JP2010199130A - Method of manufacturing thin film transistor - Google Patents

Abstract

Provided is a method for manufacturing a thin film transistor with which a semiconductor film and a protective film can be accurately formed at predetermined positions with an appropriate film thickness and which is excellent in productivity.
In a method of manufacturing a thin film transistor having a protective film for protecting a semiconductor film, the surface of the base layer is higher than the predetermined region with respect to the semiconductor solution so as to surround the predetermined region of the surface of the base layer. A step of forming a liquid repellent layer having liquid repellency; a step of applying a semiconductor solution to a predetermined region to form a semiconductor film; and applying a protective film material solution to the surface of the semiconductor film, Forming a covering protective film, and the liquid repellency of the surface of the liquid repellent layer has an in-plane strength distribution and is the highest in the vicinity of a predetermined region, and the liquid to which the protective film material solution is applied The amount is made larger than the amount of liquid to be applied with the semiconductor solution.
[Selection] Figure 3

Description

  The present invention relates to a method for manufacturing a thin film transistor, and more particularly to a method for manufacturing a thin film transistor having a semiconductor protective film.

  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 currently in practical use are manufactured using Si-based inorganic materials such as a-Si and poly-Si as semiconductor materials. In manufacturing TFTs using such inorganic materials, a vacuum process is used. And high-temperature processes are required, greatly affecting production costs.

  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 a flexible substrate such as a plastic film substrate having poor heat resistance, and is expected to be applied to various fields such as a curved display.

  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 can be performed, 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 using the above-described inkjet method, dispenser method, or the like, the surface state of the substrate (liquid repellency / lyophilicity) before the applied ink is dried and solidified. In some cases, the wet area spreads due to the influence of a dry atmosphere or the like, and reaches 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, in order to cope with such a problem, in Patent Document 1, liquid repellent treatment is performed on a region surrounding a region where a droplet is applied, thereby preventing the droplet from spreading out from the coating region. A method of attaching and fixing to a region has been proposed.

JP 2002-124381 A

  By the way, an organic semiconductor material is a chemically unstable material compared to an inorganic semiconductor material such as silicon, and changes in characteristics due to irradiation with visible light, ultraviolet light, contact with an organic solvent, oxygen, moisture, etc. Degradation of performance occurs. Therefore, in order to protect the organic semiconductor film from such factors affecting the performance, a protective film having a light shielding property and a gas barrier property is formed so as to cover the organic semiconductor.

  As in the method of Patent Document 1, an organic liquid repellent region is provided so as to surround a droplet application region, and a droplet is applied so that the droplet does not spread out from the application region. Application to an ink application method for TFT has been studied. However, as a method for forming a protective film for protecting the formed organic semiconductor film on the organic semiconductor film, a droplet coating technique with excellent productivity such as an inkjet method or a dispenser method is used exclusively. A low productivity method such as a spin coating method or a film forming method using a vacuum process is used. This is because the protective film material solution is repelled in the liquid repellent region and cannot sufficiently cover the organic semiconductor film.

  Specifically, this will be described with reference to FIG. 11 (a) to 11 (d) show problems when an organic semiconductor film is formed using a conventional method for providing a liquid repellent region and then a protective film is formed using a droplet coating method. It is a schematic diagram to explain. In each figure, the upper diagram is a schematic sectional view, and the lower diagram is a schematic plan view.

  First, a liquid repellent layer CF is formed on the base layer LF so as to surround the ink application region IA (FIG. 11A). Next, the ink IK is applied to the ink application area IA (FIG. 11B) and dried to form the organic semiconductor film SF (FIG. 11C). Thereafter, a protective film material solution is applied on the organic semiconductor film SF to form a protective film PF (FIG. 11D).

  In FIG. 11D, the central portion A of the organic semiconductor film SF is sufficiently covered with the protective film PF, but the peripheral portion B has a reduced thickness due to the influence of the liquid repellent layer CF. Yes. For this reason, there is a problem that the organic semiconductor film SF cannot be sufficiently covered. FIG.11 (e) shows the enlarged view of the peripheral part B vicinity in FIG.11 (d). Therefore, if the amount of the protective film material solution is increased in order to increase the thickness of the protective film PF, the attached solution cannot remain in that place and flows out of the liquid repellent layer CF. As a result, there is a problem in that the covering with the protective film PF cannot be performed sufficiently and the organic semiconductor film SF is easily deteriorated.

