WO2007132845A1

WO2007132845A1 - Organic semiconductor device and method for manufacturing same

Info

Publication number: WO2007132845A1
Application number: PCT/JP2007/059959
Authority: WO
Inventors: Hiroshi Imada; Hiroyuki Hanato; Toshihiro Tamura
Original assignee: Sharp Kabushiki Kaisha
Priority date: 2006-05-16
Filing date: 2007-05-15
Publication date: 2007-11-22

Abstract

An organic semiconductor device includes a substrate, and an organic semiconductor film formed in a prescribed region on the substrate. The organic semiconductor device is characterized in that the surface of the substrate whereupon the organic semiconductor film is formed has a surface free energy difference 5mJ/m2 or more larger than that of the surface of the substrate whereupon no organic semiconductor film is formed. The organic semiconductor device is also characterized in having lyophobic characteristics and liquid repellency brought by the surface free energy.

Description

Specification

Organic semiconductor device and manufacturing method thereof

Technical field

The present invention relates to an organic semiconductor device and a manufacturing method thereof. More specifically, the present invention relates to an organic semiconductor device having an organic semiconductor film in a predetermined region and a method for manufacturing the same.

Background art

In recent years, IC technology using a transistor using an organic semiconductor film has been proposed.

The transistor has the advantage that it can be easily manufactured and a flexible substrate can be used. Transistors with these advantages are expected to reduce costs when used in applications such as smart cards, electronic tags and displays.

[0003] Here, among the transistors, for example, members constituting a thin film transistor (TFT) are formed by a dry process such as a vacuum evaporation method or a wet process such as an inkjet method. However, the dry process is not preferred because it requires a vacuum line in the process. On the other hand, the wet process is a simple, low-temperature process and low-cost process, and therefore, the above advantages of the organic semiconductor film can be utilized.

[0004] It should be noted that in an example of actually producing and evaluating an organic TFT!

2

In many cases, an organic semiconductor film is formed as a gate insulating film by depositing an organic semiconductor material such as pentacene on the gate insulating film.

However, a material such as pentacene is strongly affected by the surface of the inorganic oxide constituting the gate insulating film. Therefore, the stacking property peculiar to organic substances is hindered, and there is a problem that the crystallinity of the organic semiconductor film in the vicinity of the gate insulating film interface, that is, in the carrier accumulation layer, is greatly reduced.

[0006] That is, since the surface energy of the gate insulating film, which is an inorganic acid / physical force, is large, this suppresses the diffusion of molecules on the substrate during the thin film growth process of the organic semiconductor material. As a result, many adsorption sites were generated, and as a result, a film with a small grain size and low crystallinity could not be obtained. This decrease in crystallinity of the organic semiconductor film is a factor that greatly affects the characteristics of devices such as organic TFTs.

[0007] In recent years, in order to suppress the deterioration of crystallinity, the gate insulating film is treated with octadecyltrichlorosilane (OTCS) to adjust the surface energy of the gate insulating film. There is a report that a film was made (IEEE Electron Device

Lett., 18, 606, 1997: Non-patent literature: 0.

[0008] As described above, the organic semiconductor film is produced by vapor deposition, but as described above, the gate insulating film is treated with a surface treatment agent such as OTCS, so that the crystallinity and TFT characteristics of the organic semiconductor film are obtained. It has become clear that this can be improved.

On the other hand, as a method for forming an organic semiconductor film by the above-described wet process, a spin coat method, a dip coat method, an ink jet method, a dispense method, and the like can be given (Japanese Patent Laid-Open No. 200).

4 No. 253375: Patent Document 1). Among these wet processes, it is preferable to use an ink jet method and a dispense method because of excellent material recoverability and high selectivity of film forming position.

Patent Document 1: Japanese Patent Application Laid-Open No. 2004-253375

Non-Patent Document 1: IEEE Electron Device Lett., 18, 606, 1997

Disclosure of the invention

Problems to be solved by the invention

[0011] The inkjet and dispensing methods are methods in which a nozzle head is moved to a desired position and a solution of several pL to several / zL is ejected electrically and mechanically. In these methods, since the nozzle head can be mechanically powered arbitrarily, the film forming position of the organic semiconductor film can be controlled. However, the solution discharged from the nozzle head is affected by the surrounding atmosphere, temperature, and pressure, and may develop without staying at the discharge position on the substrate.

For example, the substrate may be heated in order to improve the crystallinity of the organic semiconductor film or promote the evaporation of the solvent in the solution. This heating reduces the viscosity of the solution by activating the thermal mobility of the solution. Therefore, the solution develops on the substrate without staying at the discharge position. In other words, despite the solution being discharged between the source Z and drain electrodes, the solution spreads to a position other than between the source Z and drain electrodes, and the film is formed at that position. There was a problem of being done.

[0013] In order to solve this problem, a method of providing a bank surrounding a predetermined region, a method of processing a gate insulating film only in a predetermined region, and the like have been proposed.

[0014] A method of providing a bank is not preferable because the number of substrate processing processes increases. The method of treating the gate insulating film only in a predetermined region is a method in which only a predetermined region of a substrate surface-treated with OTCS or the like is exposed with ultraviolet rays or the like (hereinafter, this method is a one-component nodule). Called turning). However, with this method, the film-forming surface of the organic semiconductor film, that is, the channel is exposed to a gate insulating film that has not been treated with OTCS or the like. Therefore, the effect of improving the crystallinity of the organic semiconductor film by the surface treatment of the gate insulating film such as OTCS cannot be obtained.

[0015] The surface of the gate insulating film has dangling bonds of oxygen and the like, and has various chemical states. For this reason, the crystal growth of the organic semiconductor film is hindered. Therefore, the adhesion at the interface between the gate insulating film and the organic semiconductor film has been reduced, and the film uniformity of the organic semiconductor film has been reduced. These reductions have the problem of lowering the crystallinity and carrier transfer characteristics of the organic semiconductor film.

