JP2013065671A - Thin film preparation apparatus, electromechanical conversion film prepared by the thin film preparation apparatus, electromechanical conversion element, droplet discharge head, and droplet discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a thin film with good quality.SOLUTION: When, in a thin film preparation apparatus, a functional ink membrane 302 discharged on a substrate 11 by a droplet discharge head 300 is irradiated with a laser beam to be heated, a solvent is evaporated and a solution is dried. A dried condition of the functional ink membrane 302 is detected by a real time laser controller 600. An optimum laser beam irradiation condition corresponding to the detected dried condition of the functional ink membrane 302 is determined while collating characteristic data on the relation of an optimum laser beam irradiation condition relative to the dried condition of the functional ink membrane 302.

Description

  The present invention relates to a thin film manufacturing apparatus, an electromechanical conversion film manufactured by the thin film manufacturing apparatus, an electromechanical conversion element, a droplet discharge head, and a droplet discharge device.

  Conventionally, an electromechanical conversion element configured such that an electromechanical conversion film is sandwiched between electrodes includes, for example, a liquid discharge head that discharges ink droplets, and forms an image by adhering ink droplets to a sheet while conveying a medium. Used in an ink jet recording apparatus. The medium here is also referred to as “paper”, but the material is not limited, and a recording medium, a recording medium, a transfer material, a recording paper, and the like are also used synonymously. The image forming apparatus means an apparatus for forming an image by discharging a liquid onto a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics. The image formation is not only giving an image having a meaning such as a character or a figure to the medium but also giving an image having no meaning such as a pattern to the medium (simply ejecting a droplet). Also means. The ink is not limited to so-called ink, and is not particularly limited as long as it becomes liquid when ejected. For example, the ink is a generic term for liquids including DNA samples, resists, pattern materials, and the like. Use.

  The ink jet recording apparatus mainly includes a nozzle that discharges ink droplets, a discharge chamber that communicates with the nozzle, a liquid chamber called a pressurized liquid chamber, a pressure chamber, and an ink flow path chamber, and ink in the liquid chamber. And pressure generating means for discharging. As this pressure generating means, there is known a piezo-type pressure generating means for discharging ink droplets by deforming and displacing a vibration plate forming the wall surface of the discharge chamber using an electromechanical conversion element such as a piezoelectric element. . The electromechanical conversion element used for this piezoelectric type pressure generating means is formed by laminating a lower electrode, an electromechanical conversion layer, and an upper electrode. Individual electromechanical conversion elements are arranged to generate ink discharge pressure in each pressure chamber. The electromechanical conversion layer is formed by performing the process of forming the electromechanical conversion film a plurality of times. For example, lead zirconate titanate (PZT) is used as the electromechanical conversion film, and these are generally referred to as metal composite oxides because they contain a plurality of metal oxides as main components.

  The electromechanical conversion film can be produced by sputtering, sol-gel method, CVD method, laser ablation method, etc., of which sol coating, drying, thermal decomposition, and crystallization are performed. The sol-gel method is excellent in controllability of the crystal state. As a method for producing an electromechanical conversion film using this sol-gel method, the one described in Patent Document 1 is known. In the manufacturing method of Patent Document 1, platinum serving as the lower electrode has high wettability, and the surface of the lower electrode becomes a lyophilic surface having lyophilic properties. When the solution containing the PZT component is applied to the surface of the lower electrode, the surface becomes less wettable and becomes a lyophobic surface having lyophobic characteristics. Then, a photoresist formed in a predetermined pattern by photolithography is placed on the applied PZT solution film, and etching according to the predetermined pattern of the photoresist is performed. Specifically, the PZT solution film that has been exposed without being covered with the photoresist by oxygen plasma irradiation or UV light irradiation is removed, and the PZT solution film that has been coated with the photoresist remains. . Thereafter, the photoresist used for the processing is removed, and the patterning of the PZT solution film covered with the photoresist is completed. By performing the above steps, surface modification is performed so that the surface other than the predetermined portion to which the PZT liquid on the lower electrode is applied is made lyophobic.

  Next, in a predetermined portion on the lower electrode from which the film of the PZT solution has been removed by the etching, a droplet of a PZT liquid in which a raw material for forming an electromechanical conversion film is melted in a precursor solvent is dropped. Dropped from the nozzle of the discharge head. Then, a heat treatment process at a predetermined temperature is performed only on the film of the PZT liquid dropped on the predetermined portion. This heat treatment step includes a step of drying the PZT liquid, a step of thermally decomposing the dried film of the PZT liquid, and a step of crystallizing the thermally decomposed film of the PZT liquid. There are several methods for this heat treatment. In general, there is a rapid thermal annealing device using a halogen lamp or the like, and a heating device that heats by infrared rays. In addition, a heating apparatus using laser light irradiation is often used because of the advantages that energy exchange efficiency is good, process work time is short, and rapid heating is possible. As a heating device using this laser light irradiation, the one described in Patent Document 2 is known. In the heating apparatus using laser beam irradiation of Patent Document 2, droplets of an electromechanical conversion component solution are discharged to a predetermined portion of a substrate by a droplet discharge head, and the component solution of the electromechanical conversion film is irradiated with laser light. A heat treatment process is performed.

  However, in the heating apparatus using laser light irradiation in Patent Document 2 described above, if the laser power of the laser light in the heat treatment process is too high, the electromechanical conversion film is cracked and the function as the electromechanical conversion film is lost. When the laser power is too low, the solvent of the precursor contained in the PZT liquid is not completely evaporated, or the electromechanical conversion film is not completely crystallized, and the function as the electromechanical conversion film is deteriorated.

  The present invention has been made in view of the above problems, and the object thereof is a thin film manufacturing apparatus capable of manufacturing a high-quality thin film by heating under optimal heating conditions, an electromechanical conversion film manufactured by the thin film manufacturing apparatus, An electromechanical transducer, a droplet discharge head, and a droplet discharge device are provided.

  In order to achieve the above object, a thin film production comprising: an application means for applying a solution obtained by dissolving a thin film forming material in a solvent to a predetermined portion of an object; and a heating means for heating the solution applied by the application means. In the apparatus, a dry state detection means for detecting a dry state of the heated solution, a storage means for storing characteristic data of a relationship of an optimum heating condition with respect to the dry state of the solution, and the solution heated by the heating means The dry state is detected by the dry state detection means, and an optimum heating condition corresponding to the detected dry state of the solution is determined from the characteristic data stored in the storage means, and the determined heating condition is used to determine the heating condition. And control means for controlling heating by the heating means.

