JP2010278173A - Thin film transistor and method of manufacturing the same, display device, and electronic devices - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin film transistor that reliably improves a current driving capability in a top gate structure using an organic semiconductor layer. <P>SOLUTION: The top gate type thin film transistor 1-1 has an organic semiconductor layer 15 prepared between a source electrode 13s and a drain electrode 13d, and a gate electrode 19 prepared on top of these through the intermediary of a gate insulating film 17. Especially, the gate insulating film 17 has a trilaminar structure in which a fluororesin layer 17a composed of a resin soluble in a fluorine solvent, an adhesion layer 17b composed of an inorganic material, and a high-dielectric resinous layer 17c composed of a resinous material with a dielectric constant higher than that of the resin composing the fluororesin layer 17a are laminated in this order. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a thin film transistor using an organic semiconductor and a manufacturing method thereof, and further relates to a display device and an electronic apparatus using the thin film transistor.

  Of the thin film transistors that use organic semiconductor layers as channels, in top-gate thin film transistors, it is important to form a gate insulating film without damaging the organic semiconductor layer in order to obtain good device characteristics. Become. As one of such gate insulating films, a configuration using amorphous fluororesin has been proposed. A certain type of amorphous fluororesin that is soluble in a solvent is a material that can be formed by a simple method such as a coating method without damaging the organic semiconductor layer (see, for example, Non-Patent Document 1 below).

  However, a fluororesin including an amorphous fluororesin is a low dielectric constant material having a relative dielectric constant of about 2. For this reason, in a thin film transistor using a gate insulating film made of a fluororesin, it is difficult to obtain a sufficient current driving capability while suppressing the occurrence of leakage current.

  Therefore, it is conceivable to adopt a two-layer gate insulating film structure (see Patent Document 1 below) in which a high dielectric constant material layer is laminated on a low dielectric constant material layer such as a fluororesin. According to such a configuration, the fluororesin film is formed on the organic semiconductor layer without causing damage, and the mutual conductance is ensured while suppressing the generation of leakage current by the high dielectric constant material layer provided on the organic semiconductor layer. The current drive capability is improved.

US2005 / 0104058A1

“Gate insulators in organic field-effect transistors”, “Chem. Mater.”, No. 16, 2004, p.4543≡4555

  However, in the above-described two-layer gate insulating film structure, the surface of the fluororesin layer provided in the lower layer has high water and oil repellency. For this reason, even if the fluororesin layer is formed without damaging the organic semiconductor layer, it is difficult to uniformly coat and form a high dielectric constant resin layer on the top of the fluororesin layer. Therefore, the thin film transistor having the two-layer gate insulating film structure has a large variation in the thickness of the gate insulating film, and it has been difficult to reliably improve the transistor characteristics including the current driving capability.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a thin film transistor capable of reliably improving current driving capability in a top gate structure using an organic semiconductor layer, and to provide a method for manufacturing the same. It is another object of the present invention to provide a display device with excellent display characteristics and a highly reliable electronic device by using such a thin film transistor.

  In order to achieve such an object, the thin film transistor of the present invention has a top gate structure in which a gate electrode is provided on an organic semiconductor layer via an insulating gate insulating film, and in particular, the gate insulating film has a three-layer structure. It is characterized by that. That is, the gate insulating film includes a fluorine resin layer made of a resin soluble in a fluorine-based solvent, an adhesion layer made of an inorganic material, and a high dielectric constant resin layer made of a resin material having a dielectric constant higher than that of the resin constituting the fluorine resin layer. Are stacked in this order.

  The present invention is also a method of manufacturing a thin film transistor having such a structure, in which a gate insulating film having the above three-layer structure is formed on a substrate on which a source electrode, a drain electrode, and an organic semiconductor layer are formed, and then a gate is formed. In this method, a gate electrode is formed on an insulating film.

  The present invention is also a display device in which the thin film transistor having the above structure is connected to a pixel electrode, and an electronic device in which the thin film transistor is connected to a conductive pattern.

  In the thin film transistor having the above-described configuration and the manufacturing method thereof, an upper layer is formed in a state where the film quality of the organic semiconductor layer is ensured by providing a fluororesin layer made of a resin soluble in a fluorine-based solvent on the organic semiconductor layer. be able to. Thus, charge mobility can be ensured in the channel portion formed in the organic semiconductor layer. Further, since the high dielectric constant resin layer is provided on the fluororesin layer via the adhesion layer, the high dielectric constant resin layer is uniformly provided on the fluororesin layer having high water and oil repellency. Thereby, a uniform high dielectric constant resin layer can be used as a gate insulating film, and a mutual conductance can be improved reliably.