That is, an object of the present invention is to provide an organic semiconductor device having a structure capable of improving the carrier transfer characteristic of an organic semiconductor film and maximizing the carrier transfer characteristic of the organic semiconductor film. . Furthermore, an object of the present invention is to make it possible to control the formation position of an organic semiconductor film formed by a coating method. It is an object of the present invention to provide a method for controlling the materials and interface conditions used in the present invention.

Means for solving the problem

As a result of intensive studies, the present inventors have completed the present invention by finding a method for greatly improving crystallinity and electrical properties in an organic semiconductor film.

[0018] According to the present invention, it is an organic semiconductor device that includes a substrate and an organic semiconductor film formed in a predetermined region on the substrate, wherein the substrate on which the organic semiconductor film is formed. An organic semiconductor characterized in that the surface of the plate has a surface free energy difference of 5 mjZm ² or more larger than the surface of the substrate on which the organic semiconductor film is not formed, and is lyophobic due to the surface free energy. A device is provided. Furthermore, according to the present invention, the predetermined region where the organic semiconductor film is formed on the substrate surface has a surface free energy difference of 5 mjZm ² or more larger than the region where the organic semiconductor film is not formed. There is provided a method of manufacturing an organic semiconductor device, which includes a step of processing and then forming an organic semiconductor film in a predetermined region of the substrate surface. The invention's effect

According to the present invention, it is possible to provide an organic semiconductor device including an organic semiconductor film that is accurately patterned by a simple method using the difference in surface free energy.

The patterning is, for example, applying two different types of surface treatment agents (for example, organosilane compounds) to a predetermined region where the organic semiconductor film is formed and a region other than the predetermined region. Then, it can be carried out by forming a self-assembled film comprising these surface treatment agents. By utilizing the lyophobic property due to the difference in surface free energy between the two types of self-assembled film formed by this patterning, the application position of the solution containing the compound for forming the organic semiconductor film can be strictly controlled. Control is possible. Furthermore, the formation position of the organic semiconductor film and the size of the organic semiconductor film can be easily controlled by the shape of the mask used for patterning.

In addition, since a self-organized film derived from an organic silane compound is formed on the surface of an inorganic gate insulating film such as silicon oxide, the affinity between the organic semiconductor film and the gate insulating film is increased. Can be improved.

Brief Description of Drawings

FIG. 1 is a schematic configuration diagram of an organic thin film transistor of the present invention.

Explanation of symbols

[0022] 1 substrate

2 Gate electrode

3 Gate insulation film

4, 5 source Z drain electrode

6, 7 Self-assembled film

8 Organic semiconductor film BEST MODE FOR CARRYING OUT THE INVENTION

[0023] (1) Configuration and driving principle

The present invention can be used for any organic semiconductor device as long as it includes a substrate and an organic semiconductor film formed in a predetermined region on the substrate. Furthermore, in the present invention, the surface of the substrate on which the organic semiconductor film is formed has a difference in surface free energy that is 5 mjZm ² or more larger than the surface of the substrate, as opposed to the formation of the organic semiconductor film. Such surface free energy imparts lyophobic properties to the substrate surface. The upper limit of the difference in surface free energy is preferably 50 mjZm ² . A more preferable difference in surface free energy is 5 to 35 mjZm ² .

[0024] Here, the term "liquid repellency" used in the present invention means that the surface of the substrate and the liquid are difficult to adapt, and "liquid repellency" means that the surface of the substrate has the above surface free energy. Based on the difference, it means that it is more difficult to blend with liquid compared to the above “liquid repellency”.

Therefore, the term “liquid repellency” used in the present invention means having both liquid repellency and liquid repellency. Furthermore, the predetermined region has liquid repellency by having a surface free energy larger than that of other regions. The predetermined region has liquid repellency and thus has a property of preventing the organic semiconductor film from being formed in a region other than the predetermined region.

In the organic semiconductor device as described above, a predetermined region where the organic semiconductor film is formed on the substrate surface is subjected to a lyophobic liquid treatment so that the surface free energy difference is 5 mjZm ² or more larger than the region where the organic semiconductor film is not formed. Subsequently, it can be manufactured by including a step of forming an organic semiconductor film in a predetermined region of the substrate surface.

[0025] Specific examples of organic semiconductor devices include organic TFTs, organic capacitors, organic capacitors, and organic solar cells. Of these, the present invention is preferably applied to organic TFTs.

In the organic TFT, the substrate includes a gate electrode and a gate insulating film thereon. Therefore, the predetermined region is on the gate insulating film. Further, the self-assembled film is formed on the gate insulating film, and the organic semiconductor film is formed on the self-assembled film. Source Z Drain electrode 1S Formed on the gate insulating film to sandwich the organic semiconductor film before forming the organic semiconductor film Or formed on the organic semiconductor film.

[0026] As a method of giving the specific surface free energy difference, for example, the first self-assembled film is formed on a region other than the predetermined region, and the first self-assembled film is formed on the predetermined region by 5 mJ Zm. ^One example is a method of forming a second self-assembled film that gives a difference in surface free energy of ² or more. Due to such first and second self-assembled films, the entire film is lyophobic and the second self-assembled film is lyophobic, so that an organic semiconductor film is efficiently formed in a predetermined region. Can be made.

[0027] The thicknesses of the first and second self-assembled capsules vary depending on the material constituting them, but are preferably lOnm or less. If it is thicker than lOnm, the gate voltage applied to the organic semiconductor film coated on the self-assembled film is affected, which is not preferable. Therefore, the film thickness is more preferably 0.5ηm to 10nm, and further preferably 0.5nm to 5nm.

[0028] The organic semiconductor device provided with the two self-assembled films will be described with reference to FIG. 1, taking an organic TFT as an example.

FIG. 1 is a conceptual diagram of an example of an organic TFT. In FIG. 1, 1 is a substrate, 2 is a gate electrode, 3 is a gate insulating film, 4 and 5 are source Z drain electrodes, 6 and 7 are self-organized from the first and second organosilane compounds. Each means a film, and 8 means an organic semiconductor film. The organic TFT in Fig. 1 has a bottom gate and bottom contact structure. The organic TFT of FIG. 1 includes two self-organized film 6 and 7 having different components on a gate insulating film 3, and an organic semiconductor film 8 is formed through the self-assembled film 7.

