JP2017034026A - Metal oxide precursor thin film patterning method, metal oxide thin film patterning method and metal oxide thin film pattern produced by that method and electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal oxide precursor thin film patterning method not requiring photolithography process or etching process in printing manufacturing technology, and to provide a metal oxide thin film patterning method, a metal oxide thin film pattern manufactured by the manufacturing method, and an electronic component including that pattern.SOLUTION: After coating a substrate with a precursor thin film for forming a metal oxide thin film, an adhesive sheet is abutted against the semi-dried precursor thin film, and then the unnecessary region is peeled off from the substrate, thus patterning a metal oxide precursor thin film. A metal oxide thin film pattern can be obtained by performing oxidation treatment, such as heating treatment, following to the patterning of the precursor thin film.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing a metal oxide precursor thin film pattern, a method for producing a metal oxide thin film pattern, and a metal oxide thin film produced by the method for obtaining a metal oxide thin film pattern used for electronic parts and the like. The present invention relates to patterns and electronic components.

  In recent years, metal oxide thin films have been used as semiconductors, insulating films, conductive films, magnetic bodies, piezoelectric bodies, ferroelectrics, etc. in general electronic components, and the productivity of these pattern layers in the manufacturing process has been improved. It is desired. For example, a semiconductor pattern layer in a thin film transistor used for a display, a memory, or the like, or a conductive film pattern layer typified by ITO (indium tin oxide) can be used.

  Conventionally, a metal oxide thin film layer is formed by sputtering or coating, and is patterned by the following method.

  In the case of a metal oxide thin film formed by sputtering, (A) a step of forming a metal oxide thin film first, a step of forming a resist mask by photolithography technology, and wet etching the region without the resist mask A patterning method comprising a step of performing, or (B) a step of forming a metal oxide thin film on a substrate on which a resist pattern has been previously formed, and a patterning method comprising a step of removing unnecessary portions by a lift-off method are performed.

  On the other hand, in the case of a metal oxide thin film formed by a coating method, it is a method of applying a film to a substrate using a solution containing a metal that is a precursor of the metal oxide thin film. Patterning is performed (see Patent Documents 1, 2, and 3). In addition, after the coating film is formed, after the film is solidified by thermal oxidation treatment or plasma oxidation treatment, a patterning method such as etching can be used similarly to the sputtering method (see Patent Document 4).

  As a technique for producing a metal oxide thin film containing zinc, indium, gallium, etc., as a technique for producing a prior art document related to the present application, after applying a solution containing a metal oxide precursor, the precursor is heated or oxidized. A technique for converting to a metal oxide semiconductor by chemical decomposition has been reported (see Patent Document 5). In the above document, patterning is exemplified by an ink jet method, a photolithographic method, laser ablation, or the like.

JP 2010-283002 A JP 2010-21333 A International Publication 2010/047177 JP 2011-79735 A JP 2010-283190 A

  A conventional patterning method using a photolithography process requires an expensive exposure apparatus and has a problem that the capital investment cost is high. Further, in the resist development and etching process, there is a problem that chemical damage to the lower layer occurs due to the solvent used. In addition, when an exposure machine is used, there is a problem that productivity is low because the sheet format must be intermittently fed.

  On the other hand, with the recent development of printing manufacturing technology, there is a need for a method that enables a continuous patterning process without intermittent stop by a roll-to-roll process.

  The present invention is intended to solve these problems, and the present invention relates to an inkjet method, a photolithographic method, a laser ablation method and an etching method for manufacturing a metal oxide thin film formed by coating. An object of the present invention is to provide a method for producing a metal oxide precursor thin film pattern and a method for producing a metal oxide thin film pattern without using a metal oxide. Another object of the present invention is to provide a metal oxide thin film pattern patterned by a novel method and an electronic component including the metal oxide thin film pattern.

  The present invention has the following features in order to achieve the above object.

  The present invention relates to a method for producing a metal oxide precursor thin film pattern, and a thin film formed by applying a solution containing a metal oxide precursor on a substrate is removed by removing a part of the evaporation component of the thin film. The thin film that has been dried and semi-dried is subjected to patterning of the thin film containing the metal oxide precursor by removing only the abutted part by separating the thin film after contacting the adhesive material. To do. For example, the semi-dried thin film preferably has a volume solid content of the metal oxide precursor of about 30% to 60%.