  As described above, according to the present invention, in the thin film transistor having the top gate structure using the organic semiconductor layer, the charge mobility of the channel portion and the improvement of the mutual conductance are surely improved, so that the current driving capability is surely improved. Improvements can be made. In a display device in which such a thin film transistor is connected to a pixel electrode, display characteristics can be improved. Further, in an electronic device in which such a thin film transistor is connected to a conductive pattern, it is possible to improve the reliability of operating characteristics.

It is sectional drawing of the semiconductor device of 1st Embodiment. FIG. 4 is a cross-sectional process diagram illustrating a method of manufacturing the semiconductor device illustrated in FIG. 1. It is sectional drawing of the semiconductor device of 2nd Embodiment. FIG. 3 is a cross-sectional process diagram illustrating a characteristic part of the method for manufacturing the semiconductor device shown in FIG. It is a circuit block diagram of the display apparatus of 3rd Embodiment. It is sectional drawing which shows an example of the display apparatus of 3rd Embodiment. It is a block diagram which shows the module-shaped display apparatus of the sealed structure to which this invention is applied. It is a perspective view which shows the television using the display apparatus of this invention. It is the perspective view which shows the digital camera using the display apparatus of this invention, (A) is the perspective view seen from the front side, (B) is the perspective view seen from the back side. 1 is a perspective view showing a notebook personal computer using a display device of the present invention. It is a perspective view which shows the video camera using the display apparatus of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows the portable terminal device using the display apparatus of this invention, for example, a mobile telephone, (A) is the front view in the open state, (B) is the side view, (C) is in the closed state (D) is a left side view, (E) is a right side view, (F) is a top view, and (G) is a bottom view.

Hereinafter, embodiments of the present invention will be described in the following order based on the drawings.
1. First embodiment (a configuration example in which the fluororesin layer and the adhesion layer have the same pattern)
2. Second embodiment (configuration example in which the adhesion layer is slightly smaller than the fluororesin layer)
3. Third Embodiment (Application Example to Display Device Using Thin Film Transistor)
4). Fourth Embodiment (Application Example to Electronic Device)
In the first and second embodiments, a method for manufacturing a thin film transistor will be described, and then the configuration of the obtained thin film transistor will be described.

<< 1. First Embodiment >>
FIG. 1 is a cross-sectional view of the thin film transistor 1-1 according to the first embodiment. A thin film transistor 1-1 shown in this figure is of a top gate / bottom contact type, and an organic semiconductor layer 15 is provided on a source electrode 13s and a drain electrode 13d on a substrate 11, and a gate insulating film 17 is provided on the upper portion thereof. An electrode 19 is provided. In particular, the gate insulating film 17 is characterized by a three-layer structure of a fluororesin layer 17a, an adhesion layer 17b, and a high dielectric constant resin layer 17c.

  Hereinafter, details of each component will be described in the order of the manufacturing process based on the cross-sectional process diagram of FIG.

  First, as shown in FIG. 2A, a source electrode 13s and a drain electrode 13d are formed on a substrate 11 having at least a surface made of an insulating material. Here, for example, a metal material film such as gold (Au), platinum (Pt), copper (Cu), and aluminum (Al) is deposited, and a resist pattern is formed thereon by a photolithography method, and this is used as a mask. Then, the metal material film is subjected to pattern etching. Thereby, the source electrode 13s and the drain electrode 13d made of a metal material film are formed.

  After the formation of the source electrode 13s and the drain electrode 13d, the resist pattern is removed. At this time, if the resist pattern is a positive type, the entire surface is irradiated with ultraviolet light (UV light) and then immersed in a developer (a 3% aqueous solution of Tetra Methyl Anmonium Hydroxide) to peel and remove the resist pattern. The formation method including the material of the source electrode 13s and the drain electrode 13d and the film formation method of the material film is not limited, and a lift-off method or a printing method may be applied.

  Next, as shown in FIG. 2B, the organic semiconductor layer 15 is formed on the entire surface of the substrate 11 on which the source electrode 13s and the drain electrode 13d are formed. Here, for example, an organic semiconductor material such as pentacene or triisopropyl silylethynyl (TIPS) pentacene is used, and the film is formed by a coating method such as a spin coating method, a cap coating method, a dip coating method, or a vacuum deposition method. In addition, the organic semiconductor material which comprises the organic-semiconductor layer 15, and its film-forming method are not limited.

  Next, as shown in FIG. 2C, a fluororesin layer 17a is formed on the entire surface of the organic semiconductor layer 15, and an adhesion layer 17b is further formed on the fluororesin layer 17a.

  The fluororesin layer 17a is a film whose interface with the organic semiconductor layer 15 is a channel region. Such a fluororesin layer 17a can be easily formed by applying a resin soluble in a fluorine-based solvent without damaging the organic semiconductor layer 15 and by a coating method such as a spin coating method. . At this time, for example, a fluororesin material made into an ink with a coating solvent is applied on the organic semiconductor layer 15 with a predetermined coating thickness, and then the coating solvent is removed by baking to obtain the fluororesin layer 17a.

