JP2011111355A - Method for manufacturing thin film, and thin film element - Google Patents

Abstract

A thin film manufacturing method capable of manufacturing a thin film of stable quality at a low cost is provided.
A method of manufacturing a thin film, in which a substrate is placed in a raw material solution of a thin film to be formed on a first main surface 20a of the substrate 20, and light is irradiated from the first main surface 20a side. And a forming step of forming a thin film on the first main surface 20a of the substrate 20.
[Selection] Figure 1

Description

  The present invention relates to a thin film manufacturing method and a thin film element.

  Conventionally, a chemical solution deposition method (CSD method) is known as a method for forming a thin film such as a piezoelectric element. In the CSD method, a raw material solution is applied on a substrate and dried to form a thin film on the substrate surface. For example, Patent Document 1 discloses a method for forming a dielectric thin film using a metal oxide precursor solution containing a metal oxide precursor and a dye.

  However, in the CSD method, a very large labor is required in the coating and drying process of the metal oxide precursor solution, resulting in high costs. Furthermore, the drying process has a problem that the thin film is easily cracked.

  The present invention has been made in view of the above, and an object of the present invention is to provide a thin film manufacturing method and a thin film element capable of manufacturing a thin film of stable quality at low cost.

  In order to solve the above-described problems and achieve the object, the present invention is a method for manufacturing a thin film, wherein the substrate is disposed in a raw material solution of a thin film to be formed on the first main surface of the substrate; And forming a thin film on the first main surface of the substrate by irradiating light from the first main surface side.

  Another embodiment of the present invention is a thin film manufacturing method, comprising: a disposing step of disposing the substrate in a thin film raw material solution formed on the first main surface of the substrate; and a back surface of the substrate. Forming a thin film on the first main surface of the substrate by irradiating light from the second main surface side.

  According to another aspect of the present invention, there is provided a thin film element, an arrangement step of arranging the substrate in a raw material solution of a thin film formed on the first main surface of the substrate, and light from the first main surface side. The thin film manufactured by the thin film manufacturing method which has the formation process which forms the said thin film on the 1st main surface of the said board | substrate by irradiating is characterized by the above-mentioned.

  According to another aspect of the present invention, there is provided a thin film element, the disposing step of disposing the substrate in a thin film raw material solution formed on the first main surface of the substrate, and a second surface which is the back surface of the substrate. The thin film manufactured by the thin film manufacturing method having a forming step of forming the thin film on the first main surface of the substrate by irradiating light from the main surface side is used.

  According to the present invention, it is possible to produce a thin film having a stable quality at a low cost.

FIG. 1 is a diagram for explaining a thin film manufacturing method according to a first embodiment of the present invention. FIG. 2 is a diagram showing the thin film pattern 30. FIG. 3 is a diagram for explaining the irradiation position of the laser beam. FIG. 4 is a diagram showing a piezoelectric element 50 using, as an active layer, a thin film formed by the thin film manufacturing method according to the present embodiment. FIG. 5 is a diagram for explaining a first modification of the thin film manufacturing method according to the first embodiment. FIG. 6 is a view showing the thin film pattern 30 formed on the first main surface 40 a of the electrode layer 40. FIG. 7 is a diagram for explaining a fourth modification of the first embodiment. FIG. 8 is a diagram for explaining the thin film manufacturing method according to the second embodiment. FIG. 9 is a diagram illustrating a first modification of the second embodiment. FIG. 10 is a diagram for explaining the thin film manufacturing method according to the third embodiment.

  Exemplary embodiments of a thin film manufacturing method and a thin film element according to the present invention will be explained below in detail with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a diagram for explaining a thin film manufacturing method according to a first embodiment of the present invention. In the present embodiment, a thin film manufacturing method for a thin film used for a piezoelectric element will be described as an example. As shown in FIG. 1, a holding table 11 is installed in a reaction vessel 10, and a substrate 20 on which a thin film is formed is arranged on the holding table 11. The reaction vessel 10 is filled with a metal oxide precursor solution 12. The light source 13 is installed above the substrate 20, that is, on the first main surface 20 a side of the substrate 20. The light source 13 emits laser light from above the metal oxide precursor solution 12.