  The present invention relates to a method for producing a metal oxide thin film pattern, wherein the thin film containing the metal oxide precursor is patterned and then heat-treated.

  The present invention relates to a metal oxide thin film pattern, which is manufactured by the method for manufacturing a metal oxide precursor thin film pattern. The present invention relates to a metal oxide thin film pattern, which is produced by the method for producing a metal oxide thin film pattern of the present invention.

  The present invention relates to an electronic component, and includes a metal oxide thin film pattern manufactured by the method for manufacturing a metal oxide precursor thin film pattern. The present invention relates to an electronic component, and includes the metal oxide thin film pattern manufactured by the metal oxide thin film pattern manufacturing method of the present invention.

  According to the present invention, since the patterning can be realized by peeling the coating film using an adhesive material, a conventional expensive apparatus is not required and can be performed by a simple process. That is, since it is not necessary to perform a conventional lithography process or etching process, the present invention is an inexpensive and resource-saving patterning method.

  Furthermore, in the conventional resist development process, resist removal process, etching process, and the like, chemical damage occurs to the lower layer of the coating film and the surrounding layers. According to the method of the present invention, the manufactured metal Does not cause damage to the function of the oxide thin film and the function of the lower layer and the peripheral layer. In the patterning method of the present invention, it is possible to avoid contact between the solvent and, for example, the lower oxide semiconductor layer. Therefore, it has the desired characteristic which was excellent as the whole product provided with a metal oxide thin film pattern. For example, when applied to an electronic component, it was possible to obtain excellent evaluation of semiconductor characteristics as a whole laminated structure including a metal oxide thin film.

  According to the present invention, patterning is realized by peeling off the coating film using an adhesive material in an intermediate step in the conventional manufacturing process of the coating film, so that shortening of the manufacturing process can be appropriately realized. The present invention can be easily applied to a continuous patterning method adapted to a roll-to-roll process. For example, if a roll having an adhesive material on the surface is brought into contact with a semi-dried coating film and removed while rotating the roll, patterning can be completed, so that continuous production can be performed without waiting time.

  In the present invention, since the film thickness is first uniformly formed on the substrate to be coated, and then only unnecessary portions are removed, the cross-sectional rectangularity of the patterned thin film is high. This is advantageous for the coffee ring phenomenon and the problem of curved film shape after solidification, which are often problems in the ink jet method.

  In addition, according to the present invention, since the coating solution can be composed only of the metal oxide precursor and the solvent, an additive that can reduce the functionality of the metal oxide thin film, such as a surfactant or a fine particle dispersant. In this case, a higher-purity metal oxide film pattern can be obtained.

  Further, the present invention has revealed that peeling from the base material of the coating film by the adhesive material is possible for the first time during the drying of the coating film. On the other hand, for example, in the case of a film formed by sputtering, the sputtered film is firmly adhered to the substrate, and the cohesive force of the film itself is large, so partial removal with an adhesive is impossible. The method of the present application is an effective and effective method for a metal oxide precursor formed by a coating method.

  According to the present invention, the method for producing the pattern of the metal oxide precursor thin film is characterized and effective in the technique for producing the pattern of the metal oxide thin film. By using other electronic materials and other functional metal oxides that require a thin film pattern, it is possible to realize a film having desired characteristics according to the application.

It is a schematic diagram explaining the manufacturing method of embodiment of this invention. It is a figure explaining the volume solid content rate in a semi-dry state of an embodiment of the invention. It is a microscope picture figure of the pattern of the metal oxide precursor thin film of Example 1 of this invention. It is a microscope picture figure of the pattern of the metal oxide precursor thin film of the comparative example 1 of this invention.

  Embodiments of the present invention will be described below.