  As a resin soluble in the fluorine-based solvent used for such coating film formation, for example, an amorphous fluororesin such as Cytop (registered trademark) is used. Further, for example, a perfluoro solvent is used as the fluorine-based solvent as the coating solvent. In this case, baking for 10 minutes is performed at a baking temperature of 100 ° C. for a layer formed by coating with a coating film thickness of 100 nm.

The adhesion layer 17b is a film for improving the surface wettability of the fluororesin layer 17a and improving the adhesion with the upper layer, and is formed by a vacuum process using an inorganic material. As the inorganic material used here, a light-shielding metal material such as gold (Au), copper (Cu), nickel (Ni) is preferably used, but silicon oxide (SiO ₂ ), silicon nitride (SiN), An inorganic insulating film such as aluminum oxide (Al ₂ O ₃ ) may be used.

  Further, the adhesion layer 17b made of these materials is formed with a film thickness of, for example, 1 nm or more as a film thickness that can improve the surface wettability of the fluororesin layer 17a serving as a base. Further, a more preferable value for the film thickness of the adhesion layer 17b is that the ultraviolet ray irradiated in the subsequent steps can be shielded. For example, when the adhesion layer 17b made of Au is formed, the film thickness is 20 nm. The film is formed to the extent.

  Further, as a vacuum process for forming the adhesion layer 17b made of these materials, for example, a resistance heating method or a sputtering method is applied for a metal material, and a sputtering method is applied for an inorganic insulating material. However, in the case where the adhesion layer 17b is formed by applying the sputtering method, the film formation conditions are selected so as not to damage the organic semiconductor layer 15 further below through the fluororesin layer 17a. .

  Next, as shown in FIG. 2D, an island-shaped resist pattern 21 is formed on the adhesion layer 17b by photolithography. The resist pattern 21 is formed using, for example, a positive resist material. Next, using the resist pattern 21 as a mask, the adhesion layer 17b, the fluororesin layer 17a, and further the organic semiconductor layer 15 are pattern-etched into islands by an appropriate method to perform element isolation. Thereby, while protecting the organic semiconductor layer 15 with the fluororesin layer 17a and the adhesion layer 17b, the “mesa” formed by patterning the laminated structure of the organic semiconductor layer 15, the fluororesin layer 17a, and the adhesion layer 17b into an island shape is formed. Form.

At this time, first, pattern etching of the adhesion layer 17b made of Au is performed by wet etching using an aqueous potassium iodide solution or the like. Next, the fluororesin layer 17a and the organic semiconductor layer 15 are subjected to pattern etching by a dry etching method such as a reactive ion etching (RIE) method. At this time, oxygen (O ₂ ) or a mixed gas of oxygen O ₂ and tetrafluoromethane (CF ₄ ) is used as a reactive gas species.

  After the above, the entire surface of the positive resist pattern 21 is irradiated with ultraviolet light (UV light), and then immersed in a developer (a 3% aqueous solution of Tetra Methyl Anmonium Hydroxide) to remove and remove the resist pattern 21. At this time, if the adhesion layer 17b is made of a light-shielding metal material, deterioration of the organic semiconductor layer 15 due to ultraviolet (UV) light irradiation can be prevented.

  Note that the island shape formed by patterning the adhesion layer 17b, the fluororesin layer 17a, and further the organic semiconductor layer 15 is a size that is arranged at least between the source electrode 13s and the drain electrode 13d within a range where elements can be separated. I just need it.

  Thereafter, as shown in FIG. 2 (5), a high dielectric constant is formed on the substrate 11 in a state of covering an island shape composed of the element-separated organic semiconductor layer 15 and the fluororesin layer 17a and the adhesion layer 17b thereabove. A resin layer 17c is formed, and the sidewall of the organic semiconductor layer 15 is protected with a high dielectric constant insulating film 17c.

  As the resin material constituting the high dielectric constant resin layer 17c, a resin material having a dielectric constant higher than that of the fluororesin is used, and the higher the dielectric constant, the better. Among such materials, a material having no hydroxyl group at the end, such as Poly (vinyl cinnamate): PVCN, is particularly preferable. It is reported that organic thin film transistors using PVCN as a gate insulating film can obtain bias stress stability (Jang, J. Kim, S. Nam, S. Chung, D. Yang, C. Yun, W Park, C and Koo, J; “Hysteresis-free organic field-effect transistors and inverters using photocrosslinkable poly (vinyl cinnamate) as a gate dielectric”, “Appl. Phys. Lett”, 92 (2008) 143306) ing. Here, it is explained that PVCN is composed of a molecule having no hydroxyl group at the terminal. Therefore, even if it is other than PVCN, bias stress stability is ensured by using a resin composed of a molecule having no hydroxyl group at the terminal as a constituent material of the high dielectric constant resin layer 17.

