JP2008270544A - Organic transistor and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic transistor having a small off-current and a large (ON/OFF) ratio and a manufacturing method for the organic transistor, and also to provide an organic transistor array having the organic transistor and a display device having the organic transistor array. <P>SOLUTION: In the organic transistor 10, a first electrode layer 12 has electrically connected gate electrodes 12a and 12b, and a second electrode layer 14 has a source electrode 14a, a drain electrode 14b, and an island electrode 14c. The island electrode 14c is formed between the source electrode 14a and the drain electrode 14b via respective gaps. A gap between the island electrode 14c and the source electrode 14a, and a gap between the island electrode 14c and the drain electrode 14b are formed on the gate electrode 12a and the gate electrode 12b, respectively, and are covered with an organic semiconductor layer 15. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an organic transistor, an organic transistor manufacturing method, an organic transistor array, and a display device.

  Organic transistors using organic semiconductor materials have been intensively studied. Advantages of using organic semiconductor materials for transistors include a variety of material configurations, manufacturing methods, high flexibility in product form, etc., easy area enlargement, and simple layer configuration and a simple manufacturing process. And an inexpensive manufacturing apparatus is possible. Furthermore, by using means such as a printing method, a spin coating method, and an immersion method, a thin film and a circuit can be easily formed. As a result, an organic transistor can be manufactured by orders of magnitude less than a conventional Si transistor.

  When organic transistors are integrated, it is essential to form a pattern. When transistors are integrated without forming a pattern, off-state current increases during operation of the transistors, and power consumption increases. In addition, when displaying pixels, it also causes crosstalk. In a transistor using a Si-based semiconductor material, a pattern is formed by photolithography and etching.

  On the other hand, in the case of an organic transistor, pattern formation by ink jet printing is promising, and a method of forming an organic transistor using patterning by charge application, patterning by a concave portion, and patterning by laser irradiation has been proposed ( For example, see Patent Document 1).

  In addition, a method of patterning source / drain electrodes by ejecting a material by inkjet after producing an indent has been proposed (see, for example, Patent Document 2).

  As a pattern formation method of the organic semiconductor layer, after applying a photoresist, a desired pattern is exposed and developed to form a resist pattern (photolithography), and etching is performed using this as an etching mask to remove the resist Can be used. However, when a polymer material is used as the organic semiconductor material, transistor characteristics may be deteriorated when a pattern or the like is formed by applying a photoresist on the polymer material. This is because, for example, when a solution obtained by dissolving a novolak resin having naphthoquinonediazide as a photosensitive group in an organic solvent such as xylene or cellosolve solvent is used as a photoresist, a polymer material can be used for the organic solvent contained in the photoresist. This is because of dissolution. In addition, when a crystalline material such as pentacene is used as the organic semiconductor material, the transistor characteristics may be deteriorated after photolithography although there is a difference in degree. Further, the resist may be damaged by a stripping solution such as ethylene glycol monobutyl ether or monoethanolamine used for stripping the resist, or may be damaged by pure water rinsing after stripping.

  Further, a method of patterning a crystalline material such as pentacene by a vacuum vapor deposition method using a shadow mask has been proposed (see, for example, Patent Document 3). However, this method is not suitable for forming a large area because the pattern size is limited by the shadow mask. Moreover, since the shadow mask has a lifetime, as a result, it is difficult to manufacture it at low cost.

  On the other hand, when a polymer material soluble in an organic solvent is used as the organic semiconductor material, a pattern can be formed by ink jet printing. However, in consideration of the ink landing accuracy, it is difficult to form a pattern of 50 μm or less, and higher definition than photolithography cannot be achieved.

  Note that ink-jet printing can directly draw a pattern, which increases the material usage rate. For this reason, there is a possibility that the manufacturing process can be simplified, the yield can be improved, and the cost can be reduced by applying the patterning to the organic semiconductor layer. However, in inkjet printing, it is difficult to reduce the discharge amount. Therefore, in order to further increase the definition, in particular, regarding the formation of the source / drain electrodes, it is necessary to devise the surface to be landed.

  Therefore, when water-soluble ink is ink-jet printed on a surface having a high energy surface and a low energy surface, the ink is formed only on the high energy surface, and a high-definition pattern can be formed (for example, , See Patent Document 4). Since the organic semiconductor material has lower mobility than the inorganic semiconductor material, it is necessary to shorten the channel length in order to increase the on-state current of the semiconductor element. There is a problem that the OFF ratio becomes small.

On the other hand, in a field effect transistor using an inorganic semiconductor material, it is known that off current can be reduced by adopting a so-called dual gate structure in which a plurality of field effect transistors are connected in series (see, for example, Patent Document 5). ). However, in an organic transistor, such a structure is not known and the off-current cannot be reduced, so the ON / OFF ratio becomes small.
JP 2004-297011 A JP 2004-141856 A Special table 2003-536260 gazette JP-A-2005-310962 Japanese Patent No. 3514002

  An object of the present invention is to provide an organic transistor having a small off-state current and a large ON / OFF ratio, and a method for manufacturing the organic transistor, in view of the above-described problems of the related art. Another object of the present invention is to provide an organic transistor array having the organic transistor and a display device having the organic transistor array.

  The invention according to claim 1 includes a substrate, a first electrode layer formed on the substrate, and a wettability changing layer formed on the substrate on which the first electrode layer is formed. A second electrode layer formed in a region where the surface energy of the wettability changing layer is high, and an organic semiconductor layer formed on the wettability changing layer on which the second electrode layer is formed An organic transistor, wherein the first electrode layer includes a first gate electrode and a second gate electrode that are electrically connected, and the second electrode layer includes a source electrode, a drain electrode, and An island electrode, and the island electrode is formed between the source electrode and the drain electrode via a gap, the gap between the island electrode and the source electrode, and the island electrode and the drain electrode The gap between the first gate Together they are formed in the upper and said second gate electrode, characterized in that it is covered with the organic semiconductor layer. Thereby, an organic transistor having a small off-current and a large ON / OFF ratio can be provided.

  The invention according to claim 2 is the organic transistor according to claim 1, further comprising a wettability changing layer between the substrate and the first electrode layer, wherein the first electrode layer has the wettability. The property change layer is formed in a region having a high surface energy. Accordingly, an increase in off current can be suppressed even when the channel length is shortened.