  In the present invention, when a solution in which the thin film forming material is dissolved in a solvent is heated, the solvent evaporates and the solution is dried. It has been found that the dry state of this solution affects the quality of the thin film. For this reason, the dry state of the solution is detected and collated with the characteristic data of the relationship of the optimum heating condition with respect to the detected dry state of the solution. And the optimal heating conditions corresponding to the dry state of a solution are determined. The solution is heated by controlling the heating means under the determined optimum heating condition. Thereby, it is possible to manufacture a high-quality thin film by reducing excessive heating or insufficient heating.

  According to the present invention, an effect that a high-quality thin film can be manufactured is obtained.

It is a schematic block diagram which shows the example of 1 structure of the droplet discharge apparatus of embodiment of this invention. It is a schematic perspective view of the droplet discharge device of the present embodiment. It is process sectional drawing which shows the manufacturing process of the electromechanical conversion element accompanied with formation of the electromechanical conversion film which concerns on one Embodiment of this invention. It is a characteristic view which shows the hysteresis curve of P (polarization) -E (electric field strength). It is a schematic block diagram which shows the example of 1 structure of the droplet discharge head comprised using the electromechanical conversion element manufactured with the thin film manufacturing apparatus. FIG. 6 is a schematic configuration diagram illustrating a configuration example in which a plurality of liquid ejection heads of FIG. 5 are arranged. It is a schematic diagram which shows the manufacturing process in the thin film manufacturing apparatus of this embodiment. It is a schematic diagram which shows the structure of a real-time laser beam control apparatus. It is a flowchart which shows the laser beam control process of this embodiment. It is a characteristic view which shows the reflectance with respect to the wavelength of a laser beam. It is explanatory drawing which shows each mode of the contact angle of the pure water in the electrode exposure surface which removed the SAM film, and the surface where the SAM film has been arrange | positioned.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram showing a configuration example of a droplet discharge apparatus according to an embodiment of the present invention. FIG. 2 is a schematic perspective view of the droplet discharge device of this embodiment. An ink jet recording apparatus 100 as an example of the droplet discharge apparatus of the present invention shown in both figures mainly includes a carriage 101 that can move in the main scanning direction inside the recording apparatus main body, and the present invention mounted on the carriage 101. The printing mechanism unit 104 is configured to include a recording head 102 including an inkjet head, which is an example of a liquid droplet ejection head manufactured as described above, and an ink cartridge 103 that supplies ink to the recording head 102. In addition, a sheet feeding cassette 106 capable of stacking a large number of sheets 105 can be detachably attached to the lower part of the apparatus main body from the front side, and a manual feed tray 107 for manually feeding sheets 105 is provided. The paper 105 fed from the paper feed cassette 106 or the manual feed tray 107 can be taken in, and a required image is recorded by the printing mechanism 104, and then discharged to a paper discharge tray 108 mounted on the rear side. Make paper.

  The printing mechanism unit 104 holds a carriage 101 slidably in the main scanning direction by a main guide rod 109 and a sub guide rod 110 which are guide members horizontally mounted on left and right side plates (not shown). (Y), cyan (C), magenta (M), and black (Bk) ink droplets are ejected from a recording head 102, which is an example of a droplet ejection head according to the present invention that ejects ink droplets of each color. Outlets (nozzles) are arranged in a direction crossing the main scanning direction, and are mounted with the ink droplet ejection direction facing downward. In addition, each ink cartridge 103 for supplying ink of each color to the recording head 102 is replaceably mounted on the carriage 101. The ink cartridge 103 has an air port that communicates with the atmosphere upward, a supply port that supplies ink to the recording head 102 below, and a porous body filled with ink inside. The ink supplied to the recording head 102 by the force is maintained at a slight negative pressure.

  Further, although the heads of the respective colors are used here as the recording heads 102, a single head having nozzles for ejecting ink droplets of the respective colors may be used. Here, the carriage 101 is slidably fitted to the main guide rod 109 on the rear side (downstream side in the paper conveyance direction), and is slidably mounted on the sub guide rod 110 on the front side (upstream side in the paper conveyance direction). doing. In order to move and scan the carriage 101 in the main scanning direction, a timing belt 114 is stretched between a driving pulley 112 and a driven pulley 113 that are rotationally driven by a main scanning motor 111, and the timing belt 104 is moved to the carriage 101. The carriage 101 is reciprocally driven by forward and reverse rotations of the main scanning motor 111.

  On the other hand, in order to convey the paper 105 set in the paper feed cassette 106 to the lower side of the recording head 102, the paper feed roller 115 and the friction pad 116 for separating and feeding the paper 105 from the paper feed cassette 106 and the paper 105 are guided. A guide member 117 that rotates, a conveyance roller 118 that reverses and conveys the fed paper 105, a conveyance roller 119 that is pressed against the peripheral surface of the conveyance roller 118, and a feeding angle of the sheet 105 from the conveyance roller 118. A tip roller 120 is provided. The transport roller 118 is rotationally driven by a sub-scanning motor 121 through a gear train. A printing receiving member 122 is provided as a paper guide member that guides the paper 105 fed from the transport roller 118 on the lower side of the recording head 102 corresponding to the movement range of the carriage 101 in the main scanning direction. A conveyance roller 123 and a spur 124 that are rotationally driven to send the paper 105 in the paper discharge direction are provided on the downstream side of the printing receiving member 122 in the paper conveyance direction, and the paper 105 is further delivered to the paper discharge tray 108. A roller 125 and a spur 126, and guide members 127 and 128 that form a paper discharge path are disposed.

  At the time of recording, the recording head 102 is driven in accordance with the image signal while moving the carriage 101, thereby ejecting ink onto the stopped paper 105 to record one line. Record the line. Upon receiving a recording end signal or a signal that the trailing edge of the paper 105 has reached the recording area, the recording operation is terminated and the paper 105 is discharged.

