JP5737506B2 - Method for manufacturing organic semiconductor element - Google Patents

Description

  The present invention relates to a method for manufacturing an organic semiconductor element.

  Conventionally, various methods have been proposed as a method for manufacturing an organic semiconductor element.

  In particular, as a method for patterning an organic semiconductor, a method for patterning an organic semiconductor by forming a pattern having different surface wettability with respect to a liquid has been proposed.

  For example, a transparent conductive film is formed in a pattern on a substrate, and an insulating film is formed in the opening of the transparent conductive film using a material whose surface wettability with respect to the liquid thin film material is changed by light irradiation. And selectively irradiate a portion of the insulating film through a photomask to increase the wettability of the light-irradiated region on the surface of the insulating film to the liquid thin film material, and liquid on the light-irradiated region of the transparent conductive film and the insulating film. A method of forming a thin film in a pattern by applying a thin film material has been proposed (see Patent Document 1). According to this method, by irradiating the insulating film with light, regions having different wettability with respect to the liquid thin film material are formed on the film surface, and by utilizing the difference in wettability of the film surface, the thin film can be efficiently and accurately produced. It can be formed in a pattern.

JP 2004-288469 A

  Regarding the method described in Patent Document 1, the wettability change due to light irradiation has a large effect due to the reaction between the active species of oxygen in the vicinity of the insulating film and the surface of the insulating film, and light in the vacuum ultraviolet region is preferable. In addition, the highest accuracy is obtained when the substrate and the photomask are brought into close contact with light irradiation. However, if the contact is made, the photomask is damaged or contaminated, so that the gap between the substrate and the photomask is as much as possible. It is preferable to make it smaller. However, if there is a space between the substrate and the photomask, when oxygen is irradiated with vacuum ultraviolet rays, the active species of oxygen will also circulate into the area where vacuum ultraviolet rays are not irradiated, resulting in a problem that the pattern is blurred and accuracy is lowered. is there.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for manufacturing an organic semiconductor element that can be efficiently patterned with high accuracy.

  In order to achieve the above object, the present invention provides a first step of preparing a substrate having a liquid repellent portion having liquid repellency with respect to an organic semiconductor layer forming solution containing an organic semiconductor material in a solvent, A second step of forming a shielding layer on the liquid repellent part, a third step of modifying a part of the liquid repellent part of the substrate into a lyophilic part having lyophilicity with respect to the organic semiconductor layer forming solution, And a step of forming a substrate for an organic semiconductor element having a fourth step of forming a source electrode and a drain electrode on the substrate, which is performed after the first step, the second step, or the third step, and the shielding. An organic semiconductor layer in contact with the source electrode and the drain electrode by removing the layer from the liquid repellent portion of the substrate of the organic semiconductor element substrate, applying the organic semiconductor layer forming solution on the organic semiconductor element substrate; Organic semiconductor to form on the lyophilic part To provide a manufacturing method of an organic semiconductor device having a step of forming the layer, the.

  In the present invention, in the step of forming the organic semiconductor element substrate, when a part of the liquid-repellent part on the base is modified into a lyophilic part, the part that wants to maintain the liquid-repellent part is covered with a shielding layer, Since it is protected, the organic semiconductor can be efficiently patterned with high accuracy.

It is process drawing which shows an example (when performing a 4th process after the 1st process of a top gate / bottom contact type structure) of the manufacturing method of the organic-semiconductor element of this invention. It is process drawing which shows an example (when performing a 4th process after the 2nd process of a top gate / bottom contact type structure) of the manufacturing method of the organic-semiconductor element of this invention. It is process drawing which shows an example (when performing a 4th process after the 3rd process of a top gate / bottom contact type structure) of the manufacturing method of the organic-semiconductor element of this invention. It is process drawing which shows an example (when performing a 4th process after the 1st process of a bottom gate and a bottom contact type structure) of the manufacturing method of the organic-semiconductor element of this invention. It is process drawing which shows an example (when performing a 4th process after the 2nd process of a top gate / bottom contact type structure) of the manufacturing method of the organic-semiconductor element of this invention. It is process drawing which shows an example (when performing a 4th process after the 3rd process of a bottom-gate bottom contact type structure) of the manufacturing method of the organic-semiconductor element of this invention.

  Hereinafter, the manufacturing method of the organic-semiconductor element of this invention is demonstrated in detail.

