JP2010192568A - Method of manufacturing organic tft array - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an organic TFT (Thin Film Transistor) array capable of stably providing excellent characteristics and high reliability by: preventing leakage of ink into an unnecessary region; and improving adhesiveness of the ink. <P>SOLUTION: The method of manufacturing an organic TFT array including a plurality of organic TFTs arranged in a matrix includes steps of: manufacturing a first substrate having liquid repellency on the front surface; manufacturing a second substrate having a plurality of source electrodes/drain electrodes formed in a matrix on a base layer; applying an organic semiconductor precursor solution on the front surface of the first substrate at intervals equal to those of a plurality of channels formed in the plurality of source electrodes/drain electrodes formed on the second substrate and drying the solution; and superposing the first substrate with the organic semiconductor precursor solution applied/dried on the second substrate to transfer the organic semiconductor precursor solution to the channels of the second substrate. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an organic TFT array, and more particularly to a method for manufacturing an organic TFT array in which an organic semiconductor film is formed by transfer.

  In recent years, a technique for forming a thin film transistor (hereinafter also referred to as TFT) on a substrate has greatly advanced, and in particular, application development to a drive element of an active matrix type large screen display device has been advanced. TFTs that are currently in practical use are manufactured with Si-based inorganic materials such as a-Si and poly-Si, but the manufacture of TFTs using such inorganic materials requires a vacuum process or a high-temperature process. And greatly affects the manufacturing cost.

  Therefore, in order to deal with such problems, various TFTs using organic materials (hereinafter also referred to as organic TFTs) have been studied in recent years. Organic materials have a wider choice of materials than inorganic materials, and the manufacturing process of organic TFTs uses processes with excellent productivity such as printing and coating instead of the vacuum process and high temperature process described above. Cost can be reduced. Furthermore, it may be formed on, for example, a plastic film substrate having poor heat resistance, and is expected to be applied to various fields.

  As a method for applying the organic semiconductor material, a droplet coating technique such as an inkjet method or a dispenser method in which a solution (hereinafter also referred to as ink) in which the organic semiconductor material is dissolved is directly applied is known. These techniques are: 1. No vacuum process is required. 2. There is no waste of materials. Since direct patterning is possible, there is an advantage that an etching process is not required as compared with the photolithography method. As a result, manufacturing costs can be reduced, and extensive research has been conducted.

  By the way, in such an organic TFT, in order to obtain excellent electrical characteristics and high reliability, it is necessary to accurately form an organic semiconductor film at a predetermined position with an appropriate film thickness. However, when the organic semiconductor film of the organic TFT is formed by using the above-described inkjet method, dispenser method, etc., the applied ink is wet and spread due to the influence of the substrate surface condition, dry atmosphere, etc. until it is solidified. It may reach an unnecessary area on the periphery. For this reason, there existed a problem that patterning defect and sufficient film thickness were not obtained, and there existed a problem that the favorable characteristic of organic TFT was not acquired.

  Therefore, various techniques have been studied to deal with such problems. For example, a technique is known in which a partition called a bank is formed of a material having liquid repellency at the periphery of an application region using a photolithography method to prevent the discharged ink from flowing out of the application region. (See Patent Document 1).

  However, the technique described in Patent Document 1 requires an unnecessary process for forming a bank structure. For this reason, there has been a problem that the manufacturing cost is increased and the yield is reduced.

  On the other hand, a method of applying ink using a printing technique is known. However, in this case, there is a problem that expensive ink is wasted.

  Therefore, in order to cope with such a problem, for example, in Patent Document 2, first, ink is applied onto a blanket (transfer body) by using an ink jet method, and the shape of the ink formed by transfer is substantially the same. A pattern having the same shape is formed. After that, a method is proposed in which the letterpress is pressed against the ink application surface, the ink in contact with the letterpress (unnecessary ink) is removed from the blanket, and then the ink remaining on the blanket is transferred to the transfer target. ing. This reduces the consumption of expensive ink.

  In Patent Document 3, ink is applied onto a cylinder (transfer body) having a predetermined releasability using an ink jet method, and a pattern having the same shape as the shape of the ink formed by transfer is formed. Then, a method for directly transferring the pattern onto the transfer target has been proposed.

