JP4783858B2 - Active drive organic EL display - Google Patents

Description

The present invention relates to an active drive organic EL display device (hereinafter sometimes referred to as an organic EL display device) and a method for manufacturing the same. More specifically, the present invention relates to an active drive organic EL display device including a thin film transistor for light emission control (hereinafter sometimes referred to as a TFT), and a manufacturing method thereof.
Note that “EL” described in the claims of the present application is an abbreviation of “electroluminescence”.

2. Description of the Related Art Conventionally, there has been known a simple drive type active drive type organic EL display device in which an organic EL element configured by sandwiching an organic light emitting layer between an anode layer and a cathode layer is driven by an electrode structure arranged in an XY matrix. For example, it is disclosed in Patent Document 1 and Patent Document 2.
In such a simple drive type organic EL display device, so-called line-sequential driving is performed, so that when there are several hundred scanning lines, the required instantaneous luminance is several hundred times the observation luminance, and as a result, The following problems have occurred.
(1) Since the drive voltage is as high as 2 to 3 times or more that of a DC steady voltage, the light emission efficiency is reduced and the power consumption is increased.
(2) Since the amount of current that flows instantaneously is several hundred times, the organic light emitting layer tends to deteriorate.
(3) Similar to (2), since the amount of current is very large, the voltage drop in the electrode wiring increases.

Therefore, in order to solve the problems of the simple drive type organic EL display device, various active drive type organic EL display devices having a thin film transistor (TFT) and driving an organic EL element have been proposed. .
FIG. 18 shows a structure example of such an active drive type organic EL display device. Compared with a simple drive type organic EL display device, the drive voltage is significantly lowered, the light emission efficiency is improved, and the consumption is improved. The effect that electric power can be reduced can be obtained.
However, even in such an active drive type organic EL display device 204, there is a problem that connection reliability, moisture resistance, and the like are poor even when an electrical connection is made between the organic EL element 202 and the TFT 200.
For example, as an electrical connection member, it has been proposed to electrically connect using a metal thin film such as aluminum or chromium. However, the transparent electrode 209 of the organic EL element 202 and the electrical connection member can be easily peeled off. Alternatively, there are problems such as corrosion of the electrical connection member due to surrounding moisture, and further generation of migration and leakage current. In FIG. 18, the transparent electrode 209 and the electrical connection member are integrally displayed.

In Patent Document 3 and Patent Document 4, as shown in FIG. 19, an organic EL element 126 and a TFT 137 are provided, and an electric material made of a composite material for electrically connecting these members 126 and 137 is provided. An active drive organic EL display device 100 having a connection member 128 is disclosed.
That is, as the electrical connection member 128 made of a composite material, an electrical connection member 128 composed of a metal thin film made of a low-resistance material of the lower layer 150 and a titanium nitride thin film excellent in corrosion resistance of the upper layer 151 is disclosed. A barrier metal made of / titanium nitride, tungsten / titanium nitride, molybdenum / titanium nitride, or the like is used.

JP-A-2-37385 JP-A-3-2333891 JP-A-8-330600 Japanese Patent Laid-Open No. 10-254383

However, the electrical connection member 128 disclosed in Patent Document 3 and Patent Document 4 must be formed by accurately superimposing the metal thin film of the lower layer 150 and the titanium nitride thin film of the upper layer 151, and the etching accuracy is high. Manufacturing problems such as a lack of manufacturing processes and an increase in the number of manufacturing processes were observed.
Further, even when a barrier metal made of a metal thin film and a titanium nitride thin film is used as the electrical connection member 128, the connection reliability of the barrier metal to the transparent electrode 122 of the organic EL element 126 is still poor. It was.

Thus, the inventors of the present invention diligently studied the above problem, and found that the above-described problem can be solved by configuring the electrical connection member between the organic EL element and the TFT from a specific oxide. It was.
That is, according to the present invention, the electrical connection member between the organic EL element and the TFT is made of an amorphous conductive oxide, so that the manufacture is easy and the connection reliability with the transparent electrode of the organic EL element is improved. It is an object of the present invention to provide an excellent active drive organic EL display device and a manufacturing method capable of efficiently obtaining such an active drive organic EL display device.

According to the present invention, an active drive organic EL display device comprising an organic EL element configured by sandwiching an organic light emitting medium between an upper electrode and a lower electrode, and a TFT for controlling light emission of the organic EL element. Thus, there is provided an active drive organic EL display device in which an electrical connection member made of an amorphous conductive oxide is provided between the organic EL element and the thin film transistor.
By configuring the organic EL display device in this way, it is possible to make good connection reliability between the organic EL element and the TFT by taking advantage of the good moisture resistance and heat resistance characteristics of the amorphous conductive oxide. Can be obtained.
In addition, since the amorphous conductive oxide has excellent etching characteristics and can be etched even using an organic acid or the like, a high-definition electrical connection member can be easily provided.

In configuring the active drive type organic EL display device of the present invention, one of the upper electrode and the lower electrode is made of indium zinc oxide (IZO) or indium tin oxide (ITO). It is preferable.
With this configuration, the electrical connectivity between the upper electrode or the lower electrode and an electrical connection member made of an amorphous conductive oxide, for example, indium zinc oxide (IZO), is further improved.

Further, in configuring the active drive type organic EL display device of the present invention, it is preferable that the specific resistance of the amorphous conductive oxide is 1 × 10 ⁻³ Ω · cm or less.
If comprised in this way, the kind of component material which can be used for an electrical connection member will not be restrict | limited too much, and resistance loss will also decrease.

Further, in configuring the active drive type organic EL display device of the present invention, it is preferable that the amorphous conductive oxide contains a dopant.
By comprising in this way, adjustment of the electrical conductivity of an electrical connection member becomes easier.

In constructing the active drive type organic EL display device of the present invention, any one of the upper electrode and the lower electrode or the cathode layer and the electrical connection member are made of an amorphous conductive oxide such as indium zinc oxide. It is preferable that they are integrally formed of (IZO).
If comprised in this way, the more excellent electrical connection property will be obtained, and also formation will become easy, and the number of electrical connection locations can be reduced.

In configuring the active drive organic EL display device of the present invention, it is preferable that a metallized portion is provided on at least a part of the electrical connection member.
If comprised in this way, the connection resistance in each electrical connection member in an organic EL element and TFT can be made lower resistance.

In configuring the active drive type organic EL display device of the present invention, it is preferable to set the thickness of the electrical connection member to a value within the range of 0.01 to 100 μm.
If comprised in this way, while being able to reduce the resistance loss in an electrical connection member, predetermined durability and uniform film-forming property can be obtained.

In configuring the active drive organic EL display device of the present invention, it is preferable to have a fluorescent medium and a color filter, or one of the color conversion media on the EL light emitting side of the organic EL element.
With such a configuration, it is possible to perform full-color display by converting the color of emitted light extracted outside using a color filter or a fluorescent medium.

In configuring the active drive type organic EL display device of the present invention, it is preferable that the color conversion medium is embedded in the support substrate.
With this configuration, not only the color conversion medium can be easily fixed, but also the step difference between the TFT connection portion and the connection portion with the organic EL element can be reduced, so that more excellent electrical connectivity is obtained. be able to.

In another aspect of the present invention, an organic EL element configured by sandwiching an organic light emitting medium between an upper electrode and a lower electrode, a TFT for controlling light emission of the organic EL element, the organic EL element, and An electrical connection member for electrical connection between TFTs, and a method of manufacturing an active drive organic EL display device comprising:
Forming a TFT;
Forming an electrical connection member made of an amorphous conductive oxide;
Forming an organic EL element;
It is characterized by including.
By carrying out like this, in the organic EL display device, it is possible to form an electrical connection member having good connection reliability and excellent accuracy.

In carrying out the manufacturing method of the active drive type organic EL display device of the present invention, it is preferable that the lower electrode and the electrical connection member are integrally formed using an amorphous conductive oxide.
When implemented in this manner, the electrical connection member can be formed easily and in a short time, and the number of electrical connection locations can be reduced.