  The manufacturing method of the organic semiconductor element of this invention is comprised at least by the formation process of the board | substrate for organic semiconductor elements, and the formation process of an organic-semiconductor layer. The organic semiconductor element substrate forming step includes a first step of preparing a substrate having a liquid repellent portion having liquid repellency with respect to an organic semiconductor layer forming solution containing an organic semiconductor material in a solvent. A second step of forming a shielding layer on the liquid part, a third step of modifying a part of the liquid repellent part of the substrate into a lyophilic part having lyophilicity with respect to the organic semiconductor layer forming solution, and At least a fourth step is performed after the first step, the second step, or the third step to form a source electrode and a drain electrode on the substrate. The organic semiconductor layer forming step includes removing the shielding layer from the liquid repellent portion of the base of the organic semiconductor element substrate, applying the organic semiconductor layer forming solution on the organic semiconductor element substrate, An organic semiconductor layer in contact with the electrode and the drain electrode is formed on the lyophilic portion.

    The manufacturing method of the organic semiconductor element of this invention is demonstrated referring drawings.

    1A to 1H are process diagrams showing an example of a method for manufacturing an organic semiconductor element when a fourth process is performed after the first process of the top gate / bottom contact type structure of the present invention.

  First, a substrate having a liquid repellent portion having liquid repellency to an organic semiconductor layer forming solution containing an organic semiconductor material in a solvent is prepared (FIG. 1 (1a)) (first step). Next, a source electrode and a drain electrode are formed on the substrate (FIG. 1 (1b)) (fourth step). Next, a shielding layer is formed on the liquid repellent portion of the substrate (FIG. 1 (1c)) (second step). Next, a part of the lyophobic portion of the substrate is modified into a lyophilic portion having lyophilicity with respect to the organic semiconductor layer forming solution (FIG. 1 (1d)) (third step). By the first to fourth steps, a substrate for an organic semiconductor element including a base body having a lyophilic portion, a shielding layer, a source electrode, and a drain electrode is manufactured. Subsequently, the shielding layer is removed from the liquid repellent portion of the organic semiconductor element substrate (FIG. 1 (1e)). Next, an organic semiconductor layer forming solution is applied on the organic semiconductor element substrate to form an organic semiconductor layer in contact with the source electrode and the drain electrode (FIG. 1 (1f)). Subsequently, a gate insulating layer is formed on the organic semiconductor element substrate on the side where the source electrode and drain electrode of the organic semiconductor element substrate are formed (FIG. 1 (1g)). Next, a gate electrode is formed on the gate insulating layer (FIG. 1 (1h)).

  FIG. 2 is a process diagram showing an example of a method for manufacturing an organic semiconductor element when the fourth process is performed after the second process of the top gate / bottom contact type structure, and the fourth process is performed after the second process. Except for this, it is the same as FIG.

  FIG. 3 is a process diagram showing an example of a method for manufacturing an organic semiconductor element when the fourth step is performed after the third step of the top gate / bottom contact type structure, and the fourth step is performed after the third step. Except for this, it is the same as FIG.

  FIG. 4 is a process diagram showing an example of a method for manufacturing an organic semiconductor device in the case where the fourth process is performed after the first process of the bottom gate / bottom contact type structure. The structure of the base includes a gate insulating layer and a gate electrode. Except for the points included, it is the same as FIG.

  FIG. 5 is a process diagram showing an example of a method of manufacturing an organic semiconductor device when the fourth process is performed after the second process of the bottom gate / bottom contact type structure, and the structure of the base includes a gate insulating layer and a gate electrode. 1 is the same as FIG. 1 except that the fourth step is performed after the second step.

  FIG. 6 is a process diagram showing an example of a method of manufacturing an organic semiconductor device in the case where the fourth process is performed after the third process of the bottom gate / bottom contact type structure. The structure of the base includes a gate insulating layer and a gate electrode. 1 is the same as FIG. 1 except that the fourth step is performed after the third step.

According to the present invention, in the step of forming the substrate for an organic semiconductor element, when a part of the liquid-repellent part on the substrate is modified into the lyophilic part, the part where the liquid-repellent property is to be maintained is covered with the shielding layer. Therefore, the organic semiconductor can be patterned with high accuracy and efficiency.
Hereinafter, each process in the manufacturing method of the organic-semiconductor element of this invention is demonstrated.
1. Step of forming substrate for organic semiconductor element The step of forming the substrate for organic semiconductor element of the present invention comprises a substrate having a liquid repellent portion having liquid repellency with respect to a solution for forming an organic semiconductor layer in which an organic semiconductor material is dissolved in a solvent. A first step of preparing a second step of forming a shielding layer on the liquid-repellent part of the substrate; a part of the liquid-repellent part of the substrate that is lyophilic with respect to the organic semiconductor layer forming solution; The third step is a liquid step, and the fourth step is performed after the first step, the second step, or the third step to form a source electrode and a drain electrode on the substrate. The substrate for an organic semiconductor element includes a base having a lyophilic portion, a shielding layer, a source electrode, and a drain electrode.