  Further, by selecting and using an ultraviolet (UV light) curable resin as the high dielectric constant resin material, it becomes possible to reduce the process temperature. For this reason, a plastic material can be used for the substrate 11.

  The film formation of the high dielectric constant resin layer 17 using such a high dielectric constant resin material is performed by a coating method such as a spin coating method, a cap coating method, or a dip coating method. As a solvent constituting the coating ink together with the high dielectric constant resin material, it is preferable to select a solvent that does not attack the organic semiconductor layer 15 exposed on the island-shaped side walls. For example, when the organic semiconductor layer 15 is made of TIPS pentacene and PVCN is used as the high dielectric constant resin material, γ-butyllactone is suitably used as such a solvent.

  Here, for example, a γ-butyllactone solution of PVCN is applied over the entire surface by spin coating. Subsequently, after baking for solvent volatilization, ultraviolet light (UV light) is irradiated from the entire surface of the substrate 11 to cure the high dielectric constant resin material, thereby obtaining the high dielectric constant resin layer 17c. Thereby, sufficient chemical resistance capable of forming an electrode, an interlayer insulating film, or the like on the high dielectric constant resin layer 17c is expressed, and sufficient insulation is obtained for reducing interlayer leakage. At this time, if the adhesion layer 17b is made of a light-shielding metal material, deterioration of the organic semiconductor layer 15 due to ultraviolet (UV) light irradiation can be prevented.

  As described above, the fluororesin layer 17a and the adhesion layer 17b provided in the same shape on the island-shaped organic semiconductor layer 15 and the film formed on the entire surface of the substrate 11 so as to cover these island-shaped portions. A gate insulating film 17 having a three-layer structure with the high dielectric constant resin layer 17c is formed.

  After the above, as shown in FIG. 2, on the gate insulating film 17, the gate electrode 19 and a wiring led out from the gate electrode 19 are formed at a position extending at least between the source electrode 13s and the drain electrode 13d. The gate electrode 19 can be formed in the same manner as the source electrode 13s and the drain electrode 13d.

  As described above, a top gate / bottom contact type thin film transistor 1-1 in which the gate insulating film 17 has a three-layer structure of the fluororesin layer 17a, the adhesion layer 17b, and the high dielectric constant resin layer 17c is obtained.

  According to the first embodiment as described above, the film quality of the organic semiconductor layer 15 is ensured because the fluorine resin layer 17a made of a resin soluble in a fluorine-based solvent is applied and formed on the organic semiconductor layer 15. In this state, an upper layer can be further formed. Thereby, the mobility of electric charges can be ensured in the channel portion formed in the organic semiconductor layer 15.

  Further, since the high dielectric constant resin layer 17c is provided on the fluororesin layer 17a via the adhesion layer 17b, the high dielectric constant resin is uniformly formed on the fluororesin layer 17a having high water and oil repellency. A layer can be provided. Thereby, the uniform high dielectric constant resin layer 17c can be used as a constituent element of the gate insulating film 17, and the mutual conductance can be improved reliably.

  Furthermore, as a method for improving the surface wettability (adhesion) of the fluororesin layer 17a, surface modification by ashing is known. The method for forming the adhesion layer 17b of the first embodiment is an ashing process. In comparison, the adhesion of the lower ground of the high dielectric constant resin layer 17c is surely improved. Moreover, there is no concern of plasma damage of the organic semiconductor layer 15 due to the ashing process. For this reason, the fluororesin layer 17a having a low dielectric constant can be thinned. As a result, the entire gate insulating film 17 can be reliably increased in dielectric constant. Also from this, mutual conductance can be improved.

  As described above, since it is possible to reliably improve the charge mobility and the mutual conductance of the channel portion, it is possible to reliably improve the current driving capability in the thin film transistor 1-1. Become.

≪2. Second Embodiment >>
FIG. 3 is a cross-sectional view of the thin film transistor 1-2 of the second embodiment. The thin film transistor 1-2 shown in this figure differs from the thin film transistor of the first embodiment in that the adhesion layer 17b ′ is slightly smaller than the fluororesin layer 17a in the gate insulating film 17 ′ having a three-layer structure. In the configuration. Such a configuration is particularly effective when the adhesion layer 17b ′ is made of a metal material.

  A characteristic part of the method of manufacturing the thin film transistor 1-2 having such a configuration will be described with reference to the sectional process diagram of FIG.

  First, steps similar to those described in the first embodiment with reference to FIGS. 2A to 2C 3 are performed to form the source electrode 13 s and the drain electrode 13 d on the substrate 11, and further on the substrate 11. The organic semiconductor layer 15, the fluororesin layer 17a, and the adhesion layer 17b are formed on the entire surface. At this time, the adhesion layer 17b is formed by applying a vacuum process using an inorganic material as in the first embodiment. Among the inorganic materials, gold (Au), copper (Cu), nickel (Ni A metal material having a light shielding property such as) is selected and used.