  For this reason, when an organic semiconductor film is formed with a liquid repellent region, a protective film is formed using a spin coating method or a film forming method utilizing a vacuum process. For this reason, there was a problem that productivity was impaired.

  The present invention has been made in view of the above problems, and provides a method for manufacturing a thin film transistor that can accurately form a semiconductor film and a protective film at predetermined positions with an appropriate film thickness, and that is excellent in productivity. The purpose is to provide.

  The above object is achieved by the invention described in any one of 1 to 9 below.

1. In a method for manufacturing a thin film transistor having a protective film for protecting a semiconductor film,
Forming a liquid repellent layer having a higher liquid repellency than the predetermined region on the surface of the base layer so as to surround a predetermined region of the surface of the base layer;
Applying the semiconductor solution to the predetermined region to form the semiconductor film;
Applying a protective film material solution to the surface of the semiconductor film to form the protective film covering the semiconductor film, and
The liquid repellency of the surface of the liquid repellent layer has an in-plane strength distribution and is highest in the vicinity of the predetermined region,
The method for producing a thin film transistor, wherein the amount of liquid applied to the protective film material solution is larger than the amount of liquid applied to the semiconductor solution.

2. The liquid repellent layer includes two regions, a first region around the predetermined region and a second region surrounding the first region,
The liquid repellency of the first region is higher than the liquid repellency of the second region,
The peripheral portion of the droplet of the semiconductor solution dropped is in contact with the predetermined region or the first region, and the peripheral portion of the droplet of the protective film material solution is in contact with the second region. As described above, the method for producing a thin film transistor according to 1 above, wherein the amount of each solution is adjusted.

  3. 3. The method of manufacturing a thin film transistor according to 1 or 2 above, wherein the liquid repellent layer is formed by a photolithography method using a light shielding mask having an in-plane intensity distribution of light transmittance.

  4). 4. The method of manufacturing a thin film transistor according to any one of 1 to 3, wherein the semiconductor solution is a solution in which an organic semiconductor material is dissolved.

  5. 5. The method of manufacturing a thin film transistor according to any one of 1 to 4, wherein the semiconductor solution and the protective film material solution are applied using an inkjet method.

6). The thin film transistor has a bottom gate bottom contact structure,
The foundation layer is a source electrode and a drain electrode,
6. The method of manufacturing a thin film transistor according to any one of 1 to 5, wherein the predetermined region is at least a channel region between the source electrode and the drain electrode.

7). The thin film transistor has a bottom gate top contact structure,
The foundation layer is a gate insulating film;
6. The method of manufacturing a thin film transistor according to any one of 1 to 5, wherein the predetermined region is a region corresponding to at least a gate electrode formed in a lower layer of the gate insulating film.

8). The thin film transistor has a top gate bottom contact structure,
The foundation layer is a source electrode and a drain electrode,
6. The method of manufacturing a thin film transistor according to any one of 1 to 5, wherein the predetermined region is at least a channel region between the source electrode and the drain electrode.

9. The thin film transistor has a top gate top contact structure,
The foundation layer is a substrate;
The thin film transistor according to any one of 1 to 5, wherein the predetermined region is a region corresponding to a channel region between at least a source electrode and a drain electrode formed in an upper layer of the substrate. Production method.

  According to the present invention, since the liquid repellent layer having higher liquid repellency than the predetermined region is formed on the semiconductor solution so as to surround the region to which the semiconductor solution is applied, the droplets of the semiconductor solution are discharged from the application region. It is possible to prevent the semiconductor film from being wet and spread outside, and to form the semiconductor film with a proper film thickness at a predetermined position with high accuracy.

  Further, the liquid repellency of the surface of the liquid repellent layer has an in-plane strength distribution so as to be the highest in the vicinity of the region where the semiconductor solution is applied, and the amount of liquid applied to the protective film material solution More than the amount of liquid applied. As a result, when forming a protective film for protecting the semiconductor film, the protective film material solution can reach the area of the periphery of the liquid repellent layer where the liquid repellency is reduced, so that the protective film material solution is repellent. The semiconductor film can be sufficiently covered without being repelled by the liquid layer.

  Furthermore, since the semiconductor solution and the protective film material solution are applied using, for example, a droplet coating method typified by an ink jet method, productivity can be improved.