  The present inventors formed a thin film on a substrate by a coating method such as spin coating or slit coating using a solution containing a metal as a precursor of the metal oxide thin film, and then evaporated the thin film. At the stage where a part of the components is removed, selective removal is realized in which only the region where the adhesive material is in contact is removed. Here, the step of removing a part of the evaporation components contained in the thin film refers to a step in which the thin film is semi-dried (also referred to as “semi-dry”), for example, the metal oxide precursor. This is a stage before the thin film is fixed to the substrate by drying, or a stage before the thin film itself is solidified and toughened. In this invention, the predetermined area | region of the coating film of a semi-dry state is peeled off from a base material by contact | abutting and peeling of an adhesive sheet. The predetermined region corresponds to a region other than the target metal oxide thin film pattern and is a removal pattern region (also referred to as a non-pattern region).

The patterning process of the embodiment of the present invention will be described with reference to FIG.
(1) [Coating process] The thin film 2 is formed on the substrate 1 by a coating method such as spin coating or slit coating, using a solution containing a metal that is a precursor of the metal oxide thin film. This thin film is called a metal oxide precursor thin film.
(2) [Partial evaporation component removing step or semi-drying step] Part of the evaporation component contained in the thin film formed by coating is removed. The film from which part of the evaporation component has been removed is referred to as a semi-dried metal oxide precursor thin film 3. The said process can be implemented by heating, pressure reduction, or normal temperature standing.
(3) [Adhesive material attaching step] At the stage where a part of the evaporated components contained in the thin film is removed, the adhesive material 4 is brought into contact with and adhered to a predetermined region.
(4) [Selective peeling / removing step] The metal oxide which has been semi-dried by applying a force to separate it from the base material by the pressure-sensitive adhesive material in contact with a part of the evaporated component contained in the thin film. Only the region of the precursor thin film 3 to which the adhesive material 4 is attached is peeled off from the substrate 1 and removed.

  After the step (4), the semi-dried metal oxide precursor thin film 3 on the substrate 1 can be oxidized by heat treatment such as baking to obtain a metal oxide thin film pattern.

[Metal oxide thin film]
As the metal oxide thin film in this embodiment, for example, a thin film of an electronic material such as a semiconductor thin film, a conductor thin film, an insulator thin film, a dielectric thin film, a magnetic thin film, a piezoelectric thin film, and a ferroelectric thin film, and a thin film pattern are required. And other functional metal oxide thin films. The metal oxide thin film can be implemented by appropriately selecting the type and ratio of metal atoms. In examples described later, examples of oxide semiconductors (oxides containing In, Ga, and Zn metal elements (hereinafter also referred to as IGZO)), ferroelectrics (BiFeO ₃ ), oxide insulating films (Al ₂ O ₃ ) However, patterning can also be performed on other metal oxide precursors in the same manner. For example, as a metal oxide thin film, an oxide conductor and an oxide semiconductor (SrRuO ₃ , ZnO, TiO ₂ , SnO ₂ , In ₂ O ₃ , SrTiO ₃ ), an insulator (SiO ₂ , ZrO ₂ , Y ₂ O ₃ , La ₂ O ₃ , LaTiO ₃ , HfO ₂ ), ferroelectric (PbBaO ₃ , BaTiO ₃ , Sr ₂ TaO ₇ , Sr ₂ Nb ₂ O ₇ , La ₂ Ti ₂ O ₇ , CdTiO ₃ , Bi ₂ WO ₆ ), etc. Is mentioned.

[Solution containing a metal to be a precursor of a metal oxide thin film]
The solution containing a metal to be a precursor of a metal oxide thin film described in the embodiment of the present invention refers to a solution in which a metal compound is dissolved before the metal oxide is generated by oxidation treatment, and is specifically Refers to a metal salt containing a metal cation constituting a metal oxide thin film dissolved in a solvent or an organometallic compound containing an alkoxy group dissolved in a solvent.

  The metal that is the precursor of the metal oxide thin film is Li, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Rb, Sr, Y, Zr, Nb, Mo, Cd, In, Ir, Sn, Sb, Cs, Ba, La, Hf, Ta, W, Tl, Pb, Bi, and the like.

  In the present invention, oxygen and metal are combined by oxidation treatment to form a precursor (or a metal oxide precursor) before the “metal-oxygen” bond is continuously formed, and oxidized to a metal oxide. A material in which is formed is called a metal oxide.