  Thereby, as shown in FIG. 2, the metal oxide amorphous or metal oxide crystal obtained from the metal oxide precursor at a position on the first main surface 20a of the substrate 20 according to the irradiation position of the laser beam. A thin film pattern 30, that is, a metal oxide thin film is formed. The light source 13 can irradiate a laser beam at a position corresponding to each position on the first main surface 20 a of the substrate 20. Thereby, the thin film pattern 30 can be formed at a desired position on the first main surface 20a of the substrate 20. In addition, as the light irradiated to the board | substrate 20, what is necessary is just to select the light of an appropriate wavelength for thin film formation according to the metal oxide precursor solution 12, and it is not limited to a laser beam.

As shown in FIG. 3, the irradiation position of the laser beam from the light source 13 includes the surface 12a of the metal oxide precursor solution 12, the solution 12b of the metal oxide precursor solution 12, and the first main surface 20a of the substrate 20. In addition, there are five ways of the inside 20c of the substrate 20 and the second main surface 20b which is the back surface of the first main surface 20a of the substrate 20. By adjusting the focal point of the laser beam, light irradiation is performed on each irradiation position. In addition, when the metal oxide precursor solution 12 is used as the irradiation position, the first main surface 20a of the substrate 20 does not cause a deviation between the irradiation position and the position where the thin film on the first main surface 20a is formed. The substrate 20 is arranged so that the position of the metal oxide precursor solution 12 is relatively shallow. Table 1 shows each irradiation position and its effect.

  In Case A, the water surface of the metal oxide precursor solution 12 is set as an irradiation position, that is, a heating position. In this case, the light energy is absorbed by several tens of percent in the metal oxide precursor solution 12, and the remainder reaches the substrate 20 and is absorbed or transmitted. The solution reaction form is direct heating of the solution. In Case B, the metal oxide precursor solution 12 is heated. The light energy in this case is absorbed in the metal oxide precursor solution 12. The solution reaction form is direct heating.

  In Case C, the boundary surface between the metal oxide precursor solution 12 and the substrate 20, that is, the first main surface 20a of the substrate 20 is set as the heating position. In case D, the inside 20c of the substrate 20 is the heating position. In case E, the 2nd main surface 20b of the board | substrate 20 is made into a heating position. In cases C, D, and E, most of the light energy passes through the metal oxide precursor solution 12 and is absorbed by several percent in the substrate 20. The solution reaction mode of cases C, D, and E is indirect heating of the metal oxide precursor solution 12 by heating the substrate 20. In the case of direct heating, light having a wavelength of 400 nm or less is irradiated, and in the case of indirect heating, light having a wavelength of 400 nm or more is irradiated.

  For thin film formation (a) with less impurities, direct heating cases A and B are excellent. In cases A and B, the light energy can directly break the bond between carbon and oxygen in the metal oxide precursor solution 12. For this reason, residual carbon and soot are hardly generated. Therefore, a high-quality thin film free from impurities can be manufactured. On the other hand, in cases C, D, and E, incomplete thermal decomposition of the metal oxide precursor solution 12 easily occurs due to indirect heating. For this reason, the generation of residual carbon and soot becomes a problem.

  Cases A and B are also excellent in damage (b) to the substrate 20. In cases A and B, since light energy hardly reaches the substrate 20, damage to the substrate 20 can be kept low. On the other hand, in cases C, D, and E, since the substrate 20 is heated, the substrate 20 may be thermally damaged.

  Cases C, D, and E are excellent for the adhesion (c) of the substrate thin film. In cases C, D, and E, the phase of the solution is changed in the vicinity of the first main surface 20a of the substrate 20, so that the adhesion between the substrate 20 and the thin film can be enhanced. On the other hand, in cases A and B, the phase change is performed at the surface 12a of the metal oxide precursor solution 12 or 12b in the solution of the metal oxide precursor solution 12, so that the adhesion between the substrate 20 and the thin film is relatively low. .

  Cases A and B are excellent for high-precision and high-resolution patterning (d). In cases A and B, high-precision and high-resolution patterning according to the light energy spot diameter is possible. On the other hand, cases C, D, and E are inferior to cases A and B because the heating region may be larger than the light energy spot diameter due to the thermal characteristics of substrate 20.

In all cases, the selectivity (e) of the substrate material is excellent. As the substrate 20, for example, a silicon substrate can be used. As for the light source (f), in cases A and B, the irradiated light has a wavelength as low as 400 nm or less, and it is necessary to use an expensive and highly difficult apparatus such as a UV laser. On the other hand, since the light irradiated in cases C, D, and E has a long wavelength of 400 nm or longer, it is relatively inexpensive, such as a CO ₂ laser, and a device that has generally been used for processing is generally used. Can do.