It is a cross-sectional schematic diagram which shows schematic structure of TFT which concerns on embodiment of this invention. It is a schematic diagram which shows an example of the manufacturing process of the bottom gate bottom contact type TFT which concerns on embodiment of this invention. It is a schematic diagram which shows another example of the manufacturing process of the bottom gate bottom contact type TFT which concerns on embodiment of this invention. It is a schematic diagram showing a manufacturing process of a bottom gate top contact type TFT according to an embodiment of the present invention. It is a schematic diagram which shows the manufacturing process of the top gate bottom contact type TFT which concerns on embodiment of this invention. It is a schematic diagram which shows the manufacturing process of the top gate top contact type TFT which concerns on embodiment of this invention. It is a cross-sectional schematic diagram explaining the relationship between the liquid repellency of a liquid repellent layer, and the liquid quantity of a semiconductor solution. It is a cross-sectional schematic diagram explaining the aspect of adhesion of the protective film material solution by the liquid repellency of the liquid repellent layer. It is a plane schematic diagram which shows the structure of the light shielding mask used when the material of a liquid repellent layer is a positive type material. It is a plane schematic diagram which shows the structure of the light shielding mask used when the material of a liquid repellent layer is a negative material. It is a schematic diagram explaining the problem at the time of forming an organic-semiconductor film using the conventional method which provides a liquid repellent area | region, and forming a protective film using the droplet coating method.

  Embodiments of a method for manufacturing a TFT according to the present invention will be described below 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 TFT according to the present invention will be described with reference to FIG. 1A is a bottom gate bottom contact TFT 1, FIG. 1B is a bottom gate top contact TFT 1, FIG. 1C is a top gate bottom contact TFT 1, and FIG. 2 is a schematic cross-sectional view showing a schematic configuration of a gate top contact type TFT1. FIG.

  As shown in FIGS. 1A to 1D, the TFT 1 includes a substrate P, a gate electrode G, a gate insulating film IF, a source electrode S, a drain electrode D, a semiconductor film SF, a protective film PF, and a liquid repellent. It is composed of a layer CF or the like. In the case of the top gate / bottom contact TFT 1 shown in FIG. 1C and the top gate / top contact TFT 1 shown in FIG. 1D, the gate insulating film IF functions as the protective film PF.

  As a material of the substrate P, polyimide, polyamide, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (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 using a photolithography method. Moreover, it can also form using a mask vapor deposition 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.

  As a method for forming the gate insulating film IF, sputtering, vapor deposition, CVD, spin coating, ink jet, 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.

  As a method for forming the source electrode S / drain electrode D, similarly to the method for forming the gate electrode G, it can be formed by using a photolithography method, various printing methods, a droplet coating method, or the like. 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.

  The liquid repellent layer CF can be formed by forming a liquid repellent layer material using a spin coat method or the like and then patterning using a photolithography method. As the material of the liquid repellent layer CF, a photosensitive bank agent or the like can be used. As will be described later, the liquid repellent layer CF is a region (ink application region) to which the semiconductor solution (ink IK) on the surface of the base layer (source electrode S / drain electrode D, gate insulating film IF, or substrate P) is applied. IA) is formed so as to surround it. The liquid repellent layer CF is formed by a photolithography method using a light shielding mask M, which will be described later, having an in-plane intensity distribution of light transmittance, so that the liquid repellency on the surface of the liquid repellent layer CF is improved. An in-plane intensity distribution is provided so as to be the highest in the vicinity of an area (ink application area IA) to which (ink IK) is applied.

  As a method for forming the semiconductor film SF, an inkjet method can be used. The material of the semiconductor film SF can be a polycyclic aromatic compound, a conjugated polymer, or the like, but is not particularly limited. A polymer material, an oligomer, or a low-molecular material may be used, and a material in which molecules are regularly arranged and formed into crystals by intermolecular interaction after coating is particularly preferable. Pentacene, porphyrin, phthalocyanine, oligothiophene, oligophenylene, polythiophene, polyphenylene, and derivatives thereof can be used. Specifically, pentacene, 6,13-bis (triisopropylsilylethynyl) pentacene, tetrabenzoporphyrin, poly (3-hexylthiophene), or the like can be used.

  As a method for forming the protective film PF, an inkjet method can be used. As a material for the protective film PF, polyvinyl alcohol, 2-hydroxyethyl methacrylate (HEMA), acrylic acid, acrylamide, or the like can be used.

  In the TFT 1 having such a configuration, the present invention surrounds an area (ink application area IA) to which the semiconductor solution (ink IK) is applied in order to accurately form the semiconductor film SF at a predetermined position with an appropriate film thickness. Thus, the liquid repellent layer CF having higher liquid repellency than the ink application area IA is formed on the ink IK. Then, the semiconductor solution (ink IK) is applied to the liquid repellency of the surface of the liquid repellent layer CF so that the protective film material solution can be sufficiently covered without being repelled by the liquid repellent layer CF. The in-plane strength distribution so as to be the highest in the vicinity of the area to be applied (ink application area IA), and the amount of liquid applied to the protective film material solution is greater than the amount of liquid applied to the semiconductor solution (ink IK) To do more. Details will be described below.