  Next, as shown in FIG. 4A, an island-shaped resist pattern 21 is formed on the adhesion layer 17b by photolithography. The resist pattern 21 is formed using, for example, a positive resist material. Next, using the resist pattern 21 as a mask, the adhesion layer 17b, the fluororesin layer 17a, and further the organic semiconductor layer 15 are pattern-etched into islands by an appropriate method to perform element isolation. As a result, a “mesa” is formed by patterning the laminated structure of the organic semiconductor layer 15, the fluororesin layer 17a, and the adhesion layer 17b into an island shape.

  At this time, in the pattern etching of the adhesion layer 17 b ′, the etching side wall of the adhesion layer 17 b ′ is made to recede from the side wall surface of the resist pattern 21 by performing isotropic etching such as wet etching. As a result, the adhesion layer 17 b ′ is patterned into a planar island shape slightly smaller than the resist pattern 21. For example, in the case of the adhesion layer 17b ′ made of Au, wet etching using a potassium iodide aqueous solution or the like is performed, but by performing over-etching, the adhesion layer 17b ′ is formed in an island shape that is slightly smaller than the resist pattern 21. Is patterned.

  Next, isotropic etching such as reactive ion etching (RIE) method similar to the first embodiment is performed on the fluororesin layer 17a and the organic semiconductor layer 15. As a result, the fluororesin layer 17 a and the organic semiconductor layer 15 are pattern-etched into the same planar shape as the resist pattern 21. After the pattern etching is completed, the entire surface of the positive resist pattern 21 is irradiated with ultraviolet light (UV light), and then immersed in a developer (a 3% aqueous solution of TetraMethylAniumium Hydrooxide) to remove and remove the resist pattern 21.

  Thereafter, as shown in FIG. 4A, a high dielectric constant is formed on the substrate 11 in a state of covering an island formed of the element-separated organic semiconductor layer 15 and the fluororesin layer 17a and the adhesion layer 17b ′ on the upper side. A rate resin layer 17c is formed. The dielectric constant resin layer 17c is formed in the same manner as described with reference to FIG. 2 (5) in the first embodiment.

  As described above, the three-layer structure of the fluororesin layer 17a formed in the same island shape as the organic semiconductor layer 15, the adhesion layer 17b 'that is slightly smaller than the fluororesin layer 17a, and the high dielectric constant resin layer 17c covering these layers. The gate insulating film 17 ′ is formed.

  After the above, as shown in FIG. 3, the gate electrode 19 and the wiring led out therefrom are formed on the gate insulating film 17 ′ at least at a position extending between the source electrode 13 s and the drain electrode 13 d. The gate electrode 19 can be formed in the same manner as the source electrode 13s and the drain electrode 13d.

  As described above, the gate insulating film 17 ′, the island-shaped fluororesin layer 17a, the island-shaped adhesion layer 17b ′ that is one size smaller than the gate insulating film 17 ′, and the high-dielectric-constant resin layer 17c that covers these tops A gate / bottom contact type thin film transistor 1-2 is obtained.

  According to the second embodiment as described above, in the gate insulating film 17 ′ having a three-layer structure, the adhesion layer 17 b ′ is configured as an island shape that is slightly smaller than the fluororesin layer 17 a. Accordingly, it is possible to prevent the high dielectric constant resin layer 17c covering the island shape from being thinned at the peripheral corner portion above the adhesion layer 17b '. For this reason, in addition to the effects of the first embodiment, leakage between the adhesion layer 17b ′ made of a metal material, the gate electrode 19 provided on the high dielectric constant resin layer 17c, and the wiring in the same layer is performed. It has the effect of preventing the occurrence.

  In the first embodiment and the second embodiment described above, the top gate / bottom contact type is exemplified as the top gate type thin film transistor. However, the thin film transistor of the present invention can also be applied to a top gate / top contact type.

≪3. Third Embodiment >>
Next, a display device including the thin film transistor described in the above embodiment will be described as a third embodiment of the present invention. Here, an active matrix display device 30 using the organic electroluminescent element EL together with the thin film transistor 1-2 described in the second embodiment will be described.

  FIG. 5 shows a circuit configuration diagram of the display device 30. As shown in this figure, a display area 11 a and a peripheral area 11 b are set on the substrate 11 of the display device 30. In the display area 11a, a plurality of scanning lines 31 and a plurality of signal lines 33 are wired vertically and horizontally, and configured as a pixel array section in which one pixel a is provided corresponding to each intersection. . In the peripheral region 11b, a scanning line driving circuit 35 that scans and drives the scanning line 31 and a signal line driving circuit 37 that supplies a video signal (that is, an input signal) corresponding to the luminance information to the signal line 33 are arranged. Yes.