1-1. 1st process 1st process of this invention prepares the base | substrate which has a liquid repelling part which has liquid repellency with respect to the solution for organic-semiconductor-layer formation which made the organic semiconductor material contain the solvent.

1-1-1. Solution for forming an organic semiconductor material layer The solution for forming an organic semiconductor layer contains an organic semiconductor material in a solvent. All of the organic semiconductor material may be dissolved in the solvent, a part of the organic semiconductor material may be dispersed without dissolving in the solvent, or all of the organic semiconductor material may be dispersed in the solvent. Examples of the organic semiconductor material of the organic semiconductor layer forming solution include polyacetylene derivatives, polythiophene derivatives having a thiophene ring, poly (3-alkylthiophene) derivatives, poly (3,4-ethylenedioxythiophene) derivatives, and polythienylene vinylene derivatives. And conjugated polymer compounds such as a polyphenylene derivative having a benzene ring, a polyphenylene vinylene derivative, a polypyridine derivative having a nitrogen atom, a polypyrrole derivative, a polyaniline derivative, and a polyquinoline derivative. A polythiophene derivative suitable for coating formation is preferable.

  The solvent of the organic semiconductor layer forming solution is not particularly limited as long as the organic semiconductor contains, but is preferably trichlorobenzene having high solubility of the organic semiconductor, such as water, dichloromethane, toluene, chlorobenzene, dichlorobenzene, and trichlorobenzene.

  The method for producing the organic semiconductor layer forming solution is not particularly limited as long as it is a general solution producing method such as a method of adding an organic semiconductor material to a solvent or a method of adding a solvent to an organic semiconductor material.

1-1-2. Substrate The substrate is not particularly limited as long as it has a function of supporting the organic semiconductor element.

  As the substrate, resin, plastic film, glass, quartz, aluminum oxide, sapphire, silicon nitride, silicon carbide and other ceramic substrates, silicon, germanium, gallium arsenide, gallium phosphide, gallium nitrogen and other semiconductor substrates, paper, nonwoven fabric, etc. Can be used. Among these, since flexibility can be imparted to the organic semiconductor element, it is preferably made of a resin or a plastic film. Examples of the resin include polyester resin, polycarbonate resin, cellulose resin, gelatin, acrylic resin, polyurethane resin, polyethylene resin, polypropylene resin, polystyrene resin, phenoxy resin, norbornene resin, epoxy resin, vinyl chloride-vinyl acetate copolymer, vinyl chloride. Resin, vinyl acetate resin, copolymer of vinyl acetate and vinyl alcohol, partially hydrolyzed vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, ethylene-vinyl alcohol Copolymers, polyvinyl alcohol, chlorinated polyvinyl chloride, ethylene-vinyl chloride copolymers, vinyl polymers such as ethylene-vinyl acetate copolymers, polyamide resins, ethylene-butadiene resins, butadiene-acrylonites Rubber-based resins such as Le resins, alkyd resins, phenol resins, urea resins, silicone resins, fluorine-based resins. In addition, as a plastic film, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC), Examples thereof include films made of cellulose triacetate (TAC), cellulose acetate propionate (CAP), and the like. Furthermore, a thin film made of a metal such as stainless steel or aluminum having a thickness that can be bent can also be used. Moreover, the base | substrate may have a base material on the opposite side to the surface which forms the organic-semiconductor element of a base | substrate. As the base material, in addition to the same material as the liquid repellent part, a thin film made of a metal such as stainless steel or aluminum having a thickness capable of bending can be used. Preferably, a plastic film that can reduce the weight as compared with the case where glass is used for the base material, can improve portability, and can improve resistance to impact is preferable. In addition, when a plastic film is used as a base material, it is possible to incorporate or integrate a field effect transistor into a display device or electronic device having a curved shape. Further, in the case of a bottom gate type structure, the substrate may also serve as a gate insulating layer. Furthermore, you may provide a gate electrode and a base material on the opposite side to the surface which forms the organic-semiconductor element of a gate insulating layer.