In carrying out the method for manufacturing an active drive organic EL display device of the present invention, it is preferable that the electrical connection member is formed by a sputtering method.
By carrying out in this way, an electrical connection member made of an amorphous conductive oxide can be easily and accurately formed.

In carrying out the method for producing an active drive organic EL display device of the present invention, it is preferable that the electrical connection member is formed by a sol-gel method.
By carrying out in this way, the electrical connection member made of an amorphous conductive oxide can be easily formed by coating and heating at a relatively low temperature.

In carrying out the manufacturing method of the active drive type organic EL display device of the present invention, the electrical connection member is preferably formed by etching with an organic acid.
By carrying out in this way, even when Al or Cr is used for a part of the TFT or organic EL element, only the amorphous conductive oxide is etched without damaging the Al or Cr. be able to.

Moreover, when implementing the manufacturing method of the active drive type organic EL display device of this invention, it is preferable to include the process of metallizing at least one part of an electrical-connection member.
By carrying out in this way, it is possible to efficiently obtain an active drive organic EL display device having further reduced resistance at an electrical connection location and excellent connection reliability.

According to the active drive type organic EL display device of the present invention, the electrical connecting member is made of an amorphous conductive oxide, so that the space between the lower electrode of the organic EL element and the drain region of the TFT can be easily achieved. Electrical connection with high connection reliability has become possible.
Moreover, according to the manufacturing method of the active drive type organic EL display device of the present invention, such an active drive type organic EL display device can be obtained efficiently.

1 is a cross-sectional view of an active drive organic EL display device according to a first embodiment. It is a figure which shows the structural example of a lower electrode. It is a figure provided in order to demonstrate the structure of a thin-film transistor (TFT). It is a circuit diagram which shows the electrical switch connection structure containing TFT. It is a plane perspective view which shows the electrical switch connection structure containing TFT. It is a figure which shows an example of the X-ray-diffraction chart of indium zinc oxide (IZO). It is a figure which shows the modification (via hole) of an electrical connection member. It is a figure which shows the modification (metallization) of an electrical connection member. It is sectional drawing of the active drive type organic electroluminescent display apparatus in 2nd Embodiment. It is a figure provided in order to demonstrate a skew member. It is sectional drawing of the active drive type organic electroluminescent display apparatus in 3rd Embodiment. It is a figure provided in order to demonstrate the position adjustment layer of TFT. It is a figure which shows a part of formation process of TFT. It is a manufacturing process figure of the active drive type organic electroluminescence display in 4th Embodiment (the 1). It is a manufacturing process figure of the active drive type organic electroluminescence display in 4th Embodiment (the 2). It is a figure which shows the modification (integral molding) of an electrical connection member. It is a figure which shows the etch process of an electrical connection member. It is sectional drawing of the conventional active drive type organic electroluminescence display (the 1). It is sectional drawing of the conventional active drive type organic electroluminescence display (the 2).

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The drawings to be referred to merely schematically show the size, shape, and arrangement relationship of each component to the extent that the present invention can be understood. Therefore, the present invention is not limited to the illustrated example. In the drawings, hatching indicating a cross section may be omitted.

[First Embodiment]
As shown in FIG. 1, the organic EL display device of the first embodiment is
A support substrate 10;
A TFT 14 embedded in an electrical insulating film 12 (also serving as a gate insulating film) on the support substrate 10;
An interlayer insulating film (planarizing film) 13 formed on the TFT 14;
An organic EL element 26 formed on the interlayer insulating film 13;
A color conversion medium 60 provided on the light emitting surface side of the organic EL element 26;
Furthermore, an electrical connection member 28 made of an amorphous conductive oxide for electrically connecting the TFT 14 and the organic EL element 26;
It is the organic EL display apparatus 30 provided with.
Hereinafter, in the first embodiment, components and the like will be described with reference to FIG. 1 and the like as appropriate.

1. Support Substrate A support substrate (hereinafter sometimes referred to as a substrate) in an organic EL display device is a member for supporting an organic EL element, a TFT, and the like, and therefore has excellent mechanical strength and dimensional stability. Preferably it is.
Specifically, as such a substrate, a glass plate, a metal plate, a ceramic plate, or a plastic plate (polycarbonate resin, acrylic resin, vinyl chloride resin, polyethylene terephthalate resin, polyimide resin, polyester resin, epoxy resin, phenol resin) , Silicon resin, fluororesin, etc.).

In addition, the substrate made of these materials is further subjected to moisture-proofing treatment or hydrophobic treatment by forming an inorganic film or applying a fluororesin in order to avoid moisture intrusion into the organic EL display device. Preferably there is.
In particular, in order to avoid intrusion of moisture into the organic light emitting medium, it is preferable to reduce the moisture content and gas permeability coefficient in the substrate. Specifically, the moisture content of the support substrate is 0.0001% by weight or less and the gas permeability coefficient is 1 × 10 ⁻¹³ cc · cm / cm ² · sec. It is preferable that the value is not more than cmHg.
In the first embodiment, since EL emission is extracted from the opposite side of the substrate, that is, the upper electrode side, the substrate does not necessarily have transparency.

2. Organic EL Element (1) Organic Light-Emitting Medium An organic light-emitting medium can be defined as a medium including an organic light-emitting layer capable of EL emission by recombination of electrons and holes. Such an organic light-emitting medium can be configured, for example, by laminating the following layers on the lower electrode.
[1] Organic light emitting layer
[2] Hole injection layer / organic light emitting layer
[3] Organic light emitting layer / electron injection layer
[4] Hole injection layer / organic light emitting layer / electron injection layer
[5] Organic semiconductor layer / organic light emitting layer
[6] Organic semiconductor layer / electron barrier layer / organic light emitting layer
[7] Hole injection layer / organic light emitting layer / adhesion improving layer Among these, the configuration of [4] is usually preferably used because it provides higher emission luminance and is excellent in durability.

a. Constituent materials Examples of light emitting materials in organic light emitting media include p-quarterphenyl derivatives, p-quinckphenyl derivatives, benzothiazole compounds, benzimidazole compounds, benzoxazole compounds, metal chelated oxinoid compounds, oxadiazoles Compounds, styrylbenzene compounds, distyrylpyrazine derivatives, butadiene compounds, naphthalimide compounds, perylene derivatives, aldazine derivatives, pyrazirine derivatives, cyclopentadiene derivatives, pyrrolopyrrole derivatives, styrylamine derivatives, coumarin compounds, aromatic dimethylidin compounds Examples thereof include a compound, a metal complex having an 8-quinolinol derivative as a ligand, a single type of polyphenyl compound, or a combination of two or more types.

Among these organic light-emitting materials, 4,4′-bis (2,2-di-t-butylphenylvinyl) biphenyl (abbreviated as DTBPBBi) or 4,4 as an aromatic dimethylidin-based compound. '-Bis (2,2-diphenylvinyl) biphenyl (abbreviated as DPVBi) and derivatives thereof are more preferable.
Furthermore, an organic light-emitting material having a distyrylarylene skeleton or the like is used as a host material, and the host material is doped with a strong fluorescent dye from blue to red as a dopant, for example, a coumarin-based material, or a fluorescent dye similar to the host It is also suitable to use together. More specifically, it is preferable to use the above-described DPVBi or the like as the host material and N, N-diphenylaminobenzene (abbreviated as DPAVB) or the like as the dopant.

b. Thickness The thickness of the organic light-emitting medium is not particularly limited, but for example, the thickness is preferably set to a value in the range of 5 nm to 5 μm.
The reason for this is that when the thickness of the organic light emitting medium is less than 5 nm, the light emission luminance and durability may be reduced. On the other hand, when the thickness of the organic light emitting medium exceeds 5 μm, the value of the applied voltage increases. Because there is.
Therefore, the thickness of the organic light emitting medium is more preferably set to a value within the range of 10 nm to 3 μm, and further preferably set to a value within the range of 20 nm to 1 μm.

