JP3302262B2 - Organic electroluminescence display device and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescence (hereinafter, referred to as EL) display device used as a display device or a light source, and a method of manufacturing the same.
In particular, the present invention relates to a device in which element separation is easy and a photolithography process can be used.

[0002]

2. Description of the Related Art Liquid crystal displays are currently used as thin flat panel displays.
A display device using an L element has the following advantages.

(1) The viewing angle is wide because of self-emission. (2) A display having a thickness of about 2 to 3 mm can be easily manufactured. (3) Since no polarizing plate is used, the luminescent color is natural.

(4) Since the dynamic range of light and dark is wide, more vivid display is possible. (5) Operable in a wide temperature range.

(6) Since the response speed is about three orders of magnitude faster than that of liquid crystal, moving images can be easily displayed. However, organic E
The organic layer constituting the L element, or an electrode containing a metal having a small work function, which is usually used as a cathode for injecting electrons into the organic layer, is easily deteriorated by moisture or oxygen. There were manufacturing difficulties such as easy melting and weakness to heat.

In other words, when an organic EL display of a class equivalent to a display currently realized by liquid crystal is to be manufactured, mature semiconductor manufacturing technology and liquid crystal display manufacturing are required in order to reduce the size of elements. There was a difficulty that technology could not be applied as it was.

Therefore, it has been proposed that a wall having a thickness higher than the thickness of the film constituting the organic EL film is formed between display line electrodes to be separated, and the organic EL film is formed obliquely to the substrate plane.
This method utilizes the fact that the material of the organic EL element is not deposited on the shadowed portion of the high wall by vacuum-depositing the material of the element (Japanese Patent Application Laid-Open No. 5-275172,
U.S. Pat. No. 5,276,380, JP-A-5-258
No. 859, U.S. Pat. No. 5,294,869).

In this method, it is very important that the directions of atoms and molecules scattered from the evaporation source to the substrate are aligned.
That is, as shown in FIG.
The material evaporates on the concentric sphere centering on the evaporation source 101 on which the material to be evaporated is set, and adheres to the substrate. At this time, the incident angle of the material differs depending on the position of the substrate, and the film thickness varies depending on the distance from the evaporation source.

[0009]

However, in the above-described conventional method, it is difficult to stably separate display lines, and it is also not easy to form a film uniformly on the substrate surface. Although it is possible to manufacture a small display, for example, in order to apply it to a medium-sized or large-sized substrate of a class of 10 inches or more, the substrate must be sufficiently separated from the evaporation source, and the The size is not practical.

Even if such a large film forming apparatus can be manufactured, the amount of the organic EL material that does not reach the substrate, that is, the amount of the waste organic EL material becomes very large, which is a major factor of high cost.

In order to uniformly deposit a thin film on a substrate, a method of rotating the substrate and a method of using a plurality of deposition sources are generally considered, and are actually adopted in a semiconductor device manufacturing process and a liquid crystal display manufacturing process. However, when such a method is used, element separation cannot be performed by a method using a wall.

Further, in the conventional method, unless the protective layer is continuously formed in the same direction, the organic EL film and the metal electrode having a small work function are always exposed. It is difficult to remove, and organic E
It is apparent that it is impossible to perform a photolithography step having a step of using an organic solvent or water after the formation of the L film.

Therefore, according to the present invention, element separation is easy regardless of how the organic EL material is deposited, and moisture, oxygen,
Furthermore, since a film stable to an organic solvent can be formed without breaking a vacuum, and the organic EL layer and a metal having a small work function can be completely covered, a highly reliable organic EL display device can be manufactured. It is an object of the present invention to provide a manufacturing method that enables a substrate of an organic EL display device to be enlarged.

Another object of the present invention is to provide an organic EL display device manufactured by such a manufacturing method.

[0015]

In order to achieve the above object, according to the present invention, as shown in FIG. 1A, first, a first electrode 2, for example, ITO (Indium Oxide Indium Oxide) is formed on an insulating substrate 1. After patterning tin), pattern it into a desired shape. Next, an insulating film 3 such as polyimide or SiO ₂
Is formed, and the organic EL film and the second electrode in contact with the organic EL film are formed, and the insulating film also formed on the portion where light is emitted is removed.