  First, the relationship between the liquid repellency of the liquid repellent layer CF and the liquid amount of the ink IK when the ink IK is applied to the ink application area IA will be described with reference to FIG. When the liquid repellency of the liquid repellent layer CF is low, as shown in FIGS. 7 (a1) to 7 (a3), as the amount of ink IK applied is increased, the ink IK is removed at a relatively small amount. It protrudes from the ink application area IA. If the amount of ink IK applied is reduced so that it does not protrude from the ink application area IA in a state of low liquid repellency, the semiconductor material component contained in the ink IK is only a few percent at most. The film SF becomes thin and desired electrical characteristics cannot be obtained. On the other hand, if the amount of ink IK applied is increased and the ink IK protrudes from the ink application area IA, the semiconductor film SF is not necessarily formed in the ink application area IA after drying, which may cause current leakage. There is. For this reason, the liquid repellency of the liquid repellent layer CF needs to be higher than that of the ink application area IA. When the liquid repellency of the liquid repellent layer CF is high, as shown in FIGS. 7B1 to 7B3, the ink IK does not protrude from the ink application area IA even if the application amount of the ink IK is increased. Therefore, the semiconductor film SF having a desired film thickness can be obtained after drying, and since the semiconductor film SF is formed in the ink application region IA, current leakage can be prevented.

  Next, the relationship between the liquid repellency of the liquid repellent layer CF and the liquid amount of the protective film material solution when the protective film material solution is applied so as to sufficiently cover the semiconductor film SF will be described with reference to FIG. When the liquid repellency of the liquid repellent layer CF is high, as shown in FIG. 8A, the thickness of the protective film material solution near the side wall of the semiconductor film SF is reduced. When the protective film PF is formed by drying the protective film material solution in this state, the thickness of the protective film PF in the vicinity of the side wall of the semiconductor film SF becomes thin, and the protective performance is deteriorated. On the other hand, when the application amount of the protective film material solution is increased, the protective film PF near the side wall of the semiconductor film SF is also thickened, so that the protective performance is improved. However, the protective film PF is perpendicular to the underlying layer LF. Since the film thickness increases, an extra post-processing step is required. For example, when a display panel is manufactured by laminating a display element on the created TFT 1, a process for smoothing irregularities due to the protective film PF on the surface of the TFT 1 is required. For this reason, when the protective film material solution is applied, it is preferable that the liquid repellency of the portion of the liquid repellent layer CF touched by the peripheral edge of the protective film solution droplet is not so high.

  Therefore, in the present invention, the liquid repellency of the liquid repellent layer CF is increased in the vicinity of the ink application area IA of the liquid repellent layer CF, and is decreased in a place away from the ink application area IA. Then, the application amount of the ink IK is set to an amount that does not protrude from the ink application area IA, and the application amount of the protective film material solution reaches a point where the peripheral edge of the droplet of the protective film material solution has become low in liquid repellency. We decided to make it about the amount. By doing so, as shown in FIG. 8B, the protective film material solution can be applied in a shape that sufficiently covers the semiconductor film SF.

  Here, a light shielding mask used when forming the liquid repellent layer CF will be described with reference to FIGS.

  First, the configuration of the light shielding mask M when a positive photosensitive material is used as the material of the liquid repellent layer CF will be described with reference to FIG. FIG. 9A is a schematic plan view showing an example of the light shielding mask, and FIG. 9B is a schematic plan view showing another example of the light shielding mask.

  The light shielding mask M1 shown in FIG. 9A includes a region Mo having a transmittance of about 100% at the center, a first region Ma having a low transmittance (for example, 0%) around the region Mo, and a first region Ma. The second region Mb having a high transmittance (for example, 20%) surrounding the region is formed.

  In the region of the positive photosensitive material exposed corresponding to the region Mo of the light shielding mask M1, the liquid repellent layer CF is not formed and becomes the ink application region IA.

  A liquid repellent layer CF having high liquid repellency is formed in a region of the positive photosensitive material exposed corresponding to the first region Ma of the light shielding mask M1, and becomes a first region CFa described later.