  The invention according to claim 3 is the organic transistor according to claim 1 or 2, wherein the island electrode is composed of two or more electrodes formed through a gap, and the first electrode layer is One or more gate electrodes that are electrically connected to the first gate electrode and the second gate electrode are further included, and a gap between the two or more electrodes is the one or more gate electrodes. It is formed on and covered with the said organic-semiconductor layer. Thereby, the ON / OFF ratio can be further increased.

  Invention of Claim 4 is a manufacturing method of the organic transistor as described in any one of Claim 1 thru | or 3, Comprising: The process of forming a 1st electrode layer on a board | substrate, This 1st electrode A step of forming a wettability changing layer on the substrate on which the layer is formed, a step of forming a region having a high surface energy by applying energy to the wettability changing layer, and a liquid containing a conductive material A step of forming a second electrode layer in a region having a high surface energy, and a step of forming an organic semiconductor layer on the wettability changing layer on which the second electrode layer is formed. Thereby, an organic transistor having a small off-current and a large ON / OFF ratio can be provided.

  According to a fifth aspect of the present invention, in the method of manufacturing an organic transistor according to the fourth aspect, the high surface energy region includes a first region and a second region that is narrower than the first region. The second electrode layer is formed by supplying a liquid containing the conductive material to the first region. As a result, the width of the source / drain electrode can be narrowed. As a result, the parasitic capacitance between the gate electrode and the source / drain electrode is reduced, and the operation speed can be improved.

  According to a sixth aspect of the present invention, in the method of manufacturing an organic transistor according to the fourth or fifth aspect, the step of forming the first electrode layer on the substrate forms a wettability changing layer on the substrate. A step of forming a region having a high surface energy by applying energy to the wettability changing layer; and a step of forming the first electrode layer in the region having a high surface energy using a liquid containing a conductive material. It includes a step of forming. Accordingly, an increase in off current can be suppressed even when the channel length is shortened.

  According to a seventh aspect of the present invention, in the method of manufacturing an organic transistor according to the sixth aspect, the region having a high surface energy formed in the step of forming the first electrode layer on the substrate is the first region. And a second region narrower than the first region, and the liquid containing the conductive material is supplied to the first region to form the first electrode layer. And As a result, the width of the gate electrode can be reduced. As a result, the parasitic capacitance between the gate electrode and the source / drain electrodes is reduced, and the operation speed can be improved.

  The invention according to an eighth aspect is characterized in that the organic transistor array includes a plurality of the organic transistors according to any one of the first to third aspects. Thereby, an organic transistor array having a low off-current and a high ON / OFF ratio can be provided.

  According to a ninth aspect of the present invention, in the display device, the organic transistor array according to the eighth aspect is provided. Thereby, it is possible to provide a display device capable of displaying a good image at high speed.

  According to the present invention, an organic transistor having a small off-current and a large ON / OFF ratio and a method for manufacturing the organic transistor can be provided. Moreover, according to the present invention, an organic transistor array having the organic transistor and a display device having the organic transistor array can be provided.

  Next, the best mode for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 shows an example of the organic transistor of the present invention. 1A is a top view and FIG. 1B is a cross-sectional view.

  In the organic transistor 10, a first electrode layer 12 is formed on a substrate 11. A method for forming the first electrode layer 12 is not particularly limited, and a known method such as etching, printing, or cutting using photolithography can be used. As shown in FIG. 2, the first electrode layer 12 feeds power to the gate electrodes 12a and 12b adjacent to each other, the wiring portion 12c that electrically connects the gate electrodes 12a and 12b, and the gate electrodes 12a and 12b. Terminal portion 12d and a lead-out wiring portion 12e to the terminal portion 12d. In addition, in this invention, a gate electrode means the electrode part as a component of a field effect transistor.

  Further, in the organic transistor 10, the wettability changing layer 13 is formed on the substrate 11 on which the first electrode layer 12 is formed. The wettability changing layer 13 is a layer made of a material whose surface energy (critical surface tension) changes by applying energy, and two regions having different surface energies, that is, a region having a high surface energy and a region having a low surface energy. Is formed. Further, the wettability changing layer 13 functions as a gate insulating layer.

  The organic transistor 10 is formed by supplying a liquid containing a conductive material to a region where the surface energy of the wettability changing layer 13 is high, thereby forming the second electrode layer 14. As shown in FIG. 3, the second electrode layer 14 includes a source electrode 14a, a drain electrode 14b, an island electrode 14c, terminal portions 14d and 14e for supplying power to the source electrode 14a and the drain electrode 14b, and terminal portions 14d and 14e. Lead-out wiring portions 14f and 14g. The island electrode 14c is formed between the source electrode 14a and the drain electrode 14b via a gap (channel), and the gap between the island electrode 14c and the source electrode 14a and the gap between the island electrode 14c and the drain electrode 14b. Are respectively formed on the gate electrodes 12a and 12b and covered with the organic semiconductor layer 15. In the present invention, the source electrode and the drain electrode mean an electrode part as a component of the field effect transistor, like the gate electrode.

  In general, the shorter the channel length, the larger the current when the transistor is on (on current), but the larger the current when the transistor is off (off current), the lower the on / off ratio. However, since the organic transistor 10 has a dual gate structure as shown in FIG. 4, the distance between the island electrode 14c and the source electrode 14a (channel length) and the distance between the island electrode 14c and the drain electrode 14b (channel length) are shortened. Even if the on-current is increased, the off-current can be reduced and the ON / OFF ratio can be increased.

  FIG. 5 shows another example of the organic transistor of the present invention. 5A is a top view and FIG. 5B is a sectional view. In FIG. 5, the same components as those in FIG.

  In the organic transistor 20, a wettability changing layer 21 is formed on the substrate 11. The wettability changing layer 21 is a layer made of a material whose surface energy (critical surface tension) is changed by applying energy, and two regions having different surface energies, that is, a region having a high surface energy and a region having a low surface energy. Is formed. Furthermore, the wettability changing layer 21 functions as an insulating layer. The organic transistor 20 is formed by supplying a liquid containing a conductive material to a region where the surface energy of the wettability changing layer 21 is high, whereby the first electrode layer 12 is formed.

  FIG. 6 shows another example of the organic transistor of the present invention. 6A is a top view and FIG. 6B is a cross-sectional view. In FIG. 6, the same components as those in FIG. In the organic transistor 30, the first electrode layer 12 has gate electrodes 12 a and 12 b formed through slits 31.