1-1-3. Liquid repellent part The liquid repellent part is liquid repellent with respect to a solution for forming an organic semiconductor layer containing an organic semiconductor material in a solvent. As the liquid repellency, the contact angle of the solvent of the organic semiconductor layer forming solution at 25 ° C. on the surface of the liquid repellent part is formed on the surface of the liquid repellent part in the step of forming the substrate for the organic semiconductor element. It must be higher than the contact angle of the solvent of the organic semiconductor layer forming solution at 25 ° C. on the surface of the lyophilic portion having lyophilicity to the solution for use. This is because it is necessary to fix the organic semiconductor layer forming solution only on the lyophilic portion in order to pattern the organic semiconductor layer in the step of forming the organic semiconductor layer. Preferably, the contact angle of the solvent of the solution for forming an organic semiconductor layer at 25 ° C. on the surface of the liquid repellent portion is preferably 80 ° or more, particularly 100, in order to easily widen the difference from the lyophilic portion described later. It is preferable that it is more than °.

  The contact angle can be measured, for example, by dropping 1 microliter of liquid onto the substrate, observing the shape of the dropped droplet from the side, and measuring the angle formed by the droplet and the substrate. it can. Such a measurement can be performed by, for example, a contact angle measuring device manufactured by Imoto Seisakusho.

  The form of the liquid repellent part is not particularly limited as long as the liquid repellent part is provided on the side of the base on which the organic semiconductor layer is formed. For example, the whole substrate may be a liquid repellent material, or a liquid repellent material may be formed on a part of the surface of the substrate on the side where the organic semiconductor layer is formed. .

  As a method for preparing a substrate having a liquid repellent portion, a material having liquid repellency may be prepared when the entire substrate is in a form of a material having liquid repellency. In the case where a material having liquid repellency is formed on a part of the surface of the base on which the organic semiconductor layer is formed, the material having liquid repellency may be formed on the substrate. The method for forming a liquid repellent material on the substrate is not particularly limited as long as the liquid repellent material can be formed on the substrate.

  As the material for the liquid repellent portion, the above-mentioned base material can be used. Preferably, acrylic resin, silicone resin, and fluorine resin are preferable because of high liquid repellency.

1-2. Second Step The second step of the present invention is to form a shielding layer on the liquid repellent part of the substrate.

1-2-1. Shielding layer The shielding layer is provided in a region on the base where it is desired to maintain liquid repellency when the liquid repellent part is modified into a lyophilic part. The position of the shielding layer is adjacent to the source electrode and the drain electrode on the substrate. The shielding layer is not particularly limited as long as it is stable to a physical method or a chemical method to be described later when the liquid repellent part is modified into a lyophilic part, but it is preferably handled. Photoresist is good because it is easy to remove.

  When a metal is used for the shielding layer, the material is not particularly limited, but metal particles or metal oxides containing one or more of Cu, Ag, Al, Zn, W, Mo, V, Cr, Ni, Mn, Co, etc. And particles. As a method for forming a metal on a substrate, metal is deposited by sputtering or vapor deposition, and patterning is performed by etching or the like.

  When a resin is used for the shielding layer, the same material as the liquid repellent part can be used. Preferably, thermosetting resin such as phenol resin, epoxy resin, urea resin, alkyd resin is preferable because of high durability. As a method for forming the resin on the substrate, the same method as that for the liquid repellent portion can be used.

  When a photoresist is used for the shielding layer, either a positive photoresist or a negative photoresist may be used. Among these, a positive photoresist is preferable in consideration of the ease of removing the photoresist in the step of removing the shielding layer described later. As the photoresist, a general one can be used. Among these, it is preferable that the photoresist contains a surfactant containing a fluorine group. With such a photoresist, the surface tension of the photoresist can be effectively reduced. Therefore, even if the liquid repellency of the liquid repellent part is high, the photoresist is satisfactorily coated on the liquid repellent part. Because it can. The surfactant containing a fluorine group is not particularly limited as long as it is soluble in a photoresist, and both a high molecular weight type and a low molecular weight type can be used. Agents can be used.

  Further, the photoresist preferably has a contact angle of 15 ° or less of the photoresist on the surface of the liquid repellent part, and more preferably 10 ° or less. This is because if the contact angle is in the above range, a photoresist can be satisfactorily applied on the liquid repellent portion.

  The method for forming a photoresist on a substrate is not particularly limited as long as it is a method capable of forming a photoresist on a substrate. Usually, a photoresist is coated on a substrate and patterned. A method of forming a photoresist is used.

  The method for applying the photoresist is not particularly limited as long as it can be applied on the liquid repellent portion. For example, spin coating, casting, dip coating, bar coating, blade coating, roll coating, gravure A coat, spray coat, flexographic printing or the like is used.

