Display and method of manufacturing the same

A display, a method of manufacturing the display, and an electronic apparatus are provided. The display includes a resin, a transistor; and a light shielding material positioned between the resin and the transistor. The light shielding material is configured to suppress an incidence of light on the transistor. Light is prevented from entering an oxide semiconductor layer to be used as an active layer so as to suppress deterioration of transistor characteristics.

CROSS REFERENCES TO RELATED APPLICATIONS

The present application claims priority to Japanese Patent Application No. 2011-180778 filed on Aug. 22, 2011, the disclosure of which is incorporated herein by reference.

BACKGROUND

The present disclosure relates to a display employing a thin film transistor (TFT) in which an active layer is made of an oxide semiconductor and a method of manufacturing the display.

TFTs are widely applied, as a basic technology, to liquid crystal displays, organic EL displays, and the like. Generally, a semiconductor layer serving as an active layer of a TFT is made of amorphous silicon (a-Si:H) or poly silicon, but in recent years, oxide semiconductors such as metal oxides which may be formed by inexpensive apparatuses adopting a sputtering method or the like are also used to form such a semiconductor layer. However, if light (especially ultraviolet light of 420 nm or less) is irradiated on a semiconductor layer made of an oxide semiconductor, its TFT characteristics may be varied by photoinduction, or more specifically, its threshold level voltage (Vth) may be shifted to negative (−) direction.

In order to solve this issue, for example, Japanese Unexamined Patent Application Publication No. 2007-115902 discloses a TFT employing a light shielding film provided on the rear face of a substrate. In addition, for example, Japanese Unexamined Patent Application Publication No. 2009-224354 discloses a bottom-gate type TFT employing a light-absorbing layer provided between a gate electrode and an active layer, and Japanese Unexamined Patent Application Publication No. 2007-150157 discloses a TFT employing a base material (substrate) made of a material in which transmittance of light having a wavelength shorter than the band gap energy is 10% or less.

SUMMARY

With the above-mentioned TFTs disclosed in Japanese Unexamined Patent Application Publication Nos. 2007-115902, 2009-224354, and 2007-150157, light incident on an active layer from a rear side of a substrate may be shielded; however, light irradiated from a side direction of the substrate may not be sufficiently shielded. In recent years, narrower frame is desired in displays, especially in mobile displays, and the distance between a terminal section provided in a peripheral region (frame region) and pixels provided in a display region (pixel region) is significantly shortened. Under this circumstance, there is an issue that light irradiated from a frame region side, that is, an oblique direction enters a semiconductor layer (oxide semiconductor layer) of a TFT, leading to deteriorated TFT characteristics.

It is desirable to provide a display and electronic apparatus which prevent light from entering an oxide semiconductor layer to be used as an active layer so as to suppress deterioration of TFT characteristics, and a method of manufacturing the display.

According to an embodiment of the present technology, there is provided a display including a resin, a transistor; and a light shielding material positioned between the resin and the transistor. The light shielding material is configured to suppress an incidence of light on the transistor.

According to an embodiment of the present technology, there is provided a method of manufacturing a display. The method includes forming a resin, a transistor, and a light shielding material. The light shielding material is positioned between the resin and the transistor, and the light shielding material is configured to suppress an incidence of light on the thin film transistor.

According to an embodiment of the present technology, there is provided an electronic apparatus including a resin, a transistor; and a light shielding material positioned between the resin and the transistor. The light shielding material is configured to suppress an incidence of light on the transistor.

In the display, the method of manufacturing the display, and the electronic apparatus according to the embodiments of the present technology, after the thin film transistor and the light emitting device are formed, the side face of the thin film transistor, the side face of the light emitting device, and a part of the top face of the light emitting device are covered by the light shielding film. In this way, light coming from an oblique direction, especially from a frame region side, to enter the thin film transistor is shielded. Furthermore, since the side face of the thin film transistor, the side face of the light emitting device, and a part of the top face of the light emitting device are covered by the light shielding film, it is possible to shield light coming from an oblique direction, especially from a frame region side, and it is thus possible to suppress deterioration of characteristics of the thin film transistor.

DETAILED DESCRIPTION

Embodiments of the present application will be described below in detail with reference to the drawings.

Referring to the figures, an embodiment of the present disclosure will be described in detail. It is to be noted that description will be given in the following order.1. Embodiment1-1. General Configuration1-2. General Configuration of Display1-3. Manufacturing Method2. Application Example

1-1. General Configuration

FIG. 1shows a cross-sectional configuration of a part of a display1according to an embodiment of the present disclosure. In the display1, on a pixel region2of a substrate11, a plurality of pixels (not shown) is disposed in matrix (grid). The pixels include red pixels R, green pixels G, and blue pixels B, which are disposed on a color by color basis in a line shape. Each of the pixels (R, G, and B) is provided with an organic EL device20(light emitting device) which outputs a corresponding color. Each organic EL device20is formed on a thin film transistor (TFT)10for driving devices. It is to be noted that, in this instance, a combination of the red pixel R, the green pixel G, and the blue pixel B configures one display pixel (pixel). A frame region3is provided at the periphery of the pixel region2, and a terminal section4is provided at a peripheral portion of the frame region3.

In the display1of the present embodiment, a light shielding film5is provided in the frame region3(between the pixel region2and the terminal section4) as illustrated inFIG. 1andFIG. 2A. The light shielding film5is made of a material having a light shielding function by scattering or absorbing light, especially light having a wavelength of 420 nm or less (ultraviolet light). The light shielding film5is formed so as to cover side faces of the TFT10and the organic EL device20provided in the pixel region2and a part of the top face of the organic EL device20. Thus, in the manufacturing process of the display1described later, incidence of ultraviolet (UV) light, which is outputted at the time of providing damp-proof reinforcing materials35A and35B to the terminal section4, on the TFT10may be suppressed. In the present embodiment, the light shielding film5(5A and5B; seeFIG. 10) is provided, not only on the side face of the TFT10, the side face of the organic EL device20, and a part of the top face of the organic EL device20, but also on a layer formed extending from the end portion of the TFT10and configuring the organic EL device20, in such a manner as to sandwich the organic EL device20. It should be noted that this is not limitative, and, for example, the above-described incidence of UV light on the TFT10may be suppressed if the light shielding film5is provided so as to cover at least part of the top face and the side face of the organic EL device20, and further the extended line from the side face of the organic EL device20to the substrate11.