  Although the above organic transistor has two gate electrodes and one island electrode, the organic transistor of the present invention may have three or more gate electrodes and two or more island electrodes. FIG. 7 shows an example of such an organic transistor. 7A is a top view, and FIG. 7B is a cross-sectional view. In FIG. 7, the same components as those in FIG.

  In the organic transistor 40, the first electrode layer 12 has three gate electrodes, and the second electrode layer 14 has two island electrodes. At this time, as the number of stages in which the field effect transistors are connected in series is larger, the effect of reducing the off-current is increased. Therefore, the organic transistor 40 having the triple gate structure can further increase the ON / OFF ratio.

  Next, the wettability changing layer will be described. The wettability changing layer may be made of a single material or two or more materials. At this time, by mixing a material having high electrical insulation and a material having large wettability change, a wettability changing layer having excellent electrical insulation and excellent wettability change can be formed. Furthermore, a wettability change layer with excellent electrical insulation and excellent wettability can be obtained by mixing materials with high wettability change, low film formability, and high electrical insulation and high film formability. Can be formed. At this time, in the case of the wettability changing layer 13 functioning as a gate insulating layer, it is important that the electrical insulation is high.

  The weight ratio of the material with high electrical insulation to the material with large wettability change is usually 50/50 to 99/1, preferably 60/40 to 95/5, and more preferably 70/30 to 90/10. . If this weight ratio is less than 50/50, the electrical insulation of the wettability changing layer may be insufficient, and if it exceeds 99/1, the wettability change of the wettability changing layer may be insufficient. There is.

  FIG. 8 schematically shows an example of the wettability changing layer. The wettability changing layer 13 is a layer made of the second material 13b, which is more excellent in wettability change than the first material 31a, on the layer made of the first material 13a, which is more excellent in electrical insulation than the second material 13b. Are stacked. Such a structure can be obtained by forming a layer made of the first material 13a and then forming a layer made of the second material 13b. As a film forming method, a vacuum process such as vacuum deposition or a coating process using a solvent can be used.

  It is also possible to form the wettability changing layer 13 by applying a solution obtained by mixing the first material 13a and the second material 13b to the substrate and drying it. When the polarity of the second material 13b is lower than that of the first material 13a, when the molecular weight of the second material 13b is smaller than that of the first material 13a, etc., the second material 13b is required until the solvent evaporates during drying. 13b moves to the surface side. When the coating process is used, the first material 13a and the second material 13b are not clearly separated into the first material 13a and the second material 13b, as shown in FIG. In many cases, a phase in which the material 13b is mixed is formed.

  Further, as shown in FIG. 10, the wettability changing layer 13 may be formed with a phase in which the first material 13a and the second material 13b are mixed with a predetermined concentration distribution in the film thickness direction.

  Although the wettability changing layer 13 has been described with reference to FIGS. 8 to 10, the same applies to the wettability changing layer 21.

  Further, when the wettability changing layer is composed of two or more materials, two or more layers may be laminated, or two or more materials with a predetermined concentration distribution in the film thickness direction. May be mixed.

  The surface of the wettability changing layer 13 on which the second electrode layer 14 is formed is preferably made of the second material 13b as shown in FIG. However, if fine patterning is possible, as shown in FIG. 12, the first material 13a is dispersed in the second material 13b, as shown in FIG. It may be a sea-island structure in which a region to be formed and a region made of the second material 13b are separated. Such a sea-island structure can be observed using an optical microscope, microscopic infrared spectroscopy, Raman spectroscopy, or the like. In particular, the diameter of the region made of the first material 13a is about 5 μm. If there is, it is possible to specify the constituent material by micro infrared spectroscopy.

  In addition, in FIGS. 11-13, although the surface of the wettability change layer 13 in which the 2nd electrode layer 14 was formed was demonstrated, also about the surface of the wettability change layer 21 in which the 1st electrode layer 12 is formed It is the same.

  Moreover, it is preferable that a wettability change layer contains the polymeric material which has a hydrophobic group in a side chain. In the polymer material 50 having a hydrophobic group in the side chain, for example, as shown in FIG. 14, a side chain 52 having a hydrophobic group is bonded to a main chain 51 having a skeleton such as polyimide or poly (meth) acrylate. is doing. In FIG. 14, the side chain 52 is directly bonded to the main chain 51, but may be bonded via a bonding group.

The hydrophobic group of the side chain 52, the formula _{-CF 2 CH 3, -CF 2 CF} 3, -CF (CF 3) 2, -C (CF 3) 3, -CF 2 H, in -CFH _2, etc. The functional group which has the terminal group represented is mentioned. In order to facilitate the alignment of the molecular chains of the polymer material 50, the hydrophobic group is preferably a carbon chain having a long chain length, and more preferably a carbon chain having 4 or more carbon atoms. The hydrophobic group is preferably a polyfluoroalkyl group in which two or more hydrogen atoms of the alkyl group are substituted with a fluoro group, more preferably a polyfluoroalkyl group having 4 to 20 carbon atoms, and a carbon number of 6 ˜12 polyfluoroalkyl groups are particularly preferred. The polyfluoroalkyl group may be linear or branched, but is preferably linear. Further, the hydrophobic group is preferably a perfluoroalkyl group in which substantially all of the hydrogen atoms of the alkyl group are substituted with fluoro groups. The perfluoroalkyl group has a general formula C _n F _{2n + 1} − (where n is an integer of 4 to 16, preferably 6 to 12).
It is preferable that it is a functional group represented by these. The perfluoroalkyl group may be linear or branched, but is preferably linear.

  Such a polymer material 50 is described in Japanese Patent Application Laid-Open No. 3-178478, etc., and is well known, and becomes lyophilic when brought into contact with a liquid or solid in a heated state, and becomes lyophobic when heated in air. It has the property to become. That is, the surface energy can be changed by selecting a contact medium and applying thermal energy.

Further, examples of the hydrophobic group that the side chain 52 has include chemical formulas —CH ₂ CH ₃ , —CH (CH ₃ ) ₂ , —C (CH ₃ ) _3.
And a functional group having a terminal group that does not have a fluoro group. In order to facilitate the alignment of the molecular chains of the polymer material 50, the hydrophobic group is preferably a carbon chain having a long chain length, and more preferably a carbon chain having 4 or more carbon atoms. The hydrophobic group may be linear or branched, but is preferably linear. Further, the hydrophobic group has a halogen group, a cyano group, a phenyl group, a hydroxyl group, a carboxyl group, or a phenyl group substituted with a linear, branched or cyclic alkyl group or alkoxy group having 1 to 12 carbon atoms. May be.