[0029] When the present invention is used for an organic TFT, the structure has a structure in which a gate insulating film, two kinds of self-assembled films of different components, and an organic semiconductor film are laminated in this order. As long as this is done, the structure is not limited to that shown in FIG.

As another structure, for example, a structure in which a gate electrode, a gate insulating film, two self-assembled films having different components, an organic semiconductor film, and a source Z drain electrode are provided in this order on a substrate. This structure is an example in which a source Z drain electrode is formed on the upper surface of an organic semiconductor film. In the structure of FIG. 1, a source Z drain electrode is formed on the lower surface of the organic semiconductor film.

Here, the organic TFT according to the present invention includes an organic semiconductor between a gate insulating film and an organic semiconductor film. In order to control the formation position of the coating film containing the conductive film material, two self-assembled film films having different components may be provided in a predetermined pattern.

These two self-assembled films not only have the function of controlling the formation position of the organic semiconductor film, but also the function of controlling crystallinity and the device characteristics of the organic semiconductor film (carrier mobility, on-Z-off ratio, threshold voltage, etc.) It has a function to improve.

The former function is a function exhibited when the gate insulating film, the self-assembled film, and the organic semiconductor film are formed in this order. In addition, the latter function is a function achieved by providing a self-organizing capsule.

[0031] The function of controlling the crystallinity of the organic semiconductor film is achieved by the two self-assembled films adjusting the surface free energy of the gate insulating film. In other words, by interposing the self-assembled film, the solution containing the organic semiconductor film material can be uniformly adsorbed. As a result, an organic semiconductor film having a large grain size and improved crystallinity can be formed.

[0032] (Gate, source Z drain electrode)

The material of the gate and source Z drain electrodes is not particularly limited, and any material known in the art can be used. Specifically, metals such as gold, platinum, silver, copper and aluminum; refractory metals such as titanium, tantalum and tungsten; silicides and polycides with refractory metals; p-type or n-type highly doped silicon; ITO, Examples include conductive metal oxides such as NESA; conductive polymers such as polyethylene dioxythiophene (PEDOT).

[0033] The film thickness is not particularly limited, and can be appropriately adjusted to a film thickness (for example, 30 to 60 nm) used for a normal transistor.

[0034] The method for producing these electrodes can be appropriately selected depending on the electrode material. Examples of the manufacturing method include vapor deposition, sputtering, and coating.

[0035] (Gate insulating film)

The gate insulating film is not particularly limited, and any film known in the art can be used. Specifically, silicon oxide film (thermal acid film, low-temperature acid film: LTO film, etc., high-temperature oxide film: HTO film), silicon nitride film, SOG film, PSG film, BSG film, BPSG Insulating films such as films; PZT, PLZ IV, ferroelectric or antiferroelectric films; SiOF-based films, SiOC-based films or CF-based films, or HSQ (hydrogen silsesquioxane) -based films (inorganic) that are formed by coating, MSQ (methvl sil sesquioxane) -based films, PAE (polyarylene ether) -based films, BCB-based films, porous-based films, CF-based films, and other low dielectric films.

[0036] The film thickness is not particularly limited, and is normally used for a transistor (for example, 5

0 to 500 nm) can be appropriately adjusted.

[0037] The method for producing the gate insulating film can be appropriately selected depending on the type thereof, and examples thereof include vapor deposition, sputtering, and coating.

[0038] (Self-assembled film)

As a material for self-assembled film, the formula (1)

R'-Six'x'x ³ (1)

(In the formula, R ¹ is a linear or branched unsubstituted alkyl group, or a fluorine atom, a hydroxyl group, a thiol group, an amino group, a silyl group, a phenyl group, or a chenyl group. Means an alkyl group, a monocyclic aromatic group, a condensed aromatic group, a monocyclic heterocyclic group or a condensed heterocyclic group substituted with one or more selected same or different groups, X ¹ , X ² and X ³ are the same or different from each other, and represent a halogen atom or an alkoxy group having 1 to 5 carbon atoms)

The organosilane compound represented by these can be used.

[0039] The alkyl group R ¹ means the above formula (1), preferably 3 to 30 carbon atoms, more preferably an alkyl group having 8 to 18 carbon atoms.

Examples of the halogen atom represented by X ¹ , X ² and X ³ include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, preferably a chlorine atom.

Examples of the alkoxy group having 1 to 5 carbon atoms represented by X ¹ , X ² and X ³ include a methoxy group, an ethoxy group, a propoxy group, a butoxy group and a pentoxy group, and structural isomers thereof.

[0040] The liquid repellency of the self-assembled film is controlled by selecting the type and length of the functional group bonded to the silyl group of the silane compound used as a material for forming the film. It can be done.

[0041] In the case where the first and second self-assembled films are provided, the first self-assembled film has an R ¹ composed of an alkyl group having 8 to 18 carbon atoms and a fluoroalkyl group having 8 to 18 carbon atoms. Organic system An organosilane compound having a R ¹ derived from a orchid compound, wherein the second self-assembled film comprises a monocyclic aromatic group, a condensed aromatic group, a monocyclic heterocyclic group or a condensed heterocyclic group. It is preferable that the film is derived.

[0042] Further, the R ¹ group of the organosilane compound for the second self-assembled film is preferably a group containing a π-electron conjugated molecule.

Such a self-assembled film derived from an organic silane compound can have carrier mobility not only by the organic semiconductor film formed thereon but also by the self-assembled film itself.

Such a group containing a π-electron conjugated molecule is, for example, a group containing a monocyclic aromatic group, a condensed aromatic group, a monocyclic heterocyclic group, a condensed heterocyclic group, or the like.

On the other hand, a self-assembled film having an organic group exhibiting insulating properties can also act as part of the gate insulating film. Examples of such an organic group exhibiting insulating properties include an alkyl group and a fluoroalkyl group. Examples of these alkyl groups or fluoroalkyl groups include groups having 3 to 30 carbon atoms.

[0043] Examples of the method for forming the self-assembled film include gas phase and liquid phase adsorption methods.