In addition, as illustrated inFIG. 2B, one or more recessed portions5aare provided on the surface of the light shielding film5in the present embodiment (on the substrate11and the top face of the organic EL device20, seeFIG. 1). By providing this recessed portion5a, in addition to the light shielding function for UV light offered by the characteristics of the material configuring the light shielding film5, a reflecting function offered by the form (or the recessed portion5a) is added, and thus UV light incident on the TFT10from an oblique direction is shielded more securely. Concrete examples of the material for configuring the light shielding film5are titanium oxide (TiO2), and zinc oxide (ZnO). General metals such as Aluminum (Al), Copper (Cu), Tungsten (W), Gold (Au), Tantalum (Ta), Cobalt (Co), and silicides thereof may also be used as the light shielding film5. Barrier metals such as titanium nitride (TiN) and tantalum nitride (TaN) may also be used. Other materials may also be used as long as the above-described light shielding function for UV light is obtained. In addition, the light shielding film5may include materials other than those having the light shielding function.

The film thickness of the light shielding film5is preferably 380 nm or more. For example, as illustrated inFIGS. 3A to 3C, TiO2(FIG. 3B) has a function to shield light in the ultraviolet region as compared with ITO (FIG. 3A) and silica (FIG. 3C). Specifically, when the film thickness is 500 nm, UV light shielding capability of 90% is obtained. Since the irradiation amount of UV light in the case where the above-described damp-proof reinforcing material is cured is typically about 1000 mJ/cm2, when light is shielded by a TiO2film having a film thickness of 500 nm, about 10% (100 mJ/cm2) of UV light is allowed to pass therethrough.FIG. 4shows a relationship between the UV irradiation amount and the amount of variation (ΔVth) of the threshold level (Vth) of the TFT10after UV irradiation. As shown inFIG. 4, when UV light of 100 mJ/cm2is irradiated, the threshold level (Vth) is shifted by about 0.1 V. Generally, acceptable ΔVth of a TFT is 0.2 V or less. Referring toFIG. 4, ΔVth becomes 0.2 V when the UV irradiation amount is 175 mJ/cm2. On the other hand, intensity L of transmitting light in the case where the intensity of UV incident light is represented by L0has a relationship of L(t)=L0×ηt, where transmittance per unit length (film thickness) is represented by η. It is assumed that the intensity of incident light L0is the UV irradiation amount (1000 mJ/cm2) which is applied on the damp-proof reinforcing materials35A and35B when they are cured, and transmittance η per unit length (film thickness) is the transmittance corresponding to the film thickness of 500 nm, that is, η=10%=0.1. In addition, if intensity L(t) of transmitting light is acceptable ΔVth (0.2 V) of a TFT, then 175=1000×0.1(t/500), and t=378.5 nm. Specifically, the film thickness of the light shielding film5for effectively suppressing incidence of UV light on the TFT10is preferably 378.5 nm or more, and more preferably, 380 nm or more.

1-2. General Configuration of Display

Next, the cross-sectional configuration of the display1is described.FIG. 5shows a block configuration of the display1according to the present embodiment. The display1is used as, for example, an organic EL television or the like. As described above, the pixel region2in which a plurality of the organic EL devices20(20R,20G, and20B) are disposed in matrix is formed on the substrate11, and the frame region3is disposed in such a manner as to surround the pixel region2. The frame region3is provided with a signal line driving circuit120and a scan line driving circuit130as drivers for image display.

In the pixel region2, a pixel driving circuit140is provided.FIG. 6shows an example of the pixel driving circuit140. The pixel driving circuit140is an active-type driving circuit formed in a lower layer of a lower electrode21described later. In other words, the pixel driving circuit140includes a driving transistor Tr1, a writing transistor Tr2, a capacitor Cs provided between the transistors Tr1and Tr2, and the red organic EL device20R (or the green organic EL device20G, or the blue organic EL device20B) connected in series to the driving transistor Tr1between a first power-source line (Vcc) and a second power-source line (GND). Each of the driving transistor Tr1and the writing transistor Tr2is configured of a common TFT, and the configuration thereof is not specifically limited, and may be either of, an inversely-staggered structure (so-called bottom-gate type) or a staggered structure (top-gate type), for example.

In the pixel driving circuit140, a plurality of signal lines120A are disposed in the column direction, and a plurality of scan lines130A are disposed in the row direction. Each intersection between the signal line120A and the scan line130A corresponds to one of the red organic EL device20R, the green organic EL device20G, and the blue organic EL device20B. The signal lines120A are connected to the signal line driving circuit120, and an image signal is supplied from the signal line driving circuit120to a source electrode of the writing transistor Tr2through the signal line120A. The scan lines130A are connected to the scan line driving circuit130, and a scanning signal is sequentially supplied from the scan line driving circuit130to a gate electrode of the writing transistor Tr2through the scan line130A.

FIG. 7shows a cross-sectional configuration of a part of the display1. In the display1, the TFT10which is driven by, for example, the active matrix system is provided on the substrate11, and the organic EL device20(20R,20G, and20B) which includes a light emitting layer23C corresponding to the pixel (R, G, and B) is provided on the TFT10.

The TFT10is a TFT of a so-called bottom-gate type, and its channel (active layer) is made of, for example, an oxide semiconductor. In the TFT10, a gate electrode12, a gate insulating film13, an oxide semiconductor layer14, a channel protect film15, and a source/drain electrodes16A and16B are formed in this order on the substrate11made of glass or the like. A planarizing film18configured to planarize the irregularities of the TFT10over the entire face of the substrate11is formed on the source electrode16A and the drain electrode16B.

The gate electrode12plays a role in controlling the career density (here, electron density) in the oxide semiconductor layer14by a gate voltage applied to the TFT10. The gate electrode12is configured of a single layer film made of one of molybdenum (Mo), aluminum (Al), an aluminum alloy, and the like, or a laminated film made of two or more of them. It is to be noted that, examples of the aluminum alloy include an aluminum-neodymium alloy, for example.

The gate insulating film13is a single layer film made of one of SiO2, Si3N4, silicon nitride oxide (SiON), hafnium oxide (HfO), aluminum oxide (Al2O3), tantalum oxide (TaO), zirconium oxide (ZrO), and the like, and oxynitrides thereof. In addition, the gate insulating film13may be a laminated film made of two or more of them. With such a configuration, it is possible to improve the boundary surface characteristics between the gate insulating film13and the oxide semiconductor layer14, and prevent impurities contained in the substrate11from diffusing into the oxide semiconductor layer14. The film thickness of the gate insulating film13is 200 nm to 300 nm, for example.