Other hydrophobic groups include those represented by the general formula -SiR ₃ (where R is an organic group having a siloxane bond).
The organosilicon group represented by these is mentioned.

  As the polymer material 50 has more side chains 52, the surface energy decreases and becomes hydrophobic. By applying light energy such as ultraviolet rays to the polymer material 50, a part of the hydrophobic group is dissociated or the surface energy is increased due to the change in the orientation state, so that the polymer material 50 becomes hydrophilic. It is assumed that

  In consideration of forming the organic semiconductor layer 15 on the wettability changing layer, the polymer material 50 preferably contains polyimide. Since polyimide is excellent in solvent resistance and heat resistance, when forming a semiconductor layer on the wettability change layer, it suppresses swelling and cracking due to temperature change due to solvent and firing. be able to.

  When the wettability changing layer is composed of two or more materials, it is preferable that the material other than the polymer material 50 is also made of polyimide in consideration of heat resistance, solvent resistance, and affinity.

  Examples of the diamine having a hydrophobic group used when synthesizing a polyimide having a hydrophobic group in the side chain include compounds represented by general formulas (1) to (5).

（式中、Ｘは、メチレン基又はエチレン基であり、Ａ^１は、１，４−シクロヘキシレン基、１，４−フェニレン基又は１〜４個のフルオロ基で置換された１，４−フェニレン基であり、Ａ^２、Ａ^３及びＡ^４は、それぞれ独立に、単結合、１，４−シクロヘキシレン基、１，４−フェニレン基又は１〜４個のフルオロ基で置換された１，４−フェニレン基であり、Ｂ^１、Ｂ^２及びＢ^３は、それぞれ独立に、単結合又はエチレン基であり、Ｂ^４は、炭素数１〜１０のアルキレン基であり、Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４及びＲ^５は、それぞれ独立に、炭素数１〜１０のアルキル基であり、ｐは、１以上の整数である。）

(In the formula, X is a methylene group or ethylene group, and A ¹ is 1,4-phenylene substituted with 1,4-cyclohexylene group, 1,4-phenylene group, or 1 to 4 fluoro groups. Each of A ² , A ³ and A ⁴ is independently a single bond, 1,4-cyclohexylene group, 1,4-phenylene group or 1,4-substituted with 1 to 4 fluoro groups -Phenylene group, B ¹ , B ² and B ³ are each independently a single bond or an ethylene group, B ⁴ is an alkylene group having 1 to 10 carbon atoms, and R ¹ , R ² , R ³ , R ⁴ and R ⁵ are each independently an alkyl group having 1 to 10 carbon atoms, and p is an integer of 1 or more.)

（式中、Ｔ、Ｕ及びＶは、それぞれ独立に、フェニレン基又はシクロヘキシレン基であり、ｍ及びｎは、それぞれ独立に、０〜２の整数であり、ｈは、０〜５の整数であり、Ｒは、水素原子、フルオロ基、クロロ基、シアノ基又は１価の有機基である。なお、ｍが２である場合の２個のＵ及びｎが２である場合の２個のＶは、それぞれ同じであってもよいし、異なっていてもよい。また、Ｔ、Ｕ及びＶは、炭素数１〜３のアルキル基、フルオロ基で置換された炭素数１〜３のアルキル基、フルオロ基、クロロ基又はシアノ基で置換されていてもよい。）

(In the formula, T, U, and V are each independently a phenylene group or a cyclohexylene group, m and n are each independently an integer of 0-2, and h is an integer of 0-5. R is a hydrogen atom, a fluoro group, a chloro group, a cyano group, or a monovalent organic group, where two U's when m is 2 and two V's when n is 2. May be the same or different from each other, and T, U and V are each an alkyl group having 1 to 3 carbon atoms, an alkyl group having 1 to 3 carbon atoms substituted with a fluoro group, (It may be substituted with a fluoro group, a chloro group or a cyano group.)

（式中、Ｚは、メチレン基、フルオロメチレン基、ジフルオロメチレン基、エチレン基又はジフルオロメチレンオキシ基であり、Ｙは、１，４−シクロへキシレン基、１，４−フェニレン基又は１〜４個の水素原子がフルオロ基若しくはメチル基で置換されている１，４−フェニレン基であり、Ａ^１、Ａ^２及びＡ^３は、それぞれ独立に、単結合、１，４−シクロへキシレン基、１，４−フェニレン基又は１〜４個の水素原子がフルオロ基若しくはメチル基で置換されている１，４−フェニレン基であり、Ｂ^１、Ｂ^２及びＢ^３は、それぞれ独立に、単結合、炭素数１〜４のアルキレン基、オキシ基又は炭素数１〜３のオキシアルキレン基であり、Ｒは、水素原子、炭素数１〜１０のアルキル基又は炭素数１〜９のアルコキシ基若しくはアルコキシアルキル基である。但し、Ｚがメチレン基である場合には、Ｂ^１、Ｂ^２及びＢ^３が炭素数１〜４のアルキレン基であることはなく、Ｚがエチレン基であって、Ｙが１，４−フェニレン基である場合には、Ａ^１及びＡ^２が単結合であることはなく、Ｚがジフルオロメチレンオキシ基である場合には、Ｙが１，４−シクロへキシレン基であることはない。また、Ｒにおいて、炭素数１〜１０のアルキル基は、任意のメチレン基がジフルオロメチレン基で置換されていてもよく、炭素数１〜９のアルコキシ基若しくはアルコキシアルキル基は、１個のメチレン基がジフルオロメチレン基で置換されていてもよい。）

(In the formula, Z is a methylene group, a fluoromethylene group, a difluoromethylene group, an ethylene group or a difluoromethyleneoxy group, and Y is a 1,4-cyclohexylene group, a 1,4-phenylene group, or 1-4. Is a 1,4-phenylene group in which one hydrogen atom is substituted with a fluoro group or a methyl group, and A ¹ , A ² and A ³ are each independently a single bond, 1,4-cyclohexylene group, 1,4-phenylene group or 1,4-phenylene group in which 1 to 4 hydrogen atoms are substituted with fluoro group or methyl group, and B ¹ , B ² and B ³ are each independently a single bond , An alkylene group having 1 to 4 carbon atoms, an oxy group, or an oxyalkylene group having 1 to 3 carbon atoms, and R is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, or an A Kokishiarukiru group. However, when Z is a methylene group, B ^1, B ² and B ³ is not an alkylene group having 1 to 4 carbon atoms, a Z is an ethylene group, Y is When it is a 1,4-phenylene group, A ¹ and A ² are not a single bond, and when Z is a difluoromethyleneoxy group, Y is a 1,4-cyclohexylene group. In R, in the alkyl group having 1 to 10 carbon atoms, an arbitrary methylene group may be substituted with a difluoromethylene group, and an alkoxy group or alkoxyalkyl group having 1 to 9 carbon atoms is 1 The methylene groups may be substituted with difluoromethylene groups.)