The gas-phase adsorption method is a Teflon (registered trademark) crucible or glass sealed container in which a self-organized film raw material (for example, an organic silane compound) and a substrate are placed together, at a high temperature of 100 ° C or higher, 2 to This is a method of heat treatment for 3 hours and adsorbing to the substrate surface.

When an organic silane compound is used as a raw material, a Si—O—Si network is formed between the gate insulating film and the self-assembled film due to the terminal silyl group. With this network, an organic silane compound film covalently bonded to the gate insulating film can be formed. The self-assembled film may be a monomolecular film or a cumulative film in which monomolecular films are laminated.

Si-O-Si networks can also be formed between adjacent organic silane compounds.

[0044] In the liquid phase adsorption method, the raw material of the self-assembled film is dissolved in a solvent such as toluene, ethanol, chloroform, etc. to prepare a solution of about 20 mM of the raw material, and the substrate is placed in this solution. Is immersed in the substrate surface for about 24 hours. At this time, in order to shorten the reaction time, the solution in which the substrate is immersed may be heated to a temperature below the boiling point of the solvent. You can also. Other examples of the liquid phase reaction include spin coating, ink jet, dispensation, and dip coating.

[0045] After the adsorption, in both the gas phase and liquid phase methods, it is preferable to ultrasonically wash with the solvent to remove the material that remains without being adsorbed on the substrate.

When the material is the above organic silane compound, it is preferable to hydrophilize the substrate in advance before the compound is adsorbed, because it can be adsorbed efficiently.

As the hydrophilization treatment method, there are a method in which the substrate is irradiated with ultraviolet rays or plasma, and a method in which the substrate is immersed in a mixed solvent of sulfuric acid Z hydrogen peroxide.

[0046] When the self-assembled film is the first and second self-assembled films having the above-mentioned organosilane compound force, the second self-assembled film is hydrophilized as follows in addition to the hydrophilization treatment. A force may also be formed upon treatment. That is, by irradiating the predetermined region of the first self-organized film with ultraviolet rays or plasma with a mask pattern having an opening in the predetermined region, the first self-organized film is peeled from the region. This peeling is performed under the condition that only R ¹ is removed and the component derived from the silyl group remains in a predetermined region. This component hydrophilizes the predetermined area.

Next, the second self-assembled film formed is so that the hydrophilic silyl group side faces the substrate side.

, It is preferentially formed in a predetermined hydrophilic region. Thereafter, an organic semiconductor film is formed only in the predetermined region due to the difference in surface free energy.

[0047] In the above method, the coating solution containing the organic semiconductor film material can be applied by using the difference in surface energy between the two self-assembled films (this coating can be divided into two components). Called turning). Therefore, the organic semiconductor film can be formed by a simple method.

[0048] This is because the inventors of the present invention have a surface freeness between the second self-assembled film other than the region where the organic semiconductor film is formed and the predetermined region where the organic semiconductor film is formed, that is, the first self-assembled film. This is based on the finding that when the energy difference is 5 miZm ² or more, the coating solution containing the organic semiconductor film material can be applied separately.

[0049] Note that the organosilane compound constituting the first self-assembled film exhibiting lyophobic properties is specifically preferably a silane compound containing an alkyl group or a fluoroalkyl group. More preferably, the fluoroalkyl group has 8 or more carbon atoms.

[0050] More specifically, the organosilane compound includes n-octadecyltriethoxysila. (OTES) (CAS.No. (hereinafter the same): 7399—00—0, manufactured by Alphamax Co., Ltd.), n—otadecyltrichlorosilane (112—04—9, manufactured by Alphamax Co., Ltd.), n —Decyltrichlorosilane (13829—21—5, manufactured by AMAX Co., Ltd.), (Heptadecafluor mouth 1, 1, 2, 2-tetrahydrodecyl) triethoxysilane (HFTHTES) (101947—16—4, AMAX Co., Ltd.) Manufactured).

[0051] The organic silane compound constituting the second self-assembled film exhibiting liquid repellency is specifically a silane compound containing a phenyl group, a chael group, an amino group, or a hydroxyl group. It is preferable that it exists.

[0052] More specifically, the organosilane compound includes p-aminophenol trimethoxysilane (33976-43-1, manufactured by AMAX Co., Ltd.), phenol triethoxysilane (PTES) (780 69-8). (Manufactured by AMAX Co., Ltd.), phenethyltrichlorosilane (940-41-0, manufactured by Amatsu Tas Co., Ltd.), 2-channel trimethylsilane (18245-28-8, manufactured by AMAX Co., Ltd.), n- (2 aminoethyl) 3 aminopropyltrimethoxysilane (1760-24-3, manufactured by Amatsu Tas Co., Ltd.), aminomethyltrimethylsilane (AMTMS) (18166-02-02, manufactured by Amax Co., Ltd.), 3 Examples include aminopropyltriethoxysilane (919-30-2, manufactured by AMAX Co., Ltd.) and hydroxymethyltrimethylsilane (HMTMS) (3319-6-4, manufactured by AMAX Co., Ltd.).

[0053] Here, the organosilane compound can be synthesized using, for example, a silly cocoon by the following Grignard reaction.

For example:

R ² — MgX ⁴

(Wherein R ² has the same meaning as R ¹ in the above formula (1), and X ⁴ is a halogen atom), and a compound represented by the following formula:

[0054] R'-SiX'x

(Wherein R ³ is a hydrogen atom, a halogen atom or a lower alkoxy group, and X ⁵ , X ⁶ and X ⁷ may be the same or different from each other, and a hydrogen atom, a halogen atom or an alkoxy group having 1 to 5 carbon atoms. It is a group that can give a hydroxyl group by hydrolysis like a group)

Is subjected to Grignard reaction to give the following formula: R'-SiX'x

(Wherein R ² , X ⁵ , X ⁶ and X ⁷ have the same meaning as above)

Can form organosilane compounds.