  Further, a recovery device 129 for recovering the ejection failure of the recording head 102 is disposed at a position outside the recording area on the right end side in the movement direction of the carriage 101. The recovery device 129 includes a cap unit, a suction unit, and a cleaning unit. The carriage 101 is moved to the recovery device 129 side during printing standby, and the recording head 102 is capped by the capping means, and the ejection port portion is kept in a wet state to prevent ejection failure due to ink drying. Further, by ejecting ink that is 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.

  As described above, since the ink jet recording apparatus is equipped with the ink jet head of the present embodiment, there is no ink droplet ejection failure due to vibration plate drive failure, stable ink droplet ejection characteristics are obtained, and image quality is improved. .

  Next, the manufacturing process of the electromechanical conversion film according to the embodiment of the present invention will be described. In this embodiment, an electromechanical conversion element having a transverse vibration (bend mode) type electromechanical conversion film using deformation of the piezoelectric constant d31 will be described as an example. The present invention is an electromechanical conversion film of this type. It is applicable without being limited to.

  When the electromechanical conversion film is a PZT film, a PZT precursor solution synthesized using lead acetate trihydrate, isopropoxide titanium, and normal butoxide zirconium as starting materials can be used. The crystal water of lead acetate is dissolved in methoxyethanol and then dehydrated. The lead amount is 10 [mol%] excess with respect to the stoichiometric composition. This is to prevent crystallinity deterioration due to so-called lead loss during heat treatment. It is possible to synthesize PZT precursor solution by dissolving isopropoxide titanium and normal butoxide zirconium in methoxyethanol, proceeding with alcohol exchange reaction and esterification reaction, and uniformly mixing with methoxyethanol solution in which lead acetate is dissolved. it can. The PZT concentration of this PZT precursor solution is, for example, 0.1 [mol / l].

  The PZT precursor solution in the case where the electromechanical conversion film is a PZT film is prepared by dissolving lead acetate, zirconium alkoxide, and titanium alkoxide compounds described in Non-Patent Document 1 as starting materials and dissolving them in methoxyethanol as a common solvent. Alternatively, a uniform solution may be obtained. The PZT precursor solution is also called “sol-gel solution”.

PZT is a solid solution of lead zirconate (PbZrO ₃ ) and lead titanate (PbTiO ₃ ), and the characteristics differ depending on the ratio. In general, the composition exhibiting excellent piezoelectric characteristics has a ratio of PbZrO ₃ and PbTiO ₃ of 53:47. When expressed by a chemical formula, Pb (Zr0.53, Ti0.47) O ₃ , generally PZT (53/47) It is indicated. The starting materials for lead acetate, zirconium alkoxide and titanium alkoxide compounds are weighed according to this chemical formula. Since the metal alkoxide compound is easily hydrolyzed by moisture in the atmosphere, an appropriate amount of a stabilizer such as acetylacetone, acetic acid or diethanolamine may be added to the precursor solution as a stabilizer.

  Examples of composite oxides other than PZT include barium titanate. In this case, it is also possible to prepare a barium titanate precursor solution by dissolving barium alkoxide and a titanium alkoxide compound in a common solvent. is there.

  Further, when obtaining a patterned PZT film as an electromechanical conversion film on the surface of the first electrode on the base substrate, a coating film is formed by applying the above solution as a coating liquid by a droplet discharge method. A patterned PZT film can be obtained by performing heat treatments of solvent drying, thermal decomposition, and crystallization. Since transformation from the coating film to the crystallized film involves volume shrinkage, it is preferable to obtain a film thickness of 100 [nm] or less in one step in order to obtain a crack-free film. And it is preferable to adjust so that a precursor density | concentration may be optimized from the relationship between the film-forming area of an electromechanical conversion film, and the application quantity of a PZT precursor solution. Further, when used as an electromechanical conversion element of a droplet discharge device, the thickness of the PZT film is required to be 1 [μm] to 2 [μm]. In order to obtain this film thickness, the process is repeated 10 to 20 times.

  Further, in the case of forming a patterned electromechanical conversion layer by the sol-gel method, the PZT precursor solution in which the wettability of the base substrate is controlled is separately applied. This utilizes the phenomenon of alkanethiol self-arranged on a specific metal shown in Non-Patent Document 2, and first, a SAM (Self assembled monolayer) film of thiol on the surface of the platinum group metal of the substrate. Form. Since the alkyl group is arranged on the SAM film, it becomes lyophobic. This SAM film can be patterned using a photoresist by, for example, well-known photolithography etching. Since the patterned SAM film remains even after the resist is peeled off, this portion is lyophobic. On the other hand, the portion from which the SAM film has been removed is lyophilic because the platinum surface is exposed. Using this surface energy contrast, the PZT precursor solution can be applied separately. In the present embodiment, after the SAM film is selectively formed in a region where the PZT precursor solution is not applied, as shown below, the droplet discharge method can reduce the consumption of the PZT precursor solution. The PZT precursor solution is selectively applied by coating (inkjet coating).

FIG. 3 is a process cross-sectional view illustrating a manufacturing process of an electromechanical conversion element accompanied with formation of an electromechanical conversion film according to an embodiment of the present invention. A platinum electrode made of a platinum group metal (not shown) as a first electrode excellent in reactivity with thiol is formed on the surface (upper surface) of the substrate 11 shown in FIG. Yes. A SAM film 12 is formed on the surface of the platinum electrode of the substrate 11 as shown in FIG. The SAM film 12 can be obtained by dipping the substrate 11 in an alkanethiol solution and making it self-align. In this example, an alkanethiol solution obtained by dissolving alkanethiol molecules of CH ₃ (CH ₂ ) —SH in a general organic solvent (alcohol, acetone, toluene, etc.) at a predetermined concentration (for example, several [mol / l]). Was used. After immersing the substrate 11 in this alkanethiol solution and taking it out after a predetermined time, the SAM film 12 can be formed on the surface of the platinum electrode by replacing and washing excess molecules with a solvent and drying. Next, as shown in (c) of the figure, a photoresist 13 is patterned by photolithography, and dry etching (for example, oxygen plasma irradiation or UV light irradiation) is performed as shown in (d) of the figure. Then, the SAM film 12 is removed, and the photoresist 13 used for processing is removed, and the patterning of the SAM film 12 is completed. The SAM film 12 formed in this manner has a contact angle with respect to pure water of, for example, 92 degrees and exhibits lyophobic properties. On the other hand, the surface of the platinum electrode of the substrate 11 exposed by removing the SAM film 12 has a contact angle with pure water of, for example, 54 degrees and exhibits lyophilicity.