  Examples of the metal salt used as the precursor include nitrate, sulfate, phosphate, carbonate, acetate, oxalate, and halogen salt. Examples of the halogen salt include chloride, iodide, bromide and the like.

  Examples of the alkoxy group used in the organometallic compound used as the precursor include a methoxy group, an ethoxy group, a propyl group, and an isopropyl group.

  The solvent used for the precursor containing the metal salt is not particularly limited as long as it dissolves the metal salt. Examples thereof include water, methanol, ethanol, 2-methoxyethanol, fluoromethanol, trifluoromethanol, 2-fluoroethanol, and trifluoroethanol. The said solvent used for the precursor containing a metal salt may be used with a mixed solvent, or may be used with a single solvent. Moreover, in order to improve the solubility of a metal salt, nitric acid etc. may be added. Further, ethanolamine having a higher coordinating power may be added as a stabilizer for the solution. When it is desired to reduce the drying rate, a solvent having a boiling point higher than that of the main solvent, such as ethylene glycol or glycerin, may be added.

  The solvent used for the precursor containing the organometallic compound is not particularly limited as long as it dissolves the organometallic compound without dissolving water. Examples include dehydrated alcohol, xylene, hexane, and toluene.

  The solvent used for the solution containing the metal that is the precursor of the metal oxide thin film preferably has a low evaporation rate. The metal salt is preferably one that exhibits deliquescence. The solute concentration is not particularly limited, and may be adjusted according to a desired film thickness.

[Base material]
In the present embodiment, a base material (also referred to as a substrate to be coated) on which a thin film is applied may be any material that can be applied without repelling the precursor solution. For example, a silicon wafer or glass can be used. A film-like flexible substrate may be used.

  In addition, since the precursor solution needs to form a uniform film on the substrate to be coated by application such as spin coating, the surface of the substrate to be coated is subjected to plasma treatment, ultraviolet irradiation treatment, ozone treatment, piranha. It is desirable to make it hydrophilic by washing, nitric acid washing or the like.

[Coating process]
In the embodiment of the present invention, a solution containing a metal to be a precursor of a metal oxide thin film is applied to a substrate by a known application method. There is no restriction | limiting in particular in the application method. Examples of suitable coating methods for forming a thin film include spin coating and slit coating.

[Steps in which some of the evaporation components contained in the thin film have been removed]
In the embodiment of the present invention, the vaporized component contained in the thin film as in the stage before the metal oxide precursor coating film is fixed to the substrate by drying, or before the coating film itself is solidified and toughened. When a part of the sheet is removed, if a sheet having an adhesive material on one side is attached to the coating film and peeled off, the coating film adheres to the sheet side, and the coating film peels from the substrate. The coating film can be peeled off from the substrate together with the film at the above-described stage. Is larger than the cohesive force

  When a sheet having an adhesive material on one side is attached to a thin film and peeled off, the boundary between the area where the thin film peels from the base material (non-pattern area) and the area where the base material remains as it is (pattern area) is Since it becomes a side part or an end part of the pattern region, it is desired that the cross-sectional rectangularity of the pattern is high and the side wall of the thin film is not rough. For example, when the drying is insufficient, the pattern area flows after the pattern area is formed, and the rectangularity deteriorates. On the other hand, if the thin film itself is solidified and toughened, the cohesive force inside the thin film and the adhesive force at the interface between the thin film and the substrate to be coated increase, and the non-pattern region cannot be formed satisfactorily. For this reason, it is important to peel off and pattern a part of the thin film using the adhesive material as described above at the stage where only a part of the evaporation component contained in the thin film is removed. As can be seen from the results of Examples to be described later, according to the present application, the pattern has a rectangular cross-section and the thin film sidewall is not rough.

  The film thickness at the stage where a part of the evaporated components contained in the thin film is removed may be adjusted according to the desired film thickness, but is preferably about 200 nm or less.

  In the present embodiment, the state of “semi-drying” is a state in which a part of the evaporation component contained in the coating film is removed, and as a result, the state of the ratio of the solvent component of the thin film is reduced, And it is not completely dry.

