light irradiation area was 350 μm × 350 μm.

As shown in FIG. 16, the total thickness of the formed functional ink 43c (PZT film) is about 66.5 nm, about 77% falls to about 51.6nm is crystallized crystal region 43c ₁ next to them, About 14.9 nm corresponding to the remaining 23% remained amorphous (amorphous region 43c ₂ ).

In FIG. 16, the reason why crystallization proceeds from the lower side of the functional ink 43c is that the functional ink 43c almost transmits laser light having a wavelength of 400 nm or more and hardly absorbs it. That is, in this embodiment, since laser light of 980 nm is irradiated, the laser light passes through the functional ink 43c to heat the lower electrode 42 (platinum film), and the functional ink 43c is indirectly heated accordingly. . Thus, the functional ink 43c is crystallized from the lower electrode 42 side, believed crystal region 43c ₁ from the side near to the lower electrode 42 is formed.

  Thus, it has been found that unless the relationship between the solid content concentration of the functional ink to be applied and the irradiation time of the laser beam is optimized, a functional ink film in which the entire region is crystallized cannot be obtained. That is, as described with reference to FIG. 10, it was found that the solid content concentration of the functional ink and the irradiation time of the laser light need to be optimized in advance. The relationship between the solid content concentration of the functional ink and the irradiation time of the laser beam varies depending on the material used as the functional ink and the power of the laser beam to be irradiated. Therefore, the material used as the functional ink and the power of the laser beam to be irradiated. Every time, it is necessary to optimize the solid content concentration of the functional ink and the irradiation time of the laser beam in advance.

[Example 2]
In Example 2, the electrical characteristics of a functional ink film including a crystalline region and an amorphous region and a functional ink film including only a crystalline region were compared.

  First, PZT (functional ink) having a solid content concentration of 3 mol / l was applied on the lower electrode 42 made of a platinum film by using the thin film manufacturing apparatus 3, and dried and thermally decomposed by heating using an oven. . Thereafter, the dried and thermally decomposed PZT is continuously irradiated with a laser beam having a wavelength of 980 nm with a predetermined power in the range of 40 W to 90 W for an irradiation time of 3.5 ms (scanning speed 100 mm / s), and a functional ink film (PZT film) Got. The estimated heating temperature at this time is about 700 ° C. The laser light irradiation area was 350 μm × 350 μm.

  When the cross section of the obtained functional ink film (PZT film) was observed with SEM, it was confirmed that the total thickness was about 44 nm and the entire region was crystallized. If the irradiation time is set to 3.5 ms using the same laser power as described with reference to FIG. 10, PZT (functional ink) with a solid content concentration of 3.9 mol / l is applied and the total is applied. A functional ink film (PZT film) consisting only of a crystalline region having a thickness of about 52 nm is obtained. In Example 2, a functional ink film (PZT film) consisting only of a crystalline region having a total thickness of about 44 nm was formed by applying PZT (functional ink) with a solid content concentration of 3 mol / l. This is because of consideration.

  Next, for each of the functional ink film formed in Example 2 and the functional ink film formed in Example 1, X-ray diffraction (XRD) measurement and PE hysteresis curve measurement were performed. . FIG. 17 is a graph showing the results of X-ray diffraction measured in Example 2, where (a) shows the measurement results of the functional ink film formed in Example 2, and (b) shows the film formation in Example 1. The measurement result of the functional ink film is shown.

  FIG. 17 shows that X-rays are incident at an angle of θ with respect to the horizontal direction of the functional ink film, and among the X-rays reflected from the functional ink film, the angle of 2θ with respect to the incident X-rays. It is the result of detecting the X-ray of and measuring the intensity change. As can be seen from FIG. 17, in the functional ink film formed in Example 2, a sharper peak appears than the functional ink film formed in Example 1 at 21.9 ° or 31.0 °. It was confirmed that the crystallinity was high.

  18 is a graph showing a PE hysteresis curve measured in Example 2. FIG. 18A is a measurement result of the functional ink film formed in Example 2, and FIG. 18B is a film formed in Example 1. The measurement result of the functional ink film is shown. As can be seen from FIG. 18, a normal hysteresis curve appears in the functional ink film formed in Example 2 of (a), but the functional ink film formed in Example 1 of (b) It was confirmed that a normal hysteresis curve did not appear. That is, it was confirmed that the functional ink film composed only of the crystalline region has higher electrical characteristics than the functional ink film including the crystalline region and the amorphous region.