  Next, after performing the steps shown in FIGS. 3A to 3D, a droplet discharge method in which the droplets of the PZT precursor solution are discharged from the nozzles, specifically, the PZT precursor by the droplet discharge head 14 is used. The body solution 15 is applied (see (e) of FIG. 3). The application of the PZT precursor solution 15 is performed such that the PZT film 16 is not formed on the SAM film that is a lyophobic part, and the PZT film is formed only on the lyophilic part from which the SAM film has been removed. Finally, the electromechanical conversion film 17 is obtained by performing heat treatments such as solvent drying, thermal decomposition, and crystallization (see (f) of FIG. 3).

  In the method of FIG. 3, the heat treatments of PZT precursor solution application, solvent drying, thermal decomposition, and crystallization are performed once by (a) to (d) of FIG. As shown in the case of obtaining an electromechanical conversion film having a film thickness, (a) to (d) of FIG. 3 above, (e) of FIG. 3 of application of the PZT precursor solution by the droplet discharge method, and solvent drying, 3 (f) of the thermal decomposition and crystallization heat treatments are repeatedly performed a predetermined number of times (two or more times) to form thin electro-mechanical conversion films in multiple layers, and the electric film having a predetermined thickness is formed. A mechanical conversion film may be obtained. In this case, generation of cracks in the electromechanical conversion film can be prevented more reliably.

  Further, in the method of FIG. 3 described above, the surface modification other than the predetermined portion on which the PZT precursor solution on the first electrode is applied is made a lyophobic surface by the SAM film. When the surface is a lyophobic surface, surface modification may be performed so that the surface of a predetermined portion to which the PZT precursor solution on the first electrode is applied becomes a lyophilic surface.

The manufacturing process described above was repeated 15 times to obtain a film of 500 [nm]. No defects such as cracks occurred in the film produced at this time. Further, selective application of the PZT precursor and laser irradiation were performed 15 times to perform crystallization treatment. Defects such as cracks did not occur in the film. The film thickness reached 1000 [nm]. An upper electrode (platinum) was formed on this patterned film, and electrical characteristics and electromechanical conversion ability (piezoelectric constant) were evaluated. As a result, a hysteresis curve of P (polarization) -E (electric field strength) in FIG. 4 was obtained. The relative dielectric constant of the film is 1220, the dielectric loss is 0.02, the remanent polarization is 19.3 [μC / cm ² ], and the coercive electric field is 36.5 [kV / cm], which is equivalent to a normal ceramic sintered body It was found that it has the characteristics of In addition, the electromechanical conversion ability 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 value is a characteristic value that can be sufficiently designed as a piezoelectric element for use in a liquid discharge head. An electrode film can be formed in the same manner as the piezoelectric layer by dissolving an oxide such as platinum, SrRuO ₃ , LaNiO _3, or IrO ₂ in a solvent as an electrode film, applying it by an ink jet method, and irradiating it with a laser.

  FIG. 5 is a schematic configuration diagram showing a configuration example of a droplet discharge head configured using the electromechanical conversion element manufactured by the manufacturing method. In the illustrated example, a diaphragm 30, an adhesion layer 41, and a lower electrode (first electrode) 42 are stacked on a silicon substrate 20 serving as a liquid chamber substrate, and a predetermined on the lower electrode (first electrode) 42 is formed. The electromechanical conversion element (PZT element) 43 and the upper electrode 44 having the same performance as that of bulk ceramics can be patterned and formed on the portion by the simple manufacturing method described above. Thereafter, the liquid chamber 22a is formed from the back surface (the lower surface in the drawing) of the silicon substrate 20 by an etching removal process, and the nozzle plate 22 having the nozzle holes 21 is joined, whereby the liquid discharge head 50 can be manufactured. In the figure, descriptions of the liquid supply means, the flow path, and the fluid resistance are omitted. Further, a plurality of the droplet discharge heads 50 shown in FIG. 5 can be arranged as shown in FIG.

  FIG. 7 is a schematic view showing a manufacturing process in the thin film manufacturing apparatus of this embodiment. In the figure, a stage 202 for fixing the substrate 11 is installed on a Y-axis driving means 201 that moves to the Y-axis. Above the Y-axis driving unit 201, a droplet discharge device 300, a continuous irradiation laser device 400, and a pulse irradiation laser device 500 are arranged from the upstream side to the downstream side in the movement direction. The stage 202 is accompanied by suction means such as vacuum and static electricity not shown, and the substrate 11 is fixed. Although not shown, the stage 202 is also equipped with an X-axis driving unit, and can scan the substrate 11 two-dimensionally in conjunction with the Y-axis driving unit 201. Further, although not shown, a Z-axis driving unit is also mounted, and the distance between the droplet discharge device 300 or the laser irradiation system of the continuous irradiation laser device 400 and the pulse irradiation laser device 500 and the substrate can be controlled. it can. Further, although not shown, the stage 202 is also equipped with a driving unit that rotates about the Z axis, and can correct the relative inclination between the droplet discharge device 300 or the laser irradiation system and the substrate. it can. The drive system can be mounted on the droplet discharge device 300 or the laser irradiation system to obtain the same function as described above.