Japanese Patent No. 3692524 JP 2007-268853 A JP 2004-42584 A

  By the way, for a higher density organic TFT, the amount of ink applied to the channel (region sandwiched between the source electrode and the drain electrode) becomes very small, and the drying of the ink is accelerated. For this reason, the method disclosed in Patent Document 2 has a problem that when the unnecessary ink is removed from the blanket by the relief printing, the ink is already dried and cannot be removed accurately. Furthermore, this method requires a relief plate (printing plate) for removing unnecessary ink, and there is a problem that the manufacturing process becomes complicated and expensive.

  Further, in the method disclosed in Patent Document 3, a pattern having the same shape as the shape of ink formed by transfer is formed on a cylinder (transfer body), and the pattern is directly transferred to a transfer target. It does not require a step of removing ink, and is excellent in productivity. However, when the ink on the cylinder (transfer body) is insufficiently dried and transferred to the transfer body, the surface of the transfer body may be wetted and reach an unnecessary area on the periphery. For this reason, there is a problem that a patterning defect or a sufficient film thickness cannot be obtained, and this is not suitable particularly for a high-density organic TFT array.

  On the other hand, even if the ink on the cylinder (transfer body) is properly dried, the surface of the organic semiconductor ink dried and solidified, and the electrodes (source electrode, drain electrode) and gate insulation are transferred. It is very difficult to ensure sufficient adhesion at the interface with the film, and it is not easy to stably ensure good performance.

  The present invention has been made in view of the above problems, and without causing the manufacturing process to be complicated and expensive, while suppressing the leakage of ink to unnecessary areas and improving the adhesion of the ink, An object of the present invention is to provide an organic TFT array manufacturing method capable of stably obtaining excellent characteristics and high reliability.

  The above object is achieved by the invention described in any one of 1 to 5 below.

1. In a method for manufacturing an organic TFT array having a plurality of organic TFTs arranged in a matrix,
Creating a first substrate having a liquid repellent surface;
Creating a second substrate having a plurality of source / drain electrodes formed in a matrix on the underlayer;
Applying and drying an organic semiconductor precursor solution on the surface of the first substrate at intervals equal to the intervals of the plurality of channels formed by the plurality of source / drain electrodes formed on the second substrate When,
A step of transferring the organic semiconductor precursor solution to the channel of the second substrate by superimposing the first substrate on which the organic semiconductor precursor solution has been applied and dried and the second substrate; A method for producing an organic TFT array, comprising:

  2. 2. The method of manufacturing an organic TFT array as described in 1 above, wherein the organic semiconductor precursor solution is applied using an inkjet method.

3. The organic TFT has a bottom gate structure,
3. The method of manufacturing an organic TFT array according to 1 or 2, wherein the underlayer is a gate insulating film.

4). The organic TFT has a top gate structure,
3. The method for manufacturing an organic TFT array according to 1 or 2, wherein the underlayer is a substrate.

  5. The liquid repellent property of the region to which the organic semiconductor precursor solution is applied on the surface of the first substrate is lower than the liquid repellent property of the region surrounding the region. The manufacturing method of the organic TFT array of description.

  According to the present invention, the surface of the substrate (first substrate) used for transfer has liquid repellency. As a result, wetting and spreading of the applied organic semiconductor solution can be suppressed, and it can be applied to a predetermined position with an appropriate film thickness with high accuracy.

  Further, a solution in which an organic semiconductor precursor material is dissolved (hereinafter also referred to as precursor ink) is used as the organic semiconductor solution. When the organic semiconductor precursor changes from the precursor to the organic semiconductor, the shape of the molecule changes, the orientation state of the molecule changes so far, and reorientation occurs. Thereby, adhesiveness with a to-be-transferred substrate (2nd board | substrate) can be improved.

  As a result, the leakage of the precursor ink to unnecessary areas can be suppressed, and the adhesion of the precursor ink can be enhanced, and excellent characteristics and high reliability can be stably obtained.