The oxide semiconductor layer14contains an oxide of one or more of, for example, indium (In), gallium (Ga), zinc (Zn), tin (Sn), and Ti as a main component. The oxide semiconductor layer14forms a channel between the source/drain electrodes16A and16B by an application of a gate voltage. The film thickness of the oxide semiconductor layer14is 5 nm to 200 nm, for example.

The channel protect film15is formed on the oxide semiconductor layer14, and configured to prevent the channel from being damaged at the time of forming the source/drain electrodes16A and16B. The thickness of the channel protect film15is 20 to 300 nm, for example. In addition, as the material for the channel protect film15, any materials similar to that of the gate insulating film13may be used.

Each of the source/drain electrodes16A and16B is a single layer film made of one of, for example, metals such as Mo, Al, copper (Cu), and Ti, and their alloys, and conductive materials such as ITO and TiO, or a laminated film made of two or more of them. For example, it is desirable to use a three-layer film in which three layers made of Mo, Al, and Mo, respectively, and having the film thickness of 50 nm, 500 nm, and 50 nm, respectively, are laminated in this order, or metals or metal compounds such as ITO and titanium oxide, which are metal compounds containing oxygen and form a weak bond with oxygen. With such a configuration, the electrical characteristics of the oxide semiconductor may be stably maintained.

The planarizing film18is made of an inorganic insulation material such as Al2O3, TiO2, and nitrides thereof, for example. The thickness of the planarizing film18is, for example, 20 nm to 200 nm, preferably 50 nm or less. When the planarizing film18has the film density of 3.0 g/cm3or more, it offers high barrier performance against oxygen and hydrogen. The lower electrode21of the organic EL device20is formed on the planarizing film18.

Organic EL Device

The organic EL device20is a light emitting device of the top emission type configured to extract, from a side opposite to the substrate11(cathode electrode side), light which is generated when holes injected from the lower electrode21(anode electrode) and electrons injected from an upper electrode24(cathode electrode) are recombined in the light emitting layer23C. By using the organic EL device20of the top emission type, the aperture ratio of a light emitting section of the display is improved. It is to be noted that, the configuration of the organic EL device20of the present disclosure is not limited to this, and, for example, a light emitting device of a transmission type which extracts light from the substrate11side, that is, the bottom emission type, may also be adopted.

In the case where the display1is of the top emission type, for example, in the organic EL device20, the lower electrode21made of a high reflectivity material such as Al, Ti, and Cr is formed on the planarizing film18. On the other hand, in the case where the display1is of the transmission type, a transparent material such as ITO, IZO, and IGZO is used.

In this instance, a partition wall22which ensures an insulation property between the lower electrode21and the upper electrode24described later is provided on the lower electrode21and on the planarizing film18. The partition wall22is provided on a connection section between the gate/source electrodes16A and16B of the TFT10and the lower electrode21. The partition wall22is made of, for example, an organic material such as polyimide and novolac, specifically, a photosensitive resin such as a positive-type photosensitive polyimide, and by applying a plasma treatment, hydrophobicity may be added thereto.

As illustrated inFIG. 7, for example, an organic layer23has a configuration in which a hole injection layer23A, a hole transport layer23B, a light emitting layer23C, and an electron transport layer23D are laminated in this order from the lower electrode21side. The organic layer23is formed by a vacuum deposition method, a spin coating method, and the like, and detailed description thereof will be given later. The top face of the organic layer23is covered by the upper electrode24. While the film thickness, the configuration material, and the like of the layers configuring the organic layer23are not specifically limited, examples of the film thickness, the configuration material, and the like are illustrated below.

The hole injection layer23A is a buffer layer that enhances hole injection efficiency to the light emitting layer23C, and prevents leakage. The thickness of the hole injection layer23A is preferably 5 nm to 200 nm, more preferably 8 nm to 230 nm, for example. The configuration material of the hole injection layer23A may be appropriately selected based on the relationship with the material of electrodes and adjacent layers, and examples of the configuration material of the hole injection layer23A include polyaniline, polythiophene, polypyrrol, polyphenylenevinylene, polythienylenevinylene, polyquinoline, polyquinoxaline and derivatives thereof, a conductive polymer including a polymer containing an aromatic amine structure in the main chain or the side chain, metal phthalocyanine (such as copper phthalocyanine), and carbon. Specific examples of the conductive polymer include polydioxythiophene such as oligoaniline and poly (3,4-ethylenedioxythiophene) (PEDOT).

The hole transport layer23B enhances the hole transport efficiency to the light emitting layer23C. Although depending on the general configuration of the device, the thickness of the hole transport layer23B is preferably 5 nm to 200 nm, more preferably 8 nm to 230 nm, for example. As the material for configuring the hole transport layer23B, light emitting materials which are soluble in an organic solvent, such as polyvinyl carbazole, polyfluorene, polyaniline, polysilane and derivatives thereof, a polysiloxane derivative containing an aromatic amine structure in the main chain or the side chain, polythiophene and a derivative thereof, polypyrrol, and Alq3 may be used.

When an electric field is applied to the light emitting layer23C, recombination of electrons and holes is caused to generate light. Although depending on the general configuration of the device, the thickness of the light emitting layer23C is preferably 10 nm to 200 nm, more preferably 20 nm to 230 nm, for example. The light emitting layer23C may have either of a single-layer structure or a laminated structure. Specifically, it is possible to adopt not only the configuration in which light emitting layers23CR,23CG, and23CB corresponding to red, green, and blue, respectively are provided as single layers on the hole transport layer23B as is the case of the organic EL device20of the present embodiment, but also the configuration in which the blue light emitting layer is provided as a common layer of the organic EL devices20R,20G, and20B, for example. In this case, in the red organic EL device20R, the blue the light emitting layer23CB is laminated on the red light emitting layer23CR, whereas in the green organic EL device20G, the blue the light emitting layer23CB is laminated on the green light emitting layer23CG. In addition, although not shown here, the red light emitting layer23CR, the green light emitting layer23CG, and the blue light emitting layer23CB may be laminated, and by laminating these layers, a white organic EL device is formed.