  A SAM film pattern is formed on a substrate as shown in FIG. The position and inclination of the substrate 11 are aligned using a commonly used alignment device (CCD camera, CMOS camera) or the like. The stage 202 is driven along the Y axis and, if necessary, the X axis, and the functional ink 301 is patterned in a region (lyophilic portion) on the substrate 11 where the SAM film does not exist as shown in FIG. The functional ink film 302 that has landed on the lyophilic portion on the substrate 11 spreads over time. Next, the stage 202 is driven to the Y axis and, if necessary, the X axis, and the functional ink film 402 is dried by irradiating the functional ink pattern wetted and spread by the continuous irradiation laser device 400. Let In general, a semiconductor laser or a YAG laser can be used as the laser. The wavelength is in a region where the light absorption rate of the substrate is relatively high, for example, around 400 [nm] to 10,000 [nm]. The laser power is several [W] to several tens [W], and the solvent of the functional ink can be evaporated and further thermal decomposition is possible. Of course, depending on the moving speed of the substrate, there is no problem in the power setting as long as the speed is in the range of 10 [mm / s] to 1000 [mm / s]. The beam diameter is several tens [μm] to several hundreds [μm], and the beam profile is a general Gaussian profile without any problem. Although the laser light also irradiates the region where the SAM film is present, the substrate temperature remains below 500 [° C.] under the above setting conditions, and therefore the SAM film does not disappear. Finally, the laser beam 501 is irradiated only on the functional ink pattern by the pulse irradiation laser device 500 on the thermally decomposed functional ink film. The laser power is also several [W] to several tens [W], the irradiation time is several [[mu] seconds] to several hundred [[mu] seconds], and the light emission frequency is adjusted to the functional ink pattern and the moving speed of the substrate. For example, when the pattern interval is 100 [μm] and the substrate moving speed is 100 [mm / s], the emission frequency of the pulse laser is 1 [kHz]. Therefore, a semiconductor fiber coupling laser device generally sold in the market Alternatively, a semiconductor laser stack device can be used. When the substrate 11 moves during pulse laser emission, for example, when the irradiation time is 100 [μsec] and the substrate moving speed is 100 [mm / s], the range of irradiation of 10 [μm] is expanded. In consideration of such spread, it is necessary to control the irradiation timing according to the pattern shape so as not to irradiate the SAM film region. By repeating the above steps and laminating, a functional ink film 502 having an arbitrary pattern and thickness crystallized can be efficiently manufactured on the substrate 11.

  FIG. 8 is a schematic diagram showing the configuration of the real-time laser light control device. In the figure, the same reference numerals as those in FIG. 7 denote the same components. A real-time laser control device 600 shown in the figure includes a laser light irradiation device 601 and an infrared light source of a Fourier Transform Infrared (hereinafter abbreviated as FT-IR) measuring device including a Fourier transform infrared spectrophotometer. 602 and a detector 603 of the FT-IR measuring device. The laser beam irradiation device 601 irradiates the functional ink film 302 on the substrate 11 with the laser beam 604. Then, the infrared light source 602 of the FT-IR measuring apparatus irradiates the functional ink film 302 on the substrate 11 with infrared rays 605. Reflected light 606 that is transmitted through and reflected by the functional ink film 302 enters the detector 603. An interferometer 607 of the FT-IR measurement apparatus is disposed between the infrared light source 602 and the functional ink film 302. Then, information on the dry state of the functional ink film 302 obtained based on the infrared rays detected by the detector 603 of the FT-IR measurement apparatus is supplied to the laser light source control unit 608. The laser light source control unit 608 compares the detected dry state information with characteristic data stored in advance, which will be described later, and determines the laser light irradiation condition corresponding to the dry state detected as a result of the comparison. Then, the laser light source control unit 608 controls the laser light irradiation of the laser light irradiation apparatus 601 under the determined laser light irradiation conditions. Since the principle of FT-IR measurement is generally known, a description thereof is omitted here.

Next, the laser beam control process of this embodiment will be described according to the operation flow of FIG. 9 showing the process.
First, a functional ink is uniformly applied on the substrate 11 of FIG. 7 by an ink jet method or a spin coat method to form a functional ink film 302 (step S101). Then, in order to evaporate the solvent of the functional ink film 302 under the initial laser beam irradiation conditions, the laser beam is irradiated and heated, and the laser beam is irradiated while finely adjusting the laser beam irradiation conditions to completely evaporate the solvent. (Step S102). In general, an oven or RTA can be used, but in this embodiment, a laser device 400 manufactured by Dilas is used. Next, the dry state of the functional ink film 302 is measured by the FT-IR measuring device (step S103). For example, as a commercially available FT-IR measuring device, Nocolet series manufactured by Thermo Scientific can be used. With this apparatus, a spectral range of 27000-15 [cm ^ -1] (370-666, 667 [nm]) can be measured in several [msec] at one wavelength. An example of information obtained by this measurement is shown in FIG. FIG. 10 shows the measurement results before and after laser heating. Characteristic peaks that decrease when the solvent evaporates are observed around a wavelength of 6500 [nm], around a wavelength of 7100 [nm], and around a wavelength of 7500 [nm]. The measurement result without functional ink (platinum substrate) is shown as the reflectance. Since there is no solvent, no peak at the wavelength is observed. A waveform 700 in FIG. 10 shows an FT-IR spectrum result for a platinum substrate when there is no functional ink film. A waveform 701 shows a FT-IR spectrum result after heating by performing laser irradiation four times at 36 [W] when there is a functional ink film. A waveform 702 shows the result of FT-IR spectrum after heating with one laser beam irradiation at 36 [W] when there is a functional ink film. A waveform 703 shows the FT-IR spectrum result immediately after application in the case where there is a functional ink film. A waveform 704 shows a peak value per wavelength 6500 [nm] of the waveform 703. A waveform 705 indicates a peak value of the waveform 703 per wavelength 7100 [nm]. A waveform 706 shows a peak value per wavelength 7500 [nm] of the waveform 703.

  Next, a target characteristic peak is selected (step S104). For example, in this embodiment, it is known that a peak around 6500 [nm] indicates the evaporation state of the solvent. Therefore, it is assumed that the reflectance of the wavelength 6500 [nm] is 98% or more as the target value of this embodiment. Generally, measurement results vary greatly depending on the measurement region. Noise is smaller when the FT-IR measurement area is the same as the functional ink pattern shape or the FT-IR measurement area is smaller, and more efficient measurement is possible. Since the actual measurement of the solvent evaporation state in FT-IR is performed in real time during laser irradiation, the measurement time is only several [msec] to several tens [[mu] sec]. If the measurement time is short, the amount of light entering the detector is small, and as a result, the reflectance is low. Therefore, it is preferable to set the measurement time in consideration of real-time measurement in advance measurement. Of course, it goes without saying that the target value also changes if the target solvent evaporation state (peak to be seen in the spectrum) is different. For example, it is preferable to set the peak value around 7100 [nm] as a condition. Furthermore, it is also preferable to set conditions around 7500 [nm]. Further, it is also effective to determine a certain ratio of a plurality of peak values and set it as a target value. For example, 6500 [nm] has a reflectance of 95% or more, 7100 [nm] has a reflectance of 98% or more, 7500 [nm] has a reflectance of 93% or more, and the like. Furthermore, the setting condition of the target value may be simply set to a peak value of a certain wavelength. For example, the peak in the vicinity of 6500 [nm] shown in FIG. 10 has a width. In this case, it can be seen that there is a range from 6250 [nm] to 6750 [nm]. For example, a target value can be added on condition that the peak width is narrowed from 6400 [nm] to 6600 [nm].

