JP2012204661A - Thin film transistor device and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thin film transistor device and a manufacturing method of the same, which achieve sufficient capacitor capacitance and inhibit a leakage current and parasitic capacity.SOLUTION: A thin film transistor device comprises a thin film transistor. All or a part of a gate electrode 111, a source electrode 131, a drain electrode 132, bus wiring, a pixel electrode 133, a gate insulation film 121, an interlayer insulation film 122 and a semiconductor layer 141 of the thin film transistor is formed by a coating method or a printing method. The gate insulation film 121 and/or the interlayer insulation film 122 are formed by a continuous film, and the continuous film includes a thin film part and a thick film part.

Description

  The present invention relates to a field in which a fine pattern needs to be printed, specifically, a liquid crystal display device, an organic EL display device, an electrophoretic display device, an electronic fluid separation display device, a microcapsule display device, and an electrowetting display. The present invention relates to a technique in the case of forming a resist pattern or an insulating film pattern of a back plate in the manufacture of a device, an electrochromic display device or the like.

  Conventionally, photolithography and vacuum processes have been used to form electronic components such as circuit boards and display devices. In recent years, with the advancement of electronic technology, the size of elements has become smaller and the pattern forming the elements has been required to be miniaturized, while the size of the mother substrate has increased. . Therefore, compared with the manufacturing method using a conventional photoresist, a fine pattern using various printing methods instead of the photolithography method for productivity, cost, high accuracy, large area, and further miniaturization. The manufacturing method of this is proposed.

  Printing methods include printing methods such as letterpress printing, intaglio printing, planographic printing, screen printing, and ink jet printing. These methods have a resolution limit of about 30 μm, which is a low resolution for forming a semiconductor device or a display device. In these printing methods, the alignment accuracy is about several tens of μm. Even if a pattern with high resolution can be formed, if the alignment accuracy is poor, the accuracy as a pattern laminate is lacking.

  Among the printing methods, a microcontact printing method can be cited as a printing method capable of forming a fine line pattern (Non-Patent Documents 1 and 2). These printing methods use a relatively soft plate with a low surface energy, such as polydimethylsiloxane (PDMS), to transfer the dried (semi-dried) ink from the plate to the substrate without tearing the ink (cohesive failure). By doing this, a highly detailed pattern can be obtained.

  The difference between the general printing method and the micro contact printing method will be described with reference to FIG. In general printing methods such as letterpress printing, intaglio printing, ink jet printing, screen printing, and offset printing, the liquid ink 400 is brought into contact with the substrate to be printed 500 (FIG. 5a) and then dried or annealed. The ink pattern flows and a flowing ink pattern is obtained (FIG. 5b). In this case, the high fluidity of the ink causes low resolution and unclear image lines.

  On the other hand, in the microcontact printing method, the ink 410 that is mostly dried is transferred from the printing plate to the substrate 500 to be printed (FIG. 5c). Is obtained (FIG. 5d). Due to the low fluidity of the ink 410 on the substrate 500, the microcontact printing method can provide a highly detailed and well-defined pattern.

  Problems related to the gate insulating film and interlayer insulating film of a thin film transistor manufactured by a printing method are pointed out below.

  It has been reported that a gate insulating film of a thin film transistor manufactured by a printing method is relatively thick as a thin film transistor (Non-Patent Documents 3 and 4). When the gate insulating film is thick, there is a problem that the pixel capacitor capacity is insufficient.

  By reducing the thickness of the gate insulating film, the pixel capacitor capacity can be increased, the on / off characteristics can be improved, and the operating voltage can be reduced. However, if the gate insulating film is too thin, the leakage current increases and the insulation is reduced. The withstand voltage of the film is also reduced. Further, there is a problem that the operating speed is lowered because the penetration voltage is increased and the parasitic capacitance between the gate electrode and the source / drain electrodes is increased.