  The film thickness of the photoresist is not particularly limited as long as it can protect the liquid repellent part in the fourth step described later.

  For patterning the photoresist, a method of patterning the photoresist and developing it is usually used. As a method for pattern exposure of the photoresist, for example, a general method such as a method of exposing through a photomask or a laser drawing method can be used. As a method for developing the photoresist, for example, a method using a developer can be applied. As the developer, a commonly used organic alkaline developer can be used. In addition, an inorganic alkaline developer or an aqueous solution can also be used as the developer. It is preferable to wash with water after developing the photoresist. The photoresist is not particularly limited as long as it is a pattern capable of forming a desired lyophilic portion, and is appropriately selected.

1-3. Third Step In the third step of the present invention, a part of the lyophobic portion of the substrate is made a lyophilic portion that is lyophilic with respect to the organic semiconductor layer forming solution.

1-3-1. Lipophilic part The lyophilic part is lyophilic with respect to the organic semiconductor layer forming solution. As the lyophilic property, the contact angle of the solvent of the organic semiconductor layer forming solution at 25 ° C. on the surface of the lyophilic portion is the solvent of the organic semiconductor layer forming solution at 25 ° C. of the surface of the liquid repellent portion before the third step. It is necessary to be lower than the contact angle. This is because it is necessary to fix the organic semiconductor layer forming solution only on the lyophilic portion in order to pattern the organic semiconductor layer in the step of forming the organic semiconductor layer. Preferably, the contact angle of the solvent of the organic semiconductor layer forming solution at 25 ° C. on the surface of the lyophilic part is preferably 30 ° or less, more preferably 10 ° or less, and 5 ° or less. Is more preferable. Also, the contact angle of the solvent of the organic semiconductor layer forming solution at 25 ° C. on the surface of the lyophilic part, and the contact angle of the solvent of the machine semiconductor layer forming solution at 25 ° C. on the surface of the liquid repellent part before the third step The difference is preferably 50 ° or more, more preferably 70 ° or more, still more preferably 80 ° or more, and particularly preferably 90 ° or more. When the difference between the contact angle of the lyophilic part and the contact angle of the lyophobic part is in the above-described range, the organic semiconductor layer forming solution is more highly selective on the lyophilic part when manufacturing an organic semiconductor element. This is because the organic semiconductor layer can be formed with high accuracy.

    The contact angle can be measured, for example, by dropping 1 microliter of liquid onto the substrate, observing the shape of the dropped droplet from the side, and measuring the angle formed by the droplet and the substrate. it can. Such a measurement can be performed by, for example, a contact angle measuring device manufactured by Imoto Seisakusho.

  The method for making a part of the liquid repellent portion of the substrate a lyophilic portion having lyophilicity with respect to the organic semiconductor layer forming solution is not particularly limited as long as it is a method for improving wettability. Preferably, a method for increasing the surface roughness of the liquid repellent part (hereinafter referred to as a physical method) and / or a method for modifying a polar group on a substance on the surface of the liquid repellent part (hereinafter referred to as a chemical method). ). Examples of the physical method include a method of scraping the surface of the liquid repellent portion with a material harder than the liquid repellent portion, and a method of scraping the surface of the liquid repellent portion by irradiating the liquid repellent portion with momentum of the liquid. In the case of a physical method, even if the functional group on the surface of the liquid repellent part cannot be changed to a polar group, a part of the liquid repellent part of the substrate is a lyophilic parent with respect to the organic semiconductor layer forming solution. It can be a liquid part. As a chemical method, in order to modify a hydroxyl group on a functional group on the surface of the liquid repellent part, a method of irradiating the surface of the liquid repellent part with an ultraviolet light in an oxygen atmosphere such as in the atmosphere or in a state of oxygen filling in a vacuum. Alternatively, a method of irradiating the surface of the liquid repellent part with oxygen-containing plasma can be used. Of the ultraviolet light, vacuum ultraviolet light is preferred. This is because vacuum ultraviolet rays have high energy, can generate active species of oxygen more effectively, and can efficiently denature the surface of the liquid repellent part into a lyophilic part in a short time. The wavelength of the vacuum ultraviolet ray may be any wavelength as long as the surface of the liquid repellent part can be modified into a lyophilic part, and is appropriately selected according to the type of material of the liquid repellent part. Usually, it is preferably within a range of 100 nm to 250 nm, and more preferably within a range of 150 nm to 200 nm. This is because if the wavelength is longer than the above range, the generation efficiency of oxygen radicals is lowered, and the sensitivity may be lowered depending on the type of material of the liquid repellent part. Further, if the wavelength is shorter than the above range, stable vacuum ultraviolet irradiation may be difficult. Examples of the light source that can be used for irradiation with vacuum ultraviolet rays include an excimer lamp, a low-pressure mercury lamp, and various other light sources. The irradiation amount of vacuum ultraviolet rays is appropriately adjusted according to the type of material of the liquid repellent part. If it is a chemical method, a high-definition pattern can be formed. It is also possible to perform both physical and chemical methods simultaneously. When both the physical method and the chemical method are performed simultaneously, the wettability of the liquid repellent part can be effectively improved.