[0055] In these organosilane compounds, X ^{5 to} X ⁷ can be halogen atoms such as chlorine and bromine, alkoxy groups having 1 to 5 carbon atoms such as methoxy groups, ethoxy groups, and butoxy groups. Furthermore, as long as any one of X ^{5 to} X ⁷ gives a hydroxyl group, the other may be an alkyl group having 1 to 5 carbon atoms such as a methyl group, an ethyl group, or a butyl group! /.

[0056] Specific examples of the organic silane compound obtained by the Grignard reaction include biphenylene triethoxysilane (2PTES), terferene triethoxysilane (3PTES), quater terferene triethoxysilane ( 4PTES), quinkefene-lentriethoxysilane (5P TES), tert-off-entry ethoxysilane (3TTES), quaternary-off-entry ethoxysilane (4TTES), quinquethiophenetriethoxysilane (5TTES), naphthalene entroxysilane (NTES) ) And anthralene triethoxysilane (ATES).

The organosilane compound can also be obtained by the methods described in JP-A-2004-277413, JP-A-2005-298485, and the like.

[0057] Production Example 1

Synthesis of 3PTES

In a 500 ml four-necked flask equipped with a stirrer, reflux condenser, thermometer, and dropping funnel, 1.5 mol of turf was dissolved in 300 ml of carbon tetrachloride, and then 2,2'-azobisisobuty-trill (AIBN) l. 5 moles and N-bromosuccinimide (NBS) l. The mixture was stirred at C for 3 hours, cooled and filtered under reduced pressure, and the solvent was distilled off under reduced pressure to obtain bromoterphel.

[0058] Subsequently, 0.5 mol of magnesium metal and 300 ml of tetrahydrofuran (THF) were charged into a 500 ml four-necked flask equipped with a stirrer, a reflux condenser, a thermometer, and a dropping funnel, and 0.5 mol of bromoterphel obtained above was added. The mixture was added dropwise with stirring over 2 hours while maintaining the temperature at 50 to 60 ° C. After completion of the addition, stirring was continued for another 2 hours at 65 ° C to prepare a Grignard reagent.

[0059] In a 1-liter four-necked flask equipped with a stirrer, reflux condenser, thermometer, and dropping funnel, Si (0 CH) (Tetraethoxysilane) 1.0mol, 300ml toluene, ice-cooled, internal temperature 20 ° C

2 5 4

While maintaining the following, the Grignard reagent obtained above was added over 2 hours with stirring, and after completion of the dropwise addition, stirring was continued for 1 hour at 30 ° C.

[0060] Next, the reaction solution was filtered under reduced pressure to remove magnesium chloride, and then the filtrate was concentrated under reduced pressure to remove toluene and unreacted tetraethoxysilane, and the resulting solution was distilled. 3PTE

S was obtained in 50% yield.

The synthesized product obtained here was confirmed to be 3PTES by measuring —NMR and ¹³ C-NMR.

[0061] Production Example 2

Biphenyl-triethoxysilane (2PTES) was obtained in a yield of 50% in exactly the same manner as in Production Example 1 except that 1.5 mol of biphenyl was used in place of the terphenyl of Production Example 1.

The synthesized product obtained here was confirmed to be 2PTES by measuring —NMR and ¹³ C-NMR.

[0062] Production Example 3

Quarter-phenol triethoxysilane (4PTES) was obtained in a yield of 40% in exactly the same manner as in Production Example 1 except that 1.5 mol of quarter-fouling was used instead of the terfal of Production Example 1.

In addition, it was confirmed by measuring —NMR and ¹³ C—NMR that the resultant compound force was 4PTES.

[0063] Production Example 4

Quinchephe-lentriethoxysilane (5PTES) was obtained in 35% yield in exactly the same manner as in Production Example 1 except that 1.5 mol of quinkefel was used in place of the terferol of Production Example 1. In addition, it was confirmed by measuring —NMR and ¹³ C—NMR that the resultant compound strength was 5PTES.

[0064] Production Example 5

Tertoffene ethoxysilane (3TTES) was obtained in 40% yield in exactly the same manner as in Production Example 1 except that 1.5 mol of terthiophene was used in place of the terferol of Production Example 1. Note that it is a composite force 3TTES obtained here, - the NMR, ¹³ C-NMR Confirmed by measuring.

[0065] Production Example 6

Quotathiophene mole 1.5 mol was used in place of the terferol of Production Example 1, and Quarti-Off-Entry ethoxysilane (4TTES) was obtained in 40% yield exactly as in Production Example 1. .

In addition, it was confirmed by measuring —NMR and ¹³ C—NMR that the resultant compound strength was 4TTES.

[0066] Production Example 7

Quinquetiophene triethoxysilane (5TTES) was obtained in 40% yield exactly as in Production Example 1 using 1.5 moles of Quinquetiophene instead of the terferol of Production Example 1. It was confirmed by measuring NMR and ¹³ C-NMR that the resultant compound strength was 5TTES.

[0067] Production Example 8

Naphthalene 1.5 mol was used instead of terphenyl of Production Example 1, and naphthalene triethoxysilane (NTES) was obtained in a yield of 40% in exactly the same manner as Production Example 1.

It was confirmed by measuring 'H-NMR, ¹³ C-NMR that the compound strength NTES obtained here was NTES.

[0068] Production Example 9

Anthralene triethoxysilane (ATES) was obtained in a yield of 40% in exactly the same manner as in Production Example 1, except that 1.5 mol of anthracene was used in place of the terfal of Production Example 1.

In addition, it was confirmed by measuring —NMR, ¹³ C—NMR that the resultant compound strength was ATES.

[0069] Test Examples 1 to 14

Using the above OTES, AMTMS, HMTMS, HFTHTES and PTES, and each organosilane compound obtained in the above Production Examples 1 to 9, mixing hydrogen peroxide and concentrated sulfuric acid by the gas phase adsorption method. A self-assembled film was formed on a Si wafer hydrophilized with the solution. That is, a Si wafer that has been preliminarily heated to 80 ° C and immersed in a mixed solution of hydrogen peroxide and concentrated sulfuric acid (3: 7) for 20 minutes, then washed with water, dried, and hydrophilized, and the above production Each of the organosilane compounds lml obtained in Examples 1 to 9 was placed in a Teflon (registered trademark) crucible and heat-treated at 120 ° C. for 2 hours to form a self-organized film of each organosilane compound on Si. It was formed on the wafer.