  When an interlayer insulating film is provided on a thin film transistor, if the interlayer insulating film is too thick, the operation of the front plate is hindered. If it is too thin, leakage current from the bus wiring to the front plate becomes a problem.

  In order to solve the problem of electrical operation of thin film transistors manufactured by printing, an insulating film structure with an uneven shape that partially or thinned the thickness of the gate insulating film and interlayer insulating film. A method of optimizing the electrical operation depending on the element configuration provided is conceivable. A method for manufacturing the thin film transistor device having such an element structure will be described below.

  Nanoimprint, which was proposed by Chou et al. In Princeton University in 1995 and forms a pattern by pressing a stamper corresponding to a mold against a resist or the like, is inexpensive and has attracted attention as a processing technique having high resolution (Non-Patent Document 5, 6). Although it is conceivable to provide an insulating film structure having a concavo-convex shape using nanoimprint, nanoimprint has the following problems in alignment of a large area device such as a display that requires alignment of an upper layer and a lower layer.

  Several methods are known as nanoimprint alignment methods. As one of them, an alignment method employed in a nanoimprint apparatus of “Molecular Imprints, Inc.” will be described. In this method, first, the transfer surface of the transfer plate and the transfer surface on which the uneven shape of the mold is formed are arranged to face each other, and the gap between them is filled with a low-viscosity liquid. Then, two alignment marks (marks provided on the transfer surface and the transfer surface) are read from above the transfer surface and the mold by an alignment optical system having an optical axis perpendicular to the transfer surface and observed. This is a method of aligning the mold and the transferred plate using the result.

  In addition, an alignment method employed in the nanoimprint apparatus of “SUSS MicroTec Inc.” will be described. In this method, first, a transfer plate and a mold are arranged to face each other with a predetermined gap, and two CCD cameras are inserted between them. Then, the alignment mark formed on the transferred plate is detected by one CCD camera, and the alignment mark formed on the mold is detected by the other CCD camera. Finally, in this state, the mold and the transferred plate are aligned, and the pattern is transferred by bringing them closer together so as not to change the relative positional relationship in the in-plane direction.

  However, in the conventional alignment method described above, the following problems remain. That is, in the conventional alignment method, it is necessary to insert an alignment mark detection light-receiving device for detecting the alignment mark at the time of alignment directly above the mold or between the transferred plate and the mold. For this reason, when irradiating light from above the mold, it is necessary to retract the alignment detection light receiving device so as not to hinder exposure. As a result, the throughput decreases. In addition, in order to perform superposition precisely, it is necessary that the parallelism between the mold and the transferred plate is obtained. However, since the conventional alignment method does not consider the parallelism between the mold and the transferred plate, it is difficult to perform accurate alignment.

  Nanoimprint materials are limited in thermoplasticity and UV effect and have low selectivity. Thermoplastic materials are difficult to laminate in terms of solvent resistance. UV materials have the problem that UV light degrades semiconductors. Furthermore, when forming a level | step difference by nanoimprint, a square-shaped protrusion is often formed in the edge part of a convex part, and there exists a problem which causes an open and a short circuit.

  In addition to the formation method by nanoimprint, as a method for producing an insulating film structure having a concavo-convex shape, a photolithographic method using a halftone mask (Patent Document 1), a concavo-convex shape thin film using a photolitho method and a printing method a plurality of times Although the method of forming a part and a thick film part separately is mentioned, it is expensive.