It is a cross-sectional schematic diagram which shows schematic structure of the bottom gate type organic TFT which concerns on embodiment of this invention. It is a cross-sectional schematic diagram which shows schematic structure of the top gate type organic TFT which concerns on embodiment of this invention. It is a plane schematic diagram which shows schematic structure of the organic TFT array which concerns on embodiment of this invention. It is a cross-sectional schematic diagram which shows the outline | summary of the manufacturing process of a 1st board | substrate and a 2nd board | substrate. It is a schematic diagram which shows a transcription | transfer process.

  Hereinafter, an embodiment of a method for producing an organic TFT array according to the present invention will be described with reference to the drawings. In addition, although this invention is demonstrated based on embodiment of illustration, this invention is not limited to this embodiment.

  First, a schematic configuration of a bottom gate type organic TFT, which is one of the typical embodiments of the organic TFT constituting the organic TFT array according to the present invention, will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view showing a schematic configuration of a bottom gate type organic TFT 1.

  As shown in FIG. 1, the organic TFT 1 includes a substrate P2, a gate electrode G, a gate insulating film IF, a source electrode S, a drain electrode D, an organic semiconductor film SF, a passivation film PF, a pixel electrode E, and the like. The pixel electrode E is an electrode that drives a display layer (not shown) when the organic TFT 1 is used as a drive element of a display device, for example. Details of the material and forming method of each member will be described later. Further, in the present embodiment, the configuration of the bottom gate type organic TFT 1 is shown, but the element configuration of the organic TFT according to the present invention is not particularly limited, and for example, a top gate type as shown in FIG. 2 may be used. .

  Next, a schematic configuration of the organic TFT array having the organic TFT 1 having such a configuration will be described with reference to FIG. FIG. 3 is a schematic plan view showing a schematic configuration of the organic TFT array 1A.

  As shown in FIG. 3, the organic TFT array 1 </ b> A has pixels Px each including the organic TFT 1 arranged in a two-dimensional matrix. In the organic TFT array 1A, a row driver and a column driver (not shown) for driving the organic TFT 1 based on a video signal input from the outside are connected to the organic TFT array 1A via a row selection line HL and a column signal line VL, respectively. ing. All the pixels Px (organic TFT 1) in the corresponding row are connected to one row selection line HL, and all the pixels Px (organic TFT 1) in the corresponding column are connected to one column signal line VL.

  Here, the flow of the display control operation performed in the organic TFT array 1A will be described.

  First, only one row for which display data is to be set is selected via the row selection line HL by the row driver. The selection of a row is performed by activating (ON) the row selection line HL of the selected row and inactivating (OFF) the other row selection lines HL. Next, display data is transmitted from the column driver to the pixel Px via the column signal line VL. Here, when the row selection line VL is deactivated, the signal transmitted to the pixel Px is stored, and the pixel Px drives the display layer based on the stored signal. By performing this series of operations for all rows, display driving for one screen is performed.

  In the organic TFT array 1A having such a configuration, in order to stably obtain excellent characteristics and high reliability, the organic semiconductor film SF is accurately formed at a predetermined position with an appropriate film thickness, and adhesion is improved. It is important to increase

  Therefore, in order to satisfy such a demand, in the present invention, the organic semiconductor film SF is formed by transfer, and the surface of the substrate (first substrate) used for transfer is made to have liquid repellency. A solution (precursor ink) in which an organic semiconductor precursor material is dissolved is used as the organic semiconductor solution applied to the first substrate. Then, the first substrate on which the precursor ink is applied and dried and the transferred substrate (second substrate) on which the source electrode S and the drain electrode D are formed are overlapped, and the precursor ink is applied to the second substrate. Are transferred to a channel formed by the source electrode S and the drain electrode D.

  Specifically, usually, an organic semiconductor solution (ink) is applied to the surface of a substrate having sufficiently high liquid repellency using an inkjet method in order to accurately form an organic semiconductor film at a predetermined position with an appropriate film thickness. It is necessary to dry it. However, in general, since the surface of the substrate used for the organic TFT has high wettability, it is difficult to control the thickness and shape of the applied ink by direct ink-jet patterning.