The surface free energy of the self-assembled film formed on each Si wafer obtained in Test Examples 1 to 14 above was determined using pure water and iodine using MCA-2 (manufactured by Kyowa Interface Chemical Co., Ltd.). The surface of the self-assembled film derived from each organosilane compound obtained in Production Examples 1 to 9 obtained above based on the Zisman method based on the value of the contact angle with methylene chloride The measurement results of free energy are shown in the following table.

[0070] [Table 1]

[0071] (Organic semiconductor film)

As the organic semiconductor film formed on the self-assembled film, a film made of a material known in the art can be used. Examples of the organic semiconductor material include the following low-molecular compounds and high-molecular compounds in consideration of transistor driving or material supply.

[0072] As the low molecular weight compound for organic semiconductor film materials, a compound having a molecular weight of less than 1,000 is preferred. Specifically, oligocenes condensed with 3 to 10 benzene rings, oligothiophenes with 3 to 10 repeats of thiophene, oligoligene with 3 to 10 repeats of benzene, benzene and bilene. Examples thereof include oligophenol-lentiophene compounds having 1 to 10 repeating oligophenol-lylene-benzenes, benzene and thiophene repeating 1 to 10 compounds, and derivatives thereof.

Further, fullerene compounds such as fullerene (C60) and [6,6] -phenol C61 butanoic acid methyl ester (PCBM) can also be used.

[0073] The polymer compound for organic semiconductor film material is preferably a compound having a number average molecular weight of 10,000 or more. For example, thiophene, phenylene bilene, phenylene type, and derivatives thereof are compounds having a repeating unit force selected. Specifically, poly-3-hexylthiophene (P3HT), polyphenylene-lene (PPV), and derivatives thereof are particularly preferable.

[0074] (Solvent for forming organic semiconductor film)

As the solvent for forming the organic semiconductor film, a solvent having high solubility and boiling point for the material of the organic semiconductor film is preferable. Specific examples include aromatic hydrocarbons such as benzene, toluene, and p-xylene, aliphatic halogenated hydrocarbons such as chloroform, formaldehyde, dichloroethylene, trichloroethylene, tetrachloroethylene, and 1,2-dichloroethylene, Aromatic halogenated hydrocarbons such as dichroic benzene and 1,2,4 triclonal benzene

[0075] (Method for producing organic semiconductor film)

As a method for producing the organic semiconductor film, all coating methods such as the LB method, the dip method, and the casting method (spin coating method, ink jet method, and dispense method) can be applied. Of these, the casting method (inkjet method, dispense method) is preferable in consideration of material and mass production costs.

[0076] The definitions of the LB method, the dip method, and the casting method in this specification are as follows.

[0077] The LB method is an abbreviation of the Langmuir-Blodgett method. An amphiphilic substance in which a hydrophobic group and a hydrophilic group are balanced is developed on the water surface to produce a single-layer film called a monomolecular film.

Further, it is a method of transferring it to the substrate. [0078] The dip method is a method of forming a film by immersing a substrate in a solution and then pulling it up. In the case of a material having crystallinity, a crystal having a specific structure can be grown. .

[0079] The casting method means a method of forming a film by dropping a solution containing a raw material at a desired position and drying, and includes a spin coating method, an ink jet method, and a dispensing method.

[0080] Test Examples 15-24

Next, based on the results shown in Table 1, we examined the application of the organic semiconductor film material solution to two self-assembled film films with different component forces.

That is, as Test Example 15, OTES was used as an organic silane compound for forming the first self-organized film (lyophobic component), and an organic silane compound for forming the second self-organized film (liquid repellent). Using PTES obtained in Production Example 1 as a component), we examined the coating properties of the organic semiconductor film material solution on the substrate on which the first and second self-assembled films were formed. In Test Examples 16 to 24, the organosilane compound obtained in Production Examples 2 to 9 was used in place of PTES.

Specifically, first, a first self-assembled film derived from OTES was formed on a Si wafer by the method described in Test Example 1 using OTES.

[0081] Next, the Si mask obtained above was fixed with a metal mask having a hole of 0.8 mm diameter, irradiated with 172 nm vacuum ultraviolet light for 20 minutes, and the first self-organization of the region corresponding to the hole was performed. The formed film was peeled off and hydrophilized. Next, each second self-assembled film was formed in the region using PTES by the method described in Test Example 1.

[0082] A solution of an organic semiconductor film material was prepared using an organic semiconductor film material using black mouth form, toluene, p-xylene, benzene, and 1,2,4-trichloro mouth benzene as solvents. The following table shows the results of examining the application of the organic semiconductor film material solution on the Si wafer obtained above.

[0083] [Table 2] Test example f machine Silane 匕 ^ 1 surface self-width; Ε · ^ noregy evaluation 1 evaluation 2

(mj / m ² )

1 5 PTES 39. 1 〇

1 6 2PTES 3 7. 7 〇

1 7 3 PTES 3 7.4 〇

1 8 4 PTES 34. 8 〇

1 9 5 PTES 30.4 o

20 3TTES 3 3. 7 〇

2 1 TTES 28. 7 〇

22 5TTES 3 1. 7 〇

23 NTES 38. 7 〇

24 ATES 3 7. 9 〇

[0084] In the above table, evaluation 1 means that the second self-organization is performed on all the solutions of the organic semiconductor film material using chloroform-form, toluene, p-xylene, benzene, 1,2,4 trichloro-benzene as a solvent. This means that the organic semiconductor film can be formed only on the film.

On the other hand, evaluation 2 means that an organic semiconductor film can be formed only on the second self-assembled film with a solution using 1,2,4 trichlorobenzene, among the above solvents. This means that the second self-assembled force cannot be formed only on the capsule.

As a result, it has been empirically found that the surface free energy difference between the two self-assembled films is required to be about 5 mjZm ² in order to pattern the solvent.