  A liquid repellent layer CF having low liquid repellency is formed in a region of the positive photosensitive material exposed corresponding to the second region Mb of the light shielding mask M1, and becomes a second region CFb described later.

  Further, the light shielding mask M, like the light shielding mask M2 shown in FIG. 9B, has the lowest transmittance in the region near the central region Mo, and the transmittance gradually increases toward the periphery. It is good also as a simple structure.

  Next, the configuration of the light shielding mask M when a negative photosensitive material is used as the material of the liquid repellent layer CF will be described with reference to FIG. FIG. 10A is a schematic plan view showing an example of a light shielding mask, and FIG. 10B is a schematic plan view showing another example of the light shielding mask.

  The light shielding mask M3 shown in FIG. 10A has a region Mo having a transmittance of about 0% at the center, a first region Ma having a high transmittance around the region Mo (for example, 90%), and a first region Ma. The second region Mb having a low transmittance (for example, 50%) surrounding the region is formed.

  In the area of the negative photosensitive material exposed corresponding to the area Mo of the light shielding mask M3, the liquid repellent layer CF is not formed and becomes the ink application area IA.

  A liquid repellent layer CF having high liquid repellency is formed in a region of the negative photosensitive material exposed corresponding to the first region Ma of the light shielding mask M3, and becomes a first region CFa described later.

  A liquid repellent layer CF having a low liquid repellency is formed in a region of the negative photosensitive material exposed corresponding to the second region Mb of the light shielding mask M3, and becomes a second region CFb described later.

  Further, the light shielding mask M has the highest transmittance in a region in the vicinity of the central region Mo as in the light shielding mask M4 shown in FIG. 10B, and the transmittance gradually decreases toward the periphery. It is good also as a simple structure.

  In the following examples, a positive photosensitive liquid repellent material is used to form the liquid repellent layer CF. However, the same effect can be obtained even with a negative type.

(Example 1-1)
An example of the manufacturing method of the bottom gate bottom contact type TFT 1 according to the embodiment of the present invention will be described with reference to FIG. FIG. 2A to FIG. 2G are schematic views showing an example of a manufacturing process of the bottom gate bottom contact type TFT 1 according to the embodiment of the present invention. In each figure, the upper figure is a schematic sectional view and the lower figure is a schematic plan view.

  First, glass was used as the substrate P, and a Cr film was formed thereon with a thickness of 50 nm using a sputtering method, and then patterned using a photolithography method to form a gate electrode G (FIG. 2A). ).

Next, a SiO ₂ film was formed using a TEOS • CVD method to form a gate insulating film IF having a thickness of 500 nm (FIG. 2B).

  Next, after forming a Cr film with a thickness of 5 nm and an Au film with a thickness of 50 nm by sputtering, patterning was performed using photolithography to form a source electrode S and a drain electrode D (FIG. 2C).

  Next, after applying a positive photosensitive bank agent NPAR-502 (manufactured by Nissan Chemical Co., Ltd.) using a spin coat, patterning was performed using a photolithography method to form a liquid repellent layer CF (FIG. 2D). ). At this time, the liquid repellent layer CF was formed so as to surround the channel region between the source electrode S and the drain electrode D. Further, the light shielding mask M2 shown in FIG. 9B is used for the exposure, and the liquid repellency of the liquid repellent layer CF is highest in the vicinity of the ink application area IA, and gradually decreases toward the periphery. I made it.

  Next, a solution (ink IK) in which 6,13-bistriethylsilylethynylpentacene is dissolved in tetrahydronaphthalene is applied to an area (ink application area IA) surrounded by the liquid repellent layer CF by using an inkjet method (FIG. 2 (e)) and dried to form a semiconductor film SF (FIG. 2F).

  Next, an aqueous polyvinyl alcohol solution was applied onto the semiconductor film SF using an ink jet method and dried to form a protective film PF, thereby completing the TFT 1 (FIG. 2G).

When the TFT 1 thus completed is observed with an optical microscope and an AFM (manufactured by Keyence Corporation), it is found that the semiconductor film SF and the protective film PF are accurately formed at predetermined positions with appropriate film thicknesses. It could be confirmed.
(Example 1-2)
Another example of the manufacturing method of the bottom gate bottom contact type TFT 1 according to the embodiment of the present invention will be described with reference to FIG. FIG. 3A to FIG. 3G are schematic views showing another example of the manufacturing process of the bottom gate bottom contact type TFT 1 according to the embodiment of the present invention. In each figure, the upper figure is a schematic sectional view and the lower figure is a schematic plan view.