Further, a film to be a spacer 4 composed of at least one layer, for example, a polyimide film is formed, a photosensitive film 5 such as a resist is formed between electrodes to be separated, and a portion on the insulating film 3 is formed by photolithography. leave.
Subsequently, the exposed spacer film is removed by etching.
During this etching, a sufficiently long undercut is generated under the photosensitive film 5. As a result, the photosensitive film 5 and the undercut spacer 4 are formed into a roof eave, hat or hat-shaped structure as shown in FIG. Can be done.

According to this configuration, the subsequent operation shown in FIG.
As shown in (B), an organic EL responsible for light emission and carrier transport
When the film 6 and the second electrode 7 which is in direct contact with the organic EL film 6 are deposited, the element is always separated regardless of the positional relationship between the deposition source and the substrate and various means for improving the uniformity of the film. Will be possible. For this reason, it is possible to select a method that places the highest priority on improving the uniformity of the formation of the organic EL film 6, for example, a rotation method in the case of vapor deposition.

After the organic EL film 6 and the second electrode 7 which is in direct contact with the organic EL film 6 are formed,
A method in which the film 6 and the second electrode 7 are formed, that is, when these are formed by vapor deposition, a method in which step coverage is better than vapor deposition. For example, a stable metal that is not easily attacked by moisture, oxygen, or an organic solvent by sputtering. Is formed as a protective film. This hardly eroded film is, for example, a metal film of a stable metal such as Al, an insulating protective film such as SiO ₂ , or a second protective film 9 such as SiO ₂ formed on a metal film such as Al. Can be configured. FIG.
(B) shows a third example.

It is desirable that the protective film be formed continuously after forming the organic EL film 6 and the second electrode 7 without breaking the vacuum state. As a film formation method, for example, a sputtering method or a method of vapor deposition with a low degree of vacuum may be employed.
Alternatively, as shown in FIG. 2, by rotating the substrate 10 at a large inclination with respect to the deposition direction of the deposition source 10, a film can be formed with good step coverage.

By forming the film in this manner, the protective film made of the stable metal film 8 or the stable metal film 8 and the second protective film 9 formed thereon are placed under the undercut. A structure as shown in FIG. 1B is obtained in which the organic EL film 6 and even the end of the second electrode 7 are not exposed. In other words, the transparent electrode 2, the insulating film 3, and the metal film 8 of a stable metal in which the organic EL constituent film is completely the first electrode.
(Furthermore, it turns out that it is enveloped by the protective layer 9). Therefore, it is possible to withstand a process using water or an organic solvent such as a photolithography process used in a process of forming an extraction electrode on a stable metal film 8.

As a result, it has become possible to manufacture a flat panel organic EL display having a stable yield, uniform luminous properties, high reliability, and increased flexibility in the manufacturing process, and to provide an apparatus.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) First Embodiment of the Present Invention A first embodiment of the present invention will be described with reference to FIGS. FIG. 3 is an explanatory view of a first manufacturing state of the present invention (part 1), and FIG. 4 is an explanatory view of the first manufacturing state (part 2), which is composed of dots having a pixel size of 0.4 mm × 0.6 mm. An example of manufacturing a type of dot matrix display having a 5 × 8 dots character display area of 2 rows × 16 columns.

In the first embodiment of the present invention, the organic EL
Amorphous silicon (a-si) solar cells and STN (super tw)
Inexpensive soda glass, which is also used in isted nematic liquid crystal displays and the like, was used, and the entire surface was coated with silica (SiO ₂ ). This is because while suppressing sodium eluted during heating, it is possible to protect soda glass that is weak against acids and alkalis, and to obtain the effect of improving the flatness of the glass surface.
Immersion in an iO ₂ solution or spin-on-glass (SO
Silica coating can be achieved by using G).

Next, on the silica coat, as a first electrode, ITO, which is a transparent conductive film, is applied by sputtering for about 1 hour.
A film was formed at 500 °. The reason why ITO was used is that the properties as a transparent conductive film are better than other materials, but a transparent electrode such as ZnO or SnO ₂ may be used if, for example, transmittance or resistivity does not cause any problem in use. It is possible.
When ITO is formed over a large area, the sputtering method is excellent in terms of uniformity, but the ITO film forming method is not particularly limited to this.

In this way, as shown in FIG. 3A, after a silica coat (not shown) is formed on the substrate 1, ITO 2
After forming a resist pattern by photolithography, unnecessary portions are removed by etching, the resist is peeled off, and ITO is formed into a desired electrode pattern. At this time, as shown in an enlarged view in FIG. 3A, it is desirable that the pattern end of the ITO 2 has a tapered shape. This is to prevent the organic layer to be deposited later or the thin film of the second electrode from being disconnected at the step portion of the ITO, thereby improving the yield and the life. In this case, the taper angle θ is desirably 45 ° or less. In FIG. 3, the right side is a plan view,
The left side is a cross-sectional view of the chain line portion.