Japanese Patent No. 4455517

A. Kumar, H. A. Biebuyck and G. M. Whitesides, Langmuir, 10, 1498 (1994) K. Matsuoka, O. Kina, M. Koutake, K. Noda, H. Yonehara, K. Nakanishi and K. Yase, Proceeding of The 16th International Display Workshops (IDW'09), (Miyazaki, Japan) 717-720 AMD6 -2 (2009). H. Maeda, M. Matsuoka, M. Nagae, H. Honda, T. Suzuki, K. Ogawa, and H. Kobayashi, Society For Information Display 2008 International Symposium Digest Of Technical Papers (SID'08), (Los Angeles, (USA) 314-317 (2008). O. Kina, M. Koutake, K. Matsuoka, and K. Yase, Japanese Journal of Applied Physics, 49 (2010) 01AB07 S. Y. Chou, P. R. Krauss, and P. J. Renstrom, Applied Physics Letters, 67, 3114 (1995). M. Komuro, J. Taniguchi, S. Inoue, N. Kimura, Y. Tokano, H. Hiroshima, and S. Matsui, Japanese Journal of Applied Physics, 39, 7075 (2000).

  In the thin film transistor device as described above, when the gate insulating film is thick, there are problems of insufficient pixel capacitor capacity, a decrease in on / off ratio, and an increase in driving voltage when performing electrical operation. When the thickness of the gate insulating film is small, there is a problem of increase in leakage current, parasitic capacitance, and punch-through voltage between the gate electrode and the source / drain electrodes. If the interlayer insulating film is too thick, the operation of the front plate is hindered. If it is too thin, the leakage current from the bus wiring to the front plate becomes a problem.

  The problem to be solved by the present invention is to provide a thin film transistor device capable of obtaining a sufficient capacitor capacity and suppressing leakage current and parasitic capacitance, and a manufacturing method thereof.

  As means for solving the above problems, the invention described in claim 1 includes a thin film transistor, and the gate electrode, the source electrode, the drain electrode, the bus wiring, the pixel electrode, the gate insulating film, the interlayer insulating film, and the entire semiconductor layer. Alternatively, a part is formed by a coating method or a printing method, the gate insulating film and / or the interlayer insulating film is composed of a continuous film, and the continuous film is composed of a thin film portion and a thick film portion. A thin film transistor device.

  The invention according to claim 2 includes a thin film transistor, and a gate electrode, a source electrode, a drain electrode, a bus wiring, a pixel electrode, a gate insulating film, an interlayer insulating film, or a semiconductor layer is entirely or partially applied by a coating method or a printing method. In the method of manufacturing a thin film transistor device having a step of forming a functional film on a substrate by a transfer step comprising the following steps 1 to 3, a chemical solution in which a functional material is dissolved or dispersed in a solvent is used. Step 1 for forming a liquid film on the transfer plate, Step 2 for drying a chemical solution on the transfer plate to form a dry liquid film, and transferring the dry liquid film on the transfer plate to a predetermined position on the thin film transistor substrate. And a step 3 for forming a functional film, and a functional film having a plurality of film thicknesses formed by copying the concavo-convex shape of the transfer plate by the single transfer step. It is a production method.

  The invention according to claim 3 is characterized in that the functional material is made of an insulating material, and the functional film functions as a gate insulating film and / or an interlayer insulating film. Is the method.

  A fourth aspect of the present invention is the method of manufacturing a thin film transistor device according to the second aspect, wherein the transfer plate is made of silicone rubber or fluorine rubber.

  The invention described in claim 5 is characterized in that the method of forming a liquid film is bar coating, spray coating, die coating, cap coating, roll coating, gravure coating, knife coating, lip coating, and ink jet. It is a manufacturing method of the described thin-film transistor device.

  The invention according to claim 6 is the method of manufacturing a thin film transistor device according to claim 2 or 4, wherein the transfer plate has a protruding shape at a portion corresponding to the capacitor electrode.

  The invention according to claim 7 is the method for manufacturing a thin film transistor device according to claim 2 or 4, wherein the transfer plate has a protruding shape in a portion corresponding to the channel portion.

  The invention according to claim 8 is the method for manufacturing a thin film transistor device according to claim 2 or 4, wherein the transfer plate has a protruding shape at a portion corresponding to the drain electrode.

As described above, according to the present invention, by providing the gate insulating film and / or the interlayer insulating film manufactured by the printing method with the concavo-convex shape of the thin film portion and the thick film portion, the element configuration suitable for the operation of the display is obtained. A thin film transistor device can be obtained.