As the material for configuring the light emitting layer23C, any materials may be used corresponding to respective emission colors, and such materials include a polyfluorene polymeric derivative, a (poly) paraphenylenevinylene derivative, a polyphenylene derivative, a polyvinyl carbazole derivative, a polythiophene derivative, a perylene pigment, a coumalin pigment, a rhodamine pigment, and any of the above-mentioned polymers doped with an organic EL material. As the dope material, rubrene, perylene, 9,10-diphenyanthracene, tetraphenylbutadiene, nile red, coumalin6, and the like may be used. It is to be noted that, as the material for configuring the light emitting layer23C, two or more of the above-mentioned materials may also be used in mixture. In addition, the above-mentioned high-molecular weight materials are not limitative, and a combination of low-molecular weight materials may also be used. Examples of the low-molecular weight materials include benzine, styrylamine, triphenylamine, porphyrin, triphenylene, azatriphenylene, tetracyanoquinodimethane, triazole, imidazole, oxadiazole, polyarylalkane, phenylenediamine, arylamine, oxazole, anthracene, fluorenone, hydrazone, stilbene and derivatives thereof, monomer or oligomer of heterocyclic conjugated system such as polysilane compounds, vinyl carbazole compounds, thiophene compounds, and aniline compounds.

In addition to the above-mentioned materials, as the material for configuring the light emitting layer23C, any of low-molecular fluorescence materials and organic light emitting materials such as phosphorescence pigments and metal complexes, which have high light emission efficiency, may be used as luminescent guest materials.

It is to be noted that, for example, the light emitting layer23C may be a hole-transportable light emitting layer serving also as the above-described hole transport layer23B, and in addition, may be an electron-transportable light emitting layer serving also as the electron transport layer23D described later.

The electron transport layer23D enhances the electron transport efficiency to the light emitting layer23C. Although depending on the general configuration of the device, the total film thickness of the electron transport layer23D is preferably 5 nm to 200 nm, more preferably 10 nm to 180 nm, for example.

It is preferable to use an organic material with high electron transporting capability as the material of the electron transport layer23D. By enhancing the transportation efficiency of electrons to the light emitting layer23C, variation in the luminescent color due to electric field strength may be suppressed. Specifically, it is preferable to use an arylpyridine derivative, a benzimidazole derivative, and the like. With such a configuration, high efficiency in supplying electrons may be maintained even with a low driving voltage. Examples of the material of the electron transport layer23D include alkali metal, alkaline-earth metal, rare-earth metal and their oxide, composite oxide, fluoride, carbonate, and the like.

For example, the upper electrode24is configured to have a thickness of about 10 nm, and made of a material with favorable light transmissivity and small work function. In addition, extraction of light may be secured also by forming a transparent conductive layer with use of oxide. In such a case, ZnO, ITO, IZnO, InSnZnO, and the like may be used. Further, while the upper electrode24may be a single layer, the upper electrode24in this instance has a structure in which a first layer, a second layer, and a third layer (all not shown) are laminated in this order from the lower electrode21side, for example.

The material of the first layer is preferably a material with small work function and favorable light transmissivity. Specifically, examples of the material of the first layer include alkaline-earth metals such as calcium (Ca) and barium (Ba), alkali metals such as lithium (Li) and cesium (Cs), indium (In), magnesium (Mg), and silver (Ag). The examples of the material further include alkali metal oxides, alkali metal fluorides, alkaline-earth metal oxides, and alkaline-earth fluorides such as Li2O, Cs2Co3, Cs2SO4, MgF, LiF, and CaF2.

The second layer is made of a material having light transmissivity and favorable electrical conductivity, and for example, configured of an MgAg electrode, a Ca electrode, or the like in the form of a thin film. The third layer is preferably made of transparent lanthanoid oxide in order to suppress degradation of the electrode. With such a configuration, the third layer may be used as a sealing electrode in which light may be extracted from the top face. In addition, in the case where the organic EL device20is of a bottom emission type, gold (Au), platinum (Pt), AuGe, or the like is used as the material for the third layer.

It is to be noted that, the first layer, the second layer, and the third layer are formed by a vacuum deposition method, a sputtering method, a plasma CVD method, or the like. In addition, in the case where the driving system of a display employing this light emitting device is the active matrix system, it is possible that the upper electrode24is formed on the substrate11in a form of a solid film to be used as an electrode common to the pixels, in a state where the upper electrode24is insulated from the lower electrode21by the partition wall22and the organic layer23covering a part of the lower electrode21.

In addition, the upper electrode24may be a mixed layer containing an organic light emitting material such as an aluminum quinoline complex, a styrylamine derivative, and a phthalocyanine derivative. In this case, the upper electrode24may separately include a layer made of MgAg having light transmissivity as the third layer (not shown). In addition, the upper electrode24is not limited to the above-mentioned laminate structure and, naturally, according to the structure of a device to be formed, any suitable combination and laminate structure may be adopted. For example, the above-mentioned configuration of the upper electrode24of the present embodiment is a laminate structure in which the functions of the electrode layers are separated from each other, that is, an inorganic layer (the first layer) for facilitating electron injection into the organic layer23, an inorganic layer (the second layer) ruling the electrode, and an inorganic layer (the third layer) for protecting the electrode are separated from each other. However, the inorganic layer for facilitating electron injection into the organic layer23may used also as the inorganic layer ruling the electrode, and these layers may be configured in a single layer structure.

Further, in the case where the organic EL device20has a cavity structure, the upper electrode24is preferably made of a semi-transmissive and semi-reflective material. With such a configuration, light which has been subjected to multiple interference between a light-reflecting surface on the lower electrode21side and a light-reflecting surface on the upper electrode24side is extracted from the upper electrode24side. In this case, it is assumed that the optical distance between the light-reflecting surface on the lower electrode21side and the light-reflecting surface on the upper electrode24side is defined according to the wavelength of light to be extracted, and that the film thicknesses of the layers are set so as to satisfy the optical distance. By actively using this cavity structure in such a light emitting device of the top emission type, improvement of light extraction efficiency to outside and control of light emission spectrum become possible.

The protect film25is configured to prevent water from infiltrating into the organic layer23, and made of a material with low transmissivity and low water permeability, with a thickness of, for example, 2 to 3 μm. The protect film25may be made of any of insulating materials and conductive materials. As the insulating materials, it is preferable to use an inorganic-amorphous insulating material such as amorphous silicon (α-Si), amorphous carbide silicon (α-SiC), amorphous silicon nitride (α-Si1-xNx), and amorphous carbon (α-C). Since such inorganic-amorphous insulating materials produce no grain, a favorable protect film with low water permeability may be obtained.

