JP5817402B2 - Thin film transistor manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing a thin film transistor.

At present, due to the remarkable development of information technology, information is frequently transmitted and received using a notebook personal computer or a portable information terminal. It is a well-known fact that in the near future, a ubiquitous society that can exchange information regardless of location will come. In such a society, a lighter and thinner information terminal is desired.
At present, the mainstream of semiconductor materials is silicon-based, and as a manufacturing method thereof, one using photolithography is common.

On the other hand, attention has been focused on printable electronics for manufacturing electronic members using printing technology.
In printable electronics, the use of a printing technique lowers the apparatus and manufacturing costs compared to photolithography, and there is an advantage that a plastic substrate can be used because no vacuum or high temperature is required.

In this case, an organic semiconductor soluble in an organic solvent, an oxide semiconductor precursor, or the like is often used as the semiconductor material. This is because the semiconductor layer can be formed by a printing method.
As a technique for forming an organic semiconductor layer using a printing technique, there are the following techniques.
For example, in the technique described in Patent Document 1, the organic semiconductor layer is formed by an inkjet method.

For example, in the technique described in Patent Document 2, the organic semiconductor layer is formed by flexographic printing.
For example, in the technique described in Patent Document 3, the organic semiconductor layer is formed by letterpress offset printing.

Japanese Patent Laid-Open No. 2005-210086 JP 2006-63334 A JP 2009-224665 A

However, when the organic semiconductor layer is formed by an inkjet method as in the technique described in Patent Document 1, generally, the organic semiconductor has low solubility in a solvent, and therefore the organic semiconductor is deposited in the vicinity of the nozzle. Therefore, there is a problem that ejection failure occurs.
In addition, in order to realize a fine pattern by the ink jet method, it is necessary to provide a partition around the pattern forming portion, or to control the wettability of the substrate surface in advance using light irradiation or the like. In addition, it is not suitable for cost reduction.

  In addition, when a low molecular weight polycrystalline material is used as the organic semiconductor material, in particular, in the bottom contact transistor, the surface free energy is different between the source electrode, the drain electrode surface, and the gate insulating film surface. It is known that the crystalline state of the organic semiconductor becomes discontinuous at the boundary between the drain electrode and the gate insulating film, and the transistor characteristics are deteriorated.

  When the organic semiconductor layer is formed by flexographic printing as in the technique described in Patent Document 2, when the organic semiconductor solution is transferred from the anilox to the flexographic plate, the convex portion of the flexographic plate is the concave portion of the anilox. The amount of liquid to be transferred is different between the case where the film enters the bank and the case where the film is applied to the bank portion, and the formed film thickness varies. The variation in film thickness is a variation in characteristics of the thin film transistor.

In addition, as in the technique described in Patent Document 3, when an organic semiconductor layer is formed by letterpress offset printing, after applying ink to the entire blanket having releasability, unnecessary portions are removed. In order to obtain a desired pattern, the use efficiency of ink is bad and cannot contribute to cost reduction.
In this case, the removed ink can be recovered and used again. However, the blanket generally used in letterpress offset printing is made of silicone, and residual silicone oligomers are mixed into the ink. It needs to be purified.

  In view of the above circumstances, in the present invention, when forming a semiconductor layer using a printing method, it is possible to form a fine pattern without the need for pretreatment, etc., and excellent in-plane uniformity of transistor characteristics, It aims at providing the manufacturing method of the thin-film transistor excellent in the utilization efficiency of ink.

In order to solve the above problems, the invention described in claim 1 of the present invention includes at least a gate electrode, a gate insulating film, a source electrode, a drain electrode, a semiconductor layer, and a sealing layer. A thin film transistor manufacturing method for manufacturing a thin film transistor formed on an insulating substrate,
An ink supply process for supplying ink to a printing plate having an uneven pattern formed using an ink supply means;
An ink liquid film removing step of removing the ink liquid film in the non-image area using a relief after the preliminary drying of the ink;
And an ink liquid film transfer step of transferring at least one of the semiconductor layer and the sealing layer by transferring the ink liquid film of the image area remaining on the printing plate to the substrate. It is what.