（式中、Ｒは、水素原子又は炭素数１〜１２のアルキル基であり、Ｚは、メチレン基であり、ｍは、０〜２の整数であり、Ａは、フェニレン基又はシクロヘキシレン基であり、ｌは、０又は１であり、Ｙ^１及びＹ^２は、それぞれ独立に、オキシ基又はメチレン基であり、ｎ^１及びｎ^２は、それぞれ独立に、０又は１である。）

(In the formula, R is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, Z is a methylene group, m is an integer of 0 to 2, and A is a phenylene group or a cyclohexylene group. Yes, l is 0 or 1, Y ¹ and Y ² are each independently an oxy group or a methylene group, and n ¹ and n ² are each independently 0 or 1.)

（式中、Ｙ^１及びＹ^２は、それぞれ独立に、オキシ基又はメチレン基であり、Ｒ^１及びＲ^２は、それぞれ独立に、水素原子、炭素数１〜１２のアルキル基又はパーフルオロアルキル基であると共に、Ｒ^１及びＲ^２の少なくとも一方は、炭素数３以上のアルキル基又はパーフルオロアルキル基であり、ｎ^１及びｎ^２は、それぞれ独立に０又は１である。）
このようなジアミンを用いて合成されたポリイミドは、特開２００２−１６２６３０号公報、特開２００３−９６０３４号公報、特開２００３−２６７９８２号公報、特開２００４−８６１８４号公報等に記載されている。また、このようなポリイミドの合成に用いられるテトラカルボン酸二無水物については、脂肪族系、脂環式、芳香族系等の種々の材料を用いることができ、例えば、ピロメリット酸二無水物、シクロブタンテトラカルボン酸二無水物、シクロヘキサンテトラカルボン酸二無水物、ブタンテトラカルボン酸二無水物等が挙げられる。これらの他に、特開平１１−１９３３４５号公報、特開平１１−１９３３４６号公報、特開平１１−１９３３４７号公報等に記載されているテトラカルボン酸二無水物も用いることができる。また、一般式（１）〜（５）で表されるジアミン以外のジアミンを用いて合成されているポリイミドを用いることもできる。例えば、特許第３０９７７０２号公報に記載されている直鎖状アルキル鎖を有する芳香族ジアミン残基を有するポリイミドが挙げられる。

(In the formula, Y ¹ and Y ² are each independently an oxy group or a methylene group, and R ¹ and R ² are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a perfluoroalkyl group. And at least one of R ¹ and R ² is an alkyl group or a perfluoroalkyl group having 3 or more carbon atoms, and n ¹ and n ² are each independently 0 or 1.)
Polyimides synthesized using such diamines are described in JP 2002-162630 A, JP 2003-96034 A, JP 2003-267982 A, JP 2004-86184 A, and the like. . In addition, for the tetracarboxylic dianhydride used for the synthesis of such polyimide, various materials such as aliphatic, alicyclic, and aromatic can be used. For example, pyromellitic dianhydride , Cyclobutanetetracarboxylic dianhydride, cyclohexanetetracarboxylic dianhydride, butanetetracarboxylic dianhydride, and the like. In addition to these, tetracarboxylic dianhydrides described in JP-A-11-193345, JP-A-11-193346, JP-A-11-193347 and the like can also be used. Moreover, the polyimide synthesize | combined using diamine other than the diamine represented by General formula (1)-(5) can also be used. For example, the polyimide which has the aromatic diamine residue which has the linear alkyl chain described in the patent 3097702 is mentioned.

  The polyimide having a hydrophobic group in the side chain is preferably a polyimide (soluble polyimide) that is soluble in a solvent, considering that the film forming process can be performed at a low temperature. The soluble polyimide is produced by imidizing in advance a polyamic acid obtained by reacting a raw acid dianhydride and a diamine. Generally, when the main chain of polyimide has a rigid structure, it is difficult to dissolve in a solvent. Then, in order to disturb the crystallinity of polyimide and make it easy to undergo solvation, soluble polyimide is produced when bulky alicyclic cyclocarboxylic dianhydride is used.

  Which acid dianhydride is used to form the main chain of the polyimide is inferred from analysis of characteristic group vibrations based on infrared absorption spectra of the polyimide thin film and measurement of ultraviolet-visible absorption spectra. A polyimide having a main chain formed using a bulky alicyclic cyclocarboxylic dianhydride skeleton has an absorption edge wavelength of 300 nm or less in the infrared absorption spectrum of the thin film. For details, see Ikuo Imai, Rikio Yokota, edited by Nihon Polyimide Research Group “Latest Polyimide: Basics and Applications” (published by NTS, 2002), “Electronics and Electronics for Next Generation” "Development of New Polyimides for Materials and High-Functionalization Technology" (published by Technical Information Association, 2003).

  Since soluble polyimide dissolves in a solvent, it becomes possible to form a film at a temperature at which the solvent is evaporated, that is, 200 ° C. or less. Further, since unreacted polyamic acid and by-product acid dianhydride do not easily remain in the polyimide thin film, the problem that the electrical characteristics of the polyimide thin film deteriorate due to these impurities hardly occurs.

  The soluble polyimide is soluble in a highly polar solvent such as γ-butyllactone, N-methylpyrrolidone, N, N-dimethylacetamide, and the like. For this reason, when the organic semiconductor layer 15 is formed on the wettability changing layer containing the soluble polyimide, if a solvent having low polarity such as toluene, xylene, acetone, isopropyl alcohol is used, the wettability changing layer of the solvent is changed. Erosion can be suppressed.