The formation of a step having a low taper angle can be achieved by any of wet etching and dry etching. For example, in wet etching, since the etching proceeds in the same direction, a taper angle of about 45 ° can be naturally obtained unless the over-etching time is too long.

Also in the dry etching method, a method utilizing the receding of the resist by dry etching, that is, if etching conditions such as dry etching gas, high frequency (RF) input power, gas pressure, etc. are selected so as to transfer the taper angle of the resist. , 20 ° to 30 ° can be easily obtained. As the dry etching gas at this time, a hydrogen halide gas such as hydrogen chloride or hydrogen iodide, a bromine gas or methanol is used.

Next, an insulating film layer serving as the insulating film 3 shown in FIG. 1A for depositing a spacer to be formed later on the ITO 2 is formed. Here, the film used for mounting the spacer may be an insulating film. For example, Si
A method of forming an inorganic thin film such as O ₂ or SiNx by sputtering or vacuum evaporation, a method of forming SiO ₂ by SOG, a method of applying resist, polyimide, acrylic resin, or the like can be used.

However, since it is necessary to expose ITO2 under the insulating film, patterning must be possible without damaging ITO2. Also, there is no limitation on the film thickness, especially when an inorganic thin film is used.
It is desirable that the thickness be thin in order to reduce the manufacturing cost.

It is desirable that the edge of the pattern formed on the ITO of the insulating film is also tapered. The taper angle may be about 60 ° or less, but is preferably 4 °.
5 ° or less is preferable. For example, when SiO ₂ is formed as an insulating film, the wet etching should also be performed if the over-etching time during the etching is not too long.
A taper angle of 5 ° is obtained. In order to make the taper angle smaller, the dry etching method is also suitable as in the case of ITO2. As a dry etching gas, a fluorocarbon-based gas such as CF ₄ + O ₂ is generally used.

FIG. 3B shows an example in which polyimide is used as the insulating film 3. For polyimide, select a non-photosensitive material and adjust the concentration to about 5% with N-methyl pyrrol.
Those diluted with idone (NMP) or γ-butyrolactone were applied by spin coating, and prebaked at 145 ° C. for 1 hour. Thereafter, a positive resist was applied and patterned to obtain the one shown in FIG.

Polyimide is a resist developer te
tra methyl ammonium sodium
An approximately 2.38% aqueous solution of de (TMAH) was subsequently removed from the exposed resist portions. Only the resist is removed with ethanol, and a desired insulating film layer is formed. In the above description, non-photosensitive polyimide is used, but photosensitive polyimide can also be used. In this case, no resist is required.

The polyimide insulating film 3 obtained in this manner is about 35 mm thick so as not to be affected by a chemical solution used later.
It is completely cured (cured) at 0 ° C. At this time, since the insulating film 3 contracted, the step was tapered.

If it is difficult to control the step shape of the ITO as described above, the insulating film formed in this step may be made of ITO.
The photomask may be designed so as to cover the stepped portion of at the same time.

Subsequently, a spacer film to be the spacer 4 shown in FIG. 1A was formed. The spacer film may be a conductor or an insulator for that purpose, and may have a single-layer structure or a multilayer structure. However, when a conductor is used for the spacer film, a metal film to be formed later may cause a current short-circuit or a current leak with an adjacent line through the spacer.
It is necessary to take a sufficiently large amount of undercut.

Further, it is necessary to select a material that does not attack the ITO in contact with the spacer film by the etching solution for the spacer film. Also, since this spacer film is for forming the spacer 4 shown in FIG.
The thickness of the thin film such as the organic EL film 6, the second electrode 7, the stable metal film 8, and the protective film 9 shown in FIG. There is a need. For this reason, a material that can easily form a thick film is preferable.

Examples of such materials include SOG and resin films. For the metal, it is preferable to use Cr, Ti, TiN, or the like as an etching barrier film of ITO, and to form a laminated structure of a material having a high film forming speed, such as Al. Of course, this etch barrier need not be limited to metal.

FIG. 3C shows a process in the case where polyimide is selected as the spacer film 4 '. First, a polyimide having a concentration of 15% was adjusted to a film thickness of 2 μm.
And prebaked at 145 ° C. for 1 hour to form a spacer film 4 ′. The thickness of the spacer film 4 'can be controlled by the concentration of polyimide and the number of rotations of the spin coater.