Next, among the present inventions, the invention described in claim 2 is the invention described in claim 1, wherein the printing plate is formed of a silicone resin.
Next, among the present inventions, the invention described in claim 3 is the invention described in claim 1 or 2, wherein the uneven pattern formed on the printing plate is formed in a stripe shape. It is characterized by that.
Next, among the present inventions, the invention described in claim 4 is the invention described in claim 3, wherein the uneven pattern formed in the stripe shape is the final formation of the semiconductor layer. It is characterized by being formed in a direction parallel to the major axis direction.
Next, among the present inventions, the invention described in claim 5 is the invention described in claim 3 or claim 4, wherein the unevenness formed on the printing plate in the ink liquid film removing step. The ink liquid film in the non-image area is removed so as to be orthogonal to the stripe direction of the pattern.

Next, of the present invention, the invention described in claim 6 is the invention described in any one of claims 1 to 5, wherein the ink supply means is anilox. It is what.
Next, among the present inventions, the invention described in claim 7 is the invention described in any one of claims 1 to 6, wherein the ink is an organic semiconductor solution. It is what.
Next, of the present invention, the invention described in claim 8 is the invention described in any one of claims 1 to 6, wherein the ink is a precursor solution of an oxide semiconductor or It is a nanoparticle dispersion of an oxide semiconductor.
Next, among the present inventions, the invention described in claim 9 is the invention described in any one of claims 1 to 8, wherein the sealing layer is an etching stopper layer. It is characterized by.

Next, among the present inventions, the invention described in claim 10 is the invention described in any one of claims 1 to 9, wherein the sealing layer is formed in the ink liquid film transfer step. The semiconductor layer is formed in a lower layer, and the semiconductor layer formed in the lower layer of the sealing layer is patterned using the sealing layer as a mask.
Next, among the present inventions, the invention described in claim 11 is the invention described in claim 10, characterized in that the patterning method of the semiconductor layer is an etching method.

  As described above, according to the present invention, an ink liquid film in an image area remaining on a printing plate after removing an ink liquid film in a non-image area using a printing plate on which an uneven pattern is formed. By transferring the substrate to the substrate and forming the semiconductor layer and sealing layer, it becomes possible to form fine patterns without the need for pretreatment, etc., and in-plane uniformity of transistor characteristics and ink utilization efficiency It is possible to manufacture a thin film transistor excellent in the above.

Moreover, if it is invention of Claim 1, it will become possible to supply ink selectively only to a convex part by supplying ink to the printing plate in which the uneven | corrugated pattern was formed. Compared with printing, the use efficiency of ink is increased, so that it is possible to contribute to cost reduction of the thin film transistor.
Further, when a bottom contact type transistor is manufactured using a low molecular polycrystal organic semiconductor, a crystal is deposited on a printing plate having a uniform surface energy, and then transferred, whereby a source electrode, Since it is possible to avoid discontinuity in the crystal state at the boundary between the drain electrode and the gate insulating film, excellent transistor characteristics can be realized.

Further, according to the invention described in claim 2, since the printing plate is made of a silicone resin, the ink releasability is increased, so that the ink remaining on the printing plate is reduced during removal and transfer. It becomes possible.
Moreover, if it is invention described in Claim 3, while making the unevenness | corrugation of a printing plate into stripe form, while being able to make high use efficiency of ink, for example, compared with dot shape etc., Since the ink liquid amount is made uniform in the stripe direction, it is possible to reduce variations in the ink liquid film in the image line portion, and to improve the in-plane uniformity of the transistor characteristics.

Further, in the case of the invention described in claim 4, when the stripe-shaped unevenness in the printing plate is parallel to the short axis direction by being parallel to the long axis direction of the finally formed semiconductor layer In comparison with the above, it is possible to increase the use efficiency of the ink.
According to the invention described in claim 5, the removal of the ink liquid film in the non-image area using the relief plate is perpendicular to the stripe direction of the printing plate, so that the transistor channels are regularly arranged. It is possible to selectively form a semiconductor layer on the part and to make the stripe-shaped semiconductor pattern on the printing plate into a dot shape, thereby reducing leakage current between adjacent pixels. Is possible.