1 is a cross-sectional view of a thin film transistor according to an embodiment of the present invention. The schematic diagram showing the formation method of the gate insulating film and / or interlayer insulation film by embodiment of this invention. FIG. 5 is a schematic diagram illustrating a method for forming a thin film transistor according to an embodiment of the present invention. FIG. 5 is a schematic diagram illustrating a method for forming a thin film transistor according to an embodiment of the present invention. Explanatory drawing which shows the difference between a general printing method and a micro contact printing method.

  Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view of a thin film transistor according to an embodiment of the present invention.

1A and 1B show a thin film transistor having a bottom gate and bottom contact structure according to this embodiment. A gate electrode 111 formed on the substrate 100, a gate insulating film 121 formed on the gate electrode 111, a source electrode 131 and a drain electrode 132 formed on the gate insulating film 121 so as to face each other with a channel portion interposed therebetween. And an organic semiconductor layer 141 formed in the channel portion, a pixel electrode 133, and an interlayer insulating film 122 provided to insulate between the source electrode 131 and the pixel electrode 133 and between the semiconductor 141 and the pixel electrode 133. It is the structure which was made. Reference numeral 112 denotes a capacitor electrode.

  FIG. 1C illustrates a configuration in which the pixel electrode and the interlayer insulating film are omitted. Depending on the application product of the transistor, a configuration in which the pixel electrode and the pixel electrode and the interlayer insulating film are omitted may be used. FIG. 1D shows a thin film transistor having a top gate and top contact structure, and the element structure of the transistor is not limited to the bottom gate, bottom contact structure, top gate, and top contact structure.

  The case where the gate insulating film 121 is provided with an uneven shape will be described. When the thin film portion of the gate insulating film 121 is provided between the capacitor electrode 112 and the drain electrode 132, the gate electrode 111 and the source electrode 131 or the gate electrode 111 and the drain electrode 132 are illustrated in FIG. Leakage current between the gate bus line and the source bus line that are not present can be suppressed. The voltage between the capacitor electrode 112 and the drain electrode 132 is lower than the voltage between the gate electrode 111 and the source electrode 131, between the gate electrode 111 and the drain electrode 132, or between the gate bus line and the source bus line not shown in FIG. There is no problem because the concern about leakage current is originally small. Further, since the capacitance between the gate electrode 111 and the source electrode 131 or between the gate electrode 111 and the drain electrode 132 is not increased, the operation speed of the transistor does not decrease.

  In the case where the thin film portion of the gate insulating film 121 is provided in the channel portion, the capacity of the channel portion can be increased, so that the transistor can be driven at a low voltage.

  When the thin film portion of the gate insulating film 121 is ta and the thick film portion is tb, the relations ta <tb, 100 nm <ta <1000 nm, and 500 nm <tb <1500 nm are established in order to satisfy the electrical requirements of the capacitor capacity and leakage. However, it is not limited to these.

A case where an uneven shape is provided in the interlayer insulating film 122 will be described. The thick portion of the interlayer insulating film 122 is provided in a portion that insulates between the source electrode 131 and the pixel electrode 133 and between the semiconductor layer 141 and the pixel electrode 133, and the thin film portion of the interlayer insulating film 122 is provided on the drain electrode 132. Yes. The pixel electrode 133 functions as a floating electrode with respect to the drain electrode 132. Alternatively, a thin film portion having such a thickness that leak current between the pixel electrode 133 and the drain electrode 132 may be formed, and the pixel electrode 133 and the drain electrode 132 may be connected via the leak current. Even when no leakage current is generated, there is no problem in the operation of the full version if it is a full version of the voltage operation. Further, the thin film portion of the interlayer insulating film 122 on the drain electrode 132 may function as a pixel region without providing the pixel electrode 133.
Further, the interlayer insulating film 122 is a single film having an uneven shape, and is excellent in gas and chemical substance barrier properties of the interlayer insulating film 122 itself. A gas or chemical substance barrier layer may be provided on the interlayer insulating film 122, and it is expected that the barrier layer is excellent in film formability because it is a single film.