  Therefore, in the present invention, first, ink is applied to the surface of the first substrate having high liquid repellency using the ink jet method and dried, and then the ink applied and dried on the first substrate is applied to the first substrate. 2 is transferred to the second substrate. Thereby, the film thickness and shape of the ink can be controlled, and the organic semiconductor film SF can be accurately formed at a predetermined position with an appropriate film thickness.

  On the other hand, the ink transferred to the second substrate in this way needs to be in close contact with the second substrate. This is to obtain a stable electrical connection with the source electrode S and the drain electrode D in the bottom contact type organic TFT, and in the bottom gate type organic TFT, the effect of the gate insulating film is sufficiently exhibited. Because of that.

  In order to improve this adhesion, it is necessary to reorient the organic semiconductor molecules to the substrate surface. However, it is difficult to cause such reorientation only by applying a normal organic semiconductor solution (ink) to the surface of the substrate. In order to promote reorientation, it is necessary to perform a thermal treatment or the like. In this case, the temperature needs to be equal to or higher than the Tg of the organic semiconductor or higher than the melting point. For this reason, there is a risk of causing thermal decomposition of the organic semiconductor, resulting in deterioration or variation in performance of the organic TFT.

  Therefore, in the present invention, in order to cope with such a problem, a solution (precursor ink) in which an organic semiconductor precursor material is dissolved is used as the organic semiconductor solution (ink).

  When the organic semiconductor precursor is changed from the precursor to the organic semiconductor, the shape of the molecule changes, and the orientation state of the molecule is always changed. At this time, since a reorientation with the substrate which is unlikely to occur in a semiconductor crystal without a change from the precursor occurs, a suitable adhesion state can be obtained. Thereby, adhesiveness with a to-be-transferred substrate (2nd board | substrate) can be improved.

Next, the outline of the manufacturing method of the organic TFT array 1A will be described with reference to FIGS. 4A is a schematic cross-sectional view illustrating the manufacturing process of the first substrate 10, and FIGS. 4B to 4D are schematic cross-sectional views illustrating the manufacturing process of the second substrate 20. FIG. FIGS. 5A to 5D are schematic plan and cross-sectional views showing a step of applying and drying the precursor ink IK on the first substrate 10 and a transfer step.
(Process for creating the first substrate 10)
A liquid repellent layer CF is formed on the surface of the substrate P1 to produce a first substrate (FIG. 4A). As a material of the substrate P1, polyimide, polyamide, polyethylene tephthalol (PET), polyethylene naphthalate (PEN), polyester sulfone (PES), glass, or the like can be used. As a material of the substrate P1, it is preferable to use a material whose thermal expansion coefficient is substantially equal to or the same as that of the substrate P2 used for the second substrate 20 in consideration of the heating process. If it is unavoidable to use materials having different thermal expansion coefficients, the thickness of the liquid repellent layer CF is reduced to 5 μm or less, preferably 1 μm or less to reduce the stress to the minimum and warp the substrate. Can be suppressed.

  The liquid repellent layer CF can be formed by coating silicon resin, Teflon (registered trademark) resin, fluorine resin, or the like. If the contact angle between the liquid repellent layer CF and the precursor ink IK is stably 20 ° or more, preferably 30 ° or more, the thickness and shape of the applied precursor ink IK can be controlled. In addition, the material of the liquid repellent layer CF is widely selected as long as it has a liquid repellent property capable of controlling the shape with respect to the inkjet solvent and has a surface energy lower than that of the second substrate 20. be able to.

Here, it is preferable that the liquid repellent layer CF has an in-plane strength distribution. The liquid repellency of the surface of the substrate is various, for example, when it is imparted by the liquid repellency treatment of the surface or when the substrate itself has. In any case, depending on the process of forming the liquid repellent layer CF, the film thickness and the like become non-uniform, and the liquid repellency of the substrate surface may not be uniform. For this reason, when the positional accuracy of the coated and dried precursor ink IK is lowered, the liquid repellent layer CF may have an in-plane strength distribution. That is, the liquid repellency of the region to which the precursor ink IK of the liquid repellent layer CF is applied should be lower than the region surrounding the region. As a method for imparting an in-plane intensity distribution, lyophilicity by exposure to ultraviolet rays or the like, apparent liquid repellency control by forming local irregularities by mechanical force such as a stamp, and the like can be used.
(Process for creating second substrate 20)
First, the gate electrode G is formed on the substrate P2 (FIG. 4B). As a material of the substrate P2, polyimide, polyamide, polyethylene tephthalol (PET), polyethylene naphthalate (PEN), polyester sulfone (PES), glass, or the like can be used.