Further, according to the invention described in claim 6, by supplying the ink using anilox, it becomes possible to selectively supply the ink to the convex portion of the printing plate, thereby improving the use efficiency of the ink. It becomes possible.
According to the invention described in claim 7, by using an organic semiconductor solution as the ink, a thin film transistor using a low temperature process can be manufactured, and a plastic substrate can be used. Therefore, not only an inexpensive thin film transistor substrate can be manufactured, but also a flexible device can be realized.

Further, according to the invention described in claim 8, by using an oxide semiconductor precursor solution or a nanoparticle dispersion as an ink, it is possible to realize higher transistor characteristics than in the case of an organic semiconductor. It becomes.
Further, according to the invention described in claim 9, the back channel can be protected even when a top contact type thin film transistor is manufactured by using the sealing layer as an etching stopper layer. Transistor characteristics can be realized.

  Further, according to the invention described in claim 10, it is possible to selectively form the sealing layer only in the channel portion of the thin film transistor by forming the sealing layer in the ink liquid film transfer process described above. Become. For this reason, for example, unnecessary portions of the organic semiconductor layer formed on the entire surface of the substrate by the spin coating method or the organic semiconductor layer roughly patterned by the ink jet method or the like are removed using a solvent, an etchant, plasma, or the like. Therefore, the semiconductor layer can be formed into a fine pattern regardless of the film formation method.

  Further, according to the invention described in claim 11, by using the etching method as the method for patterning the semiconductor layer in the invention described in claim 10, the semiconductor layer insoluble in the solvent by heat treatment, light irradiation, etc. Even in this case, unnecessary portions can be removed.

It is a schematic diagram which shows an example of the thin-film transistor manufactured using the manufacturing method of this invention. It is the sectional view on the ab line of FIG. It is a schematic diagram which shows an example of embodiment of the printing plate which has an uneven | corrugated pattern of this invention. It is a schematic diagram which shows an example of embodiment of the letterpress of this invention. 1 is a schematic diagram showing an example of a method for producing a thin film transistor of the present invention described in Example 1. FIG. 1 is a schematic diagram showing an example of a method for producing a thin film transistor of the present invention described in Example 1. FIG. 1 is a schematic diagram showing an example of a method for producing a thin film transistor of the present invention described in Example 1. FIG. It is a cross-sectional schematic diagram which shows an example of embodiment of the manufacturing method of the ink liquid film corresponding to the image part on the printing plate of this invention. It is a cross-sectional schematic diagram which shows an example of embodiment of the manufacturing method of the ink liquid film corresponding to the image part on the printing plate of this invention. 6 is a schematic diagram showing an example of a method for producing the thin film transistor of the present invention described in Example 2. FIG. 6 is a schematic diagram showing an example of a method for producing the thin film transistor of the present invention described in Example 2. FIG. 6 is a schematic diagram showing an example of a method for producing the thin film transistor of the present invention described in Example 2. FIG. 6 is a schematic diagram showing an example of a method for producing the thin film transistor of the present invention described in Example 2. FIG. 6 is a schematic diagram showing an example of a method for producing a thin film transistor of the present invention described in Example 3. FIG. 6 is a schematic diagram showing an example of a method for producing a thin film transistor of the present invention described in Example 3. FIG. It is a cross-sectional schematic diagram which shows an example of embodiment of the manufacturing method of the ink liquid film corresponding to the image part on the printing plate of this invention. It is a cross-sectional schematic diagram which shows an example of embodiment of the manufacturing method of the ink liquid film corresponding to the image part on the printing plate of this invention. It is a schematic diagram which shows an example of the thin-film transistor shown to a comparative example. It is a schematic diagram which shows an example of the thin-film transistor manufactured using the manufacturing method of this invention.

Hereinafter, an embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described with reference to the drawings.
The present invention is a method of manufacturing a thin film transistor for manufacturing the thin film transistor 1 shown in FIGS. FIG. 1 is a schematic diagram showing an example of a thin film transistor 1 manufactured using the manufacturing method of the present invention, and FIG. 2 is a cross-sectional view taken along the line ab in FIG.

As shown in FIGS. 1 and 2, the thin film transistor 1 includes a gate electrode 41, a gate insulating film 42, a source electrode 43, a drain electrode 44, and a semiconductor layer 45 formed on an insulating substrate 40. And a sealing layer 46.
Moreover, the manufacturing method of the thin-film transistor of this invention has an ink supply process, an ink liquid film removal process, and an ink liquid film transfer process.