1-4. Fourth Step The fourth step of the present invention is performed after the first step, the second step, or the third step, and forms a source electrode and a drain electrode on the substrate.

1-4-1. Source electrode and drain electrode The material of the source electrode and drain electrode is not particularly limited as long as it has conductivity, but Au, Cu, Ag, Pt, Al, Zn, W, Mo, V, Cr, Ni , Metal particles containing one or more of Mn, Co, or the like, or metal oxide particles, carbon materials such as indium tin oxide (ITO), graphene, and carbon nanotubes, and conductive polymer materials such as PEDOT / PSS.

  The source electrode and drain electrode are formed by plasma CVD method, thermal CVD method, laser CVD method and other CVD methods, vacuum deposition method, sputtering method, ion plating method and other PVD methods, electrolytic plating method, immersion plating method, There is no particular limitation as long as it is formed on the substrate by an electroless plating method, a sol-gel method, an organometallic decomposition (MOD) method, or the like. Further, the source electrode and the drain electrode may be patterned by a photolithography method or the like. Further, although the source electrode and the drain electrode are separated from each other, the distance to be separated is not particularly limited. In addition, the source electrode and the drain electrode may be in contact with the shielding layer in a cross section when the base is viewed from the semiconductor element formation direction. Further, although the base is formed away from the shielding layer in the cross section viewed from the direction perpendicular to the semiconductor element formation direction, the distance is not particularly limited.

1-4-2. Order of Fourth Step The fourth step may be performed after any step if it is performed after the first step, the second step, or the third step. The source electrode and the drain electrode may be formed before the shielding layer is formed or after the shielding layer is formed. Preferably, since it is preferable not to damage the shielding layer when forming the source electrode and the drain electrode, it is better to perform the fourth step after the first step.
2. Step of forming organic semiconductor layer In the step of forming organic semiconductor layer of the present invention, the shielding layer is removed from the base of the substrate for organic semiconductor element, the organic semiconductor layer forming solution is applied on the substrate for organic semiconductor element, and the source An organic semiconductor layer in contact with the electrode and the drain electrode is formed.

2-1. Removal of shielding layer The method of removing the shielding layer is not particularly limited as long as the material forming the shielding layer can be removed. For example, if a shielding layer is formed using a photoresist, it may be removed with a stripping solution. Further, if the shielding layer is formed using a metal, it may be removed with an etchant.

2-2. Method for applying organic semiconductor layer forming solution The method for applying the organic semiconductor layer forming solution on the lyophilic portion is not particularly limited as long as the organic semiconductor layer forming solution can be applied. Examples thereof include dip coating, bar coating, LB, roll coating, spray coating, die coating, bead coating, spin coating, ink jet, dispenser, cast, blade coating, flexographic printing, and gravure printing.

  In the organic semiconductor layer patterning method of the present invention, the organic semiconductor layer forming solution that is fixed only on the lyophilic portion is applied to the substrate divided into the lyophilic portion and the lyophobic portion. Can do.

  In the present invention, it is preferable to form the organic semiconductor layer after removing the light shielding layer. This is because if the organic semiconductor layer is formed before removing the light shielding layer, the organic semiconductor layer forming material adheres to the shielding layer, but the shielding layer is removed so that the organic semiconductor layer forming material attached to the shielding layer is reused. Can not do it. On the other hand, when the organic semiconductor layer is formed after removing the light shielding layer as in the present invention, the organic semiconductor layer forming material can be recovered and reused because it is repelled except in the lyophilic portion. . As described above, the organic semiconductor layer forming material can be efficiently used by reducing the organic semiconductor layer forming material attached to the light shielding layer.

2-3. Gate Insulating Layer and Gate Electrode The manufacturing method of the present invention includes a step for forming a substrate for an organic semiconductor element and a step for forming an organic semiconductor layer, and may include the following steps for forming a gate insulating layer and a gate electrode.