  First, glass was used as the substrate P, and a Cr film was formed thereon with a thickness of 50 nm using a sputtering method, followed by patterning using a photolithography method to form a gate electrode G (FIG. 3A). ).

  Next, using a spin coating method, an optomer PC403, which is a photosensitive acrylate material, was formed to form a gate insulating film IF having a thickness of 500 nm (FIG. 3B).

  Next, after forming a Cr film with a thickness of 5 nm and an Au film with a thickness of 50 nm by sputtering, patterning was performed by using a photolithography method to form a source electrode S and a drain electrode D (FIG. 3C).

  Next, a photosensitive bank agent NPAR-502 (manufactured by Nissan Chemical Industries, Ltd.) was applied using a spin coat, and then patterned using a photolithography method to form a liquid repellent layer CF (FIG. 3D). At this time, the liquid repellent layer CF was formed so as to surround the channel region between the source electrode S and the drain electrode D. Further, the light shielding mask M1 shown in FIG. 9A is used for the exposure, and the liquid repellency of the liquid repellent layer CF is such that the first region CFa in the vicinity of the ink application region IA is the second region around the first region CFa. It was made higher than the region CFb.

  Next, a tetrabenzoporphyrin precursor solution (ink IK) is applied to an area (ink application area IA) surrounded by the liquid repellent layer CF by using an ink jet method (FIG. 3 (e)), and heated and fired. A semiconductor film SF was formed (FIG. 3F).

  Next, an aqueous polyvinyl alcohol solution was applied onto the semiconductor film SF using an ink jet method and dried to form a protective film PF, thereby completing the TFT 1 (FIG. 3G). At this time, the droplet amount was adjusted so that the peripheral portion of the adhered droplet of the polyvinyl alcohol aqueous solution was in contact with the second region CFb of the liquid repellent layer CF having low liquid repellency.

The TFT 1 thus completed was observed with an optical microscope and an AFM (manufactured by Keyence Corporation). As in the case of Example 1, the semiconductor film SF and the protective film PF were at appropriate positions with appropriate film thicknesses. It was confirmed that it was formed accurately.
(Example 2)
An example of the manufacturing method of the bottom gate top contact type TFT 1 according to the embodiment of the present invention will be described with reference to FIG. FIG. 4A to FIG. 4G are schematic views showing a manufacturing process of the bottom gate top contact type TFT 1 according to the embodiment of the present invention. In each figure, the upper figure is a schematic sectional view and the lower figure is a schematic plan view.

  First, glass was used as the substrate P, and a Cr film was formed thereon with a thickness of 50 nm by sputtering, and then patterned by photolithography to form the gate electrode G (FIG. 4A). ).

  Next, using a spin coating method, an optomer PC403, which is a photosensitive acrylate material, was formed to form a gate insulating film IF having a thickness of 500 nm (FIG. 4B).

  Next, a photosensitive bank agent NPAR-502 (manufactured by Nissan Chemical Industries, Ltd.) was applied using a spin coat, followed by patterning using a photolithography method to form a liquid repellent layer CF (FIG. 4C). At this time, the liquid repellent layer CF was formed so as to surround a region corresponding to the gate electrode G formed in the lower layer. Further, the light shielding mask M1 shown in FIG. 9A is used for the exposure, and the liquid repellency of the liquid repellent layer CF is such that the first region CFa in the vicinity of the ink application region IA is the second region around the first region CFa. It was made higher than the region CFb.

  Next, a solution (ink IK) in which 6,13-bistriethylsilylethynylpentacene is dissolved in tetrahydronaphthalene is applied to an area (ink application area IA) surrounded by the liquid repellent layer CF by using an inkjet method (FIG. 4 (d)) and dried to form the semiconductor film SF (FIG. 4E).

  Next, using a mask vapor deposition method, a Cr film was formed with a thickness of 5 nm and an Au film was formed with a thickness of 50 nm to form a source electrode S and a drain electrode D (FIG. 4F).

  Next, an aqueous polyvinyl alcohol solution was applied onto the semiconductor film SF using an ink jet method and dried to form a protective film PF, thereby completing the TFT 1 (FIG. 4G). At this time, the droplet amount was adjusted so that the peripheral portion of the adhered droplet of the polyvinyl alcohol aqueous solution was in contact with the second region CFb of the liquid repellent layer CF having low liquid repellency.