  A transfer plate used for forming the gate insulating film 121 and / or the interlayer insulating film 122 of the present invention will be described.

  FIG. 2 (a) shows a transfer plate 290 used in the present invention. The transfer plate 290 includes small protrusions 291 and large protrusions 292. The small protrusions 291 and the large protrusions 292 are integrally formed, and may include a backing substrate or the like. Further, the large protrusion 292 may be formed on the entire surface of the substrate in pixel units or array units.

  As the material of the transfer plate 290, silicone rubber or fluororubber mainly composed of PDMS can be used. These are materials characterized by low surface energy, and liquids such as ink are difficult to spread. The surface of the transfer plate 290 may be surface-modified with UV, ozone, ashing, or the like with an appropriate strength. However, if the surface is excessively modified, transferability deteriorates. The transfer plate 290 may be composed of a plurality of layers, but the outermost layer needs to be silicone rubber or fluorine rubber for good ink transfer.

  The transfer plate 290 can be formed by a method imitating a mold made of a silicon wafer, quartz glass, a photoresist pattern, electroforming, or the like, or by RIE, laser cutting, or sandblast cutting, but is not limited to these methods.

  A method for forming the gate insulating film 121 and / or the interlayer insulating film 122 according to the present invention will be described below. 2B to 2D show a method of forming the transfer plate 290, the gate insulating film 121 and / or the interlayer insulating film 122 representing the embodiment of the present invention.

[Process 1]
Using a chemical solution in which the functional material is dissolved or dispersed in a solvent, a liquid film (ink coating film 213) is formed on the transfer plate 290 having an uneven shape (FIG. 2b). As a method for forming the liquid film, bar coating, spray coating, die coating, cap coating, roll coating, gravure coating, knife coating, lip coating, inkjet, or the like can be used.

[Process 2]
The chemical solution on the transfer plate 290 is dried to form a dry liquid film (dry ink film 214) (FIG. 2c). As the drying method, natural drying, heat / cold / room temperature air drying, infrared light drying, vacuum drying, or the like can be used. The drying of the chemical liquid refers to a state in which the chemical liquid has substantially no fluidity, and a pattern that reproduces the uneven shape of the transfer plate 290 with less ink fluidity by transferring the dried ink film to the substrate. Is obtained.

[Process 3]
The dried liquid film on the transfer plate 290 is transferred to a predetermined position on the thin film transistor substrate 200 to form a functional film (FIG. 2d). The printing pressure method at the time of transfer may be any of flat pressure, circular pressure, and rotary rotation, and temperature control such as room temperature transfer or heat transfer may be performed. The dried ink film on the transfer plate 290 has a shape in which the dried ink film surface of the concave portion of the transfer plate 290 is recessed from the film surface of the convex portion of the transfer plate 290 corresponding to the uneven shape of the transfer plate 290. There may be. When performing the transfer, the transfer can be appropriately performed by applying an appropriate printing pressure. The lower layer alignment method includes a method of observing the substrate side through the transfer plate 290, a method of observing the transfer plate 290 and the substrate with a pair of two-to-two cameras, a method of recording the discarded printing position and installing a production substrate. Can be used.

  In the present invention, ink is inked on the plate member by a wet process, and the dried ink is transferred to a substrate and heat-treated to obtain an electrode pattern. Bar coating, spray coating, die coating, cap coating, roll coating, gravure coating, knife coating, lip coating, ink jet, and the like can be used as a method for forming a thin film of ink on a plate member by a wet process.