(2) Electrode Hereinafter, the upper electrode and the lower electrode will be described. However, the upper electrode and the lower electrode may correspond to the anode layer and the cathode layer, or may correspond to the cathode layer and the anode layer, depending on the configuration of the organic EL element.

a. Lower electrode The lower electrode corresponds to an anode layer or a cathode layer depending on the configuration of the organic EL display device. For example, when it corresponds to the anode layer, a metal having a large work function (for example, 4.0 eV or more), Preference is given to using alloys, electrically conductive compounds or mixtures thereof. Specifically, electrode materials such as indium tin oxide (ITO), indium zinc oxide (IZO), copper iodide (CuI), tin oxide (SnO ₂ ), zinc oxide (ZnO), gold, platinum, and palladium are used. It is preferable to use them alone or in combination of two or more of these electrode materials.
By using these electrode materials, vacuum deposition, sputtering, ion plating, electron beam deposition, CVD (Chemical Vapor Deposition), MOCVD (Metal Oxide Chemical Vapor Deposition), plasma CVD (Plasma) A lower electrode having a uniform thickness can be formed using a method capable of forming a film in a dry state such as Enhanced Chemical Vapor Deposition.
In addition, when taking out EL light emission from the lower electrode side, it is necessary to make the said lower electrode into a transparent electrode. In that case, for example, it is preferable to use a transparent conductive material such as ITO, IZO, CuIn, SnO ₂ , and ZnO, and to set the transmittance of EL light emission to a value of 70% or more.

Also, the thickness of the lower electrode is not particularly limited, but for example, it is preferably a value in the range of 10 to 1000 nm, and more preferably a value in the range of 10 to 200 nm.
This is because, by setting the film thickness of the lower electrode to a value within such a range, for example, there is conductivity and an EL light emission transmittance of 70% or more can be obtained.

b. Upper electrode On the other hand, the upper electrode also corresponds to the anode layer or the cathode layer corresponding to the configuration of the organic EL display device. For example, in the case of the cathode layer, the work function is higher than that of the anode layer. It is preferred to use small (eg, less than 4.0 eV) metals, alloys, electrically conductive compounds or mixtures or inclusions thereof.
Specifically, sodium, sodium-potassium alloy, cesium, magnesium, lithium, magnesium-silver alloy, aluminum, aluminum oxide, aluminum-lithium alloy, indium, rare earth metal, a mixture of these metals and organic light emitting medium materials, It is preferable to use an electrode material composed of a mixture of these metals and an electron injection layer material alone, or to use a combination of two or more of these electrode materials.

Further, the film thickness of the upper electrode is not particularly limited, but specifically, it is preferably a value in the range of 10 to 1,000 nm, and a value in the range of 10 to 200 nm. More preferred.
The reason for this is that by setting the film thickness of the upper electrode within such a range, there is conductivity and an EL emission transmittance of 10% or more can be obtained, more preferably 70% or more. This is because the transmittance of EL emission can be obtained.

c. Structure 1
Further, as shown in FIGS. 2A and 2B, the structure of the lower electrode 22 may be such that the tip 29 is branched, a circular hole is formed, or FIGS. 2C and 2D are used. As shown in FIG. 4, it is preferable to provide a vertical recess or a concavo-convex structure at the tip portion 29.
If comprised in this way, while the adhesiveness of the electrical connection member 28 with respect to a lower electrode can be improved, the contact area of an electrical connection member becomes large, and a connection resistance can be reduced effectively.
2A to 2D, the electrical connection member 28 is indicated by a dotted line so that the connection position of the electrical connection member can be understood. In addition, this connection structure may be a reverse structure in this case, that is, in FIG. 2, the tip of the electrical connection member may be a solid line portion and the lower electrode may be a portion indicated by a dotted line.
In addition, although not shown, in order to further reduce the connection resistance between the lower electrode and the electrical connection member, it is also preferable to provide a metallized portion or a bump on a part of the lower electrode.

d. Structure 2
On the other hand, as shown in FIG. 1, the upper electrode 20 is preferably composed of a main electrode 16 made of a transparent conductive material and an auxiliary electrode 18 made of a low resistance material.
With this configuration, even when EL emission is taken out from the upper electrode 20 side, the surface resistance of the upper electrode 20 can be reduced by the auxiliary electrode 18. Further, since EL emission can be extracted from the upper electrode 20 side, the aperture ratio can be increased even when a TFT is provided.
Furthermore, since the arrangement of the TFT is facilitated by such a configuration, the current density flowing in the organic light emitting medium can be reduced, and as a result, the life of the organic light emitting medium can be significantly extended.

(3) Interlayer Insulating Film The interlayer insulating film in the organic EL display device of the first embodiment is present in the vicinity of or around the organic EL element and the TFT, and mainly flattens the unevenness of the fluorescent medium or the color filter. It is used as a flattened base when forming the lower electrode of the organic EL element. In addition, the interlayer insulating film is used for electrical insulation to form a high-definition wiring material, electrical insulation between the lower electrode and the upper electrode of the organic EL element (short circuit prevention), electrical insulation and mechanical protection of the TFT, Is used for the purpose of electrical insulation between the TFT and the organic EL element.
Therefore, in the first embodiment, the interlayer insulating film may be referred to as a planarizing film, an electrical insulating film, a partition wall, a spacer, a skew member, or the like as necessary. Is also included.

a. Constituent materials Constituent materials used for interlayer insulating films are usually acrylic resin, polycarbonate resin, polyimide resin, fluorinated polyimide resin, benzoguanamine resin, melamine resin, cyclic polyolefin, novolac resin, polyvinyl cinnamate, cyclized rubber, Examples thereof include polyvinyl chloride resin, polystyrene, phenol resin, alkyd resin, epoxy resin, polyurethane resin, polyester resin, maleic acid resin, polyamide resin and the like.

When the interlayer insulating film is composed of an inorganic oxide, preferred inorganic oxides include silicon oxide (SiO ₂ or SiO _x ), aluminum oxide (Al ₂ O ₃ or AlO _x ), titanium oxide (TiO ₂ ), and yttrium oxide. (Y ₂ O ₃ or YO _x ), germanium oxide (GeO ₂ or GeO _x ), zinc oxide (ZnO), magnesium oxide (MgO or MgO _x ), calcium oxide (CaO), boric acid (B ₂ O ₃ ), oxidation Strontium (SrO), barium oxide (BaO), lead oxide (PbO), zirconia (ZrO ₂ ), sodium oxide (Na ₂ O), lithium oxide (Li ₂ O), potassium oxide (K ₂ O), etc. Can do. In addition, x in structural formula showing an inorganic oxide is a value within the range of 1-3.
In particular, when heat resistance is required, it is preferable to use acrylic resin, polyimide resin, fluorinated polyimide, cyclic polyolefin, epoxy resin, or inorganic oxide among the constituent materials of these interlayer insulating films.
Note that these interlayer insulating films are preferably formed into a desired pattern by introducing a photosensitive group into a desired pattern by a photolithography method, or by a printing method.

b. The thickness of the interlayer insulating film, etc. The thickness of the interlayer insulating film is preferably a value within the range of 10 nm to 1 mm, although it depends on the definition of display and the unevenness of the fluorescent medium or color filter combined with the organic EL element. It is preferable.
The reason for this is that this configuration can sufficiently flatten the unevenness of the fluorescent medium or the color filter and reduce the viewing angle dependency of high-definition display.
Therefore, the thickness of the interlayer insulating film is more preferably set to a value within the range of 100 nm to 100 μm, and further preferably set to a value within the range of 100 nm to 10 μm.

c. Formation method The formation method of the interlayer insulating film is not particularly limited. For example, the interlayer insulation film may be formed using a spin coating method, a casting method, a screen printing method, or the like, or a sputtering method, a vapor deposition method, a chemical method, etc. It is preferable to form a film by a method such as vapor deposition (CVD) or ion plating.

3. Thin film transistor (TFT)
(1) Configuration Embodiments (including modifications) of the organic EL display device according to the first embodiment include at least one TFT 14 on a substrate 10 as shown in FIGS. 1 and 3 to 5. And an organic EL element 26 driven by the TFT 14.
Further, a flattened interlayer insulating film 13 is disposed between the TFT 14 and the lower electrode 22 of the organic EL element 26, and the drain 47 of the TFT 14 and the lower electrode 22 of the organic EL element 26 are disposed. Are electrically connected through a contact hole 54 made of an amorphous conductive inorganic oxide provided in the interlayer insulating film 13.