  When the ratio of solids in the coating film is expressed by the following formula of volume solid content, the semi-dry precursor thin film of the present invention is in a state of about 30% to 60% by volume solid content. Is preferred.

(Formula) Volume solid content ratio = (T / t) × 100 [%]

  In the equation, T is the thickness of the coating film from which the evaporation component has been removed, and t is the thickness of the coating film in a semi-dried state. Here, the thickness of the coating film from which the evaporation component has been removed is the thickness of the coating film from which the evaporation component has been completely removed. Experimentally, the thickness is equal to or higher than the boiling point of the solvent for 10 minutes at a temperature at which the oxidation reaction does not proceed. It is the thickness of the heated film.

  The drying characteristics of the coated thin film are affected by the saturated vapor pressure of the solution, the latent heat of the solvent, the boiling point of the solvent, the pressure of the surrounding environment, the solvent vapor pressure of the surrounding environment, and the heating temperature. Furthermore, in the case of a precursor thin film made of a metal salt, the drying rate of the salt becomes higher as the salt has a higher hydration power and deliquescence. Therefore, for example, when the drying speed of the coated thin film is fast and it is difficult to maintain the semi-dried state necessary for patterning, the ambient temperature is increased to a high-humidity environment, a high-boiling solvent is used, and the heating temperature is set to By taking measures such as lowering, the time for maintaining the semi-dried state can be lengthened.

  Whether or not patterning is possible depends on the brittleness of the film and the film thickness (solid content ratio), and cannot be generally limited. However, the adhesive material described later (adhesive strength of stainless steel to 1.8 N / 10 mm), the film thickness during semi-drying is desirably about 200 nm or less, and the solid content during semi-drying is desirably between 30% and 60% as described above.

[Adhesive]
In the present embodiment, an adhesive material, for example, an adhesive material on an adhesive material sheet, has only to have an adhesive force between the adhesive material and the thin film larger than an adhesive force between the thin film and the substrate to be coated. In Examples described later, a commercially available adhesive tape in which an acrylic adhesive is provided on a special polypropylene film was used. For example, the adhesive strength is preferably about 1.8 N / 10 mm or more with respect to stainless steel.

  As an adhesive material to be used, the following structure can be used. For example, a structure in which an adhesive material is applied only to a portion corresponding to the removal pattern, a structure in which a portion corresponding to the removal pattern is formed into a convex shape, and an adhesive layer is formed only on the convex portion, a substrate surface A structure in which an adhesive material is applied to the whole, an opening is provided in a non-removed portion, a structure in which an adhesive material is applied to the entire surface of the substrate, and a substrate corresponding to non-removal is cut and removed Examples thereof include a structure in which an adhesive material is applied to the entire surface of the body and the substrate, and a non-adhesive mask is provided in a non-removed portion.

[Oxidation treatment]
After the semi-dried metal oxide precursor thin film on the substrate is completely dried, the patterned precursor is transformed into an oxide by an oxidation treatment to produce a metal oxide thin film. The oxidation treatment can be carried out under the same conditions as those in the heat treatment step such as firing in the case of producing a metal oxide thin film from a coating film in the general prior art. The heat treatment temperature varies depending on the type of metal oxide precursor, the type of metal oxide, and the like, but can be performed at a temperature of about 300 to 1000 ° C. as shown in the following embodiment.

  In addition, when heat treatment is not required, for example, when using a metal oxide precursor thin film made of an organometallic compound using alkoxide, the oxidation treatment is completed by exposure to water vapor or a gas containing water vapor, for example. Can do.

(First embodiment)
In the embodiment of the present invention, a case where the metal oxide thin film is an oxide semiconductor will be described as an example. A solution having a metal oxide precursor containing indium, gallium, and zinc is prepared, applied to a substrate, and then a pressure-sensitive adhesive tape is brought into contact with a predetermined region of the semi-dried metal oxide precursor thin film. Patterning is performed by peeling (see FIG. 1). Then, the metal oxide precursor thin film (IGZO precursor thin film (referred to as a thin film before oxidation to obtain IGZO)) is heat-treated to form a pattern of the metal oxide thin film (IGZO thin film). Get.