The TFT 1 thus completed was observed with an optical microscope and an AFM (manufactured by Keyence Corporation). As in the case of Example 1, the semiconductor film SF and the protective film PF were at appropriate positions with appropriate film thicknesses. It was confirmed that it was formed accurately.
(Example 3)
An example of a manufacturing method of the top gate / bottom contact type TFT 1 according to the embodiment of the present invention will be described with reference to FIGS. FIG. 5A to FIG. 5F are schematic views showing a manufacturing process of the top gate bottom contact type TFT 1 according to the embodiment of the present invention. In each figure, the upper figure is a schematic sectional view and the lower figure is a schematic plan view.

  First, glass is used as the substrate P, and a Cr film is formed thereon with a thickness of 5 nm and an Au film is formed with a thickness of 50 nm using a sputtering method, followed by patterning using a photolithography method to form a source electrode S / drain electrode D. Was formed (FIG. 5A).

  Next, a photosensitive bank agent NPAR-502 (manufactured by Nissan Chemical Industries, Ltd.) was applied using a spin coat, followed by patterning using a photolithography method to form a liquid repellent layer CF (FIG. 5B). At this time, the liquid repellent layer CF was formed so as to surround the channel region between the source electrode S and the drain electrode D. Further, the light shielding mask M1 shown in FIG. 9A is used for the exposure, and the liquid repellency of the liquid repellent layer CF is that the first region CFa in the vicinity of the ink application region IA is the second region around the first region CFa. It was made higher than the region CFb.

  Next, a solution (ink IK) in which 6,13-bistriethylsilylethynylpentacene is dissolved in tetrahydronaphthalene is applied to an area (ink application area IA) surrounded by the liquid repellent layer CF by using an inkjet method (FIG. 5 (c)) and dried to form the semiconductor film SF (FIG. 5D).

  Next, using an inkjet method, optomer PC403, which is a photosensitive acrylate material, was applied to the surface of the semiconductor film SF and heated to form the gate insulating film IF (FIG. 5E). At this time, the droplet amount was adjusted so that the peripheral portion of the droplet adhered to the optomer PC 403 was in contact with the second region CFb of the liquid repellent layer CF having low liquid repellency. In this case, the gate insulating film IF also serves as the protective film PF.

  Next, a Cr film was formed with a thickness of 50 nm by using a mask vapor deposition method, a gate electrode G was formed, and the TFT 1 was completed (FIG. 5F).

The TFT 1 thus completed was observed with an optical microscope and an AFM (manufactured by Keyence Corporation). As in the case of Example 1, the semiconductor film SF and the protective film PF were at appropriate positions with appropriate film thicknesses. It was confirmed that it was formed accurately.
Example 4
An example of the manufacturing method of the top gate top contact type TFT 1 according to the embodiment of the present invention will be described with reference to FIG. FIG. 6A to FIG. 6F are schematic views showing the manufacturing process of the top gate top contact type TFT 1 according to the embodiment of the present invention. In each figure, the upper figure is a schematic sectional view and the lower figure is a schematic plan view.

  First, glass is used as the substrate P, and a photosensitive bank agent NPAR-502 (manufactured by Nissan Chemical Co., Ltd.) is applied thereon using a spin coat, and then patterned using a photolithography method to form a liquid repellent layer CF. Was formed (FIG. 6A). At this time, the liquid repellent layer CF was formed so as to surround a region corresponding to a channel region between the source electrode S and the drain electrode D formed in an upper layer of the substrate P in a later step. Further, the light shielding mask M1 shown in FIG. 9A is used for the exposure, and the liquid repellency of the liquid repellent layer CF is that the first region CFa in the vicinity of the ink application region IA is the second region around the first region CFa. It was made higher than the region CFb.

  Next, a tetrabenzoporphyrin solution (ink IK) is applied to the region (ink application region IA) surrounded by the liquid repellent layer CF using an ink jet method (FIG. 6B), and heated and fired to form a semiconductor film. SF was formed (FIG. 6C).

  Next, using a mask vapor deposition method, a Cr film was formed to a thickness of 5 nm and an Au film was formed to a thickness of 50 nm to form a source electrode and a drain electrode (FIG. 6D).

  Next, using an inkjet method, optomer PC403, which is a photosensitive acrylate material, was applied to the surface of the semiconductor film SF and heated to form the gate insulating film IF (FIG. 6E). At this time, the droplet amount was adjusted so that the peripheral portion of the droplet adhered to the optomer PC 403 was in contact with the second region CFb of the liquid repellent layer CF having low liquid repellency. In this case, the gate insulating film IF also serves as the protective film PF.