As shown in the circuit diagram of FIG. 4, the TFT 14 has a plurality of scanning electrode lines (Yj, where n is a value within the range of 1 to 1,000, for example, n) arranged in an XY matrix. ... Yj + n) 50 and signal electrode lines (Xi to Xi + n) 51 are electrically connected, and common electrode lines (Ci to Ci + n) provided in parallel to the signal electrode lines 51 are also connected. 52 is electrically connected to the TFT 14.
These electrode lines 50, 51, 52 are preferably electrically connected to the TFT 14, and constitute an electrical switch for driving the organic EL element 26 together with the capacitor 57. That is, the electrical switch is electrically connected to the scanning electrode line 50, the signal electrode line 51, and the like, and, for example, one or more first transistors (hereinafter may be referred to as Tr1) 55 and the first. 2 transistors 56 (hereinafter sometimes referred to as Tr 2) 56 and a capacitor 57.
Note that the first transistor 55 preferably has a function of selecting a light emitting pixel, and the second transistor 56 preferably has a function of driving an organic EL element.

Further, as shown in FIG. 3, the active layer 44 of the first transistor (Tr1) 55 and the second transistor (Tr2) 56 includes n-type doped semiconductor regions 45 and 47 and an undoped semiconductor. The region 46 is composed of n + / i / n +.
The n-type doped semiconductor regions become the source 45 and the drain 47, respectively, and together with the gate 43 provided via the gate oxide film 12 above the undoped semiconductor region, the transistors 55 and 56 as a whole. Will be configured.

  In the active layer 44, the n-type doped semiconductor regions 45 and 47 may be p + / i / p + doped to p-type instead of n-type. The active layer 44 of the first transistor (Tr1) 55 and the second transistor (Tr2) 56 is composed of an inorganic semiconductor such as polysilicon, or an organic semiconductor such as thiophene oligomer or poly (p-phenylene vinylene). It is preferable. In particular, polysilicon is a preferable material because it exhibits sufficient stability against energization compared to amorphous Si (α-Si).

(2) Driving Method Next, a driving method of the organic EL element by TFT will be described.
As shown in the circuit diagram of FIG. 4, the TFT preferably includes the first transistor (Tr1) 55 and the second transistor (Tr2) 56 and constitutes an electrical switch.
That is, by configuring the electrical switch as described above, the organic EL element 26 can be driven by inputting the scanning signal pulse and the signal pulse through the electrodes of the XY matrix and performing the switching operation.
More specifically, it is possible to display an image by causing the organic EL element 26 to emit light or stopping light emission by an electric switch.

Thus, when the organic EL element 26 is driven by the electric switch, the scanning pulse transmitted through the scanning electrode line (sometimes referred to as a gate line) (Yj to Yj + n) 50 and the signal electrode line ( The desired first transistor (Tr1) 55 is selected by the scanning pulse transmitted through (Xi to Xi + n) 51, and the common electrode line (Ci to Ci + n) 52 and the first transistor (Tr1) are selected. A predetermined charge is charged in the capacitor 57 formed between the source 55 and the source 45.
As a result, the gate voltage of the second transistor (Tr2) 56 becomes a constant value, and the second transistor (Tr2) 56 is turned on. In this ON state, since the gate voltage is held until the next gate pulse is transmitted, a current is applied to the lower electrode 22 of the organic EL element 26 connected to the drain 47 of the second transistor (Tr2) 56. Will continue to be supplied.
Therefore, the organic EL element 26 can be driven by the supplied current, the driving voltage of the organic EL element 26 can be greatly reduced, the light emission efficiency can be improved, and the power consumption can be reduced. become able to.

4). Electrical connection member (1) Constituent material a. Type 1
The first embodiment is characterized in that the electrical connection member is made of an amorphous conductive oxide.
That is, it is possible to obtain a good electrical connection between the organic EL element and the TFT by taking advantage of the excellent moisture resistance and heat resistance of the dense non-crystalline conductive oxide.
In addition, an electrical connection member having excellent accuracy can be easily formed by utilizing the excellent etching characteristics of the amorphous conductive oxide.

In the first embodiment, the crystal structure of the constituent material of the electrical connection member needs to be amorphous (non-crystalline).
The reason for this is that by making such a constituent material amorphous, the etching characteristics are remarkably improved and a high-definition electrode pitch can be formed.
However, when the total amount of the constituent material of the electrical connection member is 100% by weight, a part of the crystal structure may be included, but even in that case, the content of the crystal structure is 3% by weight or less. Preferably, the value is preferably 1% by weight or less, more preferably 0.5% by weight or less.
In addition, the non-crystallinity in the constituent material of the electrical connection member can be easily adjusted by adjusting the conditions of the vacuum vapor deposition method and the sputtering method (including the type of target) described later, or the type and amount of dopant to be added. Can be controlled. And the noncrystallinity of this constituent material can be confirmed by measuring an X-ray diffraction structure.
For example, FIG. 6 shows an example of an X-ray diffraction chart of indium zinc oxide (IZO). Since the crystal peak is not observed when 2θ is 5 ° to 60 °, the constituent material of the electrical connection member is not It can be confirmed that it is a crystal.

b. Type 2
Specific examples of preferable amorphous conductive oxides include indium zinc oxide (IZO) and indium tin oxide (ITO). Among these, indium zinc oxide can be made amorphous at a wide range of sintering temperatures, for example, a sintering temperature of 100 to 700 ° C., and the obtained thin film has excellent moisture resistance. Preferably there is.
When such an amorphous conductive oxide is prepared by a sol-gel method, a carboxylate such as indium acetate or zinc acetate, a chloride such as indium chloride or zinc chloride, indium ethoxide, zinc ethoxide. It is preferable to use an alkoxy compound such as a raw material compound.
In addition, in these raw material compounds of amorphous conductive oxide, it is preferable to use an organic solvent such as alkanolamine because excellent storage stability is obtained and a more uniform thin film is obtained.

c. Type 3
Further, when the amorphous conductive oxide is indium zinc oxide (IZO) and the molar ratio of indium is represented by In / (In + Zn), the molar ratio is within the range of 0.5 to 0.95. It is preferable to set the value of.
The reason for this is that when the molar ratio of indium is less than 0.5, the transparency and conductivity may decrease. On the other hand, when the molar ratio of indium exceeds 0.95, the crystal is crystallized. It is because it may become easy.
Accordingly, the indium molar ratio (In / (In + Zn)) is more preferably set to a value within a range of 0.75 to 0.90, and a value within a range of 0.8 to 0.90. Further preferred.
The indium molar ratio can be measured by ICP analysis (Inductively Coupled Plasma).

d. Type 4
Moreover, it is preferable that a dopant is contained in an amorphous conductive oxide. By including the dopant in this way, the conductivity of the amorphous conductive oxide can be adjusted more easily.
Here, as a preferable dopant, one kind of Sn, Sb, Ga, Ge or the like, or a combination of two or more kinds may be mentioned.
In the case of a sputtering method, such a dopant is preferably mixed with a sputtering target in advance and then sputtered using the sputtering target. On the other hand, in the case of a sol-gel method, it is uniformly in a sol state. Since it can be added, it is preferably added as an alkoxy compound such as dimethoxytin, trimethoxyantimony, triethoxygallium, and tetramethoxygermanium, and a chloride such as tin chloride, antimony chloride, gallium chloride, and germanium chloride.