  Then, the target reflectance peak value and wavelength range information are recorded (step S105). Thereafter, a functional ink is uniformly applied on the substrate by an ink jet method or a spin coating method to form a film (step S106). Next, the functional ink film is laser heated (step S107). Then, the solvent evaporation state of the functional ink film is measured by the FT-IR measurement device (step S108), and compared with the reflectance value of the target dry state recorded in step S105 in real time (step S109). Laser heating is continued until an equivalent solvent dry state is obtained (step S109: NO, steps S107, S108). In real-time measurement, there are several methods for measuring the solvent dry state at high speed and with high accuracy. One is to array multiple light sources and detectors within the required wavelength range, so that a single light source and detector, such as the commonly used FT-IR measurement device, can be used in a certain wavelength range. It can measure with higher accuracy and speed than the measurement method. The other is to limit the wavelength range to be measured. As described in step S104, if the target wavelength is determined, only the information on the wavelength range is necessary. Therefore, there is no need to measure a wide range from 370 [nm] to 666,667 [nm]. Measurement is possible. Thus, based on the information of the solvent evaporation state measured in real time, the laser heating conditions are changed in real time to form an optimum film.

  Here, parameters that can be changed depending on the laser heating conditions include laser power, laser irradiation time, number of times of laser irradiation, and the like. In general, the laser power can be adjusted in real time by changing the input voltage for controlling the power of the laser controller. The laser irradiation time can be changed by changing the moving speed of the stage 202 shown in FIG. 7 in the case of a continuous irradiation (CW) laser, and can be changed by changing the emission time in the case of a pulse laser. Furthermore, the same pattern can be irradiated multiple times by transporting the substrate under the laser again. Thus, by changing the laser heating conditions in real time, a plurality of pattern films having good quality and uniform characteristics can be manufactured. Furthermore, in order to efficiently increase the FT-IR measurement accuracy, the shape of the FT-IR measurement area and the laser irradiation area are the same, or the FT-IR measurement area is smaller, reflecting the measurement results of the useless area. Therefore, highly accurate control is possible.

  Finally, the functional ink continues to be applied repeatedly from step S101 to step S108 until the target film thickness is reached. In this embodiment, the above process was repeated to produce a piezoelectric element having a thickness of about 1 to 2 [μm]. In this embodiment, the laser irradiation area is 1000 [μm] × 50 [μm], the laser wavelength is 980 [nm], the laser beam profile is top hat (flat), the substrate scanning speed is 100 [mm / s], and 20 to 40 [W]. The optimum laser power was recognized in the vicinity and was initially set. The functional ink film produced under the above conditions had no cracks, good crystallization, and good piezoelectric element characteristics. When the heating process is finished, the SAM film is formed every time in the second and subsequent processes. In the second and subsequent procedures, when it is desired to reduce the consumption of the PZT precursor solution, a PZT pattern is formed by inkjet coating or letterpress printing, and solvent evaporation, thermal decomposition, and crystallization are performed by a laser irradiation system. The above process is repeated until a desired film thickness is obtained. Patterning by this method can form ceramics with a thickness of 5 [μm]. As a material used for the lower electrode, a metal that is heat resistant and forms a SAM film by reaction with alkanethiol is selected. Copper or silver forms a SAM film but cannot be used because it is altered in the atmosphere by heat treatment at 500 ° C. or higher.

  Furthermore, although gold satisfies both conditions, it cannot be used because it adversely affects the crystallization of the stacked PZT film. An alloy material of platinum, rhodium, ruthenium, iridium, or any other platinum group element mainly composed of platinum such as platinum-rhodium is also effective. The vibration plate disposed on the silicon substrate may be a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a film in which these films are laminated with a thickness of several microns. Further, a ceramic film such as an aluminum oxide film or a zirconia film in consideration of a difference in thermal expansion may be used. These materials are insulators. Since the lower electrode is electrically connected as a common electrode for inputting a signal to the piezoelectric element, the diaphragm underneath is used as an insulator or an insulator if it is a conductor. As the silicon-based insulating film, a thermal oxide film or a CVD deposited film can be used, and the metal oxide film can be formed by a sputtering method. When the platinum group lower electrode is disposed on these diaphragms, an adhesion layer 41 for increasing the film adhesion is required (see FIG. 5). Effective materials for the adhesion layer are titanium, tantalum, titanium oxide, tantalum oxide, titanium nitride, tantalum nitride, and laminated films thereof.

  As shown in FIG. 7, the continuous irradiation laser device and the pulse irradiation laser device are used as separate devices, but the semiconductor fiber coupling laser device or semiconductor laser stack device generally sold in the market is continuous with the pulse type. Since it is relatively easy to make the irradiation type compatible with each other, the process from solvent evaporation, thermal decomposition, and crystallization of the functional ink can be performed with one laser device. Thereby, the length of the stage drive means in the Y-axis direction can be shortened, thereby improving the movement accuracy in the Y-axis direction, further reducing the size of the apparatus, and further reducing the cost of the apparatus. .

  In addition, all heating steps from solvent evaporation, thermal decomposition, and crystallization can be performed by one continuous irradiation type laser, which leads to reduction in apparatus cost. When a continuous irradiation type laser is used, the SAM film is damaged. However, this problem is solved by performing the process of forming the SAM film after heating every time the layers are formed.