After forming the spacer film 4 'in this manner, a positive resist is subsequently applied. At this time, a resist having a high viscosity is selected so that the thickness of the resist becomes 1 μm or more, desirably 2 μm or more, or the rotation speed of spin coating is reduced.

Since the positive resist is relatively brittle, the method of increasing the thickness of the resist is adopted as described above. However, the method is not limited to the case where a harder film is formed under the resist to support the resist. By forming this support, there is an advantage that a heat treatment for removing moisture in a later step becomes possible. Conversely, when heat treatment is performed when no support is formed, the resist is easily deformed and the undercut is crushed.

As described above, the positive resist is applied, exposed to form a desired photo pattern, and developed to form a shade-like (generally overhanging) photosensitive material as shown in FIG. The resin 5 is formed. The polyimide spacer film 4 'exposed during the development of the positive resist is also removed from the positive resist again with the developing solution, as shown in FIG.
Are formed as shown in FIG.

The developing time is determined by the amount of undercut of the polyimide spacer film 4 'under the shade-shaped photosensitive resin 5 made of a positive resist. The amount of undercut is greatly affected by the prebaking temperature and time of the polyimide, and it is particularly necessary to control the temperature to be uniform over the entire surface of the substrate. In this example, the developing time was determined so that the undercut was about 4 μm. Thus, the structure shown in FIG. 3E is obtained.

Then, as the hole injection layer and the hole transport layer of the organic EL, N, N'-bis (m-methylphenyl) -N, N'-diphenyl-1,
1'-biphenyl-4,4'-diamine (N, N'-b
is (m-methylphenyl) -N, N'-
diphenyl-1,1'-biphenyl-4,
4'-diamine (hereinafter referred to as TPD)

[0044]

Embedded image

Was used as a light-emitting layer and an electron transporting layer, as tris (8-hydroxyquinoline) aluminum (tris (8-hydroxyquinolol) represented by the following chemical structural formula.
ine) aluminum (hereinafter referred to as Alq3)

[0046]

Embedded image

As a second electrode, a Mg / Ag alloy (weight ratio: 10: 1) was continuously deposited without breaking vacuum to form an electrode as shown in FIG. 4A. At this time, the thickness of the TPD constituting the organic EL film 6 is 50
0 °, the film thickness of Alq3 is 500 °, and the second electrode 7
Was made 2000 mm in thickness.

The present invention is, of course, not limited to this, and other materials may be used for the hole injection layer, the light emitting layer, and the second electrode. Layers and the like may be further formed to form a multilayer structure. From the formation of the organic layer to the formation of the second electrode, the metal mask provided on the substrate holder of the vapor deposition apparatus so that these films are formed only in the light emitting region (display screen portion). The deposition was performed through

After the organic EL film 6 and the second electrode 7 are formed in this manner, the substrate is transported to a vacuum chamber in which a film can be formed by a sputtering method without breaking a vacuum, and the substrate is stabilized by the sputtering method. A stable metal film 8 was formed by depositing Al, which is a stable metal. At this time, it is important to select a method having better step coverage than the method of forming the organic EL film 6 constituting the organic EL layer. By doing so, as shown in FIGS. 1B and 4B, the Al atoms penetrate into the undercut portion, and the organic EL film 6 that is weak against moisture and oxygen is completely enveloped in the outside air. Will be.

As a result, a remarkable merit that not only moisture and oxygen but also the organic solvent used at the time of etching can be shielded from the organic EL film 6 can be obtained. In the conventional structure, since the organic solvent permeated from the organic EL film exposed at the end of the pattern or the like peels off the entire organic EL film, the organic solvent is exposed to the organic solvent after the organic EL film is formed. Although it is taboo that the processes that can be used at the time of manufacturing are limited, manufacturing processes that can be applied by such a method of the present invention can be diversified.

In the present invention, in order to further improve the water resistance and organic solvent resistance, as shown in FIG. 4B, after forming a stable metal film 8 made of Al,
It has been found that it is better to continuously form the protective film 9 such as SiO ₂ .

In this embodiment, the stable metal Al
Was formed at a sputtering pressure of 8 × 10 ⁻³ torr.
It is desirable that the sputtering pressure be as high as possible. This is because the higher the sputtering pressure, the more easily the Al atoms scattered from the Al target collide with the sputtering gas, argon, and are scattered. As a result, Al easily enters under the undercut portion, and the organic EL film is removed. This is to cover enough.