Moreover, it is preferable to make the addition amount of a dopant into the value within the range of 0.1 to 50 weight% with respect to the whole quantity.
The reason for this is that if the added amount of the dopant is less than 0.1% by weight, the effect of the addition may not be exhibited. On the other hand, if the added amount of the dopant exceeds 50% by weight, the heat resistance and moisture resistance are reduced. This is because there is a case where the property is lowered.
Therefore, the addition amount of the dopant is more preferably set to a value within the range of 1 to 30% by weight, and further preferably set to a value within the range of 10 to 20% by weight with respect to the total amount.

e. Specific Resistance The specific resistance of the constituent material in the electrical connection member is preferably set to a value of 1 × 10 ⁻³ Ω · cm or less.
This is because when the specific resistance exceeds 1 × 10 ⁻³ Ω · cm, the resistance loss becomes excessively large, which may hinder the TFT switching operation.
Therefore, the specific resistance of the constituent material in the electrical connection member is more preferably 5 × 10 ⁻⁴ Ω · cm or less, and further preferably 1 × 10 ⁻⁴ Ω · cm or less.

f. Sheet resistance Moreover, it is preferable to set the sheet resistance of the electrical connecting member to a value within the range of 0.01 to 100Ω / □.
The reason for this is that when the sheet resistance is less than 0.01Ω / □, the types of constituent materials that can be used may be excessively limited, and the electrical connection with the lower electrode (transparent electrode) made of ITO, IZO, or the like. This is because connectivity may be reduced. On the other hand, when the sheet resistance exceeds 100Ω / □, the resistance loss becomes excessively large, which may hinder the TFT switch operation.
Therefore, the sheet resistance of the electrical connection member is more preferably set to a value within the range of 0.1 to 20Ω / □, and further preferably set to a value within the range of 0.1 to 10Ω / □.

(2) Configuration 2
Further, as shown in FIG. 7, the electrical connection member is preferably a via hole 40 formed in the interlayer insulating film 13.
This is because, if the electrical connection member is a via hole, the contact area can be increased, and thus excellent electrical connectivity can be obtained.
Moreover, it is preferable to make the diameter of a via hole into the value within the range of 0.1-100 micrometers. This is because if the diameter of the via hole is less than 0.1 μm, it may be difficult to form or the connection reliability may be reduced. On the other hand, if the diameter of the via hole exceeds 100 μm, it may be difficult to form the reverse, or a short circuit may easily occur between adjacent via holes.
Such a via hole is preferably formed by, for example, a photoetching method or mechanical cutting.

(3) Configuration 3
In addition, as shown in FIG. 8, it is preferable that the electrical connection member 28 is made of an amorphous conductive oxide, and metallized portions 31 and 35 are provided on a part or the entire surface of the electrical connection member 28.
If comprised in this way, the connection resistance in each electrical connection location between the electrical connection member 28 and the lower electrode 22 of the organic EL element 26 and between the TFTs 14 can be further reduced.
Here, the metallized portions 31 and 35 may be made of the same forming material, or may be made of different forming materials. Moreover, as a preferable forming material of the metallized portion, for example, one kind of aluminum, platinum, gold, silver, copper, nickel, chromium, tantalum, tungsten, TiN, TaN, or a combination of two or more kinds can be given. This is because, with these metals, the connection resistance at the connection end can be reliably reduced.
In particular, the metallized portion 31 is preferably formed using aluminum, and the metallized portion 35 is preferably formed using chromium or tungsten. With this configuration, it is possible to reduce the resistance of the connection at the connection end on both the upper electrode side and the lower electrode side, and to improve the corrosion resistance on the upper electrode side.
Further, the method for forming the metallized portion is not particularly limited, but it is preferable to employ, for example, a plating method, a vapor deposition method, or a sputtering method.

The thickness of the metallized portion is preferably determined in consideration of the value of the connection resistance at the electrical connection location, but specifically, it is preferably set to a value within the range of 0.01 to 50 μm.
The reason for this is that if the thickness of the metallized part is less than 0.01 μm, the value of the connection resistance at the electrical connection point may not be reduced, whereas if it exceeds 50 μm, the metallized part is formed. This is because it may take time.
Therefore, the thickness of the metallized portion is more preferably set to a value within the range of 0.01 to 30 μm, and further preferably set to a value within the range of 0.03 to 10 μm.

(4) Configuration 4
Moreover, as shown in FIG. 1, it is preferable to set the thickness of the electrical connection member 28 to a value within the range of 0.01 to 100 μm.
This is because when the thickness of the electrical connection member is less than 0.01 μm, durability may be poor or resistance loss may be significantly increased. On the other hand, when the thickness exceeds 100 μm, the electrical connection member is formed. This is because it may take too much time or become brittle.
Therefore, the thickness of the electrical connection member is more preferably set to a value within the range of 0.01 to 80 μm, and further preferably set to a value within the range of 0.03 to 50 μm.

5. Color conversion medium As the color conversion medium, there are a color filter and a fluorescent film for emitting a color different from that of EL light emission, and a combination thereof is also included.

(1) Color filter a. Structure The color filter is provided to improve the color adjustment or contrast by decomposing or cutting light, and is composed of a dye layer consisting of only a dye, or a layered material formed by dissolving or dispersing the dye in a binder resin. The
In addition, it is preferable that the color filter includes blue, green, and red pigments. This is because by combining such a color filter and a white light-emitting organic EL element, three primary colors of blue, green, and red light can be obtained, and full color display is possible.
Note that the color filter is preferably patterned using a printing method or a photolithography method, like the fluorescent medium.

b. Thickness The thickness of the color filter is not particularly limited as long as it sufficiently receives (absorbs) light emitted from the organic EL element and does not hinder the color conversion function. For example, the thickness of the color filter ranges from 10 nm to 1 mm. The value is preferably in the range of 0.5 μm to 1 mm, more preferably in the range of 1 μm to 100 μm.
When the thickness of the color filter is 5 μm or more, the height position of the lower electrode provided on the color filter is increased, and the reliability of electrical connection between the lower electrode and the TFT is lowered. It turns out. Therefore, it can be said that the inclined electrical connection member of the present invention can exert its effect more when the thickness of the color filter is 5 μm or more.

(2) Fluorescent medium a. Structure The fluorescent medium in the active drive organic EL display device has a function of absorbing light emitted from the organic EL element and emitting longer wavelength fluorescent light, and is configured as a layered material separated and arranged in a plane. ing. Each fluorescent medium is preferably arranged corresponding to the position of the light emitting region of the organic EL element, for example, the intersection of the lower electrode and the upper electrode.
With this configuration, when the organic light emitting layer at the intersection of the lower electrode and the upper electrode emits light, each fluorescent medium receives the light, and the emitted light of a different color (wavelength) is extracted to the outside. Is possible. In particular, when the organic EL element emits blue light and can be converted into green and red light emission by a fluorescent medium, the three primary colors of blue, green, and red light can be obtained even with one organic EL element, This is preferable because full color display is possible.

In addition, a light-shielding layer (black matrix) may be disposed between the fluorescent media to block light emission from the organic EL elements and light from the fluorescent media to improve contrast and reduce viewing angle dependency. preferable.
The fluorescent medium may be configured in combination with the above-described color filter in order to prevent a decrease in contrast due to external light.

b. Forming Method When the fluorescent medium is mainly composed of a fluorescent dye, it is preferable to form a film by vacuum deposition or sputtering through a mask from which a desired fluorescent medium pattern can be obtained.
On the other hand, when the fluorescent medium is composed of a fluorescent dye and a resin, the fluorescent dye, the resin, and an appropriate solvent are mixed, dispersed or solubilized to form a liquid material, and the liquid material is spin-coated, roll-coated, or cast. It is preferable to form a fluorescent medium by forming a film by a method such as patterning and then patterning the pattern to a desired fluorescent medium by a photolithography method or patterning a desired pattern by a method such as screen printing.

c. Thickness The thickness of the fluorescent medium is not particularly limited as long as the light emission of the organic EL element is sufficiently received (absorbed) and does not interfere with the fluorescence generation function. A value within the range is preferred, a value within the range of 0.5 μm to 1 mm is more preferred, and a value within the range of 1 μm to 100 μm is even more preferred.
In addition, when the thickness of the fluorescent medium becomes a value of 5 μm or more, the reliability of the electrical connection between the lower electrode and the TFT is lowered as in the case of the color filter. Therefore, it can be said that the inclined electrical connection member of the present invention can exert its effect more when the thickness is 5 μm or more even when the fluorescent medium is provided.