The ink supply step is a step of supplying ink to a printing plate on which a concavo-convex pattern is formed using an ink supply means.
Specifically, in the ink supply process, as a method of forming a concavo-convex pattern, ink is supplied from, for example, anilox to the printing plate on which the concavo-convex pattern is formed, and an ink liquid film is selectively formed on the convex portion. The method to be used is used.

The ink liquid film removing step is a step of removing the ink liquid film in the non-image area using a relief plate after preliminary drying of the ink.
Specifically, in the ink liquid film removing step, the ink is removed from the printing plate using a relief plate having a projection corresponding to a non-image portion of the uneven pattern formed in the ink supply step.
The ink liquid film transfer step is a step of transferring at least one of the semiconductor layer 45 and the sealing layer 46 by transferring the ink liquid film of the image area remaining on the printing plate to the substrate 40.

Specifically, in the ink liquid film transfer step, a desired pattern is transferred by transferring the portion of the ink liquid film corresponding to the image portion remaining on the printing plate in the ink liquid film removing step to the substrate 40. Get.
Here, the ink liquid film formed on the convex portion of the printing plate is preferably pre-dried before removing the ink liquid film on the non-image area with the convex plate. The reason for this is that in the case of liquid ink, it is difficult to completely transfer the ink from the non-image area of the printing plate to the relief plate because the cohesive force of the ink is low. This is because the cohesive force increases and complete transfer becomes possible.

Further, in this embodiment, the material used for the printing plate is not particularly limited, but it is possible to form an ink liquid film, remove the non-image area with the removal plate, and transfer to the substrate 40. Things are used.
The material used for the printing plate is preferably a material with little deformation, but a certain degree of flexibility is required.

As such a material, silicone elastomer, butyl rubber, ethylene propylene rubber, or the like can be used. In order to adjust the wettability of the blanket surface, the blanket surface may be subjected to a surface treatment such as application of fluororesin and silicone, plasma treatment, or UV ozone cleaning treatment.
In this embodiment, the material used for the relief printing plate is not particularly limited, but as a commonly used material, a metal such as glass, quartz, SUS or copper, or a photosensitizer such as acrylate or methacrylate. It is possible to use resins containing photosensitive groups such as unsaturated polyester epoxy acrylate, urethane acrylate, etc., but in particular from the viewpoint of dimensional stability, workability, etc., use glass, quartz, etc. Is preferred.

In addition, the relief printing plate can be subjected to an ink repellent treatment or the like as necessary. In this case, examples of the ink repellent treatment include chemical treatment using silicone or a silane coupling agent, physical treatment such as fluorine plasma, etc. In consideration of long-term stability, etc., silane on the surface of glass or metal is used. It is preferable to use a coupling process.
In this case, it is preferable to use a coupling agent containing a fluorine element or siloxane group having high water repellency and oil repellency, although it varies depending on the ink used.

Examples of the above-mentioned examples include, but are not limited to, long-chain fluoroalkylsilanes, hydrolyzable group-containing siloxanes, fluoroalkyl group-containing oligomers, and the like.
In the present embodiment, the method used as the ink supply means is not particularly limited, but as a generally used method, slot die coating, capillary coating, anilox and the like are preferable. The reason is that by selectively supplying ink to the convex portion, the ink use efficiency can be improved. Capillary coating, anilox, etc. are desirable, but considering the printing tact time etc., anilox is Most preferred.

In the present embodiment, the material used as the semiconductor material is not particularly limited, but it is desirable to use an organic semiconductor material or an oxide semiconductor material in consideration of inking.
As the organic semiconductor material, high-molecular organic semiconductor materials such as polythiophene, polyallylamine, fluorenebithiophene copolymer, and derivatives thereof can be used.

Examples of organic semiconductor materials include low molecular organic semiconductor materials such as pentacene, tetracene, copper phthalocyanine, perylene, 6,13-bis (triisopropylsilylethynyl) pentacene (TIPS-pentacene), and derivatives thereof, and heating. It is possible to use a precursor that is converted into an organic semiconductor by treatment or the like.
As the organic semiconductor material, a carbon compound such as carbon nanotube or fullerene, a semiconductor nanoparticle dispersion, or the like can also be used as a material for the semiconductor layer. Further, metal chlorides such as zinc, indium, and gallium, metal acetates, metal nitrates, and the like can be used.