  Gate insulating film and interlayer insulating film are polyimide, polyamide, polyester, polyvinyl phenol, polyvinyl alcohol, polyvinyl acetate, polyurethane, polysulfone, polyvinylidene fluoride, cyanoethyl pullulan, epoxy resin, phenol resin, benzocyclobutene resin, acrylic resin, Polystyrene, polycarbonate, cyclic polyolefin, fluororesin, silicone resin, and polymer alloys and copolymers of these resins can be used. The gate insulating film and the interlayer insulating film may be made of a composite material including an organic / inorganic feeler.

  Embodiments of a thin film transistor and a manufacturing method thereof according to the present invention will be described below with reference to FIGS. Although the gate insulating film 121 and the interlayer insulating film 122 constituting the thin film transistor of the present invention are formed by a printing method, other layers are not limited to being formed by a printing method, and a general method such as a printing method or photolithography is used. Can be used. As a constituent material of layers other than the gate insulating film 121 and the interlayer insulating film 122, an organic material, an inorganic material, a composite material, or the like can be used.

  First, although this embodiment is described using a thin film transistor having a bottom gate and bottom contact structure, the present invention is not limited to this. A gate electrode 111 formed on the substrate 100, a gate insulating film 121 formed on the gate electrode 111, and a source electrode 131 and a drain electrode formed on the gate insulating film 121 so as to face each other with a channel portion interposed therebetween. 132 and an organic semiconductor layer 141 formed in the channel portion. Here, the configuration of FIG. 1 is one preferable configuration, and the ink of the present invention can be used for thin film transistors of various configurations.

  In the present embodiment, the substrate 100 is in the form of glass or plastic film such as soda glass or quartz glass. Examples of plastic film resin materials include polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyetherimide, polyetheretherketone, polyetherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate, cellulose triacetate, cycloolefin polymer, polyolefin Materials such as polyvinyl chloride, liquid crystal polymer, epoxy resin, phenol resin, urea resin, melamine resin, and silicone resin can be used, and polymer alloys combining these resins and one or more of the above resins can be used. It may be configured as a plastic film having a multilayer structure in which materials are stacked in combination.

  The gate electrode 111, the source electrode 131, the drain electrode 132, the pixel electrode 133, the bus wiring, and the semiconductor can be formed by a photolithography method or a printing method.

  As the printing method, letterpress printing, intaglio printing, planographic printing, screen printing, ink jet printing, microcontact printing, reverse offset printing, thermal transfer method, laser transfer method and the like can be used.

  Metal nanoparticles can be used in the electrode printing ink. Metal nanoparticles are nanoparticles made of gold, silver, copper, platinum, palladium, nickel, cobalt, iron, aluminum, manganese metals, or gold, silver, copper, platinum, palladium, nickel, cobalt, iron, aluminum Further, nanoparticles of an alloy composed of two or more kinds of metals selected from manganese metals, metal oxides such as silver oxide, and organometallic compounds such as organic silver can also be used. The average particle size of the metal used is preferably an average particle size of 50 nm or less from the viewpoint of dispersibility in the ink, and an average particle size of 10 to 30 nm is preferable from the viewpoint of stable production of the particles, but is not limited thereto.

  The electrode formation method by the photolithography method can form a pattern by photolithography after forming a metal such as gold, silver, copper, platinum, palladium, nickel, cobalt, iron, aluminum, and manganese by PVD or CVD.

  As the semiconductor, amorphous silicon, polycrystalline silicon, oxide semiconductors such as IGZO, ITO, ZnO, and SnO, organic semiconductors, carbon semiconductors including fullerenes, carbon nanotubes, and graphene can be used.

  As an organic semiconductor, a π-conjugated polymer is used. it can. In addition, low-molecular substances having solubility in organic solvents, for example, polycyclic aromatic derivatives such as pentacene, thiophene oligomers, phthalocyanine derivatives, perylene derivatives, tetrathiafulvalene derivatives, tetracyanoquinodimethane derivatives, fullerenes Carbon nanotubes can be used.