  In the method for manufacturing an organic semiconductor element having a top gate / bottom contact structure and a top gate / top contact structure, there may be a case where a gate insulating layer and a gate electrode are formed after the organic semiconductor layer is formed. In the step of forming the gate insulating layer and the gate electrode, the gate insulating layer is formed so as to cover at least the organic semiconductor layer between the source electrode and the drain electrode, and the gate electrode is formed on the gate insulating layer. For example, a gate insulating layer material is formed by spin coating on the organic semiconductor element substrate on the side where the source electrode and drain electrode of the organic semiconductor element substrate are formed, exposed through a photomask, and heated and cured. Then, a gate insulating layer is formed. Next, a method of forming a gate electrode by depositing a gate electrode material on a gate insulating layer through a metal mask and patterning by a photolithography method can be mentioned.

  In the manufacturing method of the organic semiconductor device having the bottom gate / bottom contact type structure and the bottom gate / top contact type structure, there may be a case where the gate insulating layer and the gate electrode are formed in the substrate. It is done. For example, a gate electrode material is vapor-deposited on a substrate through a metal mask, and patterned by a photolithography method to form a gate electrode. Next, a gate insulating layer material is formed by spin coating, exposed through a photomask, heated and cured, and a gate insulating layer is formed to form a gate insulating layer and a gate electrode in the substrate. it can.

  The gate insulating layer material is polyester resin, polycarbonate resin, cellulose resin, gelatin, acrylic resin, polyurethane resin, polyethylene resin, polypropylene resin, polystyrene resin, phenoxy resin, norbornene resin, epoxy resin, vinyl chloride-vinyl acetate copolymer, Vinyl chloride resin, vinyl acetate resin, copolymer of vinyl acetate and vinyl alcohol, partially hydrolyzed vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, ethylene- Vinyl alcohol copolymers, polyvinyl alcohol, chlorinated polyvinyl chloride, ethylene-vinyl chloride copolymers, vinyl polymers such as ethylene-vinyl acetate copolymers, polyamide resins, ethylene-butadiene resins, butadiene-acrylic Rubber-based resins such as nitrile resins, silicone resins, and fluorine resins. The gate electrode material is not particularly limited as long as it has conductivity, but metal particles or metal oxide particles such as Au, Cu, Ag, ITO and Pt, carbon materials such as graphene and carbon nanotubes, PEDOT / PSS And the like, and the like.

In a method for manufacturing an organic semiconductor element having a bottom gate / bottom contact type structure, a case where a gate insulating layer and a gate electrode are included in the substrate may be considered. When the base includes a gate insulating layer and a gate electrode, the step of forming the gate insulating layer and the gate electrode is to prepare a base material, form the gate electrode on the base material, and repel the liquid so as to cover the gate electrode A gate insulating layer having a property is formed. As the substrate, those described above can be preferably used.
3. Structure of Organic Semiconductor Element The structure of the organic semiconductor element of the present invention will be described. The organic semiconductor element of the present invention includes a substrate, a source electrode, a drain electrode, an organic semiconductor layer, a gate insulating layer, and a gate electrode. Note that the gate insulating layer and the gate electrode are appropriately arranged depending on the mold. For example, in a top gate / bottom contact type structure and a top gate / top contact type structure, a gate insulating layer and a gate electrode are disposed on the organic semiconductor layer. In the bottom gate / bottom contact type structure and the bottom gate / top contact type structure, a gate insulating layer and a gate electrode are disposed on a part of the substrate.

Since the organic semiconductor element may be broken by an etchant used when forming the gate electrode and the drain electrode, a top gate / bottom contact type structure or a bottom gate / bottom contact type structure is preferable.
4). Applications Examples of the use of the organic semiconductor element produced by the method for producing an organic semiconductor element of the present invention include a liquid crystal display device, an electrophoretic display device, and an organic EL display device.

  The following examples illustrate the present invention in more detail.

  An organic semiconductor device having a top gate / bottom contact type structure described below was fabricated. A glass (thickness: 0.7 mm) made of silicon dioxide is spin-coated with an acrylic silicone resin (KP-545, manufactured by Shin-Etsu Chemical Co., Ltd.) having liquid repellency, and 30 minutes at 150 ° C. in an oven (ESPEC clean oven). A substrate having a liquid repellency (thickness: 5 μm) was formed on the substrate by heat curing. The contact angle is measured by the θ / 2 method, which is a method for determining the contact angle from the angle of the straight line connecting the left and right end points and the apex of the droplet to the solid surface by dropping 1.2 μl of 25 ° C. trichlorobenzene onto the substrate surface. As a result, the contact angle was 98.0 °. Next, Au (40 nm) was formed on the substrate by sputtering to obtain an Au film as a golden film. A positive photoresist (AZ-5206, manufactured by AZ Electronic Materials Co., Ltd.) is formed on this Ag film by spin coating, and exposed with an exposure apparatus (Seiwa Optical mask aligner) through a photomask. The photoresist was patterned by development with an aqueous tetramethylammonium hydroxide solution (concentration 2.38%). This substrate was etched by putting it into an etchant (mixed acid SEA-5 manufactured by Kanto Chemical Co., Inc.). Subsequently, the photoresist remaining on Au was peeled off to form a source electrode and a drain electrode made of Au.