Further, when the semiconductor layer 45 is patterned using the sealing layer 46 as a mask after the semiconductor layer 45 is formed on the entire surface, in addition to the semiconductor material described above, a silicon-based material such as amorphous silicon that can be vacuum-deposited is used. A semiconductor material or an oxide semiconductor such as zinc oxide can also be used.
Further, in the present embodiment, the material used as the sealing material is not particularly limited, but examples of generally used materials include fluorine-based resins and polyvinyl alcohol. However, the material used as the sealing material is not limited to these. In addition, the sealing layer 46 can be provided with a light shielding property as necessary.

In the present embodiment, the material used for the base material 40 is not particularly limited, but is flexible such as polyethylene terephthalate (PET), polyimide, polyethersulfone (PES), polyethylene naphthalate (PEN), and polycarbonate. It is possible to use a plastic material, a glass substrate such as quartz, a silicon wafer, or the like.
Hereinafter, the manufacturing method of the thin-film transistor of this invention is demonstrated using an Example.
Example 1
A printing plate 10 shown in FIG. 3 was produced as follows. FIG. 3 is a schematic diagram showing an example of an embodiment of a printing plate having a concavo-convex pattern according to the present invention.

A substrate having the concavo-convex shape of the printing plate is produced by etching glass, and then a silicone rubber (TSE3455T manufactured by Momentive Performance Materials) is poured into the substrate to form a concavo-convex pattern comprising convex portions 11 and concave portions 12. A printing plate 10 having the following was prepared.
Moreover, the letterpress 20 shown in FIG. 4 was produced as follows. FIG. 4 is a schematic diagram showing an example of the embodiment of the relief printing plate of the present invention.

By etching the glass, a relief plate 20 was produced in which the portion corresponding to the non-image portion of the semiconductor layer to be formed was a projection.
A thin film transistor was manufactured by the method shown in FIG. FIG. 5 is a schematic diagram showing an example of the method for manufacturing the thin film transistor of the present invention described in Example 1.
Polyimide (manufactured by Ube Industries) was used as the base material of the thin film transistor.

Then, as shown in FIG. 5A, 100 nm of aluminum was formed by sputtering, and the gate electrode 41 was formed by photolithography, etching, and resist removal using a positive resist.
Next, using a polyimide (Mitsubishi Gas Chemical Neoprim) as a gate insulating material, it apply | coated with the die-coater, and it dried at 180 [degreeC] for 1 hour, and formed the gate insulating film.

Next, as shown in FIG. 5B, a gold film of 50 [nm] was formed by vapor deposition, and a source electrode 43 and a drain electrode 44 were formed by photolithography, etching, and resist peeling using a positive resist. .
Here, the pattern of the image line part was produced by the method shown in FIG. FIG. 6 is a schematic cross-sectional view showing an example of an embodiment of a method for producing an ink liquid film corresponding to an image line portion on the printing plate of the present invention.

As a semiconductor material, 6,13-bis (triisopropylsilylethynyl) pentacene (TIPS-pentacene) (manufactured by Aldrich) was used. Moreover, what was dissolved in tetralin (manufactured by Kanto Chemical Co., Ltd.) at 2% by weight [%] was used as ink.
And ink was supplied to the printing plate 10 from Anilox, and the ink liquid film 31 was formed in the convex part 11 of the printing plate. Next, preliminary drying was performed at room temperature for 5 minutes, and the ink liquid film 32 in the non-image area was removed using the relief printing plate 20.

Next, as shown in FIG. 6E, the ink liquid film 33 in the image area remaining on the printing plate 10 is transferred to a portion corresponding to the channel portion of the thin film transistor substrate, and 90 ° C. ] For 1 hour to form a semiconductor layer 45 as shown in FIG.
After the semiconductor layer 45 is formed, an ink obtained by dissolving polyvinyl alcohol (manufactured by Aldrich) in pure water at 5% by weight as a sealing material is used in the same manner as the semiconductor layer 45 in FIG. The sealing layer 46 was formed as shown in FIG.