  A pixel circuit provided at each intersection of the scanning line 31 and the signal line 33 is constituted by, for example, a switching thin film transistor Tr1, a driving thin film transistor Tr2, a storage capacitor Cs, and an organic electroluminescence element EL.

  The video signal written from the signal line 33 via the switching thin film transistor Tr1 is held in the holding capacitor Cs by driving by the scanning line driving circuit 35, and a current corresponding to the held signal amount is driven by the driving thin film transistor. The organic electroluminescence device EL is supplied from the Tr2 to the organic electroluminescence device EL, and the organic electroluminescence device EL emits light with luminance according to the current value. The driving thin film transistor Tr2 is connected to a common power supply line (Vcc) 39.

  Note that the configuration of the pixel circuit as described above is merely an example, and a capacitor element may be provided in the pixel circuit as necessary, or a plurality of transistors may be provided to configure the pixel circuit. Further, a necessary drive circuit is added to the peripheral region 11b according to the change of the pixel circuit.

  FIG. 6 is a cross-sectional view of a portion in which the thin film transistors Tr2 and Tr1, the capacitor element Cs, and the organic electroluminescence element EL are stacked as a cross-sectional view for one pixel in the display device 5 having the circuit configuration as described above. .

  As shown in this figure, each pixel has thin film transistors Tr2 and Tr1, for example, the thin film transistor (1-1) of the first embodiment shown in FIG. 1 or the thin film transistor (1--) of the second embodiment shown in FIG. 2) is provided.

  The source electrode 13s of the thin film transistor Tr1 and the gate electrode 19b of the thin film transistor Tr2 are connected via a connection hole 17h provided in the high dielectric constant resin layer 17c constituting the gate insulating film 17. Further, the high-permittivity resin layer 17c in the gate insulating film 17 is sandwiched between the portion where the gate electrode 19b of the thin film transistor Tr2 is extended and the portion where the source electrode 13s is extended, thereby forming the capacitive element Cs. Yes. As shown in the circuit diagram of FIG. 5, the gate electrode 19a of the thin film transistor Tr1 is on the scanning line (31), the drain electrode 13d of the thin film transistor Tr1 is on the signal line (33), and the source electrode 13s of the thin film transistor Tr2 is on the power source. Each is extended to a supply line (39).

  Note that the signal line 33 and the power supply line 39 shown in the pixel circuit may have the same layer structure using the same layer as the source electrode 13s and the drain electrode 13d in the cross-sectional view.

  The thin film transistors Tr1 and Tr2 and the capacitor element Cs are covered with the interlayer insulating film 41 with a protective film interposed therebetween, for example. The interlayer insulating film 41 is preferably configured as a planarizing film. The interlayer insulating film 41 and the high dielectric constant resin layer 17c constituting the gate insulating film 17 are provided with a connection hole 41h reaching the drain electrode 13d of the thin film transistor Tr2.

  Each pixel on the interlayer insulating film 41 is provided with an organic electroluminescence element EL connected to the thin film transistor Tr2 through the connection hole 41a. The organic electroluminescent element EL is separated by an insulating pattern 43 provided on the interlayer insulating film 41.

  The organic electroluminescent element EL includes a pixel electrode 45 provided on the interlayer insulating film 41. The pixel electrode 45 is formed as a conductive pattern for each pixel, and is connected to the drain electrode 13d of the thin film transistor Tr2 through a connection hole 41a provided in the interlayer insulating film 41. Such a pixel electrode 45 is used as an anode, for example, and is configured to have light reflectivity.

  The periphery of the pixel electrode 45 is covered with an insulating pattern 43 for separating the organic electroluminescent element EL. The insulating pattern 43 includes an opening window 43a that exposes the pixel electrode 45 widely, and the opening window 43a is a pixel opening of the organic electroluminescent element EL. Such an insulating pattern 43 is composed of, for example, a photosensitive resin and is patterned by applying a lithography method.

  The organic layer 47 is provided so as to cover the pixel electrode 45 exposed from the insulating pattern 53. The organic layer 47 has a laminated structure including at least an organic light-emitting layer, and if necessary, sequentially from the anode (here, the pixel electrode 55) side, a hole injection layer, a hole transport layer, an organic light-emitting layer, and an electron transport. A layer, an electron injection layer, and other layers are laminated. In addition, for example, the organic layer 47 has a pattern in which at least a layer including the organic light emitting layer is formed in a different configuration for each pixel for each wavelength of emitted light generated by each organic electroluminescent element EL. In addition, the pixels of each wavelength may have a common layer. Furthermore, when this organic electroluminescent element EL is comprised as a microresonator structure, the film thickness of the organic layer 47 shall be adjusted according to the wavelength taken out from each organic electroluminescent element EL.