  Next, a Cr film was formed to a thickness of 50 nm using a mask vapor deposition method, a gate electrode G was formed, and the TFT 1 was completed (FIG. 6F).

  The TFT 1 thus completed was observed with an optical microscope and an AFM (manufactured by Keyence Corporation). As in the case of Example 1, the semiconductor film SF and the protective film PF were at appropriate positions at appropriate positions. It was confirmed that it was formed accurately.

  Thus, in the manufacturing method of TFT1 according to the embodiment of the present invention, the ink IK is higher than the ink application area IA so as to surround the area (ink application area IA) to which the semiconductor solution (ink IK) is applied. Since the liquid repellent layer CF having liquid repellency is formed, the droplet of the semiconductor solution (ink IK) is prevented from spreading out from the coating area (ink coating area IA), and the semiconductor film SF is formed with an appropriate film thickness. It can be accurately formed at a predetermined position.

  Further, the liquid repellency of the surface of the liquid repellent layer CF is given an in-plane intensity distribution so as to be highest in the vicinity of the region (ink application region IA) to which the semiconductor solution (ink IK) is applied, and the protective film The amount of liquid applied to the material solution was larger than the amount of liquid applied to the semiconductor solution (ink IK). Thereby, when the protective film PF for protecting the semiconductor film SF is formed, the protective film material solution can reach the liquid-repellent region at the periphery of the liquid-repellent layer CF. The semiconductor film SF can be sufficiently covered without the solution being repelled by the liquid repellent layer CF.

  Furthermore, since the semiconductor solution (ink IK) and the protective film material solution are applied using, for example, a droplet application method typified by an ink jet method, productivity can be increased.

1 TFT (Thin Film Transistor)
CF liquid repellent layer D drain electrode G gate electrode IF gate insulating film IK ink (organic semiconductor solution)
LF Underlayer M1, M2, M3, M4 Shading mask P Substrate PF Protective film S Source electrode SF Semiconductor film

Claims (9)

In a method for manufacturing a thin film transistor having a protective film for protecting a semiconductor film,
Forming a liquid repellent layer having a higher liquid repellency than the predetermined region on the surface of the base layer so as to surround a predetermined region of the surface of the base layer;
Applying the semiconductor solution to the predetermined region to form the semiconductor film;
Applying a protective film material solution to the surface of the semiconductor film to form the protective film covering the semiconductor film, and
The liquid repellency of the surface of the liquid repellent layer has an in-plane strength distribution and is highest in the vicinity of the predetermined region,
The method for producing a thin film transistor, wherein the amount of liquid applied to the protective film material solution is larger than the amount of liquid applied to the semiconductor solution. The liquid repellent layer includes two regions, a first region around the predetermined region and a second region surrounding the first region,
The liquid repellency of the first region is higher than the liquid repellency of the second region,
The peripheral portion of the droplet of the semiconductor solution dropped is in contact with the predetermined region or the first region, and the peripheral portion of the droplet of the protective film material solution is in contact with the second region. The method for manufacturing a thin film transistor according to claim 1, wherein the amount of each solution is adjusted.   3. The method of manufacturing a thin film transistor according to claim 1, wherein the liquid repellent layer is formed by a photolithography method using a light shielding mask having an in-plane intensity distribution of light transmittance.   4. The method of manufacturing a thin film transistor according to claim 1, wherein the semiconductor solution is a solution in which an organic semiconductor material is dissolved.   5. The method of manufacturing a thin film transistor according to claim 1, wherein the semiconductor solution and the protective film material solution are applied using an inkjet method. 6. The thin film transistor has a bottom gate bottom contact structure,
The foundation layer is a source electrode and a drain electrode,
6. The method of manufacturing a thin film transistor according to claim 1, wherein the predetermined region is at least a channel region between the source electrode and the drain electrode. The thin film transistor has a bottom gate top contact structure,
The foundation layer is a gate insulating film;
6. The method of manufacturing a thin film transistor according to claim 1, wherein the predetermined region is a region corresponding to at least a gate electrode formed in a lower layer of the gate insulating film. The thin film transistor has a top gate bottom contact structure,
The foundation layer is a source electrode and a drain electrode,
6. The method of manufacturing a thin film transistor according to claim 1, wherein the predetermined region is at least a channel region between the source electrode and the drain electrode. The thin film transistor has a top gate top contact structure,
The foundation layer is a substrate;
6. The thin film transistor according to claim 1, wherein the predetermined region is a region corresponding to at least a channel region between a source electrode and a drain electrode formed on an upper layer of the substrate. Manufacturing method.