[Example 3]
Next, an example of forming a thin film using the thin film manufacturing apparatus 3 will be described. In Example 3, a thermal oxide film (film thickness 1 μm) was formed on a silicon wafer, and a titanium film (film thickness 50 nm) was formed by sputtering as an adhesion layer. Subsequently, a platinum film (thickness: 200 nm) was formed by sputtering as the lower electrode.

Then, _CH 3 _{(CH 2)} using 6 -SH to alkanethiol, concentration 0.01 mol / l (solvent: isopropyl alcohol) is dipped into the solution, it was subjected to SAM process. Then, after washing and drying with isopropyl alcohol, the process proceeds to a patterning process.

  After the SAM film treatment, when the contact angle of water was measured at the SAM film formation site (on the SAM film), the contact angle of water on the SAM film was 92.2 ° (see FIG. 19). On the other hand, when the contact angle of water was measured on the platinum sputtered film before the SAM treatment, the contact angle of water on the platinum sputtered film was 5 ° or less (complete wetting). From this result, it can be seen that the SAM film treatment was appropriately performed.

  Next, a photoresist made by Tokyo Ohka Co., Ltd. (TSMR8800) was formed by spin coating, a resist pattern was formed by ordinary photolithography, and then an oxygen plasma treatment was performed to remove the exposed SAM film. The residual resist after the treatment was dissolved and removed with acetone, and the same contact angle evaluation was performed. As a result, the contact angle of water at the SAM film removal site was 5 ° or less (completely wet) (see FIG. 20). That of the covered site showed a value of 92.4 °. From this result, it can be confirmed that the SAM film is appropriately patterned.

  As another type of patterning, a resist pattern was formed in advance with the same resist work, and after the same SAM film treatment, the resist was removed with acetone, and the contact angle was measured. The contact angle on the resist-covered platinum film was 5 ° or less (complete wetting), and that at other sites was 92.0 °, confirming that the SAM film was appropriately patterned.

  As another method, ultraviolet irradiation using a shadow mask was performed. Specifically, irradiation was performed for 10 minutes using vacuum ultraviolet light having a wavelength of 176 nm from an excimer lamp. The contact angle of the irradiated part was 5 ° or less (complete wetting), and that of the unirradiated part was 92.2 °, confirming that the SAM film was appropriately patterned.

  Next, PZT (53/47) was formed as an electromechanical conversion film. In the synthesis of the precursor coating solution, lead acetate trihydrate, isopropoxide titanium, and isopropoxide zirconium were used as starting materials. Crystal water of lead acetate was dissolved in methoxyethanol and then dehydrated. The lead amount is 10 mol% excess relative to the stoichiometric composition. This is to prevent crystallinity deterioration due to so-called lead loss during heat treatment.

  Isopropoxide titanium and isopropoxide zirconium were dissolved in methoxyethanol, the alcohol exchange reaction and the esterification reaction were advanced, and the PZT precursor solution was synthesized by mixing with the methoxyethanol solution in which the lead acetate was dissolved. The PZT concentration was 0.1 mol / l.

  The film thickness obtained by a single sol-gel film formation is preferably 100 nm, and the precursor concentration is optimized from the relationship between the film formation area and the amount of applied precursor (thus not limited to 0.1 mol / l). .

  This precursor solution was applied onto the patterned SAM film by the ink jet method (see FIG. 7A). By discharging only the hydrophilic portion without discharging droplets on the SAM film by the ink jet method, a coating film was formed only on the hydrophilic portion due to the contact angle contrast.

  The coating film was heated by irradiating laser light with a continuous irradiation laser device 71 to evaporate the solvent, thereby obtaining a thermally decomposed coating film (see FIG. 7B). Subsequently, only the thermally decomposed coating film was irradiated with a laser beam by the pulse irradiation laser device 72 and heated to crystallize the thermally decomposed coating film (see FIG. 7C).

  At this time, since the film thickness of the coating film applied on the patterned SAM film by the inkjet method can be known from the coating amount, the laser power data corresponding to the film thickness of the coating film recorded in advance is read and the read laser power Then, the continuous irradiation laser device 71 and the pulse irradiation laser device 72 were operated (sequential irradiation with laser light).

  Liquid droplets were ejected to the same place by the ink jet method, and the process of irradiating laser light with the continuous irradiation laser device 71 and the pulse irradiation laser device 72 was repeated 15 times to perform overcoating to obtain a 500 nm electromechanical conversion film. . No defects such as cracks occurred in the electromechanical conversion film produced at this time.

  The process of ejecting droplets to the same place by the ink jet method and irradiating laser light by the continuous irradiation laser device 71 and the pulse irradiation laser device 72 was repeated 15 times (total 30 times), but the electromechanical conversion film was cracked. Such defects did not occur. The film thickness of the electromechanical conversion film reached 1000 nm.