A sealing substrate27is provided on the upper electrode24side of the organic EL device20to seal the organic EL device20in conjunction with a bonding layer26. The sealing substrate27is made of a transparent material such as glass for light generated at the organic EL device20. The sealing substrate27is provided with, for example, a color filter27A and a black matrix27B. The sealing substrate27extracts the light generated at the organic EL device20and absorbs external light reflected by wirings between the organic EL devices20to improve contrast.

The color filter27A and the black matrix27B are provided on the sealing substrate27, for example. The color filter27A includes a red filter27AR, a green filter27AG, and a blue filter27AB, and is disposed on corresponding organic EL devices20R,20G, and20B, respectively. For example, each of the red filter27AR, the green filter27AG, and the blue filter27AB has a rectangular form, and they are formed with no gap therebetween. Each of the red filter27AR, the green filter27AG, and the blue filter27AB is made of a resin mixed with a pigment, and by selecting the pigment, it is possible to adjust the light transmittance rate thereof such that the light transmittance rate of desired wavelength range of red, green, or blue is set high, and the light transmittance rate of wavelength range of the rest is set low.

The black matrix27B is configured of, for example, a black resin film mixed with a black colorant and having an optical density of 1 or more, or a thin film filter utilizing interference of a thin film. If the black resin film is adopted, the black matrix27B may be formed cheaply and easily, which is preferable. The thin film filter is a filter in which, for example, one or more thin films each made of metal, metal nitride, or metal oxide is laminated to attenuate light by utilizing interference of the thin film. A specific example of the thin film filter includes a thin film filter in which Cr and chromium oxide (III) (Cr2O3) are alternately laminated.

In addition, the organic layer23may be formed by, in addition to the above-mentioned method, an application method such as the spin coating method, a dipping method, a doctor blade method, a discharge coating method, and a spray coating method, a printing method such as an ink jet method, an offset printing method, a relief printing method, an intaglio printing method, a screen printing method, a micro-gravure coating method, or the like. Depending on the property of organic layers and other members, dry process and wet process may be concurrently used.

1-3. Manufacturing Method

For example, the display1may be manufactured in the following manner.

FIG. 8shows a flow of a method of manufacturing the display1.FIG. 9AtoFIG. 11Cshow the method of manufacturing the display1in the order of the processes. First, as illustrated inFIG. 9A, in the pixel region2, the pixel driving circuit140including the TFT10is formed on the substrate11made of the above-described material, whereas in the frame region3(seeFIG. 1), an extraction electrode31(seeFIG. 1) is formed (step S101).

Next, the lower light shielding film5A is formed on the frame region3side of the TFT10, in other words, between the pixel region2and the terminal section4(step S102). First, as illustrated inFIG. 9A, for example, a SiO2film17having a thickness of 500 nm is formed on the substrate11on the frame region2side of the TFT10with use of an area mask41, by the sputtering method or the CVD (chemical vapor deposition) method, for example. Then, as illustrated inFIG. 9B, a photoresist film42is applied on the TFT10and the SiO2film17by, for example, the spin coating method, and thereafter, as illustrated inFIG. 9C, exposure is carried out with use of a photomask43and development is carried out with use of, for example, a paddle-type developing apparatus. Next, as illustrated inFIG. 9D, after the photoresist film42is processed, the exposed SiO2film is removed by, for example, wet etching or dry etching. Then, by removing the remaining the photoresist film42, columnar recessed portions17A (FIG. 10A) each having a size of φ=1000 nm, for example, are formed. Next, as illustrated inFIG. 10B, with use of an area mask44, for example, a TiO2film is formed between the pixel region2and the terminal section4(the frame region3) by, for example, the sputtering method or the CVD method, thereby forming irregularities on a bottom face of the lower light shielding film5A and the top face in contact with the planarizing film18.

Process for Forming Planarizing Film18

Next, as illustrated inFIG. 10(C), after the planarizing film18is formed on the TFT10and a part of the lower light shielding film5A, the organic EL device20and the upper light shielding film5B are formed (steps S103to S105). First, as an insulation material having positive-type photosensitivity, for example, polyimide is applied on the TFT10and a part of the lower light shielding film5A by, for example, the spin coating method, and exposure is carried out with use of an exposure apparatus. Then, development is carried out with use of, for example, the paddle-type developing apparatus to form a polyimide film having a predetermined form, and thereafter the polyimide film is heat-cured in, for example, a clean baking furnace to form the planarizing film18having a thickness of 2 μm and including a contact hole18A.

(Process for Forming Lower Electrode21)

Subsequently, for example, a conductive film made of, for example, an Al alloy is patterned on the planarizing film18, thereby the lower electrode21is formed for each of the red organic EL device20R, the green organic EL device20G, and the blue organic EL device20B. At this time, the lower electrode21is electrically connected to the drain electrode16B of the transistor10through the contact hole18A of the planarizing film18. Specifically, for example, a film made of an Al alloy is formed on the planarizing film18to have a film thickness of, for example, 200 nm, and then patterned by the photolithography method to form the lower electrode21.

Process for Forming Partition Wall22

Next, the partition wall22is formed on the lower electrode21and the planarizing film18. Specifically, for example, polyimide is applied on the lower electrode21and the planarizing film18by the spin coating method, and thereafter the polyimide is subjected to exposure and development and is then patterned to obtain a predetermined form, thereby forming the partition wall22.

Process for Forming Organic Layer23and Upper Electrode24

Next, the hole injection layer23A, the hole transport layer23B, the light emitting layer23C, the electron transport layer23D, and the upper electrode24which are made of the above-described materials are sequentially formed on the lower electrode21. Specifically, for example, after the substrate11is baked under N2atmosphere and processed by O2plasma, the organic layer23(the hole injection layer23A, the hole transport layer23B, the light emitting layer23C, and the electron transport layer23D) and the upper electrode24are sequentially formed by, for example, a vacuum deposition method. It is to be noted that, as the method for forming the organic layer23and the upper electrode24, for example, not only the vacuum deposition method, but also the spin coating method, the spray coating method, and slit printing may be adopted.