  Next, specific Example 1 will be described. Various conditions of the semi-drying process were changed, and the results of selective peeling and removal using an adhesive tape were examined.

  Indium nitrate, gallium nitrate, and zinc nitrate are dissolved in a mixed solvent of water and trifluoroethanol (volume ratio 3: 7) at 67: 3: 30 (mol ratio), and a metal that is a precursor of the metal oxide thin film is dissolved. A containing solution was prepared. The salt concentration after preparation of the solution was 0.1 mol / l. This solution was spin-coated on a cleaned 300 nm silicon wafer with a thermal oxide film. The spin condition was 2000 rpm for 30 seconds. After that, the silicon wafer coated with the precursor solution is stopped on a hot plate through a glass plate having a thickness of 1.2 mm, heated at a predetermined temperature described later for a predetermined time, and an adhesive tape (Scotch (registered trademark)). A transparent adhesive tape (transparent color (registered trademark) (manufactured by 3M)) was brought into contact with the metal oxide precursor thin film, and was peeled off to perform patterning (see FIG. 1). The temperature of the hot plate was set at three levels of 40 ° C., 50 ° C., and 70 ° C., and the heating time was changed from 20 seconds to 180 seconds. The atmospheric environment was an air temperature of 25 ° C. and a relative humidity of 40%. The results were as follows.

  In the case of heating at 40 ° C., when the heating time was between 60 seconds and 180 seconds, all of the IGZO film at the contact portion was transferred to the adhesive tape side, and no remaining film was left. In the case of heating at 50 ° C., when the heating time was between 25 seconds and 90 seconds, all of the IGZO film at the contact portion was transferred to the adhesive tape side, and no remaining film was left. In the case of heating at 70 ° C., when the heating time was between 20 seconds and 30 seconds, all of the IGZO film at the contact portion was transferred to the adhesive tape side, and no remaining film was left.

  The film thickness after this patterning and the film thickness after heating at 130 ° C. for 10 minutes were measured using a scanning probe microscope. As a result, as an example, in the case of heating at 40 ° C., the average film thickness was 57 nm under the condition of the heating time of 60 seconds, the average film thickness was 49 nm under the condition of 120 seconds, and the average film thickness was 40 nm under the condition of 180 seconds. The average film thickness after heating at 130 ° C. for 10 minutes was 20 nm. Thus, it can be seen that the drying progresses because the heating time increases and the film thickness decreases.

  FIG. 2 shows a precursor in a semi-dry state calculated from a ratio of [film thickness of precursor thin film after heating at 130 ° C. for 10 minutes] T and [film thickness of precursor thin film in a semi-dry state immediately after patterning] t. The volume solid content rate of a thin film is shown. When the representative points shown in FIG. 2 are indicated by numerical values, in the case of heating at 40 ° C., the volume solid content rate is 35% (pre-bake time 60 seconds) to 50% (pre-bake rate). In the case of heating at 50 ° C. for a time of 180 seconds), the volume solid content is from 33% (pre-bake time of 25 seconds) to 51% of the volume solid content (pre-bake time of 90 seconds), and in the case of heating at 70 ° C. The volume solid content rate was 39% (pre-bake time 20 seconds) to 51% (pre-bake time 30 seconds). As shown in FIG. 2, it can be seen that the patterning according to this embodiment is effective in a dry state of about 30% to 60%, preferably 33% to 51%, regardless of the heating temperature.

  Using a peel tester (VPA-3, Kyowa Interface Science Co., Ltd.), an IGZO precursor thin film that was heat-dried at 40 ° C. for 60 seconds, using the adhesive tape, a peel angle of 90 °, a peel rate When the peel test was performed under the condition of 500 mm / min, the peel was successfully completed, and the peel force at that time was 0.056 N / 10 mm.

  FIG. 3 shows a photomicrograph when the IGZO precursor thin film that has been heat-dried at 40 ° C. for 180 seconds is patterned using the adhesive tape. The left side of the figure is the pattern of the IGZO precursor thin film, and the right side is a region (non-pattern region, removal pattern region) peeled off by the adhesive material. From the figure, it can be seen that the cross-sectional rectangularity of the pattern is high and the thin film sidewall is not rough. In addition, the horizontal length of the white box (scale bar) in the drawing is 50 μm.