  The gate electrode G can be formed by forming a gate electrode material on the substrate P using a sputtering method, vapor deposition, or the like and then patterning the material using a photolithography method. As the material of the gate electrode G, Al, Au, Ag, Pt, Pd, Cu, Cr, Mo, In, Zn, Mg, etc., alloys or oxides containing these, or organic conductors such as carbon nanotubes, etc. Can be used.

  Next, a gate insulating film IF is formed (FIG. 4C). As a method for forming the gate insulating film IF, sputtering, vapor deposition, CVD, or the like can be used. As a material of the gate insulating film IF, inorganic oxides such as silicon oxide, aluminum oxide, tantalum oxide, and titanium oxide, and inorganic nitrides such as silicon nitride and aluminum nitride can be used. Or, polyimide, polyamide, polyester, polyacrylate, photo-curing polymer of photo radical polymerization, photo cation polymerization, copolymer containing acrylonitrile component, organic compound such as polyvinyl phenol, polyvinyl alcohol, novolac resin, cyanoethyl pullulan Etc. can also be used.

Next, the source electrode S and the drain electrode D are formed to complete the second substrate 20 (FIG. 4D). The source electrode S and the drain electrode D are formed by photolithography, various printing methods, and droplet coating methods in the same manner as the method for forming the gate electrode G after cleaning the substrate P2 on which the gate insulating film IF is formed. Etc. can be used. As the electrode material of the source electrode S / drain electrode D, the same electrode material as that of the gate electrode G can be used.
(Precursor ink IK coating and drying process)
Next, at an interval W equal to the interval W between the plurality of channels formed by the plurality of source electrodes S and drain electrodes D formed on the second substrate 20 (FIG. 5 (b1), FIG. 5 (b2)), The precursor ink IK is applied to the surface of the first substrate 10 and dried (FIGS. 5A1 and 5A2). As a coating method of the precursor ink IK, an inkjet method can be used. The semiconductor material of the precursor ink IK is not particularly limited as long as it is an organic semiconductor precursor.

In addition, if the solvent used for the precursor ink IK is high in surface tension, the position controllability is enhanced, but the film thickness and spread after drying are also important, and the relationship with the liquid repellent layer CF of the first substrate 10 is important. It is important to select in consideration of the balance between the requirements of the entire coating process, such as matching.
(Transfer process)
Next, the first substrate 10 and the second substrate 20 on which the precursor ink IK has been applied and dried are overlaid and pressurized, and the precursor ink IK is transferred to the channel of the second substrate 20 (FIG. 5). (C)).

  Here, the shape of the first substrate 10 does not need to be flat, and may be, for example, a semi-cylindrical shape with a semicircular cross-sectional shape. In the transfer process, if the shape of the first substrate 10 is flat, the precursor ink IK can be partially or completely made into a semiconductor by superimposing and pressurizing and heating the second substrate 20. The adhesion with the second substrate 20 can be further improved.

In addition, when the transfer is performed, the surface of the second substrate 20 is moistened with an inkjet solvent, or the transfer atmosphere is filled with the inkjet solvent so that the organic semiconductor precursor adheres to the second substrate 20. The force can be increased more than the adhesion force to the first substrate 10.
(Semiconductor process)
Next, the precursor ink IK transferred to the second substrate 20 is made into a semiconductor to form an organic semiconductor film SF, thereby completing the organic TFT array 1B which is the basic structure of the organic TFT array 1A (FIG. 5 ( d)). This step is a step of enhancing the adhesion of the organic semiconductor to the second substrate 20 and developing the characteristics as the organic TFT 1. In general, an organic semiconductor precursor is converted into a semiconductor when the leaving group of the molecule receives the energy from the outside and is released, and the molecule is reoriented and adheres to the substrate.