After the upper electrode24is formed, the protect film25is formed. Specifically, first, the protect film25is formed to the extent that it does not affect the foundation by a film formation method such as a deposition method and the CVD method in which the energy of film-forming particles is small. For example, in the case where the protect film25made of SiO2is to be formed, the film is formed to have a film thickness of, for example, 5 μm by the CVD method. At this time, in order to prevent luminance from decreasing due to degradation of the organic layer23, the film formation temperature is desirably set to room temperature, and in order to prevent peel-off of the protect film25, the film is desirably formed in a condition that the stress of the film is at a minimum level.

It is to be noted that, in the case where an auxiliary electrode (not shown) is formed in the same process as the lower electrode21, the organic layer23formed on the auxiliary electrode as a solid film may be removed by a method such as a laser ablation before the upper electrode24is formed. With such a configuration, the upper electrode24may be directly connected to the auxiliary electrode, while improving the connection thereof.

Process for Forming Upper Light Shielding Film5B

After the protect film25is formed, the upper light shielding film5B is formed on the side face and a part of the top face of the organic EL device20. Specifically, with use of an area mask45, a TiO2film having a thickness of, for example, 1,500 nm is formed in the frame region3by, for example, the sputtering or the CVD method. Then, as illustrated inFIG. 10D, a photoresist film46is applied on the protect film25and the TiO2film by the spin coating method. Next, as illustrated inFIG. 11A, exposure and development are carried out with use of a photomask47, and the photoresist film46is processed as illustrated inFIG. 11B. Next, as illustrated inFIG. 11C, the recessed portions5aare formed in the exposed TiO2film by wet etching or dry etching, and thereafter the remaining photoresist film46is removed to form the upper light shielding film5B. In this way, the light shielding film5which covers a region ranging from the side face of the TFT10to a part of the top face of the organic EL device20is completed.

After the upper light shielding film5B is formed, for example, the black matrix27B made of the above-described material is formed on the sealing substrate27made of the above-described material. Next, the material of the red filter27AR is applied on the sealing substrate27by the spin coating method or the like. Then, the material is patterned by the photolithographic technique and baked to form the red filter27AR. Next, as is the case of the red filter27AR, the green filter27AG is sequentially formed. Thereafter, the bonding layer26is formed on the protect film25, the light shielding film5, and the substrate11, and the sealing substrate27is bonded thereto through the bonding layer26.

Next, for example, an anisotropic conductive film32formed on the film is disposed and temporarily fixed on a COF (Chip On Film)33including a driver IC34and the like, and then alignment of the COF33and the extraction electrode31formed in the terminal section4on the substrate11are carried out. In this state, with the anisotropic conductive film32therebetween, the extraction electrode31and the COF33are heated while being pressed, and the extraction electrode31and a wiring of the COF33are electrically connected by conductive fine particles contained in the anisotropic conductive film32, and the COF33is formed in the terminal section4of the substrate11. Then, an ultraviolet curable resin is applied in such a manner as to seal the bonding layer26sealing the TFT10, the organic EL device20, a side face of the sealing substrate27provided on the bonding layer26, a part of the COF33, and the like. Further, an ultraviolet curable resin is applied on a rear face side of the substrate11in such a manner as to seal an end face of the extraction electrode31and an end face of the anisotropic conductive film32. Thereafter, UV light (wavelength 365 nm) of 1000 mJ/cm2is applied to cure the ultraviolet curable resin, and thus the damp-proof reinforcing materials35A and35B are formed. In this way, the display1illustrated inFIG. 1andFIG. 3AtoFIG. 5is completed.

In the display1, a scanning signal is supplied from the scan line driving circuit130to each pixel through the gate electrode of the writing transistor Tr2, and an image signal supplied from the signal line driving circuit120through the writing transistor Tr2is held in the capacitor Cs. Specifically, the driving transistor Tr1is turned on or off according to the signal held in the capacitor Cs, and with this, a driving current Id is injected into the red organic EL device20R, the green organic EL device20G, and the blue organic EL device20B, whereby holes and electrons are recombined to generate light. In the case of the bottom emission, the generated light is extracted after passing through the lower electrode21and the substrate11, whereas in the case of the top emission, the light is extracted after passing through the upper electrode24and the color filter27A provided on the sealing substrate27.

As mentioned before, narrower frame is desired in displays such as mobile displays. For this reason, the distance between a terminal section provided in a frame region and pixels provided in a pixel region is significantly shortened. In the mounting process of a TFT, a light emitting device, and the like, a damp-proof reinforcing material is provided to a terminal section in order to prevent peel-off of a COF after pressure bonding of the COF and prevent corrosion of the terminal section due to infiltration of water. Since this damp-proof reinforcing material is made of an ultraviolet curable resin as described above, UV light is applied to the material in the manufacturing process. There is an issue that, at the time of such a UV light irradiation, in a display with a narrowed frame, UV light applied to cure the material passes through the damp-proof reinforcing material, and then enters a semiconductor layer of a TFT disposed in a peripheral portion of a pixel region, leading to deterioration of the TFT characteristics.

FIG. 12shows the current and voltage characteristics of a TFT disposed in a peripheral portion of a pixel region102of a known display100before and after UV irradiation. As shown inFIG. 12, the threshold level voltage (Vth) after the irradiation is shifted to the negative (−) direction than before the UV irradiation. With this, there is an issue that the TFT characteristics of the peripheral portion of the pixel region102in the display100are deteriorated to form a luminance-dropping region102A in which the luminance of the peripheral portion of the pixel region102is reduced as illustrated inFIG. 13, causing uneven luminance.

In contrast, the display1of the present embodiment is provided with the light shielding film5made of TiO2(FIG. 3B) or the like which covers the side face of the TFT10, the side face of the organic EL device20, and a part of the top face of the organic EL device20.FIG. 14shows the current and voltage characteristics of the TFT10disposed in the peripheral portion of the pixel region2of the display1of the present embodiment before and after UV irradiation. As shown inFIG. 14, the threshold level voltage (Vth) is not shifted between before and after the UV irradiation. In this way, it is possible to suppress incidence of UV light which is obliquely applied to the TFT10at the time of formation of the damp-proof reinforcing materials35A and35B or the like on the TFT10, and it is thus possible to suppress deterioration of TFT characteristics.