  The steps other than immersing the substrate in the metal oxide precursor solution are the same as those in the conventional sol-gel thin film formation process, and the metal oxide precursor solution is also attached to the substrate in the sol-gel method. This is the same as the metal oxide precursor solution.

  After the thin film is formed in the metal oxide precursor solution 12, when the substrate 20 is taken out of the metal oxide precursor solution 12, ultrasonic cleaning or rinsing cleaning with a solvent is performed. As the solvent, a solvent which is relatively volatile and has a small amount of water in the liquid is preferable. Specifically, acetone, ethanol, IPA, or the like can be used. As a result, the metal alkoxide in the metal oxide precursor solution 12 can be prevented from remaining on the substrate.

  Further, after the cleaning, heat treatment is appropriately performed depending on the state of the formed thin film (mainly the difference in crystal form). When the thin film is a crystal, a heating step of 3 to 10 minutes is performed at a temperature that does not change the crystal form in the sense of drying. The heating temperature is, for example, about 100 to 150 ° C. The atmosphere is usually an air atmosphere. However, an appropriate atmosphere is used as appropriate depending on the properties of the thin film. For example, when the thin film has deliquescence, an inert gas atmosphere with little residual moisture is used. In addition, when the thin film is amorphous, some materials, such as a piezo material, do not exhibit a function unless they are crystallized. In the case of such a material, a heating step for crystallization is performed. Although the heating temperature and time depend on the material, in the case of PZT, the heating is generally performed at 600 to 800 ° C. for 1 to 10 minutes.

  Specifically, as the metal oxide precursor, a substance capable of forming a metal oxide thin film, that is, a substance capable of forming a metal oxide amorphous or metal oxide crystal can be used. Specific examples include metal alkoxides, β-diketonate complexes, metal complexes such as metal chelates, and metal carboxylic acid salts. As the solvent, an ethanol-based organic solvent can be used.

Examples of the metal alkoxide include Si, Ge, Ga, As, Sb, Bi, V, Na, Ba, Sr, Ca, La, Ti, Ta, Zr, Cu, Fe, W, Co, Mg, Zn, Ni, and Nb. , Pb, Li, K, Sn, Al, Sm, and other metal alkoxides. Furthermore, a metal alkoxide having an alkoxyl group such as OCH ₃ , OC ₂ H ₅ , OC ₃ H ₇ , OC ₄ H ₉ , OC ₂ H ₄ OCH ₃ can be used.

  As the β-diketonate complex, for example, metal and acetylacetone, benzoylacetone, benzoyltrifluoroacetone, benzoyldifluoroacetone, benzoylfluoroacetone, or the like can be used.

  Examples of the metal carboxylate include barium acetate, copper (II) acetate, lithium acetate, magnesium acetate, lead acetate, barium oxalate, calcium oxalate, copper (II) oxalate, magnesium oxalate, and tin oxalate ( II) and the like can be used. As the solvent, an alcohol-based organic solvent can be used. The concentration of the solution is desirably 0.1 to 1 mol / l, and more desirably 0.3 to 0.7 mol / l. The upper limit of the concentration is a value defined from the viewpoint of liquid stability. The lower limit of the concentration is a value defined by the deposition rate of the thin film.

  In the present embodiment, since the laser beam is irradiated with the substrate 20 immersed in the metal oxide precursor solution 12, a thin film is formed only on the portion irradiated with the laser beam. Accordingly, it is possible to eliminate the process of attaching and drying the metal oxide precursor solution and the process of dry etching or wet etching for removing the metal oxide precursor in the conventional sol-gel method. These processes are very costly processes, and in the thin film manufacturing method according to the present embodiment, by eliminating these processes, a significant cost reduction can be realized.

  Furthermore, since the film formation reaction is performed in the metal oxide precursor solution 12, the metal oxide precursor solution 12 is always supplied during the film formation reaction, and cracks are hardly generated in the thin film.

  The thin film formed by the thin film manufacturing method according to the present embodiment can be used for, for example, an ultrasonic piezoelectric element, a nonvolatile memory element, and an actuator element. The actuator element is used for a recording head of an ink jet printer, for example.