[Second Embodiment]
As shown in FIG. 9, the organic EL display device of the second embodiment is
A support substrate 10;
TFT 14 and color conversion medium 60 formed on the support substrate 10;
An electrical connection member 28 made of an amorphous conductive oxide formed on a slope 62 provided on the side end 61 of the color conversion medium 60;
An organic EL element 26 formed on the color conversion medium 60;
This is an active drive type organic EL display device 34 provided with.
By providing the electrical connection member 28 along the inclined surface of the color conversion medium 60 in this manner, the electrical connection member 28 can easily follow the thermal expansion of the color conversion medium 60 and the like, and therefore between the TFT 14 and the organic EL element 26. Thus, better connection reliability can be obtained.
Hereinafter, feature points of the second embodiment will be described with reference to FIGS. 9 and 10 as appropriate.

(1) Configuration 1
As shown in FIG. 9, it is preferable to provide the electrical connection member 28 at an angle. With this configuration, the electrical connection member 28 can be easily formed, and the electrical connection member 28 performs a spring-like operation between the organic EL element 26 and the TFT 14, thereby obtaining good connection reliability. be able to.
Further, when the electrical connection member 28 is inclined, it is preferable that the inclination angle (θ) of the electrical connection member 28 shown in FIG. 9 is set to a value within the range of 10 ° to 80 °.
This is because when the inclination angle exceeds 80 °, it may be difficult to form the electrical connection member. On the other hand, when the inclination angle is less than 10 °, the aperture ratio may decrease. Because.
Therefore, the inclination angle of the electrical connecting member is more preferably set to a value within the range of 20 ° to 70 °, and further preferably set to a value within the range of 30 ° to 60 °.

(2) Configuration 2
In addition, as shown in FIG. 9, it is preferable that the side end 61 of the color conversion medium 60 itself is a slope 62, and the electrical connection member 28 is provided along the slope 62.
If comprised in this way, the side edge 61 of the color conversion medium 60 can be utilized as a support part of the electrical connection member 28, and the inclined electrical connection member 28 can be provided easily.
In addition, with this configuration, even when the color conversion medium 60 is heated and thermally expanded, the electrical connection member 28 can easily follow, so that excellent connection reliability can be obtained. For example, the inclined end portion 61 of the color conversion medium 60 is set as an inclined surface 62 with an inclination angle of 10 ° to 80 °, and the inclined electric connection member 28 is easily provided only by laminating a metal thin film using a sputtering method or the like. Can do.

(3) Configuration 3
As shown in FIG. 10, it is also preferable to provide a skew member 63 at the side end 61 of the color conversion medium 60 using an electrically insulating material.
By providing the skew member 63 as described above, even when the color conversion medium 60 is thermally expanded, the skew member 63 serves as a buffer material, and an excellent connection can be made via the electrical connection member 28. Reliability can be obtained. The skew member may be formed as a flattening film on the color conversion medium.
Further, as the constituent material of the skew member 63, it is preferable to use the same electrically insulating material as that of the interlayer insulating film. Therefore, for example, it is preferable to use acrylic resin, polyimide resin, fluorine resin, polyolefin resin, epoxy resin, silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), titanium oxide (TiO ₂ ), or the like.
The form of the skew member 63 is not particularly limited as long as a part of the inclined surface is provided, but it is preferable that the skew member 63 is generally triangular.

[Third Embodiment]
As shown in FIG. 11, the organic EL display device of the third embodiment is
A support substrate 10;
TFT 14 and color conversion medium 60 formed thereon,
An organic EL element 26 formed on the color conversion medium 60;
An electrical connection member 28 made of an amorphous conductive oxide for electrically connecting the TFT 14 and the lower electrode 22 of the organic EL element 26;
A sealing member 58 covering the periphery of the organic EL element 26;
This is an active drive type organic EL display device 36 comprising:
In the third embodiment, a part of the color conversion medium 60 is embedded in the interlayer insulating film 12.
Hereinafter, feature points in the third embodiment will be described with reference to FIG. 11 as appropriate.

(1) Embedded Structure In the organic EL display device 36, it is preferable that a part or all of the color conversion medium 60 is embedded in the interlayer insulating film 12 or the support substrate 10.
With this configuration, the color conversion medium can be firmly fixed without using any special fixing means, and the position of the lower electrode 22 formed thereon can be lowered.
Therefore, not only the color conversion medium can be easily handled, but also the step between the position of the electrical connection location (drain electrode) in the TFT and the location of the electrical connection location in the lower electrode can be reduced.
Therefore, the length of the electrical connection member can be shortened, and the electrical connection in the electrical connection member is facilitated, and the resistance loss can be reduced, so that the organic EL element can be driven well.

The degree of embedding of the color conversion medium is preferably determined in consideration of the ease of electrical connection and connection reliability between the TFT and the lower electrode. The amount is preferably set to a value within the range of 0.1 to 5 μm.
The reason for this is that when the embedment amount is less than 0.1 μm, the thickness of the electrical connection member 28 may be hardly shortened in a thick color conversion medium, while the embedment amount exceeds 5 μm. This is because it may be difficult to embed a color conversion medium.
Therefore, it is more preferable to set the burying amount to a value within the range of 0.2 to 4 μm, and it is even more preferable to set the value within the range of 0.3 to 3 μm.
The method for embedding the color conversion medium in the support substrate is not particularly limited. For example, it is preferable to embed a part of the color conversion medium by cutting a corresponding portion of the support substrate.

(2) Position Adjustment Layer In the third embodiment, it is also preferable to provide a TFT position adjustment layer 33 as shown in FIG.
With this configuration, it is possible to increase the position of the connection location in the TFT 14 formed thereon only by changing the thickness of the position adjustment layer 33. Therefore, the step between the position of the electrical connection location (drain electrode) in the TFT 14 and the location of the electrical connection location in the lower electrode 22 can be reduced, the length of the electrical connection member 28 can be shortened, or the electrical connection member 28 can be shortened. Resistance loss at can be reduced.

The thickness of the position adjustment layer is preferably determined in consideration of the ease of electrical connection and connection reliability between the TFT and the lower electrode. Specifically, the thickness of the position adjustment layer is set to 0. A value in the range of 1 to 5 μm is preferable.
The reason for this is that when the thickness of the position adjusting layer is less than 0.1 μm, the length of the electrical connection member 28 may not be shortened in a thick color conversion medium. If the thickness exceeds 5 μm, it may be difficult to form.
Therefore, the thickness of the position adjusting layer is more preferably set to a value within the range of 0.2 to 4 μm, and further preferably set to a value within the range of 0.3 to 3 μm.

Further, the constituent material of the position adjusting layer is not particularly limited, but it is preferable to use the same electrically insulating material as that of the interlayer insulating film. Therefore, for example, it is preferable to use acrylic resin, polyimide resin, fluorine resin, polyolefin resin, epoxy resin, silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), titanium oxide (TiO ₂ ), or the like.
In addition, although there is no restriction | limiting in particular also about the formation method of a position adjustment layer, For example, forming using the photocuring method using the vapor deposition method or photocurable resin is preferable.

(3) Sealing member The sealing member in the organic EL display device is provided around the active drive organic EL display device in order to prevent moisture from entering inside, or further provided in this manner. It is preferable to enclose a known sealing medium, for example, an inert liquid such as a desiccant, a dry gas, or a fluorinated hydrocarbon, between the sealing member and the organic EL display device. Such a sealing member can also be used as a support substrate when a fluorescent medium or a color filter is provided outside the upper electrode.
As such a sealing member, the same kind of material as the supporting substrate, for example, a glass plate can be used. Further, the form of the sealing member is not particularly limited, and for example, a plate shape or a cap shape is preferable. For example, when it is plate-shaped, the thickness is preferably set to a value within the range of 0.01 to 5 mm.
Further, the sealing member is preferably provided with a groove or the like in a predetermined place of the organic EL display device, and press-fitted into the groove, or is fixed thereto, or an organic EL display using a photo-curing adhesive or the like. It is also preferable to fix the device in place.