An upper electrode (platinum) was formed on the patterned electromechanical conversion film to produce an electromechanical conversion element, and electrical characteristics and electromechanical conversion ability (piezoelectric constant) were evaluated. FIG. 21 is a graph showing a PE hysteresis curve of the electromechanical transducer produced in Example 3. The relative dielectric constant of the electromechanical conversion film is 1220, the dielectric loss is 0.02, the remanent polarization is 19.3 uC / cm ² , and the coercive electric field is 36.5 kV / cm, which is equivalent to that of an ordinary ceramic sintered body. I understood that I have it.

  The electro-mechanical conversion ability of the electromechanical transducer was calculated by measuring the amount of deformation by applying an electric field with a laser Doppler vibrometer and fitting it by simulation. The piezoelectric constant d31 was −120 pm / V, which was also the same value as the ceramic sintered body. This is a characteristic value that can be sufficiently designed as a droplet discharge head.

Note that an electrode film can be formed in the same manner as the electromechanical conversion film by dissolving an oxide such as platinum, SrRuO _3, or LaNiO _{3 in} a solvent, applying the ink by an inkjet method, and irradiating with a laser.

  The preferred embodiments and examples have been described in detail above, but the present invention is not limited to the above-described embodiments and examples, and the above-described embodiments are not deviated from the scope described in the claims. Various modifications and substitutions can be made to the embodiments.

DESCRIPTION OF SYMBOLS 1, 2 Droplet discharge head 3 Thin film manufacturing apparatus 4 Inkjet recording apparatus 5 Substrate 10 Nozzle plate 11 Nozzle 20 Pressure chamber substrate 21 Pressure chamber 30 Vibration plate 40 Electromechanical conversion element 41 Adhesion layer 42 Lower electrode 43 Electromechanical conversion film 43a, 43b, 43c Functional ink 43c ₁ Crystal region 43c ₂ Amorphous region 44 Upper electrode 50 SAM film 51, 53 Photoresist 51x, 54x Opening 54 Photomask 60 Base 61 Y-axis drive means 62 Stage 63 X-axis drive means 64 X-axis support member 65, 69 Z-axis drive means 66 Head base 67 Inkjet head 68 Ink tank 70 Laser support member 71 Continuous irradiation laser device 71x, 72x Laser light 72 Pulse irradiation laser device 81 Recording device body 82 Printing mechanism section 83 Paper 84 Paper cassette (Or feed tray)
85 Manual feed tray 86 Paper discharge tray 91 Main guide rod 92 Subordinate guide rod 93 Carriage 94 Inkjet recording head 95 Ink cartridge 97 Main scanning motor 98 Drive pulley 99 Driven pulley 100 Timing belt 101 Paper feed roller 102 Friction pad 103 Guide member 104 Transport roller 105 Conveying roller 106 Leading roller 107 Sub-scanning motor 109 Printing receiving member 111 Conveying roller 112 Spur 113 Discharge roller 114 Spur 115, 116 Guide member 117 Recovery device A, B, C Light H Film thickness

JP 2001-327917 A

Claims (17)