  FIG. 4 is a diagram showing a piezoelectric element 50 using, as an active layer, a thin film formed by the thin film manufacturing method according to the present embodiment. The piezoelectric element 50 includes a piezoelectric film 51, a first electrode 52 formed on the first main surface 51a of the piezoelectric film 51, and a second electrode formed on the second main surface 51b of the piezoelectric film 51. 53. The piezoelectric film 51 is a thin film formed by a thin film manufacturing method. The first electrode 52 and the second electrode 53 are made of a conductive material such as platinum (Pt), lanthanum nickel oxide, strontium ruthenium oxide, or the like having high light transmittance. The first electrode 52 and the second electrode 53 can be formed by, for example, a sputtering method or a vacuum evaporation method.

  FIG. 5 is a diagram for explaining a first modification of the thin film manufacturing method according to the first embodiment. In the thin film manufacturing method according to the first modification, the substrate 20 having the electrode layer 40 already formed on the first main surface 20a is used. The electrode layer 40 is made of a conductive material and is formed by a sputtering method or the like. The electrode layer 40 may be laminated on the substrate 20 in a patterned state.

  By immersing the substrate 20 on which the electrode layer 40 is formed in the metal oxide precursor solution 12, the thin film pattern 30 is formed on the first main surface 40a of the electrode layer 40 as shown in FIG. The other steps are the same as those of the thin film manufacturing method according to the first embodiment. In addition, the effects of light irradiation on each irradiation position described with reference to Table 1 are the same as in the case where the electrode layer 40 is not laminated. In case C, the first main surface 40a of the electrode layer 40 is irradiated with laser light instead of irradiating the first main surface 20a.

As a second modification, the substrate 20 is provided with a light absorption layer that absorbs laser light of a specific wavelength irradiated from the light source 13 on the first main surface 20a of the substrate 20 instead of the electrode layer 40. May be used. Moreover, the light absorption layer may be laminated | stacked on the board | substrate 20 in the patterned state. As the light absorption layer, depending on the wavelength of the laser light, for example, metal oxides such as SiO ₂ , SiN, TiO ₂ , SiC, nitrides, and carbides can be used.

  By immersing the substrate 20 on which the light absorption layer is formed in the metal oxide precursor solution 12, a thin film pattern is formed on the first main surface of the light absorption layer. The other steps are the same as those for forming a thin film on the first main surface 40a of the electrode layer 40. By providing the light absorption layer, the light absorption rate of the substrate 20 can be improved, and more energy can be absorbed.

As a third modification, the electrode layer 40 described in the first modification may also serve as a light absorption layer. As the electrode layer 40 that also serves as the light absorption layer, a material that also functions as an electrode, that is, an oxide electrode such as LaNiO ₃ , SrRuO ₃ , or ITO can be used. In addition, in the formation of a conductive film using a lanthanum nickel oxide solution by, for example, the CSD method, a conductive film that also serves as a light absorption layer by mixing a material that increases the light absorption rate, such as a dye, into the metal oxide precursor solution 12 Can be formed.

  Further, as a fourth modification, as shown in FIG. 7, the substrate 20 is made of the metal oxide precursor solution 12 in a state where the light reflecting layer 60 is formed on the second main surface 20 b that is the back surface of the substrate 20. You may soak in. Thereby, since the light reflected by the light reflection layer 60 is incident on the substrate 20 again, the film formation reaction can be promoted. The light reflecting layer 60 can be made of metal such as Au, Ag, Al, Pt, etc., depending on the wavelength of the laser light to be used.

  Further, as the fifth modification example, in this embodiment, an example of forming a thin film used as a piezoelectric element has been described. However, the type of thin film to be formed is not limited to the embodiment. Various thin films can be formed by the above thin film manufacturing method. In manufacturing the thin film, the substrate may be immersed in a raw material solution that is a raw material of each thin film, and the raw material solution and the material of the substrate are not limited to the embodiment.

  As an example of the thin film manufactured by the thin film manufacturing method according to the present embodiment, a thin film having translucency and an electro-optical effect can be given. A thin film having translucency and an electro-optic effect can be used for an optical waveguide, an optical switch, a spatial modulation element, an image memory, and the like.