[Fourth Embodiment]
The fourth embodiment is a method of manufacturing the organic EL display device 30 of the first embodiment shown in FIG. 1, specifically, the TFT 14 embedded in the electrical insulating film 12 on the support substrate 10, An active drive comprising an organic EL element 26 including an organic light emitting medium 24 between the upper electrode 20 and the lower electrode 22, and an electrical connection member 28 for electrically connecting the TFT 14 and the organic EL element 26. This is a manufacturing method of the organic EL display device 30.
And in 4th Embodiment, as shown in FIG.13, FIG14 and FIG.15, the process of forming TFT14, the process of forming the electrical connection member 28 which consists of an amorphous conductive oxide, Organic EL And a step of forming the element 26.
Hereinafter, in the fourth embodiment, characteristic portions and the like will be described with reference to FIGS. 13, 14, and 15 as appropriate.

(1) Thin Film Transistor (TFT) Formation Step A TFT formation step (active matrix substrate production step) will be described with reference to FIGS.

a. Formation of Active Layer First, as shown in FIG. 13A, the α-Si layer 70 is laminated on the support substrate 10 by a technique such as low pressure chemical vapor deposition (LPCVD).
At this time, the thickness of the α-Si layer 70 is preferably set to a value within the range of 40 to 200 nm. The substrate 10 to be used is preferably a crystal material such as quartz, more preferably low expansion glass. In the case of using a low expansion glass substrate, in order to avoid melting and distortion during the entire manufacturing process, and further to avoid out-diffusion of the dopant in the active region. It is preferable to carry out at a low process temperature, for example, 1,000 ° C. or less, more preferably 600 ° C. or less.

Next, as shown in FIG. 13B, the α-Si layer 70 is irradiated with an excimer laser such as a KrF (248 nm) laser to perform annealing crystallization to form polysilicon (SID'96, Digest of technical). papers p17-28).
As annealing conditions using this excimer laser, it is preferable to set the substrate temperature to a value in the range of 100 to 300 ° C. and the energy amount of the excimer laser light to a value in the range of 100 to 300 mJ / cm ² .

Next, as shown in FIG. 13C, the polysilicon crystallized by annealing is patterned into islands by photolithography. As the etching gas, CF ₄ gas is preferably used because excellent resolution can be obtained.
Next, as shown in FIG. 13D, an insulating gate material 72 is laminated on the surface of the obtained islanded polysilicon 71 and the substrate 10 by chemical vapor deposition (CVD) or the like, and the gate oxide insulating layer 72 and To do.
The gate oxide insulating layer 72 is preferably made of silicon dioxide so that plasma enhanced CVD (PECVD) or chemical vapor deposition (CVD) such as low pressure CVD (LPCVD) is applicable.
The thickness of the gate oxide insulating layer 72 is preferably set to a value within the range of 100 to 200 nm.
Further, the substrate temperature is preferably 250 to 400 ° C., and in order to obtain a higher quality insulated gate material, it is preferable to perform annealing at 300 to 600 ° C. for about 1 to 3 hours.

Next, as shown in FIG. 13E, the gate electrode 73 is formed by vapor deposition or sputtering. In addition, TaN etc. are mentioned as a preferable constituent material of the gate electrode 73, It is preferable to make the thickness into the value within the range of 200-500 nm.
Next, as shown in FIGS. 13F to 13H, the gate electrode 73 is patterned and anodized. Moreover, when using an Al gate, as shown in FIGS. 13F to 13H, it is preferable to perform anodic oxidation twice for electrical insulation. The details of anodic oxidation are disclosed in detail in Japanese Patent Publication No. 8-15120.
Next, as shown in FIG. 13I, an n + or p + doped region is formed by ion doping (ion implantation), and an active layer is formed to serve as a source and a drain. In order to effectively perform ion doping, it is preferable to introduce nitrogen gas during ion doping and to perform heat treatment at 300 ° C. for about 3 hours.

On the other hand, it is also preferable to use polysilicon formed of α-silicon as the gate electrode 73. That is, after the polysilicon gate electrode 73 is formed on the gate insulating layer, an n-type dopant such as arsenic is ion-implanted, and then a source region and a drain region can be formed in the polysilicon region, respectively. Further, it can be formed by patterning on a polysilicon island by photolithography.
The gate electrode 73 made of polysilicon can be used as the bottom electrode of the capacitor.

b. Formation of Signal Electrode Line and Scan Electrode Line Next, although not shown in the figure, after an electrically insulating layer, for example, a SiO layer is provided on the obtained active layer by ECRCVD (Electron Cyclotron Resonance Chemical Vapor Deposition), And forming and connecting scanning electrode lines (sometimes referred to as wiring electrodes). Specifically, formation of the signal electrode line and the scanning electrode line, formation of the upper electrode of the capacitor, connection between the source of the second transistor (Tr2) 56 and the scanning electrode line, source of the first transistor (Tr1) 55 And signal electrode lines are connected.
At that time, metal lines such as Al alloy, Al, Cr, W, and Mo are formed by photolithography, and the drains, sources, and the like of the first transistor (Tr1) 55 and the second transistor (Tr2) 56 are formed. The contacts are preferably formed using an evaporation method or the like, with the openings of the electrical insulating layers provided on the surface side being inclined.

c. Formation of Interlayer Insulating Film In the next step, an interlayer insulating film made of silicon dioxide (SiO ₂ ), silicon nitride, polyimide, or the like is applied over the active layer and the entire electrical insulating layer thereon.
Note that the insulating film made of silicon dioxide can be obtained by PECVD, for example, by supplying TEOS (tetraethoxysilane) gas at a substrate temperature of 250 to 400 ° C.
The interlayer insulating film can also be obtained by the ECRCVD method with a substrate temperature in the range of 100 to 300 ° C.
However, since these inorganic insulating films generally require time to flatten, it is more preferable to form an interlayer insulating film made of an organic material.

(2) Electric connection member forming step a. Forming method 1
Moreover, it is preferable to employ | adopt a vacuum evaporation method and sputtering method or any one thin film formation method as a formation method of the electrical connection member which consists of an amorphous conductive oxide.
This is because, by using such a thin film forming method, an electrical connection member having a uniform thickness can be easily obtained even when the electrical connection member is formed to be inclined.
In addition, the electrical connection member made of the thin film formed in this manner is excellent in durability, and excellent connection reliability can be obtained even when heated or subjected to vibration.
In addition, although it does not restrict | limit in particular about vacuum deposition method and sputtering method conditions, For example, when forming an electrical connection member by DC sputtering method using IZO, sputtering gas pressure is 0.1-5 Pa. The value is within the range, the power is within the range of 0.1 to 10 W / cm ² , the deposition rate is within the range of 5 to 100 nm / min, and the sputtering surface temperature is 50 to 200 ° C. A value within the range is preferable.

b. Forming method 2
Further, as shown in FIG. 16, it is preferable to integrally form the electrical connection member 28 made of an amorphous conductive oxide and the lower electrode 22. In FIG. 16, the fact that there is no joint between the electrical connection member 28 and the lower electrode 22 indicates this.
By manufacturing in this way, the number of electrical connection locations can be reduced, and an electrical connection member having better connection reliability can be obtained.
In order to integrally form the electrical connection member and the lower electrode, it is preferable to employ a sputtering method, but it is also preferable to employ a sol-gel method described later using an inorganic oxide.

c. Forming method 3
It is also preferable to form an electrical connection member made of an amorphous conductive oxide by a so-called sol-gel method. Specifically, for example, after applying an amorphous conductive oxide raw material solution, it is gelled by heating to form a constituent material of the electrical connection member. Next, the electrical connection member is formed by patterning using a photolithography method.
By using the sol-gel method as described above, the raw material solution is applied to a predetermined position without requiring a special forming apparatus, and is heated (sintered) and reduced from an amorphous conductive oxide. An electrical connection member can be easily formed. Moreover, since the sintering temperature and the reduction temperature are relatively low, other components are less likely to be thermally damaged. Therefore, it is possible to form the organic EL element before forming the electrical connection member.