  After the semiconductor process, a light shielding layer, a gas barrier layer, a sealing layer, or the like may be provided, and the structure of the element can be determined as appropriate depending on the method of using the thin film transistor element.

  Hereinafter, the present invention will be described in detail by way of specific examples. However, these examples are for the purpose of explanation, and the present invention is not limited thereto. The manufacturing process will be described with reference to the schematic diagram of FIG.

  A method for manufacturing a thin film transistor having a bottom-gate / bottom-contact structure will be described. In this thin film transistor, a polyethylene naphthalate (PEN) film (manufactured by Teijin DuPont) was used as the base substrate 100.

  A gate electrode 111 was formed by depositing aluminum on the substrate 100 to a thickness of 100 nm by sputtering and patterning it by photolithography and etching (FIG. 3A).

  Next, the gate insulating film 121 is formed so as to cover the gate electrode 111. Polyvinylphenol (made by Aldrich) is used as a gate insulating material, and a gate insulating film 121 is formed on the substrate 100 including the gate electrode 111 by a printing method.

As shown in FIG. 4, the transfer plate 390 used for printing is composed of PDMS, and the portions corresponding to the pixel capacitor and the channel have protrusions 391 and 392 having a height of 750 nm. On the transfer plate 390, an organic solvent solution of polyvinylphenol was applied by die coating to form a polyvinylphenol film 323 (FIG. 4a). After application, it was naturally dried for 2 minutes (FIG. 4b). After the alignment process was performed, the dried polyvinylphenol film was pressed onto the substrate 100 including the gate electrode 111 to transfer the polyvinylphenol to the substrate 100 (FIG. 4c). Thereafter, treatment was performed at 180 ° C. for 1 hour, and a gate insulating film 121 shown in FIG.
As a result, a gate insulating film 121 having a concavo-convex structure in which the thickness corresponding to the pixel capacitor and the channel is 600 nm and the thickness of the other portions is 1000 nm is obtained.

  Subsequently, source / drain electrodes 131 and 132 are formed on the gate insulating film 121 in the following order.

  First, the source / drain electrodes 131 and 132 were formed by printing nano silver ink at a predetermined position on the gate insulating film 121 by reverse offset printing and baking at 180 ° C. for 1 hour (FIG. 3c).

  Next, a semiconductor layer 141 is formed between the source / drain electrodes 131 and 132.

  As a semiconductor material, a solution obtained by dissolving poly-3-hexylthiophene (manufactured by Merck), which is an organic semiconductor material, to 1 wt% with chloroform is dispensed with a part of the source / drain electrodes 131 and 132 using a dispenser. The organic semiconductor layer 141 was produced by printing between the source / drain electrodes 131 and 132 so as to be covered and drying at 90 ° C. for 1 hour (FIG. 3d).

  Next, an interlayer insulating film 122 is formed so as to cover the thin film transistor. A coating type fluororesin is used as an interlayer insulating film material, and an interlayer insulating film 122 is formed on a substrate 100 including a thin film transistor by a printing method. The plate used for printing has the same configuration as that used for forming the gate insulating film 121 except that a projection corresponding to a height of 900 nm is provided in a portion corresponding to the drain electrode 132.

A fluororesin solution was applied on the plate by die coating. After application, it was naturally dried for 3 minutes. The fluororesin in a dry state was subjected to alignment work and then pressed onto the substrate 100 to transfer the fluororesin to the substrate 100. Thereafter, a treatment for 1 hour at 100 ° C. was performed to produce an interlayer insulating film 122 (FIG. 3E).
An interlayer insulating film 122 having a concavo-convex structure having a thickness of 150 nm on the drain electrode 132 and a thickness of other portions of 1200 nm was obtained.

  Next, the pixel electrode 133 was printed using a silver paste by a screen printing method. The silver paste was prepared by adjusting the squeegee attack angle and the squeegee speed so as to fill the recesses of the interlayer insulating film 122. After printing, processing was performed at 100 ° C. for 1 hour to produce a pixel electrode 133 (FIG. 3f).