Next, the semiconductor characteristics were evaluated. A chamber coated with a metal oxide precursor solution is patterned at a temperature of 50 ° C. for 30 seconds and then baked at 130 ° C. for 10 minutes. Immediately thereafter, the chamber is placed in an air atmosphere with a relative humidity of 90% to 100%. Then, the mixture was irradiated with ultraviolet rays for 30 minutes using a low-pressure mercury lamp (peak wavelengths: 185 nm and 254 nm). Thereafter, baking was performed at 300 ° C. for 1 hour to complete film formation (IGZO film). On the fired IGZO film, source and drain electrodes made of aluminum having a thickness of 100 nm were formed by vapor deposition through a metal mask, and semiconductor characteristics were evaluated. As a result, an IGZO pattern film showing good semiconductor characteristics with a mobility of 2.5 cm ² / Vs was obtained.

  Next, Comparative Example 1 will be described. For the substrate coated with the metal oxide precursor solution in the same manner as in Example 1, the hot plate temperature was set to three levels of 40 ° C., 50 ° C., and 70 ° C., and the heating time was changed from 20 seconds to 300 seconds. Then, it was heated and peeled off with an adhesive tape. Also, in the case where heating by a hot plate was not performed, it was tested whether patterning was possible by the same method. The results were as follows.

  In the case of heating at 40 ° C., with a heating time of less than 60 seconds or longer than 180 seconds, a part or the entire surface of the IGZO film remained as a remaining film on the silicon wafer. In the case of heating at 50 ° C., with a heating time of less than 25 seconds or longer than 90 seconds, a part or the entire surface of the IGZO film remained as a remaining film on the silicon wafer. In the case of heating at 70 ° C., in the heating time of less than 20 seconds or longer than 30 seconds, a part of the contact portion or the IGZO film on the entire surface remained as a remaining film on the silicon wafer. In addition, when stationary at room temperature, the IGZO film partially or entirely on the contact portion remained as a remaining film on the silicon wafer even after 20 minutes or longer.

  FIG. 4 shows a photomicrograph when the IGZO film that has been heat-dried at 40 ° C. for 30 seconds is patterned using the adhesive tape. The left side of the figure is the pattern of the IGZO precursor thin film, and the right side is a region (non-pattern region, removal pattern region) peeled off by the adhesive material. From the figure, it can be seen that the sidewalls of the thin film pattern are rough and rough, and that the cross-sectional rectangularity of the pattern is low due to the shading of the photograph.

(Second Embodiment)
In the embodiment of the present invention, a case where the metal oxide thin film is a ferroelectric material or a ferromagnetic material will be described as an example. By preparing a metal oxide precursor solution containing bismuth and iron, applying the solution to a substrate, and then peeling the metal oxide precursor thin film in a semi-dried state by bringing the adhesive tape into contact with a predetermined region Patterning is performed (see FIG. 1). Thereafter, the metal oxide precursor thin film is heat-treated to obtain a metal oxide thin film (BiFeO ₃ thin film) pattern.

  Next, a specific example 2 will be described. Various conditions of the semi-drying process were changed, and the results of selective peeling and removal using an adhesive tape were examined.

  A metal that becomes a precursor of a metal oxide thin film by dissolving bismuth nitrate and iron (III) in a 1: 1 (mol ratio) in a mixed solvent of 10% aqueous nitric acid and trifluoroethanol (volume ratio 3: 7). A solution containing was prepared. The salt concentration after preparation of the solution was 0.05 mol / l. This solution was spin-coated on a cleaned 300 nm silicon wafer with a thermal oxide film. The spin condition was 2000 rpm for 30 seconds. Thereafter, the substrate coated with the metal oxide precursor solution is placed on a hot plate through a glass plate having a thickness of 1.2 mm, heated at a predetermined temperature for a predetermined time, and adhesive tape (Scotch (registered trademark) transparent) The adhesive tape transparent beautiful color (registered trademark) (manufactured by 3M)) was brought into contact with the metal oxide precursor thin film and peeled off to perform patterning (see FIG. 1). The temperature of the hot plate was one level of 30 ° C., and the heating time was 30 seconds. The atmospheric environment was an air temperature of 25 ° C. and a relative humidity of 40%. As a result, all of the BiFe precursor thin film at the contact portion was transferred to the adhesive tape side, and no residual film remained.