As described above, in the display1and the method of manufacturing the same of the present embodiment, after the TFT10and the organic EL device20are formed, the light shielding film5covering the end face of the TFT10and the like is formed, and therefore, UV light incident on the TFT10from an oblique direction, especially from the frame region3side, may be effectively shielded. In this way, deterioration of TFT characteristics is suppressed, and thus generation of unevenness of luminance in the pixel region2is reduced. In other words, it is possible to provide a high-quality display which causes less unevenness of luminance.

In addition, since, in the present embodiment, the recessed portions5aare provided on the surface of the light shielding film5, it is possible to effectively shield UV light coming from an oblique direction. Further, since UV light is reflected by the irregularities of the light shielding film5to the frame region3side, that is, the damp-proof reinforcing materials35A and35B side, it is possible to cure the ultraviolet curable resin configuring the damp-proof reinforcing materials35A and35B with a reduced amount of irradiation of UV light.

2. APPLICATION EXAMPLE

For example, the above-mentioned display1may be installed in electronic units illustrated in the following application examples 1 to 5.

Module and Application Examples

Hereinafter, application examples of the display1described in the above-mentioned embodiment will be described. The display1of the above-mentioned embodiment may be applied to displays of electronic units in various fields which display an externally inputted video signal or an internally generated video signal as an image or a video. Typical examples of such an electronic unit include televisions, digital cameras, notebook personal computers, mobile terminal units such as mobile phones, and video camcorders.

Module

The display1of the above described embodiment and so forth is incorporated in various kinds of electronic units of application examples 1 to 5 described below and the like, as a module shown inFIG. 15, for example. This module includes, for example, a region210which is provided on one side of a substrate11and exposed from a protect film and a sealing substrate30. Wirings of the signal line driving circuit120and the scan line driving circuit130are extended to configure an external connection terminal (not shown) in the exposed region210. The external connection terminal may be provided with a flexible printed circuit (FPC)220for inputting and outputting signals.

Application Example 1

FIG. 16shows an external appearance of a television to which the display1of the above-mentioned embodiment is applied. The television is provided with, for example, an image-display screen section300including a front panel310and a filter glass320, and the image display screen section300is configured of the display1according to the above-mentioned embodiment.

Application Example 2

FIGS. 17A and 17Bshow external appearances of a digital camera to which the display1of the above-mentioned embodiment is applied. This digital camera includes, for example, a light emitting section410for generating flash light, a display section420, a menu switch430, and a shutter button440, and the display section420is configured of the display1according to the above-mentioned embodiment.

Application Example 3

FIG. 18shows an external appearance of a notebook personal computer to which the display1of the above-mentioned embodiment is applied. This notebook personal computer includes, for example, a main body510, a keyboard520for inputting letters and the like, and a display section530for displaying an image, and the display section530is configured of the display1according to the above-mentioned embodiment.

Application Example 4

FIG. 19shows an external appearance of a video camcorder to which the display1of the above-mentioned embodiment is applied. This video camcorder includes, for example, a main body section610, a lens620which is adapted to take an image of a subject and provided on the front side of the main body section610, a start/stop switch630for capturing an image, and a display section640, and the display section640is configured of the display1according to the above-mentioned embodiment.

Application Example 5

FIGS. 20A to 20Geach show an external appearance of a mobile phone to which the display1of the above-mentioned embodiment is applied. This mobile phone includes, for example, an upper housing710, a lower housing720, a connecting section (hinge section)730connecting the upper housing710and the lower housing720, a display740, a sub-display750, a picture light760, and a camera770. The display740or the sub-display750is configured of the display1according to the above-mentioned embodiment.

Hereinabove, while the present disclosure has been described with reference to the embodiment, the present disclosure is not limited to the above-mentioned embodiment, and various modifications may be made. For example, in the above-mentioned embodiment, the red light emitting layer, the green light emitting layer, and the blue light emitting layer corresponding to respective pixels are provided as the light emitting layer23C, but this is not limitative, and the light emitting layers may be laminated to configure a white organic EL device. In such a case, the red light emitting layer and the green light emitting layer may be replaced by a yellow light emitting layer.

In addition, the material and thickness of each layer, the method and condition for film formation, and the like described in the above-mentioned embodiment are not limitative, and other materials and thicknesses, other methods and conditions for film formation may be adopted. For example, while an oxide semiconductor is used as the channel of the TFT10in the above-mentioned embodiment, this is not limitative, and silicon or an organic semiconductor may also be used.

Further, while the configuration of the organic EL devices20R,20G, and20B, and the like is specifically described in the above-mentioned embodiment, all of the layers need not necessarily be included, and other layers may be further included. For example, it is possible to form the light emitting layer23C directly on the hole injection layer23A without forming the hole transport layer23B, and it is also possible to provide an electron injection layer on the electron transport layer23D.

Still further, while the active-matrix type display is described in the above-mentioned embodiment, the present disclosure may also be applied to a passive matrix type display. Still further, the configuration of the pixel driving circuit for active matrix drive is not limited to the configuration described in the above-mentioned embodiment, and a capacitive element and a transistor may be added as necessary. In such a case, according to the change of the pixel driving circuit, a necessary driving circuit may be added, in addition to the above-described signal line driving circuit120and the scan line driving circuit130.

It is to be noted that the present technology may be configured as follows.

In an embodiment, a display includes a resin, a transistor, and a light shielding material positioned between the resin and the transistor, wherein the light shielding material is configured to suppress an incidence of light on the transistor.

In the display according to an embodiment, the transistor is a thin film transistor.

In the display according to an embodiment, the transistor includes an oxide semiconductor.

In the display according to an embodiment, the display further includes a light emitting device. The light emitting device and the transistor are in a pixel region, and the light shielding material is at a periphery of the pixel region.

In the display according to an embodiment, the light shielding material covers a side of the transistor facing a periphery of the display and covers a side of the light emitting device facing the periphery of the display.

In the display according to an embodiment, the display further includes a light emitting device, wherein the light shielding material covers an upper side of the light emitting device.

In the display according to an embodiment, the display further includes a light emitting device, and an insulating layer between the light emitting device and the transistor. The light shielding material is provided on a side of the insulating layer.

In the display according to an embodiment, the display further includes a light emitting device, and a protective layer provided above the light emitting device. The light shielding material is provided on at least one of an upper side and a peripheral side of the protective layer.

In the display according to an embodiment, the light shielding material includes a plurality of recessed portions.

In the display according to an embodiment, irregularities are provided on a surface of the light shielding material.