In other words, the mean free path of the Al atom is
It must be shorter than the distance between the target and the substrate. On the other hand, when the sputtering pressure is increased, the film formation rate is decreased due to a decrease in the voltage applied to the target and scattering of Al atoms. Therefore, the sputtering pressure is determined in consideration of productivity and step coverage.

In the above description, the sputtering method is adopted as a method for forming the stable metal film 8 made of Al. However, the present invention is not limited to this, and an inert gas may be introduced at the time of vapor deposition. Method of lowering vacuum degree, plasma CVD
The same effect can be obtained by other methods having good step coverage, such as a method and an optical CVD method. The same applies to the protective film 9 of SiO ₂ .

By the way, the stable contact with the second electrode 7
To the control IC to the metal film 8 of Al which is a good metal
For this reason, an extraction Al electrode pad (not shown) was formed.
When this was done,
Remove this Al electrode pad so that no defects occur on the display surface.
Position of the display on the side of the display element.
Organic EL element constituent film is formed under the take-out Al electrode pad
So that no SiO 2_TwoBut
Organic EL element constituent film and SiO_Two
When forming a protective film, use a metal mask to
The part is shielded. This is the density between Al and the substrate, respectively.
Insulation on the take-out electrode pad to improve adhesion
The purpose is to prevent the film from being formed
You. SiO _TwoAbout the film formation method with very good coverage
When using the plasma CVD method or the photo CVD method
Is formed on the pad even with a metal mask.
Sometimes In such cases, photolithography
If the connection hole is opened in the electrode extraction electrode pad part with
good.

By the way, when an insulating film such as SiO ₂ is finally formed as the protective film 9, even if the resist made of the photosensitive resin 5 is crushed by a mechanical pressure, each line becomes an insulating film. Since only the resist near the take-out Al electrode pad where the insulating film is not formed because it is covered with a certain protective film 9 is wiped off with a solvent, the organic EL element constituent film remaining on the resist near the display region is particularly removed. Failure to do so does not cause a circuit short circuit or the like via them. In this case, the step of removing the shade resist remaining on the entire surface of the substrate can be omitted, which is more advantageous in terms of manufacturing cost.

It is desirable to attach a glass substrate or the like to the organic EL film side for the purpose of protecting the film surface from physical contact or contamination and to obtain higher reliability. May dissolve the cap-shaped photosensitive resin as a resist, and a short circuit occurs between adjacent elements unless a protective film as an insulating film is formed last. Therefore, when attaching a protective glass substrate or the like to the organic EL film surface side, it is better to remove the organic EL element constituent film and Al remaining on the shade-shaped photosensitive resin 5 in advance. These films are made of a photosensitive resin as a resist or a spacer film 4.
Can be easily removed by immersing it in a solution for dissolving.

That is, if an alcohol such as ethanol or isopropyl alcohol, an ester such as butyl acetate or ethyl acetate, or an appropriate organic solvent such as acetone or xylene is used, only the photosensitive resin is removed, and FIG. ) Can be formed.

NMP, γ-butyrolactone, or a commercial product number MS-200 manufactured by Fuji Hunt Co., Ltd.
If a resist stripper such as 1 is used, both the spacer film and the photosensitive resin can be removed. At this time, the thin film formed on the photosensitive resin is lifted off. It can be said that removing the entire spacer 4 makes it easier to lift off the thin film on the photosensitive resin 5 and is easier in the manufacturing process.

On the other hand, as shown in FIG. 4C, when the spacer 4 is left, this serves as a support, and when a protection substrate (not shown) is attached to the film surface side, Since the organic EL element is not in contact with the organic EL element due to the presence of the spacer 4, the physical influence of the substrate on the organic EL element can be reduced, which is advantageous in extending the life of the organic EL element.

As described above, the manufacturing process and the organic EL element structure may be selected depending on the purpose of use of the organic EL display device to be manufactured, that is, whether the manufacturing cost is important or the life is important.

In the embodiment of the present invention, only the photosensitive resin was removed to leave the spacer 4 as shown in FIG.
Then, in order to further improve the water resistance, a fluorocarbon polymer film is formed by plasma CVD (chemical vapor deposition).
(Eposition), and further formed on the protective film 9. The fluorocarbon polymer film is not shown in FIG.