  In order to investigate the static characteristics and dynamic characteristics of the transport characteristics and output characteristics of the thin film transistor device manufactured as described above, a voltage of +20 V to −20 V is applied to the gate electrode, and a voltage of −15 V is applied to the drain electrode, so that the source current and the pixel capacitor capacitance are applied. Was measured. Electrical characteristics of 10-10 A or less leakage current, 106 or more on / off ratio, 10 V or less punch-through voltage, and a pixel capacitor capacity with a front plate voltage holding ratio of 90% or more were obtained. As a result, a thin film transistor device having good pixel characteristics and a satisfactory operation characteristic in which leakage current, parasitic capacitance and the like are suppressed can be obtained.

  The thin film transistor of the present invention is a liquid crystal display device having an active matrix transistor array as a back plate, an organic EL, an electronic display such as electronic paper, a physical sensor such as a memory, RFID, light or heat, stress, magnetism, biological Used for sensors and chemical sensors. In particular, it is used for a flexible electric device that is excellent in impact resistance, lightweight and capable of processing a curved surface.

DESCRIPTION OF SYMBOLS 100 ... Substrate 111 ... Gate electrode 112 ... Capacitor electrode 121 ... Gate insulating film 122 ... Interlayer insulating film 131 ... Source electrode 132 ... Drain electrode 133 ... Pixel electrode 141 ... Semiconductor layer 290 ... Transfer plate 291 ... Small protrusion 292 ... Large protrusion 323 ... Polyvinylphenol film 390 ... Transfer plate 391.392 ... Protrusions 1 ... Substrate

Claims (8)

It comprises a thin film transistor, and its gate electrode, source electrode, drain electrode, bus wiring, pixel electrode, gate insulating film, interlayer insulating film, or all or part of the semiconductor layer is formed by a coating method or a printing method,
A thin film transistor device, wherein the gate insulating film and / or the interlayer insulating film is composed of a continuous film, and the continuous film is composed of a thin film portion and a thick film portion. A thin film transistor is provided, and all or part of the gate electrode, source electrode, drain electrode, bus wiring, pixel electrode, gate insulating film, interlayer insulating film, and semiconductor layer are formed by a coating method or a printing method. In a method of manufacturing a thin film transistor device, including a step of forming a functional film on a substrate by a transfer step consisting of 3,
Step 1 of forming a liquid film on the transfer plate using a chemical solution in which a functional material is dissolved or dispersed in a solvent;
Step 2 of drying the chemical on the transfer plate to form a dry liquid film;
Transferring the dry liquid film on the transfer plate to a predetermined position of the thin film transistor substrate to form a functional film; and
A method of manufacturing a thin film transistor device, wherein a functional film having a plurality of film thicknesses is formed by copying the concavo-convex shape of a transfer plate by the single transfer step.   3. The method of manufacturing a thin film transistor device according to claim 2, wherein the functional material is made of an insulating material, and the functional film functions as a gate insulating film and / or an interlayer insulating film.   3. The method of manufacturing a thin film transistor device according to claim 2, wherein the transfer plate is made of silicone rubber or fluorine rubber.   3. The method of manufacturing a thin film transistor device according to claim 2, wherein the liquid film is formed by bar coating, spray coating, die coating, cap coating, roll coating, gravure coating, knife coating, lip coating, or ink jet.   5. The method of manufacturing a thin film transistor device according to claim 2, wherein the transfer plate has a convex shape at a portion corresponding to the capacitor electrode.   5. The method of manufacturing a thin film transistor device according to claim 2, wherein the transfer plate has a protruding shape at a portion corresponding to the channel portion.   5. The method of manufacturing a thin film transistor device according to claim 2, wherein the transfer plate has a protruding shape at a portion corresponding to the drain electrode.

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