  Next, Comparative Example 2 will be described. After forming a film by the same method as in Example 2, a peel test using the same adhesive tape was performed under the conditions of a heating temperature of 30 ° C. and a heating time of 10 seconds and 60 seconds. As a result, when the heating time was 60 seconds, the precursor thin film could not be transferred to the tape side and remained as a remaining film on the silicon wafer, and patterning could not be performed. When the heating time was 10 seconds, the precursor thin film remained low viscosity and could not be patterned.

(Third embodiment)
In the embodiment of the present invention, a case where the metal oxide thin film is an insulator will be described as an example. After preparing a metal oxide precursor solution containing aluminum and applying it to a substrate, patterning is performed by bringing the metal oxide precursor thin film in a semi-dried state into contact with a predetermined region and peeling it off. Perform (see FIG. 1). Thereafter, the metal oxide precursor thin film is heat-treated to obtain a metal oxide thin film (Al ₂ O ₃ film) pattern.

  Next, specific Example 3 will be described. Various conditions of the semi-drying process were changed, and the results of selective peeling and removal using an adhesive tape were examined.

  Aluminum nitrate was dissolved in a mixed solvent of water and trifluoroethanol (volume ratio 3: 7) to prepare a solution containing a metal to be a precursor of the metal oxide thin film. The salt concentration after preparation of the solution was 0.1 mol / l. This solution was spin-coated on a cleaned 300 nm silicon wafer with a thermal oxide film. The spin condition was 2000 rpm for 30 seconds. Thereafter, the substrate coated with the metal oxide precursor solution is placed on a hot plate through a glass plate having a thickness of 1.2 mm, heated at a predetermined temperature for a predetermined time, and adhesive tape (Scotch (registered trademark) transparent) The adhesive tape transparent beautiful color (registered trademark) (manufactured by 3M)) was brought into contact with the metal oxide precursor thin film and peeled off to perform patterning (see FIG. 1). The temperature of the hot plate was one level of 40 ° C., and the heating time was 60, 90 seconds. The atmospheric environment was an air temperature of 25 ° C. and a relative humidity of 40%. As a result, all of the precursor thin film at the contact portion was transferred to the adhesive tape side, and no residual film remained.

  Next, Comparative Example 3 will be described. After forming the film by the same method as in Example 3, a peel test using the same adhesive tape was performed under the conditions of a heating temperature of 40 degrees, a heating time of 10 seconds, and 200 seconds. As a result, when the heating time was 200 seconds, the precursor thin film could not be transferred to the tape side and remained as a remaining film on the silicon wafer, and patterning could not be performed. When the heating time was 10 seconds, the precursor thin film remained low viscosity and could not be patterned.

  In addition, the example shown by the said embodiment etc. was described in order to make invention easy to understand, and is not limited to this form.

  The present invention is applicable to all electronic components that require patterning of metal oxide thin films for electronic materials such as semiconductors, insulators, and conductors, and is industrially useful. Further, the present invention can be applied not only to electronic parts but also to other products using functional metal oxide thin film patterns, such as optical elements such as optical filters, and is industrially useful.

DESCRIPTION OF SYMBOLS 1 Base material 2 Metal oxide precursor thin film 3 Semi-dried metal oxide precursor thin film 4 Adhesive material

Claims (4)

A thin film formed by applying a solution having a metal oxide precursor on a substrate is semi-dried by removing a part of the evaporation component of the thin film,
Metal oxide, characterized by patterning a thin film containing a metal oxide precursor by removing only the abutted portion by separating the semi-dried thin film after contacting an adhesive material. Method for manufacturing a precursor precursor thin film pattern.   A method for producing a metal oxide thin film pattern, comprising performing heat treatment after patterning a thin film containing the metal oxide precursor according to claim 1.   A metal oxide thin film pattern produced by the method according to claim 1.   An electronic component comprising a metal oxide thin film pattern manufactured by the method according to claim 1.

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