As the gas, CF ₄ and CHF ₃ are used.
It was decomposed at a gas pressure of mtorr and formed on the protective film 9 on the substrate. Since plasma CVD has better coverage than the sputtering method, lift-off becomes difficult unless the photosensitive resin 5 on the spacer 4 is removed first. The fluorocarbon polymer film formed on the Al electrode pad was removed by enzymatic plasma by photolithography, and the resist was peeled off to produce a desired organic EL display device.

The organic EL display panel manufactured in this way is not only excellent in water resistance and organic solvent resistance, but also because each line is completely covered with a stable thin film independently. It was confirmed that the device had the same reliability as an organic EL device operated in a vacuum holding operation or in dry nitrogen.

(2) Second Embodiment of the Present Invention A second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a diagram illustrating a second manufacturing state of the present invention (part 1);
FIG. 6 is an explanatory view of the second manufacturing state (part 2), and FIG. 7 is an explanatory view of the second manufacturing state (part 3). The size of one pixel is 330 μm × 110 μm and the number of pixels is 320.
An example of manufacturing a simple matrix type display provided with a color filter of × 240 × RGB dots is shown. The differences between the second embodiment and the first embodiment are that the definition is higher and that the color filters are formed in advance.

In addition, since the electrical resistance of a transparent conductive film such as ITO becomes a problem as the definition becomes higher, a part of the film is formed by using Al having a lower resistivity of about 1/100 as compared with a transparent conductive film such as ITO. Was laminated with this transparent conductive film to reduce the resistance value. However, direct contact between Al and the transparent conductive film results in a large contact resistance, so that it is sometimes better to sandwich TiN or Cr between them. Hereinafter, a second embodiment of the present invention will be described.

First, Al is sputtered to a thickness of about 1.5 μm on a transparent substrate (not shown) such as a glass plate, and subsequently, TiN is sputtered to a thickness of about 300 ° to form an Al.
And a laminated film of TiN. By continuously forming Al and TiN without breaking the vacuum, a natural oxide film is prevented from being formed on the surface of the Al layer, and the contact between Al and TiN is improved. The Al layer may be made of an Al alloy containing another element. Rather, an Al alloy containing Sc or the like may be used to prevent generation of hillocks, which are irregular portions formed by crystal growth of Al in a later heating step. It is often more desirable.

As described above, the laminated film of Al and TiN is patterned by photolithography to obtain the Al layer 11 and the TiN layer 12 formed on the Al layer 11, as shown in FIG. It is better to etch TiN and Al simultaneously by dry etching for better throughput and processed shape.

Dry etching is performed by RIE (Reacti
2,000 IW using the Ve Ion Etching method.
At a gas pressure of 100 mTorr. The etching gas used was Cl ₂ and BCl ₃ . After the etching, an ashing process was performed without breaking the vacuum to prevent Al corrosion after dry etching, which is called after-corrosion. Here, an example of etching by the dry etching method is shown, but even if the processed shape is bad, it does not cause a serious problem, and therefore, the etching may be performed by wet etching.

Next, in order to form a color filter, an application process of a pigment dispersion type color filter, which is the most general method for colorizing a liquid crystal display, was performed. R,
The application conditions are determined so that the filter thickness of each of the G and B colors is 1.0 to 1.5 μm, and as shown in FIG. The green color filter 14 and the blue color filter 15 were patterned.

The coating process of the color filter was performed as follows, taking red (R) as an example. Spin coat the color filter material for red at 1000 rpm for about 5 seconds,
For 3 minutes. Align the photomask with an exposure machine, and irradiate it with UV light of 20 mW for 30 sec.
Developed with a concentrated TMAH aqueous solution. The development time was about 1 minute. Thereafter, the mixture was cured at 220 ° C. for 1 hour so as not to dissolve in a color filter solution of another color to be applied, thereby completing a red color filter 13. Since the other colors, that is, the green color filter 14 and the blue color filter 15 are different in the material (pigment), substantially the same steps may be sequentially performed although the formation conditions of the red color filter 13 are different. Thus, as shown in FIG. 5B, the red color filter 13 and the green color filter 1
4. A blue color filter 15 is formed.

Here, since the manufacture is relatively easy, an example using only a color filter has been described. However, green and red are output by performing color conversion using a fluorescence conversion filter, so that a higher-luminance light is emitted. It may be. In addition, a color filter and a fluorescence conversion filter may be laminated to prevent both a reduction in luminance and an improvement in color purity.

As described above, the red color filter 13,
Green color filter 14, Blue color filter 15
After forming, to improve the flatness of the surface on which an ITO film is formed, an overcoat material of, for example, polyimide or acrylic resin is applied, and patterning is performed to expose the surface of the TiN layer 12. At about 220 ° C
After curing for a time, an overcoat layer 16 was obtained as shown in FIG.