As a result, in Example 1, it was possible to form a thin film transistor having excellent transistor characteristics.
(Example 2)
The printing plate and letterpress of Example 2 were produced in the same manner as in Example 1.
The thin film transistor of Example 2 was manufactured by the method shown in FIG. FIG. 7 is a schematic diagram showing an example of a method for manufacturing the thin film transistor of the present invention described in Example 2.

Polyethylene naphthalate (manufactured by Teijin DuPont) was used as the substrate 40 of the thin film transistor.
And the gate electrode 41 was formed with the inkjet method as shown in FIG. 7 (a) using the ink (made by Harima Chemicals) in which the silver nanoparticle was disperse | distributed.
Next, using a solution obtained by dissolving poly (4-vinylphenol) (manufactured by Aldrich) and melamine resin (manufactured by Sanwa Chemical) in propylene glycol monomethyl ether acetate (manufactured by Kanto Chemical) as a gate insulating material, After coating, it was dried at 180 [° C.] for 1 hour to form a gate insulating film.

Next, as shown in FIG. 7B, a source electrode 43 and a drain electrode 44 were formed by using an ink in which silver nanoparticles were dispersed (manufactured by Harima Kasei) and using an inkjet method.
Furthermore, as a semiconductor material, 6,13-bis (triisopropylsilylethynyl) pentacene (TIPS-pentacene) (Aldrich) was used and dissolved in tetralin (Kanto Chemical Co., Ltd.) at 2% by weight as ink. The semiconductor ink was applied by spin coating to form a semiconductor layer 45 on the entire surface of the substrate as shown in FIG.

Here, the pattern of the image line part was produced by the method shown in FIG.
As a sealing material, an ink obtained by dissolving polyvinyl alcohol (manufactured by Aldrich) in pure water at 5% by weight [%] was used.
And ink was supplied to the printing plate 10 from Anilox, and the ink liquid film 32 was formed in the convex part 11 of the printing plate. Next, preliminary drying was performed at room temperature for 2 minutes, and the ink liquid film 32 in the non-image area was removed using the relief printing plate 20.

Further, after the ink liquid film 33 in the image area remaining on the printing plate is transferred to a portion corresponding to the channel portion of the thin film transistor substrate, it is dried at 90 [° C.] for 1 hour, and FIG. ) A sealing layer 46 was formed as shown in FIG.
Next, by using the sealing layer 46 as a mask, the exposed semiconductor layer 45 was washed with toluene, thereby patterning the semiconductor layer 45 as shown in FIG.

As a result, in Example 2, it was possible to form a thin film transistor having excellent transistor characteristics.
(Example 3)
The printing plate and letterpress of Example 3 were produced in the same manner as in Example 1.
The thin film transistor of Example 3 was manufactured by the method shown in FIG. FIG. 8 is a schematic diagram showing an example of a method for manufacturing the thin film transistor of the present invention described in Example 3.

Glass was used as the substrate 40 of the thin film transistor.
Then, 100 [nm] of aluminum was formed by sputtering, and a gate electrode 41 was formed as shown in FIG. 8A by photolithography using a positive resist, etching, and resist removal.
Next, a SiN sintered body was used as a target, and SiON was laminated by 300 [nm] by a sputtering method to obtain a gate insulating film.

Then, as shown in FIG. 8B, a semiconductor layer 45 having a film thickness of 40 [nm] was produced by sputtering using a shadow mask using InGaZnO ₄ as a target.
Here, the pattern of the image line part was produced by the method shown in FIG. FIG. 9 is a schematic cross-sectional view showing an example of an embodiment of a method for producing an ink liquid film corresponding to an image line portion on the printing plate of the present invention.

As an etching stopper material, a solution in which poly (4-vinylphenol) (manufactured by Aldrich) and melamine resin (manufactured by Sanwa Chemical) were dissolved in propylene glycol monomethyl ether acetate (manufactured by Kanto Chemical) was used.
Then, ink is supplied from the anilox to the printing plate 10 and an ink liquid film is formed on the convex portion 11 of the printing plate, followed by preliminary drying at room temperature for 2 minutes. The ink liquid film 32 was removed.