  A common electrode 49 is provided so as to cover the organic layer 47 as described above and sandwich the organic layer 47 between the pixel electrode 45. The common electrode 49 is an electrode on the side from which light generated in the organic light emitting layer of the organic electroluminescent element EL is extracted, and is made of a material having optical transparency. Here, since the pixel electrode 55 functions as an anode, the common electrode 49 is formed using a material that functions as a cathode at least on the side in contact with the organic layer 47. Furthermore, when this organic electroluminescent element EL is comprised as a microresonator structure, this common electrode 49 shall be the structure which has transflective property. As shown in the circuit diagram of FIG. 5, the common electrode 49 is installed on the GND.

  Each pixel portion in which the organic layer 47 is sandwiched between the pixel electrode 45 and the common electrode 49 as described above becomes a portion that functions as the organic electroluminescent element EL.

  Although not shown here, the formation surface side of each organic electroluminescent element EL is covered with a sealing resin made of a light-transmitting material, and is further opposed to the light-transmitting material through this sealing resin. The display device 5 is configured with the substrates attached to each other.

  According to the display device 30 configured as described above, as described in the first embodiment and the second embodiment, the pixel is formed using the thin film transistors (1-1, 1-2) having favorable transistor characteristics and uniform characteristics. Since the circuit is configured, it is possible to improve display characteristics. In particular, since the thin film transistors (1-1, 1-2) have high current drive capability, it is possible to display the organic electroluminescence element EL with high luminance.

  In the above-described embodiment, an active matrix display device using the organic electroluminescence element EL is exemplified. However, the display device of the present invention can be widely applied to a display device including a thin film transistor using an organic semiconductor layer, and can be applied to, for example, a liquid crystal display device or an electrophoretic display.

  Further, the display device 30 according to the present invention described above includes a module-shaped one having a sealed configuration as disclosed in FIG. For example, a sealing portion 51 is provided so as to surround the display area 11a which is a pixel array portion, and the sealing portion 51 is used as an adhesive and is attached to a facing portion (sealing substrate 53) such as transparent glass. Applicable to display modules. The transparent sealing substrate 53 may be provided with a color filter, a protective film, a light shielding film, and the like. The substrate 11 as a display module in which the display area 11a is formed may be provided with a flexible printed circuit board 53 for inputting / outputting signals and the like from the outside to the display area 11a (pixel array portion).

<< 4. Fourth Embodiment >>
8 to 12 show an example of an electronic device using the display device according to the present invention described above as a display unit. The display device of the present invention can be applied to display units in electronic devices in various fields that display video signals input to electronic devices and video signals generated in the electronic devices. An example of an electronic device to which the present invention is applied will be described below.

  FIG. 8 is a perspective view showing a television to which the present invention is applied. The television according to this application example includes a video display screen unit 101 including a front panel 102, a filter glass 103, and the like, and is created by using the display device according to the present invention as the video display screen unit 101.

  9A and 9B are diagrams showing a digital camera to which the present invention is applied. FIG. 9A is a perspective view seen from the front side, and FIG. 9B is a perspective view seen from the back side. The digital camera according to this application example includes a light emitting unit 111 for flash, a display unit 112, a menu switch 113, a shutter button 114, and the like, and is manufactured by using the display device according to the present invention as the display unit 112.

  FIG. 10 is a perspective view showing a notebook personal computer to which the present invention is applied. A notebook personal computer according to this application example includes a main body 121 including a keyboard 122 that is operated when characters and the like are input, a display unit 123 that displays an image, and the like. It is produced by using.

  FIG. 11 is a perspective view showing a video camera to which the present invention is applied. The video camera according to this application example includes a main body 131, a lens 132 for shooting an object on a side facing forward, a start / stop switch 133 at the time of shooting, a display unit 134, and the like. It is manufactured by using such a display device.

  12A and 12B are diagrams showing a mobile terminal device to which the present invention is applied, for example, a mobile phone. FIG. 12A is a front view in an opened state, FIG. 12B is a side view thereof, and FIG. (D) is a left side view, (E) is a right side view, (F) is a top view, and (G) is a bottom view. The mobile phone according to this application example includes an upper housing 141, a lower housing 142, a connecting portion (here, a hinge portion) 143, a display 144, a sub display 145, a picture light 146, a camera 147, and the like. And the sub display 145 is manufactured by using the display device according to the present invention.

  In the above-described embodiment, an electronic device including an active matrix display unit is shown as an example of the electronic device including the thin film transistor described in the first embodiment or the second embodiment. However, the electronic device of the present invention can be widely applied to electronic devices in which a thin film transistor is connected to a conductive pattern, and an electronic device such as an ID tag or a sensor can be used other than a device provided with a display portion. The same effect can be obtained.