Then, ITO was formed as a transparent conductive film by sputtering at a thickness of about 1400 °, a resist pattern was formed by photolithography, and then etched with dilute hydrochloric acid.
After removing the resist, as shown in FIG.
7 was obtained. In this way, a pattern in which the transparent conductive film and the Al wiring formed for lowering the resistance are connected to each other is formed to form a column line.

[0086] Above this patterned ITO 17
SiO as an edge film by sputtering _TwoAnd then
Except for the part where light emission is visible from the glass substrate (not shown)
SiO_TwoIs patterned so as to remain, as shown in FIG.
As shown, SiO_TwoAn insulating film 18 was formed. This
The ITO 17 formed and connected on the Al layer 11 is
This SiO_TwoBy covering with an insulating film 18, a glass substrate
This is to avoid unnecessary light emission in the part that cannot be seen from the surface.
You. Also, this part must be a hole or groove
The organic EL film such as the light emitting layer deposited on the inclined portion of
And it tends to be a current leak path,
It is desirable to form some kind of insulating film.

Here, SiO ₂ was used as the insulating film. However, since the insulating property is required, SiO ₂ or Si
The resin is not limited to an inorganic insulating film such as Nx, but may be a resin such as polyimide, acrylic resin, or epoxy resin. When patterning the insulating film, a step of providing an insulating film under the spacer film can be omitted by forming a mask pattern such that the insulating film remains even in a portion where the spacer is formed at the same time. . FIG. 6 shows a plan view of the color filter portion, and the rightmost block and the lower block are shown in white for the sake of explanation of the size. Each pixel has a size of 330 μm × 110 μm, and the TiN layer and the Al layer have a connection portion C with an ITO of 30 × 30 μm.
And a line L having a width of 10 μm. The sectional view taken along the dotted line in FIG. 6 is the portion described in FIGS.

As shown in FIG. 5E, the SiO ₂ insulating film 1
After patterning of the resist pattern 8, polyimide is used as a spacer film, and a resist 20 is formed on the spacer 19 in a cap shape (typically as shown in FIG. 7A) by the same steps as those shown in FIGS. In the above, a structure formed in an overhang body was obtained.

For colorization, the light emitting element was formed by forming the following material on the state shown in FIG. In this embodiment, an organic EL material emitting white light was used.

As the hole injection layer, poly (thiophen-2,5-diyl) represented by the following chemical structural formula

[0080]

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A luminous layer having a thickness of 100 ° was formed on the TDP as a hole transport layer and a yellow light-emitting layer.

[0082]

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Was doped at a rate of 1 wt% to form a film at 500 ° by co-evaporation to form a yellow light emitting organic EL film 21-1. The concentration of rubrene is preferably about 0.1 to 10 wt%, and light is emitted with high efficiency at this concentration. The concentration may be determined from the color balance of the luminescent color, and depends on the light intensity and the wavelength spectrum of the blue luminescent layer to be formed thereafter.

As a blue light emitting layer, 4,4′-bis [(1,1,2-triphenyl) represented by the following chemical structural formula:
Ethenyl] biphenyl

[0085]

Embedded image

[0086] The Alg was used as an electron transport layer.
3 was continuously vapor-deposited at 100 ° without breaking vacuum to form a blue light-emitting organic EL film 21-2, and a Mg / Ag alloy (weight ratio 10: 1) was used as the second electrode 22 without breaking vacuum at 2000 °. Continuously. After this, FIG.
As in (B) and (C), Al film 2 as a stable metal
3 and a SiO ₂ film 24 as a protective film were continuously formed by a sputtering method.

Finally, the cap-shaped resist 20, the thin films formed on the resist 20, and the spacers 19 are removed with a stripping solution, and as shown in FIG. The display was manufactured.

According to the present invention, the vapor deposition method can be a method emphasizing the uniformity of the film, so that the light emission characteristics are uniform with a high yield. Further, according to the present invention, the conventional drawback that the material weak to moisture or oxygen, which was the cause of the low reliability of the organic EL element, had to be temporarily exposed to the atmosphere, was eliminated. By completely covering each time with a stable material, it was possible to obtain a very high reliability.

The numerical values in the present invention are merely examples, and the present invention is of course not limited thereto.