Example

The following examples are for explaining the present invention and are not intended to limit the present invention in any way.

Example 1

In order to fabricate the organic thin film transistor shown in FIG. 1, first, chromium was vapor-deposited on a substrate 1 having a silicon force to form a gate electrode 2.

Next, after baking at 1200 ° C. to form a gate insulating film 3 made of a silicon thermal oxide film, chromium and gold are vapor-deposited in this order, and source and drain electrodes (4, 5) was formed.

[0088] Continued! Soak the resulting substrate in a mixed solution of hydrogen peroxide and concentrated sulfuric acid (3: 7) heated to 80 ° C for 20 minutes to hydrophilize the surface of the gate insulating film 3. Washed with water and dried. place The treated substrate is placed in a Teflon (registered trademark) crucible with 0.5 ml of (heptadecafluoro-1,1,2,2-tetrahydrodecyl) triethoxysilane (HFTHTES) and heated at 120 ° C for 2 hours to heat the entire surface of the substrate HFTHTES was adsorbed on the surface. A metal mask with a diameter of 0.8 mm was fixed on the treated substrate so as to fit the channel, and then 172 nm vacuum ultraviolet light was irradiated for 20 minutes to hydrophilize only the channel. The hydrophilized substrate was treated with ferretrioxysilane (PTES) in the same manner as the HFTHTES treatment method, and PTES was adsorbed only to the channel hydrophilized by the patterning treatment. By the above method, a two-component patterning substrate of HFTH TES and PTES was obtained.

[0089] Further, when adsorbing each Silane compound, the Si wafer was placed in a Teflon (registered trademark) crucible for contact angle evaluation. The contact angle values of toluene solvent for HFTHTES and PTES were 102 ° and 65 °, respectively. The contact angle was measured by MCA-2 (manufactured by Kyowa Interface Chemical Co., Ltd.).

[0090] 1,2,3,4,6,11-Hexapropylnaphthacene (HP naphthacene) [18155-96] (manufactured by Kanto Kagaku) 0.2 wt% toluene solution heated to 80 ° C. In addition, an organic semiconductor film was obtained by dropping 500 nl using a dispenser (manufactured by Musashi Engineering Co., Ltd.).

[0091] When the organic semiconductor film formed above was observed with an optical microscope, it was confirmed that an HP naphthacene film was formed only on the channel patterned with PTES. It was.

[0092] Further, when the crystallinity of the organic semiconductor film was evaluated by X-ray diffraction (XRD) measurement (RINT2000, Rigaku Co., Ltd.), 2Θ = 6.9 (plane spacing d = 1.28nm), 13.8 ° (d = (001) and (002) diffractions were observed at 0.64 nm), indicating that the crystals were highly crystallized.

[0093] The organic thin film transistor obtained above was measured for transistor characteristics using a three-probe method (4200—SCS, manufactured by Keithley Instruments Co., Ltd.). The field effect mobility was 2.2 × 10 ² cm ^2. With ZVs, the on / off ratio was about 5 digits, and it was found that good performance was obtained.

[0094] Comparative Example 1

As in Example 1, a gate electrode, a gate insulating film, a source and a drain electrode are formed on the substrate. In the same manner as in Example 1, a toluene solution of HP naphthacene was dropped onto an untreated substrate that had been formed and had no surface hydrophilization treatment, to produce an organic semiconductor film.

The organic thin film transistor thus obtained was measured for XRD, field effect mobility and on-Z off ratio in the same manner as in Example 1. As a result, (001) diffraction was observed at 2 Θ = 6.9 °, and , field mobility is 3.7 X 10- ⁴ cm ² ZVs, on / off ratio was filed in about three orders of magnitude.

[0095] Comparative Example 2

A gate electrode, a gate insulating film, a source and a drain electrode are formed on a substrate in the same manner as in Example 1, and the surface is subjected to a hydrophilic treatment, and then the entire surface is treated with HFTHTES. A toluene solution was dropped to prepare an organic semiconductor film.

The organic thin-film transistor thus obtained was measured for XRD, electrolytic effect mobility, and on-Z off ratio in the same manner as in Example 1. As a result, (001) diffraction was observed at 20 = 6.9 °, and the electric field effect mobility in 6.1 X 10- ⁴ cm ² ZVs, on / off ratio is filed in about three orders of magnitude.

[0096] Comparative Example 3

In the same manner as in Example 1, a gate electrode, a gate insulating film, a source and a drain electrode were formed on a substrate, and the surface was hydrophilized, and the entire surface was treated with PTES. A toluene solution was dropped to prepare an organic semiconductor film.

The organic thin film transistor thus obtained was measured for XRD, electrolytic effect mobility, and on / off ratio in the same manner as in Example 1, and was found to be (001) and (002) at 2 Θ = 6.9 ° and 13.8 °, respectively. ) diffraction is observed, the field effect mobility in 4.8 X 10- ³ cm ² ZVs, on Z off ratio of about 5 orders of magnitude.

[0097] Comparative Example 4

The gate electrode, gate insulating film, source and drain electrodes were formed on the substrate in the same manner as in Example 1, and the surface was hydrophilized, and the entire surface of the HFTHTES was treated in the same manner as in Example 1. In the same way as in Example 1, a solution of HP naphthacene in toluene was dropped onto a one-component patterning substrate that had been hydrophilized with a 0.8 mm φ mask to produce an organic semiconductor film. The organic thin-film transistor thus obtained was measured for XRD, electrolytic effect mobility, and on-Z off ratio in the same manner as in Example 1. As a result, (001) diffraction was observed at 20 = 6.9 °, and the electric field effect mobility in 8.1 X 10- ⁴ cm ² ZVs, on / off ratio is filed in about three orders of magnitude.

[0098] Comparative Example 5

In the same manner as in Example 1, a gate electrode, a gate insulating film, a source and a drain electrode are formed on a substrate, and the surface is subjected to a hydrophilic treatment. After the entire surface is treated with PTES as in Example 1, in Example 1, Toluene solution of HP naphthacene was dropped onto the 1-component patterning substrate that was hydrophilized with the 0.8mm φ mask used, as in Example 1. An organic thin film transistor thus obtained was prepared. , it was measured in the same manner as XRD, electrolytic effect mobility and on Z off ratio as in example 1, diffraction to 2 0 = 6.9 ° (001) is observed, the field-effect mobility 8.6 X 10- ⁴ cm ^{At 2} ZVs, the on / off ratio was about 3 digits.