  Further, the shape of the laser irradiation area is a general circle, and the beam profile is Gaussian. For example, when the substrate moves in the Y-axis direction and functional ink is irradiated in a circular laser irradiation area, the actual irradiation time is different between the circle center region and the circle end portion. The center of the circle is irradiated for a longer time, and the end of the circle is irradiated for a shorter time. Therefore, in the present embodiment, the functional ink patterned into a certain shape can be uniformly heated by making the laser irradiation area the same shape as or larger than the functional ink pattern. Furthermore, it becomes possible to heat functional ink uniformly by making a beam profile into a flat shape or a top hat shape (uniform) within an irradiation area. The shape and beam profile of the irradiation area can be mounted on both the continuous irradiation laser device and the pulse irradiation laser device. In the case of pulse laser or continuous irradiation laser, more specifically, if the direction in which the substrate can move simultaneously is one direction, the irradiation area should be rectangular and the inclination of the rectangle should be aligned with the inclination of the substrate movement direction. Is preferred. With such a configuration, the irradiation time in the substrate movement direction is always the same in the direction perpendicular to the substrate movement direction (X axis in FIG. 7), enabling uniform heating, and providing a highly reliable functional ink film. Can be formed. Furthermore, by making the length of the irradiation area in the X-axis direction equal to the length of the pattern in the X-axis direction, it is possible to efficiently heat only the functional ink without heating a useless area.

By performing the evaporation step using a laser in an atmosphere having an O ₂ concentration of 50% or more, a higher quality film can be formed. This is because C is easily removed from the film when the chemical bond of the genus organic compound is broken. Since C bonds with O ₂ in the atmosphere and escapes, it is better that the O ₂ concentration in the atmosphere is higher. Furthermore, a higher quality film can be formed by performing the crystallization process using a laser in an atmosphere having an N ₂ concentration of 50% or more. This is because Pb in the film is reduced from bonding with O _{2 in the} atmosphere and being lost during crystallization. This can be achieved by increasing the N ₂ concentration to 50% or more in order to reduce the O ₂ concentration in the atmosphere.

In general, it has been found that a piezoelectric film is improved in a conventional heat-treated film that heats a substrate and indirectly heats a functional ink and a film that is heat-treated after irradiation with an excimer laser. That is, the organic compound contained in the metal component is decomposed at different temperatures. Therefore, by irradiating the excimer laser, the chemical bond of each metal organic compound is cut to unify the way of forming crystal grains, and a dense and uniform crystal film can be formed. Will improve. The chemical bond cleaved by the excimer laser can be verified using an infrared absorption spectrum or the like. Specifically, after evaporating the solvent with a continuous irradiation laser device, the characteristics of the functional ink film can be improved by, for example, irradiating an excimer laser having a wavelength of 300 [nm] or less. For example, using a generally available continuous irradiation type KrF excimer laser device, the characteristics of the functional ink film are improved by irradiating energy of wavelengths 230 to 280 [nm], 100 [mJ / cm ² ] or more. Can be made. Furthermore, a higher quality film can be formed by performing the process in an atmosphere having an O ₂ concentration of 50% or more. This is because C is easily removed from the film when the chemical bond of the genus organic compound is broken. Since C bonds with O ₂ in the atmosphere and escapes, it is better that the O ₂ concentration in the atmosphere is higher.

Then, a thermal oxide film (film thickness 1 [μm]) was formed on the silicon wafer, and a titanium film (film thickness 50 [nm]) was formed by sputtering as an adhesion layer. Subsequently, a platinum film (film thickness 200 [nm]) was formed by sputtering as the lower electrode. SAM treatment was performed by using CH ₃ (CH ₂ ) ₆ -SH in alkanethiol and immersing it in a 0.01 [mol / l] (solvent: isopropyl alcohol) solution. Then, after washing with isopropyl alcohol and drying, the process proceeds to a patterning process.

  The lyophobic property after the SAM treatment was measured by a contact angle, and the contact angle of water on the SAM film was 92.2 °. On the other hand, that of the sputtered platinum film before SAM treatment is 5 ° or less (complete wetting), indicating that the SAM film treatment was performed.

  A photoresist made by Tokyo Ohka Co., Ltd. (TSMR8800) was formed by spin coating, a resist pattern was formed by ordinary photolithography, and oxygen plasma treatment was then 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 removed portion was 5 ° or less (completely wet), and the portion covered with the resist had a value of 92.4 °. It was confirmed that the SAM film was 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 patterned.

  As another method, ultraviolet irradiation using a shadow mask was performed. The ultraviolet rays used were irradiated with vacuum ultraviolet light having a wavelength of 176 [nm] from an excimer lamp for 10 minutes. The contact angle of the irradiated part was 5 ° or less (completely wet) (see (a) of FIG. 11), and that of the unirradiated part was 92.2 ° (see (b) of FIG. 11). It was confirmed that conversion was made.

  PZT (53/47) is deposited as a piezoelectric layer. 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 one 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. Therefore, it is not limited to 0.1 [mol / l]. This precursor solution was applied on the patterned SAM film by an ink jet method. By discharging only the lyophilic part without discharging droplets on the SAM film by the ink jet method, a coating film was formed only on the lyophilic part due to the contact angle contrast. At the time of this coating, the substrate is heated by irradiating the laser with an output according to the film thickness, and the patterned precursor ink is dried and crystallized, and the electromechanical conversion film 17 shown in FIG. Obtained.