  Further, when the wettability changing layer contains a material other than the soluble polyimide having a hydrophobic group in the side chain, that is, when it comprises two or more materials, it is preferable that the material other than the soluble polyimide is also a soluble material. . Examples of such soluble materials include, but are not limited to, phenol resins such as polyvinylphenol, melamine resins, polysaccharides such as pullulan subjected to acetylation treatment, silsesquioxane, and the like. Thereby, it becomes possible to form a wettability changing layer at a low temperature, and it is possible to improve heat resistance, solvent resistance, and affinity.

  Furthermore, it is preferable that soluble materials other than soluble polyimide have good compatibility with soluble polyimide. Thereby, two or more kinds of materials are difficult to phase-separate in the solvent, so that the wettability changing layer is easily formed.

  Examples of the diamine having a hydrophobic group used when synthesizing a soluble polyimide having a hydrophobic group in the side chain include a compound represented by the general formula (6).

（式中、Ｒは、炭素数１〜１２のアルキル基、炭素数１〜１２のハロアルキル基又はハロゲン基であり、Ｘ及びＹは、それぞれ独立に、化学式

Wherein R is an alkyl group having 1 to 12 carbon atoms, a haloalkyl group having 1 to 12 carbon atoms or a halogen group, and X and Y are each independently a chemical formula

で表わされる官能基であり、ａは、１〜５の整数である。）
このようなジアミンを用いて合成される可溶性ポリイミドは、特開平９−２７２７４０号公報等に記載されている。また、一般式（１）〜（５）で表されるジアミンを用いて合成されたポリイミドを、化学処理によって溶媒に可溶とすることも可能である。この化学処理については、ＷＯ０１／０００７３２号公報に記載されている。

A is an integer of 1-5. )
Soluble polyimides synthesized using such diamines are described in JP-A-9-272740. Moreover, it is also possible to make the polyimide synthesize | combined using the diamine represented by General Formula (1)-(5) soluble in a solvent by chemical treatment. This chemical treatment is described in WO01 / 000732.

  In the general formulas (1) to (6), examples of diamines having a hydrophobic group have been given, but tetracarboxylic acids having a hydrophobic group can also be used.

Further, when the polymer material 50 having a hydrophobic group in the side chain 52 is present on the surface of the wettability changing layer 13, the interface characteristics between the wettability changing layer 13 and the organic semiconductor layer 15 can be improved. Good interfacial properties
a. When the organic semiconductor is crystalline, the crystal grains become large and the mobility increases b. When the organic semiconductor is amorphous (polymer), the interface state density decreases and the mobility increases c. When the organic semiconductor is a polymer and has a side chain such as a long-chain alkyl group, the orientation of the organic semiconductor is restricted, so that the molecular axes of the π-conjugated main chain can be arranged in almost one direction, and the movement It means that a phenomenon such as an increase in the degree appears.

  The thickness of the wettability changing layer is preferably 30 nm to 3 μm, and more preferably 50 nm to 1 μm. If the thickness of the wettability changing layer is less than 30 nm, characteristics (insulating properties, gas barrier properties, moisture resistance, etc.) as a bulk body may be impaired, and if it is thicker than 3 μm, the surface shape may be deteriorated.

  The first electrode layer 12 and the second electrode layer 14 are formed by applying a liquid containing a conductive material and then solidifying by heating, ultraviolet irradiation, or the like. In addition, as the liquid containing the conductive material, the conductive material dissolved in the solvent, the conductive material precursor, the conductive material precursor dissolved in the solvent, the conductive material in the solvent A dispersion, a dispersion of a conductive material precursor in a solvent, or the like can be used. For example, a conductive polymer in which fine metal particles such as Ag, Au, Ni, etc. are dispersed in an organic solvent or water, doped PANI (polyaniline), PEDOT (polyethylenedioxythiophene) is doped with PSS (polystyrene sulfonic acid). An aqueous solution etc. are mentioned.

  Examples of a method for applying a liquid containing a conductive material include a spin coating method, a dip coating method, a screen printing method, an offset printing method, and an ink jet method. At this time, when the first electrode layer 12 is formed on the wettability changing layer 21 and when the second electrode layer 14 is formed on the wettability changing layer 13, the influence of the surface energy of the wettability changing layer is affected. In order to make it easy to receive, an inkjet method capable of supplying small droplets is preferable. In the inkjet method using a normal head of a level used in a printer, the resolution is 30 μm and the alignment accuracy is about ± 15 μm. However, by utilizing the difference in surface energy of the wettability changing layer, a fine pattern can be obtained. Can be formed.

  Further, as a method for imparting energy to the wettability changing layer, ultraviolet irradiation is preferable from the viewpoints that it can be operated in the atmosphere, that the resolution is high, and that the damage to the inside of the layer is small.

  The organic semiconductor layer 15 is composed of organic low molecules such as pentacene, anthracene, tetracene, and phthalocyanine, polyacetylene conductive polymers, polyparaphenylene and derivatives thereof, polyphenylene conductive polymers such as polyphenylene vinylene and derivatives, polypyrrole, and the like. It can be formed using organic semiconductors such as derivatives, polythiophene and derivatives thereof, heterocyclic conductive polymers such as polyfuran and derivatives, and ionic conductive polymers such as polyaniline and derivatives thereof.

  In FIG. 15, an example of the manufacturing method of the organic transistor of this invention is shown. A high surface energy region 61 containing a first pattern 61a and a second pattern 61b having a narrower width than the first pattern 61a is formed in the wettability changing layer 21 formed on a substrate (not shown). (See FIG. 15 (a)). Next, a liquid 62 containing a conductive material is supplied to the first pattern 61a (see FIG. 15B). At this time, since the liquid 62 containing the conductive material supplied to the first pattern 61a spreads to the second pattern 61b, the liquid 62 containing the conductive material is also supplied to the second pattern 61b. (See FIG. 15 (c)). Accordingly, the liquid 62 containing the conductive material can be supplied in a pattern finer than the resolution that can be supplied by the means for supplying the liquid 62 containing the conductive material, and the first electrode layer 12 is thinned. be able to.