  1-1, 1-2 ... thin film transistor, 11 ... substrate, 13s ... source electrode, 13d ... drain electrode, 15 ... organic semiconductor layer, 17 ... gate insulating film, 17a ... fluororesin layer, 17b ... adhesion layer, 17c ... high Dielectric constant resin layer, 19, 19a, 19b ... gate electrode, 30 ... display device, 45 ... pixel electrode (conductive pattern)

Claims (17)

A source electrode and a drain electrode on the substrate;
An organic semiconductor layer provided between the source electrode and the drain electrode;
On the substrate on which the source electrode, the drain electrode, and the organic semiconductor layer are formed, a fluororesin layer made of a resin soluble in a fluorine-based solvent, an adhesion layer made of an inorganic material, and the fluororesin layer are configured A gate insulating film in which a high dielectric constant resin layer made of a resin material having a higher dielectric constant than the resin to be laminated in this order;
A thin film transistor comprising a gate electrode on the gate insulating film. The adhesion layer is made of a light shielding material,
The thin film transistor according to claim 1, wherein the high dielectric constant resin layer is made of an ultraviolet curable resin. The thin film transistor according to claim 1, wherein the adhesion layer is made of a metal material. The thin film transistor according to claim 1, wherein the adhesion layer is made of an inorganic insulating material. The thin film transistor according to claim 1, wherein the organic semiconductor layer is provided on the substrate on which the source electrode and the drain electrode are formed. The thin film transistor according to claim 5, wherein the organic semiconductor layer is patterned in an island shape together with the adhesion layer and the fluororesin layer and covered with the high dielectric constant resin layer. The thin film transistor according to claim 6, wherein the adhesion layer is made of a metal material and patterned into an island shape that is slightly smaller than the organic semiconductor layer and the fluororesin layer. Forming a source electrode and a drain electrode on the substrate, and an organic semiconductor layer extending between the source electrode and the drain electrode;
On the substrate on which the source electrode, the drain electrode, and the organic semiconductor layer are formed, a fluororesin layer made of a resin soluble in a fluorine-based solvent, an adhesion layer made of an inorganic material, and the fluororesin layer are configured Forming a gate insulating film in which a high dielectric constant resin layer made of a resin material having a higher dielectric constant than the resin to be laminated in this order; and
And a step of forming a gate electrode on the gate insulating film. The method of manufacturing a thin film transistor according to claim 8, wherein the adhesion layer is formed by applying a vacuum process. 10. The thin film transistor according to claim 8, wherein, in the step of forming the gate insulating film, after forming the adhesion layer using a light-shielding material, the high dielectric constant resin layer is formed using an ultraviolet curable resin. Manufacturing method. The method for manufacturing a thin film transistor according to claim 8, wherein the organic semiconductor layer is formed on the substrate after the source electrode and the drain electrode are formed on the substrate. In the step of forming the gate insulating film, the fluororesin layer and the adhesion layer are formed in this order on the organic semiconductor layer, and then the adhesion layer and the fluororesin layer are formed in an island shape together with the organic semiconductor layer. The method of manufacturing a thin film transistor according to claim 11, wherein element isolation is performed by patterning and then the high dielectric constant resin layer is formed. The adhesion layer is made of a metal material,
The method for manufacturing a thin film transistor according to claim 12, wherein when performing the element isolation, the adhesion layer is patterned into an island shape that is slightly smaller than the organic semiconductor layer and the fluororesin layer. A thin film transistor and a pixel electrode connected to the thin film transistor;
The thin film transistor
A source electrode and a drain electrode on the substrate;
An organic semiconductor layer provided between the source electrode and the drain electrode;
On the substrate on which the source electrode, the drain electrode, and the organic semiconductor layer are formed, a fluororesin layer made of a resin soluble in a fluorine-based solvent, an adhesion layer made of an inorganic material, and the fluororesin layer are configured A gate insulating film in which a high dielectric constant resin layer made of a resin material having a higher dielectric constant than the resin to be laminated in this order;
And a gate electrode on the gate insulating film. The adhesion layer is made of a light shielding material,
The display device according to claim 14, wherein the high dielectric constant resin layer is made of an ultraviolet curable resin. A conductive pattern connected to the thin film transistor;
The thin film transistor
A source electrode and a drain electrode on the substrate;
An organic semiconductor layer provided between the source electrode and the drain electrode;
On the substrate on which the source electrode, the drain electrode, and the organic semiconductor layer are formed, a fluororesin layer made of a resin soluble in a fluorine-based solvent, an adhesion layer made of an inorganic material, and the fluororesin layer are configured A gate insulating film in which a high dielectric constant resin layer made of a resin material having a higher dielectric constant than the resin to be laminated in this order;
An electronic device comprising a gate electrode on the gate insulating film. The adhesion layer is made of a light shielding material,
The electronic device according to claim 16, wherein the high dielectric constant resin layer is made of an ultraviolet curable resin.

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