In the display according to an embodiment, the light shielding material is at least one of titanium oxide, zinc oxide, a metal and silicide thereof, and a material with a barrier metal, wherein the metal and barrier metal can include any suitable material or combination of materials, such as Al, Cu, W, Au, Ag, Ta, Co, and Ti for the metal; and such as Ti, Ta, TiN, and TaN for the barrier metal.

In the display according to an embodiment, the display further includes a light emitting device, and a contact layer in contact with the light emitting device and the transistor. The light shielding material is at a position equal to or higher than where the contact layer contacts the transistor.

In the display according to an embodiment, the light shielding material is provided at a position lower than a height of the transistor.

In the display according to an embodiment, the display further includes a Chip On Film, wherein the light shielding material is provided between the Chip on Film and the transistor.

In the display according to an embodiment, the display further includes an insulting layer and a light emitting device. The light shielding material is provided on a side of the insulating layer and around the light emitting device.

In the display according to an embodiment, the display further includes a light emitting device, wherein the shielding material is provided at a height of the light emitting device.

In an embodiment, a method of manufacturing a display includes forming a resin, a transistor, and a light shielding material. The light shielding material is positioned between the resin and the transistor, and the light shielding material is configured to suppress an incidence of light on the thin film transistor.

In the method according to an embodiment, the transistor is a thin film transistor.

In the method according to an embodiment, the transistor includes an oxide semiconductor.

In the method according to an embodiment, the method further including forming a light emitting device. The light emitting device and the transistor are formed in a pixel region, and the light shielding material is formed at a periphery of the pixel region.

In the method according to an embodiment, the light shielding material is positioned to cover a side of the transistor facing a periphery of the display and to cover a side of the light emitting device facing the periphery of the display.

In the method according to an embodiment, the method further includes forming a light emitting device, wherein the light shielding material is positioned to cover an upper side of the light emitting device.

In the method according to an embodiment, the method further includes forming an insulating layer and a light emitting device. The insulating layer is positioned between the light emitting device and the transistor, and the light shielding material is positioned on a side of the insulating layer.

In the method according to an embodiment, the method further includes forming a protective layer and a light emitting device. The protective layer is positioned above the light emitting device, and the light shielding material is positioned on at least one of an upper side and a peripheral side of the protective layer.

In the method according to an embodiment, the method further includes forming a plurality of recessed portions in the light shielding material.

In the method according to an embodiment, irregularities are provided on a surface of the light shielding material.

In the method according to an embodiment, the light shielding material is at least one of titanium oxide, zinc oxide, a metal and silicide thereof, and a material with a barrier metal, wherein the metal and barrier metal can include any suitable material or combination of materials, such as Al, Cu, W, Au, Ag, Ta, Co, and Ti for the metal; and such as Ti, Ta, TiN, and TaN for the barrier metal.

In the method according to an embodiment, the method further includes forming a light emitting device and forming a contact layer in contact with the light emitting device and the transistor. The light shielding material is at a position equal to or higher than where the contact layer contacts the transistor.

In the method according to an embodiment, the light shielding material is provided at a position lower than a height of the transistor.

In the method according to an embodiment, the method further includes forming a Chip On Film, wherein the light shielding material is positioned between the Chip on Film and the transistor.

In the method according to an embodiment, the method further includes forming an insulting layer and a light emitting device, wherein the light shielding material is provided on a side of the insulating layer and around the light emitting device.

In the method according to an embodiment, the method further includes forming a light emitting device, wherein the shielding material is provided at a height of the light emitting device.

In an embodiment, an electronic apparatus includes a resin, a transistor, and a light shielding material positioned between the resin and the thin film transistor. The light shielding material is configured to suppress an incidence of light on the transistor.

In the electronic apparatus according to an embodiment, the electronic apparatus further includes a display.

In the electronic apparatus according to an embodiment, the display is an OLED, electric paper, or a liquid crystal display.

In the electronic apparatus according to an embodiment, the transistor is a thin film transistor.

In the electronic apparatus according to an embodiment, the transistor includes an oxide semiconductor.

In the electronic apparatus according to an embodiment, the electronic apparatus further includes a light emitting device. The light emitting device and the transistor are in a pixel region, and the light shielding material is at a periphery of the pixel region.

In the electronic apparatus according to an embodiment, the light shielding material covers a side of the transistor facing a periphery of a display and covers a side of the light emitting device facing the periphery of the display.

In the electronic apparatus according to an embodiment, the electronic apparatus further includes a light emitting device, wherein the light shielding material covers an upper side of the light emitting device.

In the electronic apparatus according to an embodiment, the electronic apparatus further includes a light emitting device, and an insulating layer between the light emitting device and the transistor. The light shielding material is provided on a side of the insulating layer.

In the electronic apparatus according to an embodiment, the electronic apparatus further includes a light emitting device and a protective layer provided above the light emitting device. The light shielding material is provided on at least one of an upper side and a peripheral side of the protective layer.

In the electronic apparatus according to an embodiment, the light shielding material includes a plurality of recessed portions.

In the electronic apparatus according to an embodiment, irregularities are provided on a surface of the light shielding material.

In the electronic apparatus according to an embodiment, the light shielding material is at least one of titanium oxide, zinc oxide, a metal and silicide thereof, and a material with a barrier metal, wherein the metal and barrier metal can include any suitable material or combination of materials, such as Al, Cu, W, Au, Ag, Ta, Co, and Ti for the metal; and such as Ti, Ta, TiN, and TaN for the barrier metal.

In the electronic apparatus according to an embodiment, the electronic apparatus further includes a light emitting device and a contact layer in contact with the light emitting device and the transistor. The light shielding material is at a position equal to or higher than where the contact layer contacts the transistor.

In the electronic apparatus according to an embodiment, the light shielding material is provided at a position lower than a height of the transistor.

In the electronic apparatus according to an embodiment, the electronic apparatus further includes a Chip On Film. The light shielding material is provided between the Chip on Film and the transistor.

In the electronic apparatus according to an embodiment, the electronic apparatus further includes an insulting layer and a light emitting device. The light shielding material is provided on a side of the insulating layer and around the light emitting device.

In the electronic apparatus according to an embodiment, the electronic apparatus further includes a light emitting device, wherein the shielding material is provided at a height of the light emitting device.

The present disclosure contains subject matter related to that disclosed in Japanese Priority Patent Application JP 2011-180778 filed in the Japan Patent Office on Aug. 22, 2011, the entire content of which is hereby incorporated by reference.