  When semiconductorization is performed, it suffices if the organic semiconductor precursor is in contact with the second substrate 20, and the contact state with the first substrate 10 does not matter.

As a method for forming a semiconductor, a thermal process using a hot plate, a hot air circulation path, etc., annealing using a laser, or the like can be used. Microwaves, ultraviolet rays, and the like can also be used.
(Passivation film PF, pixel electrode E forming step: not shown)
Next, the passivation film PF and the pixel electrode E are formed on the organic TFT array 1B, thereby completing the organic TFT array 1A.

First, a passivation film PF is formed for shielding and protecting the organic semiconductor film SF from the external atmosphere. As a material for the passivation film PF, SiO ₂ , SiN, or the like can be used. As a method for forming the passivation film PF, a sputtering method can be used. However, since a vacuum apparatus is required and the cost is increased, it is preferable to use an atmospheric pressure plasma method. Since the atmospheric pressure plasma method can form a high-density thin film, it is suitable for forming a passivation film PF that functions as a protective layer for the organic semiconductor film SF. Note that the passivation film PF is not always necessary, and is appropriately formed according to the material of the organic semiconductor film SF.

  Next, the pixel electrode E is formed on the passivation film PF, and the organic TFT array 1A is completed. As a method for forming the pixel electrode E, the pixel electrode material can be deposited using a sputtering method and then formed using a photolithography method. It can also be formed by direct patterning using the IJ method, printing method or the like. As a material of the pixel electrode E, ITO or the like can be used.

Next, an example of the manufacturing method of the organic TFT array 1A including the bottom gate type organic TFT 1 according to the embodiment of the present invention will be described with reference to FIGS.
(Creation of the first substrate 10)
First, when the precursor ink IK is applied to a soda-lime glass substrate for STN liquid crystal (FIG. 4A: substrate P1) having a SiO ₂ / Cr film formed on the surface using a photolithography method. An alignment mark M indicating the reference position was formed (FIG. 5 (a2)).

  Next, after immersing the substrate P1 in a solution obtained by diluting KBM-903 (manufactured by Shin-Etsu Chemical Co., Ltd.) in ethanol by 0.1 mass% for 10 minutes, the substrate P1 was cured at 180 ° C. for 30 minutes to be treated with a silane coupling agent. .

Next, Cytop CTX-809AP (Asahi Glass Co., Ltd.) was applied and dried at 50 ° C. for 1 hour, followed by 180 ° C. for 1 hour to form a liquid repellent layer CF (FIG. 4A). In this way, the first substrate 10 was produced.
(Creation of the second substrate 20)
First, a gate electrode G was formed on a soda-lime glass substrate for STN liquid crystal (FIG. 4B: substrate P2) having a SiO ₂ / Cr film formed on the surface using a photolithography method (FIG. 4). (B)).

Next, a photosensitive organic insulating film was formed by sputtering to form a gate insulating film IF having a thickness of 500 nm (FIG. 4C).
Next, after applying a lift-off resist on the gate insulating film IF and patterning using a photolithography method, a Cr film was formed in this order with a thickness of 5 nm and Au with a thickness of 50 nm. Thereafter, ultrasonic cleaning was performed with dimethylformamide at room temperature to remove unnecessary lift-off resists, and source electrodes S and drain electrodes D were formed (FIG. 1D). The distance between the source electrode S and the drain electrode D, which is the channel length, was 10 μm, and the channel width was 100 μm. In this way, the second substrate 20 was produced.
(Precursor ink IK coating and drying)
Next, a precursor ink IK was prepared by diluting an organic semiconductor precursor (tetrabenzoporphyrin precursor metal complex) in an inkjet solvent (ethyl benzoate). Note that a pentacene precursor may be used as the organic semiconductor precursor, and anisole, tetralin, or the like may be used as an inkjet solvent.