  As described above, since the inkjet head embodying the present invention is mounted in this inkjet recording apparatus, there is no ink droplet ejection failure due to vibration plate drive failure, stable ink droplet ejection characteristics are obtained, and image quality is improved. improves.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect A)
Dry state detection means for detecting the dry state of the heated solution, storage means for storing the characteristic data of the relationship of the optimum heating condition with respect to the dry state of the solution, and dry state detection of the solution heated by the heating means And a control means for determining the optimum heating condition corresponding to the detected dry state of the solution from the characteristic data stored in the storage means and controlling the heating by the heating means under the determined heating condition. According to this, as described in the above embodiment, when the functional ink film 302 discharged onto the substrate 11 by the droplet discharge head 300 is irradiated with laser light and heated, the solvent evaporates and the solution is dried. The dry state of the functional ink film 302 is detected by the real-time laser controller 600. Then, the optimum laser light irradiation condition corresponding to the detected dry state of the functional ink film 302 is determined while collating with the characteristic data of the relationship of the optimum laser light irradiation condition with respect to the dry state of the functional ink film 302. Thereby, it is possible to manufacture a high-quality thin film by reducing excessive heating or insufficient heating.
(Aspect B)
In (Aspect A), the dry state detection means uses a Fourier transform infrared spectrophotometer. According to this, as described in the above embodiment, the dry state of the functional ink film is accurately detected by detecting infrared rays that are transmitted through and reflected by the functional ink film 302 according to the degree of evaporation of the solvent. Can be detected. Thereby, optimal heating conditions can be determined and a good quality thin film can be manufactured.
(Aspect C)
In (Aspect B), the shape of the irradiation part of the infrared irradiation of the Fourier transform infrared spectrophotometer is substantially the same as the shape of the solution applied on the substrate, and the size of the irradiation part of the infrared irradiation is the size of the solution. Less than that. According to this, as described in the above embodiment, it is possible to accurately detect the dry state of the functional ink film.
(Aspect D)
In (Aspect C), when the heating means is a laser light source, the shape of the infrared irradiation portion of the Fourier transform infrared spectrophotometer is substantially the same as the shape of the laser light source irradiation portion, and the infrared irradiation portion. Is smaller than the size of the irradiated portion of the laser light source. According to this, as described in the above embodiment, it is possible to accurately detect the dry state of the functional ink film.
(Aspect E)
In any one of (Aspect A) to (Aspect D), the infrared wavelength range of the Fourier transform infrared spectrophotometer is adjusted to the wavelength peak in the characteristic data when the solution coated on the substrate is dried. According to this, as described in the above embodiment, it is possible to accurately detect the dry state of the functional ink film.
(Aspect F)
In (Aspect A), the heating means is a laser light source, and the laser light irradiation condition that is a heating condition is irradiation power, number of irradiations, or irradiation time. According to this, as described in the above embodiment, it is possible to accurately detect the dry state of the functional ink film.
(Aspect G)
Using the thin film manufacturing apparatus according to any one of (Aspect A) to (Aspect F), a solution for forming an electromechanical conversion film is applied to a predetermined portion of a substrate, and the applied solution is subjected to heat treatment by a heating means. . According to this, as explained about the above-mentioned embodiment, a good-quality electromechanical conversion film can be manufactured.
(Aspect H)
After the first electrode is formed on the electromechanical conversion film of (Aspect G), the second electrode is disposed so as to sandwich the electromechanical conversion film formed on the first electrode. According to this, as explained about the above-mentioned embodiment, a good-quality electromechanical conversion element can be manufactured.
(Aspect I)
The electromechanical transducer of (Aspect H) was provided. According to this, as described in the above embodiment, it is possible to provide a liquid droplet ejection head with few ejection defects.
(Aspect J)
The liquid droplet ejection head of (Aspect I) was provided. According to this, as described in the above embodiment, it is possible to provide a droplet discharge device with few image quality defects.

11 Substrate 12 SAM Film 13 Photoresist 14 Droplet Discharge Head 15 PZT Precursor Solution 16 PZT Film 17 Electromechanical Conversion Film 20 Silicon Substrate 21 Nozzle Hole 22 Nozzle Plate 22a Liquid Chamber 30 Vibration Plate 41 Adhesion Layer 42 Lower Electrode 43 Electromechanical Conversion element 44 Upper electrode 50 Liquid discharge head 100 Inkjet recording apparatus 201 Y-axis drive unit 202 Stage 300 Droplet discharge apparatus 301 Functional ink 302 Functional ink film 400 Continuous irradiation laser apparatus 401 Laser light 402 Functional ink film 500 Pulse irradiation laser Device 501 Laser light 502 Functional ink film 600 Real-time laser control device 601 Laser light irradiation device 602 Infrared light source 603 Detector 604 Laser light 605 Infrared ray 606 Reflected light 607 Interferometer

JP 2008-187302 A JP 2007-105661 A

K. D. Budd, S.M. K. Day and D.D. A. Payne, Proc. Brit. Ceram. Soc. 36, 107 (1985) A. Kumar and G.K. M.M. Whitesides, Appl. Phys. Lett. 63, 2002 (1993)

Claims (10)

In a thin film manufacturing apparatus comprising: an application unit that applies a solution obtained by dissolving a thin film forming material in a solvent to a predetermined portion of an object; and a heating unit that heats the solution applied by the application unit.
Dry state detection means for detecting the dry state of the heated solution;
Storage means for storing characteristic data of the relationship of optimum heating conditions with respect to the dry state of the solution;
The dry state of the solution heated by the heating unit is detected by the dry state detection unit, and an optimum heating condition corresponding to the detected dry state of the solution is determined from the characteristic data stored in the storage unit. And a control means for controlling heating by the heating means under the determined heating condition. The thin film manufacturing apparatus according to claim 1,
The dry state detecting means uses a Fourier transform infrared spectrophotometer. The thin film manufacturing apparatus according to claim 2,
The shape of the irradiated part of the infrared irradiation of the Fourier transform infrared spectrophotometer is substantially the same as the shape of the solution applied on the substrate, and the size of the irradiated part of the infrared irradiation is smaller than the size of the solution. A thin film manufacturing apparatus characterized by that. The thin film manufacturing apparatus according to claim 2,
When the heating means is a laser light source, the shape of the irradiated portion of the infrared light of the Fourier transform infrared spectrophotometer is substantially the same as the shape of the irradiated portion of the laser light source, and the size of the irradiated portion of the infrared light irradiation. Is smaller than the size of the irradiated portion of the laser light source. In the thin film manufacturing apparatus according to any one of claims 1 to 4,
An apparatus for producing a thin film, characterized in that an infrared wavelength range of the Fourier transform infrared spectrophotometer is matched with a wavelength peak in the characteristic data when the solution coated on the substrate is dried. The thin film manufacturing apparatus according to claim 1,
The said heating means is a laser light source, The laser beam irradiation conditions which are the said heating conditions are irradiation power, the frequency | count of irradiation, or irradiation time, The thin film manufacturing apparatus characterized by the above-mentioned.   Using the thin film manufacturing apparatus according to any one of claims 1 to 6, a solution for forming an electromechanical conversion film is applied to a predetermined portion of a substrate, and the applied solution is subjected to heat treatment by a heating means. An electromechanical conversion film.   A first electrode is formed on the electromechanical conversion film according to claim 7, and then the second electrode is disposed so as to sandwich the electromechanical conversion film formed on the first electrode. An electromechanical conversion element characterized by the above.   A droplet discharge head comprising the electromechanical conversion element according to claim 8.   A droplet discharge apparatus comprising the droplet discharge head according to claim 9.