  FIG. 16 shows an example of the second electrode layer formed by using the method for manufacturing the organic transistor of FIG. 15, and FIG. 17 shows a part of the second electrode layer 14. 16 and 17, the same components as those in FIG. 3 are denoted by the same reference numerals and description thereof is omitted. Configurations other than the first electrode layer 12 and the second electrode layer 14 of the organic transistor having the second electrode layer 14 illustrated in FIGS. 16 and 17 are not particularly limited, and may be the above-described configurations. The source electrode 14a contains a first pattern 72a and a second pattern 73a having a narrower width than the first pattern 72a through the slit 71a. Moreover, the drain electrode 14b contains the 1st pattern 72b and the 2nd pattern 73b whose width | variety is narrower than the 1st pattern 72b through the slit 71b. Furthermore, the island electrode 14c contains the 1st pattern 72c and the 2nd pattern 73c narrower than the 1st pattern 72c through the slit 71c. As a result, the parasitic capacitance can be reduced by reducing the overlap between the gate electrode 12a and the source electrode 14a, between the gate electrode 12b and the drain electrode 14b, and between the gate electrodes 12a and 12b and the island electrode 14c.

  FIG. 18 shows an example of the organic transistor array of the present invention. FIG. 18A is a plan view, and FIG. 18B is a sectional view. In FIG. 18, the same components as those in FIG. The organic transistor array 80 includes a first electrode layer 12 having a gate electrode, a wettability changing layer 13 also serving as a gate insulating layer, and a second electrode layer having a source electrode, a drain electrode, and an island electrode on the substrate 11. 14 is patterned in a two-dimensional array, and a plurality of organic transistors are formed. The gate electrode for each organic transistor is connected to a bus line in order to be driven by a scanning signal driver IC. Further, the drain electrode for each organic transistor is also connected to the bus line in order to be driven by a data signal driver. Furthermore, the organic semiconductor layer 15 is formed in an island shape so as to cover the channel region. Note that the organic transistor array 80 is preferably covered with a passivation film in order to suppress deterioration of transistor characteristics due to oxygen, moisture, radiation, or the like. As the material for the passivation film, for example, aluminum nitride, silicon nitride, silicon nitride oxide, or the like is used. As a method for forming the passivation film, a CVD method, an ion plating method, and the like can be given.

  A display device can be formed by stacking display elements on the organic transistor array 80. Examples of the display element include a display element using a liquid crystal such as TN, STN, guest-host type, polymer-dispersed liquid crystal (PDLC), or the like. Further, an electrophoretic element that performs display by movement of colored particles contained in a cell or a microcapsule can also be used as a display element.

[Example 1]
Chemical formula

で表されるポリイミドの前駆体及び化学式

Precursor and chemical formula of polyimide represented by

で表されるポリイミドの前駆体を溶解した溶液を、スピンコート法を用いて、ガラス基板１１上に塗布した後、２８０℃で焼成して、濡れ性変化層２１を形成した。

A solution in which a polyimide precursor represented by the formula (1) was dissolved was applied onto the glass substrate 11 using a spin coating method, and then baked at 280 ° C. to form the wettability changing layer 21.

FIG. 19 shows the relationship between the UV irradiation amount of the wettability changing layer and the contact angle with water. From FIG. 19, when the ultraviolet ray is not irradiated, the contact angle with water of the wettability changing layer exceeds 90 ° and is hydrophobic (water repellency). However, when the ultraviolet ray irradiation amount is 10 J / cm ² or more, the contact angle with water is It decreases to about 20 ° and changes to hydrophilicity. It is considered that the amount of irradiation can be further reduced by using a light source adapted to the wavelength of light effective for inducing this change.

FIG. 20 shows the relationship between the surface tension of the liquid and the contact angle of the wettability changing layer with respect to the liquid. As can be seen from FIG. 20, the critical surface tension of the wettability changing layer is about 24 mN / m for the non-irradiated part and about 45 mN / m for the ultraviolet irradiated part irradiated with 8 J / cm ² . In FIG. 20, the liquids are toluene, tricresyl phosphate, ethylene glycol, formamide, and water in order from the surface having the smallest surface tension.

Next, 8 J / cm ² of ultraviolet light having a wavelength of 250 nm is irradiated through a photomask so that the width of the gate electrodes 12a and 12b is 80 μm in the shape of the first electrode layer 12 shown in FIG. Thus, a high surface energy region was formed. Further, Ag nanometal ink was applied to the high surface energy region by an inkjet method, and then dried and baked to form the first electrode layer 12 shown in FIG.

Next, the wettability changing layer 13 was formed in the same manner as the wettability changing layer 21. Furthermore, ultraviolet rays having a wavelength of 250 nm are applied at 8 mJ / cm ² so that the channel length is 10 μm and the channel width is 300 μm (see FIG. 21) in the shape of the second electrode layer 14 shown in FIG. By irradiation, a high surface energy region was formed. Further, Ag nanometal ink was applied to the high surface energy region by an inkjet method, and then dried and baked to form the second electrode layer 14 shown in FIG.

  Next, the reaction formula

に示すようなスキームにより合成した有機半導体をトルエンに溶解させた溶液をインクジェット法で塗布した後、乾燥させて有機半導体層１５を形成した。

The organic semiconductor layer 15 was formed by applying a solution obtained by dissolving an organic semiconductor synthesized by the scheme shown in FIG.

In this way, when a plurality of organic transistors were manufactured and operated, the average value of the off current was 1 × 10 ⁻¹² A, the ratio between the maximum value and the minimum value was about 10 times, and the variation was small. An organic transistor having a stable low off current was obtained. In addition, as shown in Comparative Example 1, the off-state current of the conventional configuration has an average value of 1 × 10 ⁻¹¹ A, but varies in the order of 10 ⁻⁹ A at the maximum and the order of 10 ⁻¹² A at the minimum. It was big. On the other hand, the on-current was almost the same in this example and Comparative Example 1, so the ON / OFF ratio was improved by up to three orders of magnitude compared to Comparative Example 1.
[Example 2]
An organic transistor having the first electrode layer 12 and the second electrode layer 14 shown in FIG. 6 was manufactured in the same process as in Example 1. The width of the gate electrodes 12a and 12b was 40 μm, the width of the lead-out wiring portion 12e was 100 μm, and the channel length and channel width were the same as in Example 1. Further, when the first electrode layer 12 was formed by applying the Ag nanometal ink by the inkjet method, it was applied to the terminal portion 12d and the lead-out wiring portion 12e. At this time, the Ag nanometal ink was supplied, so that the Ag nanometal ink was supplied to the gate electrodes 12a and 12b.