Next, the precursor ink IK is applied to the surface of the first substrate 10 by using an ink jet method, and intervals W between a plurality of channels formed in the second substrate 20 (FIG. 5 (b1), FIG. 5 (b2)). ) With the same interval W as that of the alignment mark M (FIG. 5 (a1), FIG. 5 (a2)). Subsequently, the applied precursor ink IK was dried at 120 ° C. for 5 minutes. The drying condition may be a temperature at which the precursor ink IK does not change to a semiconductor, and may be, for example, 80 ° C. for 10 minutes.
(Transcription)
Next, the first substrate 10 and the second substrate 20 on which the precursor ink IK has been applied and dried are overlaid and pressurized, and the precursor ink IK is transferred to the channel of the second substrate 20 (FIG. 5). (C)).

The first substrate 10 and the second substrate 20 were overlapped while observing alignment marks (not shown) provided on the respective substrates. The applied pressure was 0.3 kgf / cm ² ).
(Semiconductor)
Next, the first substrate 10 and the second substrate 20 are separated, and the second substrate 20 is heated at 200 ° C. for 30 minutes using a hot plate, thereby transferring the precursor transferred to the second substrate 20. The ink IK was made into a semiconductor to form an organic semiconductor film SF. In this way, an organic TFT array 1B, which is the basic structure of the organic TFT array 1A, was completed (FIG. 5D).

  When the organic TFT array 1B thus completed was observed with an optical microscope and AFM (manufactured by Keyence Corporation), it was confirmed that the organic semiconductor film SF having an average film thickness of 50 nm was accurately formed on the channel. It was.

  Thus, in the manufacturing method of the organic TFT array 1 according to the embodiment of the present invention, the surface of the first substrate 10 used for transfer has liquid repellency. As a result, wetting and spreading of the applied organic semiconductor solution can be suppressed, and it can be applied to a predetermined position with an appropriate film thickness with high accuracy.

  Further, a solution (precursor ink IK) in which an organic semiconductor precursor material is dissolved is used as the organic semiconductor solution. When the organic semiconductor precursor changes from the precursor to the organic semiconductor, the shape of the molecule changes, the orientation state of the molecule changes so far, and reorientation occurs. Thereby, adhesiveness with the 2nd board | substrate 20 which is a to-be-transferred board | substrate can be improved.

  As a result, the leakage of the precursor ink IK to unnecessary areas can be suppressed, and the adhesion of the precursor ink IK can be enhanced, and excellent characteristics and high reliability can be stably obtained.

1 Organic TFT (Organic Thin Film Transistor)
1A, 1B Organic TFT array 10 First substrate 20 Second substrate CF Liquid repellent layer D Drain electrode E Pixel electrode G Gate electrode HL Row selection line IF Gate insulating film IK Organic semiconductor precursor ink M Alignment mark P1, P2 Substrate PF Passivation film Px Pixel S Source electrode SF Organic semiconductor film VL Column signal line

Claims (5)

In a method for manufacturing an organic TFT array having a plurality of organic TFTs arranged in a matrix,
Creating a first substrate having a liquid repellent surface;
Creating a second substrate in which a plurality of source / drain electrodes are formed in a matrix on an underlayer;
Applying and drying an organic semiconductor precursor solution on the surface of the first substrate at intervals equal to the intervals of the plurality of channels formed by the plurality of source / drain electrodes formed on the second substrate When,
A step of transferring the organic semiconductor precursor solution to the channel of the second substrate by superimposing the first substrate on which the organic semiconductor precursor solution has been applied and dried and the second substrate; A method for producing an organic TFT array, comprising:   The method of manufacturing an organic TFT array according to claim 1, wherein the organic semiconductor precursor solution is applied using an inkjet method. The organic TFT has a bottom gate structure,
3. The method of manufacturing an organic TFT array according to claim 1, wherein the underlayer is a gate insulating film. The organic TFT has a top gate structure,
The method of manufacturing an organic TFT array according to claim 1, wherein the underlayer is a substrate.   5. The liquid repellency of the region to which the organic semiconductor precursor solution is applied on the surface of the first substrate is lower than the liquid repellency of the region surrounding the region. 6. The manufacturing method of the organic TFT array of item.

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