A liquid discharge means for discharging a liquid onto a film formation target to form a coating film;
First laser irradiation means for irradiating the coating film with a first laser beam and evaporating the solvent of the coating film;
A second laser irradiation means for irradiating the coating film obtained by evaporating the solvent with a second laser beam to crystallize the coating film obtained by evaporating the solvent;
The time required for crystal growth is calculated from the film thickness of the region where the coating film crystallizes when the coating film having a predetermined solid content concentration is irradiated with the second laser light for a predetermined irradiation time, and the calculated crystal Based on the time required for growth, the solid content concentration and irradiation time storage means for calculating and storing in advance the solid content concentration and the irradiation time that can crystallize the entire area of the coating film,
From the relationship between the film thickness of the coating film and the light absorption rate, the laser power of each of the first laser beam and the second laser beam corresponding to the film thickness of the coating film is calculated and stored in advance. Laser power storage means,
The liquid discharge means obtains the solid content concentration value from the solid content concentration and irradiation time storage means, discharges the liquid of the solid content concentration to form the coating film,
The first laser irradiation means obtains a laser power value of the first laser light corresponding to the film thickness of the coating film from the laser power storage means, and a laser power corresponding to the film thickness of the coating film. By irradiating the coating film with the first laser beam,
The second laser irradiation means obtains the irradiation time value from the solid content concentration and irradiation time storage means, and the second laser light corresponding to the film thickness of the coating film from the laser power storage means. A thin-film manufacturing apparatus that obtains the value of the laser power of and irradiates the second laser beam on the coating film for the irradiation time with the laser power corresponding to the film thickness of the coating film.   The solid content concentration and irradiation time storage means is configured to generate the crystal based on a cross-sectional state of the coating film formed by irradiating the coating film having a predetermined solid content concentration with the second laser light for a predetermined irradiation time. The thin film manufacturing apparatus according to claim 1, wherein the thickness of the region to be converted is obtained. 3. The thin film manufacturing apparatus according to claim 1, wherein the crystallized region is formed sequentially from the lower electrode side.   The thin film manufacturing apparatus according to any one of claims 1 to 3, wherein the wavelengths of the first laser beam and the second laser beam are each 400 nm or more.   5. The thin film manufacturing apparatus according to claim 1, wherein the first laser irradiation unit and the second laser irradiation unit are configured by a single laser device. 6.   6. The shape of the laser light irradiation region on the film formation target of the second laser irradiation unit is the same as the shape of the coating film obtained by evaporating the solvent. 6. Thin film manufacturing equipment.   The thin film manufacturing apparatus according to claim 6, wherein a shape of the coating film is a rectangle, and a shape of a laser light irradiation region on the film formation target of the second laser irradiation unit is a rectangle.   The thin film manufacturing apparatus according to any one of claims 1 to 7, wherein a light intensity distribution of the second laser light has a top hat shape.   The length in the direction perpendicular to the moving direction of the film forming object of the laser light irradiation region on the film forming object of the first laser irradiation means is the moving direction of the film forming object of the coating film. The thin film manufacturing apparatus according to claim 1, which has the same length in the vertical direction.   The thin film manufacturing apparatus according to claim 9, wherein a shape of the coating film is a rectangle, and a shape of a laser light irradiation region on the film formation target of the first laser irradiation unit is a rectangle.   The thin film manufacturing apparatus according to any one of claims 1 to 10, wherein a light intensity distribution of the first laser light has a top hat shape.   The ultraviolet light irradiation means which irradiates the ultraviolet light to the coating film which evaporated the solvent, and cut | disconnects the chemical bond of the metal organic compound contained in the coating film is given. Thin film manufacturing equipment.   The thin film manufacturing apparatus according to claim 12, wherein a wavelength of the ultraviolet light is 300 nm or less.   The thin film manufacturing apparatus according to claim 12 or 13, wherein the ultraviolet light irradiation means continuously irradiates the ultraviolet light. A region forming step of forming a liquid repellent region and a lyophilic region on the surface of the film formation target;
A coating film forming step of discharging a liquid to the lyophilic region to form a coating film;
A first laser irradiation step of irradiating the coating film with a first laser beam and evaporating a solvent of the coating film;
A second laser irradiation step of irradiating the coating film from which the solvent has been evaporated with a second laser beam to crystallize the coating film from which the solvent has been evaporated;
The time required for crystal growth is calculated from the film thickness of the region where the coating film crystallizes when the coating film having a predetermined solid content concentration is irradiated with the second laser light for a predetermined irradiation time, and the calculated crystal Based on the time required for growth, the solid content concentration and irradiation time storage step for calculating and storing in advance the solid content concentration and the irradiation time that can crystallize the entire area of the coating film,
Laser that calculates and stores in advance the laser power of each of the first laser light and the second laser light corresponding to the film thickness of the coating film from the relationship between the film thickness of the coating film and the light absorption rate A power storage process,
In the coating film forming step, the solid content concentration and the solid content concentration value stored in the irradiation time storage step are obtained, and the coating film is formed by discharging the liquid having the solid content concentration.
In the first laser irradiation step, the laser power value of the first laser beam corresponding to the film thickness of the coating film stored in the laser power storage step is obtained and corresponds to the film thickness of the coating film. The coating film is irradiated with the first laser beam by laser power,
In the second laser irradiation step, the irradiation time value stored in the solid content concentration and irradiation time storage step is obtained, and the film thickness of the coating film corresponding to the film thickness stored in the laser power storage step is obtained. A method for producing a thin film, wherein the laser power value of the laser light of No. 2 is obtained, and the second laser light is irradiated to the coating film for the irradiation time with the laser power corresponding to the film thickness of the coating film.   In the solid content concentration and irradiation time storage step, the crystal is formed based on a state of a cross section of the coating film formed by irradiating the coating film having a predetermined solid content concentration with the second laser light for a predetermined irradiation time. The thin film manufacturing method according to claim 15, wherein the thickness of the region to be converted is obtained. The thin film manufacturing method according to claim 15 or 16, wherein in the solid content concentration and irradiation time storing step, the crystallized region is formed sequentially from the lower electrode side.