Moreover, although it does not restrict | limit especially about the heating (sintering) conditions for making it gelatinize, For example, it is preferable to set it as the heating conditions of 100-700 degreeC and 5 minutes-20 hours, 250-500 degreeC, More preferably, the heating condition is 5 minutes to 20 hours.
This is because when the heating temperature is less than 100 ° C., gelation may be insufficient. On the other hand, when the heating temperature exceeds 700 ° C., a crystal part is easily formed.
Furthermore, although it does not restrict | limit especially also about reducing conditions, For example, it is preferable to set it as the heating conditions of 100-700 degreeC and 5 minutes-20 hours using reducing gas, such as hydrogen, nitrogen, and argon, 250 It is more preferable to set the heating conditions to ˜500 ° C. and 5 minutes to 20 hours.

d. Forming method 4
Moreover, when forming an electrical connection member, it is preferable to include the process of providing the metallization parts 31 and 35 in a part of electrical connection member 28, as shown in FIG. In this example, metallized portions 31 and 35 are provided on the TFT 14 side and the upper electrode 22 side of the electrical connection member 28, respectively.
If comprised in this way, the connection resistance in each electrical connection location in the lower electrode of an organic EL element and TFT can be made lower resistance.
The method for forming the metallized portion is not particularly limited, but for example, it is preferable to employ a plating method, a vapor deposition method, or a sputtering method.
In addition, about the structure of a metallization part, it can be set as the content similar to 1st Embodiment.

e. Forming method 5
In addition, it is preferable to pattern an electrical connection member made of an amorphous conductive oxide by etching with an organic acid. Specifically, as shown in FIGS. 17A to 17G, a photolithography method is used to form a resist film 80 on the amorphous conductive oxide 28, and then through a photomask 82, After exposure 81 and development to expose a portion 28 ′ of the crystalline conductive oxide, the electrical connection member 28 can be formed by patterning by etching with an organic acid.
By etching the electrical connection member 28 with an organic acid in this way, even when a metal material such as Al or Cr is used for a part of the TFT or organic EL element, these metal materials are affected. In addition, only the amorphous conductive oxide can be etched. Therefore, the electrical connection member 28 can be formed with high accuracy, and metal migration and the like can be easily prevented.
Even when the electrical connection member is made of an amorphous conductive oxide, it is also preferable to use a phosphoric acid-based etchant or a hydrochloric acid-based etchant in addition to the organic acid in order to increase the etching rate.

Here, preferred organic acids include oxalic acid, acetic acid, citric acid, and the like. However, it is preferable to use oxalic acid and acetic acid because etching accuracy with respect to the amorphous conductive oxide is particularly excellent. Preferred is succinic acid.
In addition, it is preferable to use the organic acid as an etching solution after dissolving the organic acid in water, an alcohol-based solvent, or another polar solvent. By using the solvent in this way, the etching accuracy for the amorphous conductive oxide can be further improved.
In that case, the organic acid concentration is preferably set to a value in the range of 0.1 to 50% by weight. The reason for this is that when the organic acid concentration is less than 0.1% by weight, the etching rate for the amorphous conductive oxide may be remarkably reduced. On the other hand, when the organic acid concentration exceeds 50% by weight, This is because metal materials such as Al and Cr may be corroded.
Therefore, the organic acid concentration is more preferably set to a value within the range of 1 to 20% by weight, and further preferably set to a value within the range of 2 to 10% by weight.

Moreover, although it does not restrict | limit especially also about etching temperature, It is preferable to set it as the temperature within the range of 20-100 degreeC. The reason for this is that when the etching temperature is less than 20 ° C., the etching rate for the amorphous conductive oxide may be remarkably reduced. On the other hand, when the etching temperature exceeds 100 ° C., a metal such as Al or Cr. This is because the material may be corroded.
Therefore, the etching temperature is more preferably set to a temperature within the range of 20 to 80 ° C, and further preferably set to a temperature within the range of 20 to 40 ° C.

(3) Organic EL Element Formation Step As shown in FIGS. 14 and 15, after the TFT 14 and the interlayer insulating film (slanting member) 63 are formed, the color conversion medium 60, the lower electrode (anode) 22, the organic By sequentially forming the light emitting medium 24 (organic light emitting layer, hole injection layer, electron injection layer, etc.) and further forming the upper electrode (cathode) 20, an organic EL device can be produced.
Here, the color conversion medium 60 is preferably formed using a method such as a vacuum deposition method, a sputtering method, a spin coating method, an ink jet method, a screen printing method, or a micelle electrolysis method.
Further, the lower electrode 22 and the upper electrode 20 are preferably formed using a method capable of forming a film in a dry state, such as a vacuum deposition method or a sputtering method.
Further, the organic light-emitting medium 24 is formed using a method such as a vacuum deposition method, a sputtering method, a spin coating method, a Langmuir Blodget method (LB method, Langumuir-Blodgett method), an ink jet method, a micelle electrolysis method, or the like. Is preferred.

(4) Sealing Step, etc. Further, for the sealing step, it is preferable to form an organic EL element and electrically connect it to the TFT, and then fix it with a sealing member so as to cover the periphery thereof.
Further, it is preferable to further encapsulate a sealing gas between the sealing member and the organic EL element or the like.
Furthermore, after sealing, moisture contained in the organic light emitting medium, the interlayer insulating film, the gate insulating film, etc. may induce the generation of dark spots or the like in the organic EL element. The rate is preferably set to a value of 0.05% by weight or less.
In addition, when applying a DC voltage to the organic EL element, if a transparent electrode is set to +, the electrode is set to a polarity of −, and a voltage of 5 to 40 V is applied, light emission can be observed. It is also preferable to judge whether the organic EL element is formed or not.

10 Support substrate 12 Interlayer insulating film (gate oxide film)
13 Interlayer insulation film (flattening film)
14 Thin film transistor (TFT)
DESCRIPTION OF SYMBOLS 16 Main electrode 17 Electrical insulator 18 Auxiliary electrode 20 Upper electrode 22 Lower electrode 24 Organic luminescent medium 26 Organic EL element 28 Electrical connection member 29 Tip part 30, 32, 34, 36 Active drive type organic EL display device 31, 35 Metallization part 40 via hole 43 gate 44 active layer 45 source 46 gate 47 drain 50 scanning electrode line 51 signal electrode line 52 common electrode line 54 contact hole 55 first transistor 56 second transistor 57 capacitor 58 sealing member 60 color conversion medium 61 side End 62 Slope 63 Skew member

Claims (10)

In an active drive organic EL display device comprising an organic EL element configured by sandwiching an organic light emitting medium between an upper electrode and a lower electrode, and a thin film transistor for controlling light emission of the organic EL element,
A planarizing film is provided as a planarized base when forming the lower electrode of the organic EL element,
An active drive type organic EL display device characterized in that an electrical connection member made of an amorphous conductive oxide is provided between the organic EL element and the thin film transistor on the slope of the side edge of the planarization film. .   2. The active drive organic EL display device according to claim 1, wherein the amorphous conductive oxide is indium zinc oxide. 3. The active drive organic EL display device according to claim 1, wherein the non-crystalline conductive oxide has a specific resistance of 1 × 10 ⁻³ Ω · cm or less.   The active drive organic EL display device according to claim 1, wherein the amorphous conductive oxide includes a dopant.   The active drive type according to any one of claims 1 to 4, wherein the upper electrode and the lower electrode, or one of the electrodes is made of indium zinc oxide or indium tin oxide. Organic EL display device.   The active drive organic according to any one of claims 1 to 5, wherein the lower electrode and the electrical connection member are integrally formed using an amorphous conductive oxide. EL display device.   The active drive organic EL display device according to claim 1, wherein a metallized portion is provided in a part of the electrical connection member.   The active drive organic EL display device according to claim 1, wherein the thickness of the electrical connection member is set to a value within a range of 0.01 to 100 μm.   The active drive organic according to any one of claims 1 to 8, wherein a fluorescent medium and a color filter, or one of the color conversion media is provided on a light emitting surface side of the organic EL element. EL display device.   The active drive organic EL display device according to claim 9, wherein the color conversion medium is embedded in a support substrate that supports the organic EL element and the thin film transistor.

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