(Second Embodiment)
FIG. 8 is a diagram for explaining the thin film manufacturing method according to the second embodiment. As shown in FIG. 8, in the present embodiment, the light source 13 is disposed on the second main surface 20b side of the substrate 20, and irradiates laser light from the second main surface 20b side. In this case as well, a thin film is formed on the first major surface 20a by heating the metal oxide precursor solution 12 or the substrate 20 as in the thin film manufacturing method according to the first embodiment. The substrate 20, the holding table 11, and the reaction vessel 10 are made of a material that transmits light from the light source 13.

There are five possible irradiation positions of the laser light from the light source 13 as described with reference to FIG. 3 in the first embodiment. Table 2 shows each irradiation position and its effect.

  In cases F, G, and H, light energy passes through the substrate 20 and is absorbed by the metal oxide precursor solution 12. The solution reaction form is direct heating. In cases I and J, light energy is absorbed by the substrate 20. The solution reaction form is indirect heating. In this case as well, as in the first embodiment, in the case of direct heating, light with a wavelength of 400 nm or less is irradiated, and in the indirect case, light with a wavelength of 400 nm or more is irradiated. .

  For thin film formation (a) with less impurities, direct heating cases F, G, and H are excellent. However, in the case H, before reaching the first main surface 20a of the substrate 20, a part of the laser light may be absorbed by the metal oxide precursor solution 12, thereby generating impurities. This is inferior to cases F and G.

  Regarding the damage (b) to the substrate 20, in cases F, G, and H, when the laser light passes through the substrate 20, a part of the light energy is converted into thermal energy, which may cause damage to the substrate 20. is there. For this reason, although inferior to cases A and B described in the first embodiment, it is superior to cases I and J.

  Regarding the adhesion (c) of the substrate thin film, cases H, I, and J in which the phase is changed near the interface of the substrate 20 are excellent. For high-precision and high-resolution patterns (d), direct heating cases F, G, and H are excellent. The substrate material selectivity (e) is excellent in cases I and J where the substrate 20 is heated, but inferior in cases F, G and H. This is because the light energy needs to pass through the substrate 20 and the selectivity of the substrate material becomes low.

  Regarding the light source (f), Cases F, G, and H require expensive and difficult-to-handle devices with low wavelengths, whereas Cases I and J are relatively inexpensive and generally used for processing. A high-wavelength device with a track record of use can be used.

  The other steps of the thin film manufacturing method according to the second embodiment are the same as those of the thin film manufacturing method according to the first embodiment. Further, it goes without saying that a substrate on which an electrode layer and a light absorption layer are stacked may be used as in the first embodiment.

  FIG. 9 is a diagram illustrating a first modification of the second embodiment. In this example, the substrate 20 is disposed on the metal oxide precursor solution 12. The substrate 20 is placed so that the first main surface 20 a faces the bottom surface of the reaction vessel 12 and is in contact with the metal oxide precursor solution 12. The second major surface 20 b is located on the metal oxide precursor solution 12. The substrate 20 is made of a material that transmits light from the light source 13. Further, the substrate 20 is fixed on the metal oxide precursor solution 12 by the fixing member 15.

  The light source 13 is arrange | positioned at the 2nd main surface 20b side, and irradiates a laser beam from the 2nd main surface 20b side. Thereby, the light irradiation to the five irradiation positions shown in FIG. 3 from the second main surface 20b side can be performed.

  As described above, in the first embodiment and the second embodiment, the cases A to J in which the irradiation direction and the irradiation position of the laser beam are different have been described, but the circle in the table is one point and the triangle is 0.5 point. Each case can also be evaluated based on the total score of the evaluation of each item (af), with a cross of 0. Furthermore, after giving a weight to the item to be regarded as important, a total score of each item may be calculated, and thereby each case may be evaluated.

(Third embodiment)
In the third embodiment, a damper 16 is installed on the inner wall surface of the reaction vessel 10 as shown in FIG. The damper 16 is provided on the entire inner wall surface of the reaction vessel 10. As the damper 16, for example, a porous member such as a sponge can be used. Further, from the viewpoint of dispersing shock waves, a member having viscoelastic characteristics equivalent to that of the metal oxide precursor solution 12 can be used. Specifically, a bag made of a resin containing a solution having the same or higher viscosity can be used. The viscosity of the metal oxide precursor solution 12 is about 1-30 mPasec.

  When a wave is generated on the surface of the metal oxide precursor solution 12, the laser beam irradiated from the light source 13 is irregularly reflected, and the shape of the irradiation spot is disturbed. That is, high-definition patterning becomes difficult.