Next, the ink liquid film 33 in the image area remaining on the printing plate is transferred onto the semiconductor layer of the thin film transistor substrate and dried at 180 [° C.] for 1 hour. As shown, a sealing layer 46 was formed. The sealing layer 46 of Example 3 also serves as an etching stopper layer.
Further, vias 47 (contact holes) are provided in the sealing layer 46.

Next, an indium tin oxide film having a thickness of 100 nm is formed by sputtering, and photolithography, etching, and resist peeling using a positive resist are performed, as shown in FIG. 8D, the source electrode 43 and the drain electrode 44. Formed.
As a result, in Example 3, it was possible to form a thin film transistor having excellent transistor characteristics.
(Comparative example)
In the comparative example, the thin film transistor 1 shown in FIG. 10 was produced. FIG. 10 is a schematic diagram illustrating an example of the thin film transistor illustrated in the comparative example.

A printing plate was produced in the same manner as in Example 1.
Further, a thin film transistor was produced in the same manner as in Example 1 except that the ink liquid film was not removed from the non-image area by the relief printing plate.
As a result, in the comparative example, since a leakage current was observed between adjacent pixels, the off-current increased and excellent transistor characteristics could not be obtained.
(Modification)
Note that the configuration of the thin film transistor 1 manufactured by using the manufacturing method of the present invention is not limited to the configuration shown in FIGS. 1 and 2, and for example, as shown in FIG. It is good also as a structure in which 46 is not formed. FIG. 11 is a schematic diagram showing an example of a thin film transistor manufactured using the manufacturing method of the present invention.

DESCRIPTION OF SYMBOLS 1 Thin-film transistor 10 Printing plate 11 Convex part 12 Concave part 20 Letter plate 31 Ink liquid film 32 Non-image part ink liquid film 33 Image part ink liquid film 40 Substrate 41 Gate electrode 42 Gate insulating film 43 Source electrode 44 Drain electrode 45 Semiconductor layer 46 Sealing layer 47 Via

Claims (11)

A thin film transistor manufacturing method for manufacturing a thin film transistor in which at least a gate electrode, a gate insulating film, a source electrode, a drain electrode, a semiconductor layer and a sealing layer are formed on an insulating substrate,
An ink supply process for supplying ink to a printing plate having an uneven pattern formed using an ink supply means;
An ink liquid film removing step of removing the ink liquid film in the non-image area using a relief after the preliminary drying of the ink;
And an ink liquid film transfer step of transferring at least one of the semiconductor layer and the sealing layer by transferring the ink liquid film of the image area remaining on the printing plate to the substrate. A method for manufacturing a thin film transistor.   2. The method for manufacturing a thin film transistor according to claim 1, wherein the printing plate is formed of a silicone resin.   3. The method for manufacturing a thin film transistor according to claim 1, wherein the uneven pattern formed on the printing plate is formed in a stripe shape.   4. The method of manufacturing a thin film transistor according to claim 3, wherein the uneven pattern formed in a stripe shape is formed in a direction parallel to a major axis direction of the semiconductor layer finally formed.   The ink liquid film in the non-image area is removed in the ink liquid film removing step so as to be orthogonal to the stripe direction of the concavo-convex pattern formed on the printing plate. A method for producing the thin film transistor according to 4.   The method of manufacturing a thin film transistor according to any one of claims 1 to 5, wherein the ink supply means is anilox.   The method of manufacturing a thin film transistor according to any one of claims 1 to 6, wherein the ink is an organic semiconductor solution.   The method of manufacturing a thin film transistor according to any one of claims 1 to 6, wherein the ink is an oxide semiconductor precursor solution or an oxide semiconductor nanoparticle dispersion.   The method of manufacturing a thin film transistor according to claim 1, wherein the sealing layer is an etching stopper layer.   In the ink liquid film transfer step, the semiconductor layer is formed under the sealing layer, and further, the semiconductor layer formed under the sealing layer is patterned using the sealing layer as a mask. A method for manufacturing a thin film transistor according to any one of claims 1 to 9.   The method of manufacturing a thin film transistor according to claim 10, wherein the patterning method of the semiconductor layer is an etching method.

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