The organic transistor thus manufactured has a small parasitic capacitance because the width of the gate electrodes 12a and 12b is narrow.
[Example 3]
An organic transistor having the first electrode layer 12 and the second electrode layer 14 shown in FIG. 7 was manufactured in the same process as in Example 1. When operated in the same manner as in Example 1, the average value of the off-current is 1 × 10 ⁻¹³ A, the ratio of the maximum value to the minimum value is about 10 times, the variation is small, and the organic compound has a small and stable off-current. A transistor was obtained. As shown in Comparative Example 1, the off-state current of the conventional configuration has an average value of 1 × 10 ⁻¹¹ A, but has a large variation in the order of 10 ⁻⁹ A at the maximum and the order of 10 ⁻¹² A at the minimum. . On the other hand, the on-current was almost the same between the present example and the comparative example 1, and therefore the ON / OFF ratio was improved by 1 to 4 digits compared to the comparative example 1.
[Example 4]
The organic transistor array (the number of elements is 32 × 32) having the first electrode layer 12 and the second electrode layer 14 shown in FIG. When the organic transistor array was operated in the same manner as in Example 1, an average value of off current was 1 × 10 ⁻¹² A, and an organic transistor array having a small off current stably was obtained.
[Example 5]
A mixture of microcapsules containing titanium oxide particles and isopar colored with oil blue mixed with PVA aqueous solution is applied onto a polycarbonate substrate on which a transparent electrode made of ITO is formed to form a layer made of microcapsules and PVA. Thus, an electrophoretic element was produced. Next, the substrate of the electrophoretic element and the organic transistor array of Example 4 were bonded together to produce a display device. When the display device was operated, an image with high contrast could be displayed.
[Comparative Example 1]
An organic transistor having a single gate structure shown in FIG. 22 was manufactured in the same process as in Example 1. When the organic transistor was operated in the same manner as in Example 1, the average value of the off current was 1 × 10 ⁻¹¹ A, the maximum value was on the order of 10 ⁻⁹ A, and the minimum value was on the order of 10 ⁻¹² A. Was big.

It is a figure which shows an example of the organic transistor of this invention. It is a figure which shows the 1st electrode layer of FIG. It is a figure which shows the 1st electrode layer and 2nd electrode layer of FIG. It is a circuit diagram which shows the organic transistor of FIG. It is a figure which shows the other example of the organic transistor of this invention. It is a figure which shows the other example of the organic transistor of this invention. It is a figure which shows the other example of the organic transistor of this invention. It is a cross-sectional schematic diagram which shows an example of a wettability change layer. It is a cross-sectional schematic diagram which shows the other example of a wettability change layer. It is a cross-sectional schematic diagram which shows the other example of a wettability change layer. It is a schematic diagram which shows an example of the surface of a wettability change layer. It is a schematic diagram which shows the other example of the surface of a wettability change layer. It is a schematic diagram which shows the other example of the surface of a wettability change layer. It is a schematic diagram which shows the polymeric material which has a hydrophobic group in a side chain. It is a top view which shows an example of the manufacturing method of the organic transistor of this invention. FIG. 16 is a top view illustrating an example of a second electrode layer formed using the method for manufacturing the organic transistor of FIG. 15. It is the elements on larger scale of the 2nd electrode layer of FIG. It is a figure which shows an example of the organic transistor array of this invention. It is a figure which shows the relationship between the ultraviolet irradiation amount of a wettability change layer, and the contact angle with respect to water. It is a figure which shows the relationship between the surface tension of a liquid, and the contact angle with respect to the liquid of a wettability change layer. It is a figure explaining channel length and channel width. 6 is a view showing an organic transistor of Comparative Example 1. FIG.

Explanation of symbols

10, 20, 30, 40 Organic transistor 11 Substrate 12 First electrode layer 12a, 12b Gate electrode 13, 21 Wetting change layer 14 Second electrode layer 14a Source electrode 14b Drain electrode 14c Island electrode 15 Organic semiconductor layer 61 High Surface energy region 61a First pattern 61b Second pattern 62 Liquid containing conductive material 80 Organic transistor array

Claims (9)

A substrate, a first electrode layer formed on the substrate, a wettability changing layer formed on the substrate on which the first electrode layer is formed, and a surface energy of the wettability changing layer An organic transistor having a second electrode layer formed in a high area and an organic semiconductor layer formed on the wettability changing layer on which the second electrode layer is formed,
The first electrode layer has a first gate electrode and a second gate electrode that are electrically connected,
The second electrode layer has a source electrode, a drain electrode and an island electrode,
The island electrode is formed between the source electrode and the drain electrode via a gap,
The gap between the island electrode and the source electrode and the gap between the island electrode and the drain electrode are formed on the first gate electrode and the second gate electrode, respectively. An organic transistor which is covered with a semiconductor layer. Further comprising a wettability changing layer between the substrate and the first electrode layer,
The organic transistor according to claim 1, wherein the first electrode layer is formed in a region where the surface energy of the wettability changing layer is high. The island electrode is composed of two or more electrodes formed through a gap,
The first electrode layer further includes one or more gate electrodes electrically connected to the first gate electrode and the second gate electrode,
3. The organic material according to claim 1, wherein a gap between the two or more electrodes is formed on the one or more gate electrodes and is covered with the organic semiconductor layer. Transistor. It is a manufacturing method of the organic transistor according to any one of claims 1 to 3,
Forming a first electrode layer on the substrate;
Forming a wettability changing layer on the substrate on which the first electrode layer is formed;
Forming a region having a high surface energy by applying energy to the wettability changing layer;
Forming a second electrode layer in a region having a high surface energy using a liquid containing a conductive material;
A method for producing an organic transistor, comprising a step of forming an organic semiconductor layer on a wettability changing layer on which the second electrode layer is formed. The region having a high surface energy contains a first region and a second region narrower than the first region,
The method for producing an organic transistor according to claim 4, wherein the second electrode layer is formed by supplying a liquid containing the conductive material to the first region.   The step of forming the first electrode layer on the substrate includes a step of forming a wettability changing layer on the substrate and a step of forming a region having a high surface energy by applying energy to the wettability changing layer. And a step of forming the first electrode layer in a region having a high surface energy using a liquid containing a conductive material. 6. The method for producing an organic transistor according to claim 4, . The region having a high surface energy formed in the step of forming the first electrode layer on the substrate includes a first region and a second region that is narrower than the first region,
The method of manufacturing an organic transistor according to claim 6, wherein the first electrode layer is formed by supplying a liquid containing the conductive material to the first region.   An organic transistor array comprising a plurality of organic transistors according to any one of claims 1 to 3.   A display device comprising the organic transistor array according to claim 8.

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