  A positive photoresist (AZ-5206, manufactured by AZ Electronic Materials Co., Ltd.) is spin-coated on the substrate surface including the source electrode and the drain electrode, exposed through a photomask, and then tetramethylammonium hydroxide aqueous solution A photoresist pattern was formed by development at a density of 2.38%. In this photoresist pattern, the photoresist in the vicinity of the source electrode and the drain electrode was removed, and Au and the liquid-repellent resin layer therebelow were exposed in the vicinity of the electrode. In this state, vacuum ultraviolet rays (wavelength: 172 nm, illuminance: 3 mW / cm 2) were irradiated for 60 seconds to make the vicinity of the source and drain electrodes without the photoresist lyophilic. In addition, 1.2 microliters of 25 degreeC trichlorobenzene was dripped on the lyophilic part, and as a result of measuring a contact angle by (theta) / 2 method, the contact angle was 5 degrees or less.

  Next, the above photoresist was removed by stripping (a stripping solution 106 manufactured by Tokyo Ohka Kogyo Co., Ltd.). Next, an organic semiconductor polythiophene dissolved in trichlorobenzene at a concentration of 0.2 wt% was subjected to inkjet coating (Fujifilm Dimatix) in the vicinity of the lyophilic source electrode and drain electrode, and then on a hot plate at 150 ° C. For 10 minutes to dry. At this time, the organic semiconductor layer (thickness: 40 nm) made of polythiophene is formed only on the lyophilic portion in the vicinity of the source electrode and the drain electrode from microscopic observation, and is patterned into a shape that turns over the photoresist. confirmed.

  Next, a resin (manufactured by Shin-Etsu Chemical Co., Ltd., KP-545) was spin-coated on the substrate on which polythiophene was patterned, and a gate insulating layer (thickness: 1 μm) was formed by exposure and heat curing. Further, Al was deposited on the gate insulating layer through a metal mask to form a gate electrode, thereby completing a top gate / bottom contact type organic semiconductor element.

As a result of measuring the current-voltage characteristics by changing the source / drain voltage of −50 V and the gate voltage from 20 V to −50 V of the manufactured organic semiconductor element, the mobility of the semiconductor element is estimated to be 0.1 cm ² / Vs. It was. The current-voltage characteristics were measured in a vacuum and protected from light. In addition, a bias stress test was performed in which −50 V was applied to the source / drain voltage and the gate voltage for 1000 seconds, and changes in the source / drain current were observed. As a result, after 1000 seconds, the current between the source electrode and the drain electrode was maintained at 85%, and good bias stress resistance was exhibited.

DESCRIPTION OF SYMBOLS 1 ... Base | substrate 2 ... Liquid repellent part 3 ... Source electrode 4 ... Drain electrode 5 ... Shielding layer 6 ... Organic-semiconductor element substrate 7 ... Lipophilic part 8 ... Organic-semiconductor layer 9 ... Gate insulating layer 10 ... Gate electrode 11 ... Base material

Claims (1)

A first step of preparing a substrate having a liquid repellent portion having liquid repellency with respect to an organic semiconductor layer forming solution containing an organic semiconductor material in a solvent, and a step of forming a shielding layer on the liquid repellent portion of the substrate. After the second step and the second step, by using the shielding layer, a part of the lyophobic portion of the substrate is modified into a lyophilic portion having lyophilicity with respect to the organic semiconductor layer forming solution. Forming a substrate for an organic semiconductor element, comprising: a third step, and a fourth step of forming a source electrode and a drain electrode on the substrate, which is performed after the first step, the second step, or the third step. Process,
The shielding layer is removed from the liquid-repellent portion of the base of the organic semiconductor element substrate, the organic semiconductor layer forming solution is applied onto the organic semiconductor element substrate, and the organic in contact with the source electrode and the drain electrode a step of forming the organic semiconductor layer for forming a semiconductor layer on the lyophilic portion,
The manufacturing method of the organic-semiconductor element which has this.

Images