[0099] From the results of the above Comparative Examples 1 to 5, in the substrate that was not subjected to the patterning treatment, the toluene solution moved without staying in the channel, so that the formed film did not completely cover the channel. Therefore, even if the crystallinity is high, the field effect mobility and the on-Z off ratio are considered to have decreased.

[0100] Further, the formation position of the organic semiconductor film could be strictly controlled by the one-component patterning treatment, and the coating film was formed in the channel. However, a high crystalline film cannot be obtained, and the off-current is 10 times larger than that of a substrate in which the surface of the gate insulating film is treated with an organosilane compound. It has been found.

[0101] From the above, it was proved that the formation position of the coating film highly crystallized by the two-component patterning can be strictly controlled and the off-current can be reduced.

Claims

The scope of the claims

[1] An organic semiconductor device including a substrate and an organic semiconductor film formed in a predetermined region on the substrate, wherein the surface of the substrate on which the organic semiconductor film is formed is the organic semiconductor film An organic semiconductor device characterized by having a surface free energy difference of 5 mjZm ² or more larger than the surface of the substrate that is not formed and lyophobic due to the surface free energy.

[2] A region other than the predetermined region includes a first self-organizing membrane, the predetermined region includes a second self-organizing membrane, and the second self-organizing membrane is a first self-organizing membrane. ^2. The organic semiconductor device according to claim 1, wherein the organic semiconductor device has a surface free energy that is 5 mjZm ² or more larger than the tissue film.

[3] The organic semiconductor device according to [2], wherein the first and second self-assembled films have a thickness of lOnm or less.

[4] The first and second self-assembled films have the formula (1)

R'-SiX'x'x ³ (1)

(In the formula, R ¹ is either a linear or branched unsubstituted alkyl group, or a fluorine atom, arsenic Dorokishi group, a thiol group, an amino group, a silyl group, the group force consisting phenyl group or thienyl group force Means an alkyl group, a monocyclic aromatic group, a condensed aromatic group, a monocyclic heterocyclic group or a condensed heterocyclic group substituted with one or more selected same or different groups, X ¹ , X ² and X ³ are the same as or different from each other and represent a halogen atom or an alkoxy group having 1 to 5 carbon atoms)

3. The organic semiconductor device according to claim 2, which is a film formed by selecting R ¹ in the organosilane compound represented by the formula:

5. The organic semiconductor device according to claim 1, wherein the organic semiconductor film is a film made of a π electron conjugated compound.

[6] The first self-assembled film is derived from an organic silane compound having R ¹ having an unsubstituted or substituted alkyl group having 3 to 30 carbon atoms, and the second self-assembled film 5. The organic semiconductor device according to claim 4, wherein the organic semiconductor device is derived from an organic silane compound having R ¹ composed of a monocyclic aromatic group, a condensed aromatic group, a monocyclic heterocyclic group, or a condensed heterocyclic group. .

[7] A predetermined region for forming the organic semiconductor film on the substrate surface is not formed on the organic semiconductor film. An organic semiconductor device comprising a step of performing a lyophobic treatment so as to have a surface free energy difference of 5 mjZm ² or more larger than a region having a large area, and then forming an organic semiconductor film in a predetermined region on the substrate surface. Production method.

[8] The organic semiconductor film is not formed and the predetermined region and the predetermined region are covered with first and second self-assembled film made of films derived from different organic silane compounds, The first and second self-assembled films are a combination of films that give a difference in surface free energy that is 5 mjZm ² or more larger than a region where the organic semiconductor film is not formed in the predetermined region, A step of forming a first self-assembled film on the entire surface of the substrate, and a step of hydrophilizing a predetermined region by peeling off the first self-assembled film by irradiating the predetermined region with ultraviolet light or plasma. And a step of forming a second self-assembled film in a predetermined region from which the first self-assembled film has been peeled off.

[9] The organic semiconductor device according to [7], wherein the organic semiconductor film is formed in a predetermined region using a difference in surface free energy by a coating method of a solution containing an organic semiconductor material and a solvent. Production method.

[10] The method for producing an organic semiconductor device according to [8], wherein the first and second self-assembled films are films derived from an organosilane compound represented by the formula (1) according to claim 4. .

[11] The method further comprises a step of hydrophilizing a predetermined region of the substrate surface before the lyophobic treatment, and the self-organized film is formed by a gas phase adsorption method or a liquid phase adsorption method. 7. A method for producing an organic semiconductor device according to 7.

12. The method for producing an organic semiconductor device according to claim 9, wherein the solvent is an aromatic halogenated hydrocarbon, an aliphatic halogenated hydrocarbon, or an aromatic hydrocarbon.

[13] The aromatic halogenated carbon is black mouth benzene, o-dichloro mouth benzene or 1,2,4-trichloro mouth benzene, and the aliphatic halogenated hydrocarbon is black mouth form, 1, 1-dichloro mouth. The method for producing an organic semiconductor device according to claim 12, which is ethylene, 1,1,2-trichloroethylene, tetrachloroethylene, or 1,2-dichloroethylene, and the aromatic hydrocarbon is benzene, toluene, or p-xylene.

14. The method for producing an organic semiconductor device according to claim 9, wherein the coating method is a spin coating method, an ink jet method, a dispense method, or a dip method. The substrate includes a gate electrode and a gate insulating film on the gate electrode, and the predetermined region is on a gate insulating film, and the organic semiconductor film is formed on the second self-assembled film. And a step of forming a source Z drain electrode on the gate insulating film so as to sandwich the organic semiconductor film before forming the organic semiconductor film, or a source Z drain electrode on the organic semiconductor film. The method for producing an organic semiconductor device according to claim 8, wherein the second self-assembled film is a monomolecular film having a carrier transport function.