  Furthermore, the height of the metal oxide precursor solution 12 locally changes due to the generation of waves. For this reason, there is a problem that the light transmission depth, the focal point, and the like of the light energy change, and the energy cannot be efficiently applied to the target region. Moreover, since the surface area of the metal oxide precursor solution 12 is increased due to the generation of waves, the evaporation rate of the metal oxide precursor solution 12 is increased. As a result, the physical properties (particularly the viscosity) of the metal oxide precursor solution 12 change, and the film formation characteristics also change.

  On the other hand, since the wave can be canceled by providing the damper 16 on the wall surface of the reaction vessel 10 as in the present embodiment, a high-quality thin film can be manufactured.

  The remaining steps of the thin film manufacturing method according to the third embodiment are the same as those of the thin film manufacturing method according to the other embodiments.

  As another example, the damper 16 is made of a highly rigid material such as aluminum, detects the wave height and phase of the metal oxide precursor solution 12, and reverses based on the wave height and phase. The wave may be relaxed by driving the damper 16 with the phase.

DESCRIPTION OF SYMBOLS 10 Reaction container 11 Holding stand 12 Metal oxide precursor solution 13 Light source 15 Fixing member 16 Damper 20 Substrate 30 Thin film pattern 51 Piezoelectric film 52 1st electrode 53 2nd electrode

Japanese Patent No. 4108502

Claims (16)

An arrangement step of arranging the substrate in a raw material solution of a thin film formed on the first main surface of the substrate;
And a forming step of forming the thin film on the first main surface of the substrate by irradiating light from the first main surface side.   The thin film manufacturing method according to claim 1, wherein the raw material solution is a metal oxide precursor solution, and the thin film is a metal oxide thin film.   3. The thin film manufacturing method according to claim 1, wherein, in the forming step, the light having a wavelength of 400 nm or less is irradiated from the first main surface side to the surface of the raw material solution as an irradiation position.   3. The thin film manufacturing method according to claim 1, wherein in the forming step, the light having a wavelength of 400 nm or less is irradiated from the first main surface side to the raw material solution as an irradiation position.   3. The thin film manufacturing method according to claim 1, wherein in the forming step, the light having a wavelength of 400 nm or more is irradiated from the first main surface side to the first main surface of the substrate as an irradiation position. .   3. The thin film manufacturing method according to claim 1, wherein, in the forming step, the light having a wavelength of 400 nm or more is irradiated from the first main surface side with the inside of the substrate as an irradiation position.   The said formation process irradiates the said light with a wavelength of 400 nm or more from the said 1st main surface side by making the 2nd main surface which is a back surface of the 1st main surface of the said board | substrate into an irradiation position. 2. The thin film manufacturing method according to 2. An arrangement step of arranging the substrate in a raw material solution of a thin film formed on the first main surface of the substrate;
Forming a thin film on the first main surface of the substrate by irradiating light from the second main surface side which is the back surface of the first main surface of the substrate. Production method.   The thin film manufacturing method according to claim 8, wherein the raw material solution is a metal oxide precursor solution, and the thin film is a metal oxide thin film.   10. The thin film manufacturing method according to claim 8, wherein, in the forming step, the light having a wavelength of 400 nm or less is irradiated from the second main surface side to the raw material solution surface as an irradiation position.   The thin film manufacturing method according to claim 8 or 9, wherein, in the forming step, light having a wavelength of 400 nm or less is irradiated from the second main surface side with the raw material solution as an irradiation position.   10. The thin film manufacturing method according to claim 8, wherein, in the forming step, the light having a wavelength of 400 nm or less is irradiated from the second main surface side to the first main surface of the substrate as an irradiation position. .   10. The thin film manufacturing method according to claim 8, wherein, in the forming step, light having a wavelength of 400 nm or more is irradiated from the second main surface side with the inside of the substrate as an irradiation position.   10. The thin film according to claim 8, wherein, in the forming step, the light having a wavelength of 400 nm or more is irradiated from the second main surface side to the second main surface which is the back surface of the substrate as an irradiation position. Production method.   The thin film manufacturing method according to any one of claims 1 to 14, wherein a damper that relaxes a wave generated in the raw material solution is provided on an inner wall of a reaction vessel that fills the reaction solution.   A thin film element using the thin film manufactured by the thin film manufacturing method according to any one of claims 1 to 15.

Images