[0090]

According to the first aspect of the present invention, an organic EL layer can be formed by forming an overhanging body wider than the spacer and narrower than the insulating film. And an excellent organic EL display device can be provided.

According to the second aspect of the present invention, the width and the width of the spacer are larger than those of the spacer by over-etching.
An overhang having a width smaller than that of the edge film can be easily formed.
The layers can be easily and satisfactorily formed for element isolation.

[0092]

According to the present invention, it is possible to provide an organic EL display device in which it is easy to provide a sealing film or a sealing plate for sealing the entire device on the organic EL layer side. .

[0094]

According to the fourth aspect of the present invention, it is possible to provide an organic EL display device that can use a wide variety of adhesives for bonding a sealing film or a sealing plate. .

According to the fifth aspect of the present invention, at least one of a metal or an insulating film stable to oxygen, moisture, and an organic solvent is formed by a method having better covering properties than the organic layer and the second electrode. Since the protective film formed on the second electrode can be formed on the second electrode, it is possible to manufacture an organic EL display device having extremely high reliability, a long life, and capable of performing a photolithography process thereafter.

[0097]

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of rotary evaporation.

FIG. 3 is an explanatory view (part 1) of a first manufacturing state of the present invention.

FIG. 4 is an explanatory view (part 2) of a first manufacturing state of the present invention.

FIG. 5 is an explanatory view (1) of a second manufacturing state of the present invention.

FIG. 6 is an explanatory view (part 2) of the second manufacturing state of the present invention.

FIG. 7 is an explanatory view (3) of a second manufacturing state of the present invention.

FIG. 8 is an explanatory view of general vacuum deposition.

[Explanation of symbols]

 Reference Signs List 1 substrate 2 ITO 3 insulating film 4 spacer 4 'spacer film 5 photosensitive resin 6 organic EL film 7 second electrode 8 metal film 9 protective film 10 evaporation source

Continuation of front page (56) References JP-A-8-315981 (JP, A) JP-A-5-258859 (JP, A) JP-A-6-96858 (JP, A) JP-A-3-250583 (JP) JP-A-9-283280 (JP, A) JP-A-9-102393 (JP, A) JP-A-7-142168 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) H05B 33/00-33/28

Claims (5)

(57) [Claims] A first electrode composed of a transparent electrode; an insulating film; a spacer formed on the insulating film; and a spacer formed on the spacer and wider than the spacer.
An overhang body having a width smaller than that of the insulating film ; an organic electroluminescence film provided between the spacers; a second electrode formed on the organic electroluminescence film; An organic electroluminescent display device comprising a protective film formed of at least one of a metal and an insulating film to be covered. 2. A first electrode comprising a transparent electrode is formed on a substrate, an insulating film is formed on the first electrode, and at least one spacer layer is formed on the insulating film. A photosensitive layer having photosensitivity is formed on the spacer layer, and simultaneously with or after patterning the photosensitive layer, the spacer layer is removed by etching to form a spacer. Over-etched to be smaller than the pattern of the layer, wider than the spacer and wider than the insulating film
A method for manufacturing an organic electroluminescent display device, comprising forming a narrow photosensitive overhang body, and separating and forming a film constituting an organic electroluminescent element between the spacers. 3. A first electrode comprising a transparent electrode on a substrate
Is formed, and an insulating film is formed on the first electrode . At least one spacer layer is formed on the insulating film.
To form a photosensitive layer having photosensitivity on this spacer layer
And, at the same time or after the patterning this photosensitive layer
The spacer layer is removed by etching to form a spacer.
Form, the spacer layer photosensitive During this etching is removed
Overetching than smaller Kunar pattern layer
To form a photosensitive overhang,
An organic electroluminescent element between the
Film is formed separately, and then the photosensitive overhang
Organic electroluminescence characterized by the removal of the body
A method for manufacturing a luminescence display device. 4. A first electrode comprising a transparent electrode on a substrate
Is formed, and an insulating film is formed on the first electrode . At least one spacer layer is formed on the insulating film.
To form a photosensitive layer having photosensitivity on this spacer layer
And, at the same time or after the patterning this photosensitive layer
The spacer layer is removed by etching to form a spacer.
Form, the spacer layer photosensitive During this etching is removed
Over-etch to be smaller than layer pattern
To form a photosensitive overhang,
An organic electroluminescent element between the
Film is formed separately, and then the photosensitive overhang
Organic matter characterized by removing the body and the spacer.
A method for manufacturing a Lectro luminescence display device. 5. A first electrode comprising a transparent electrode on a substrate
Is formed, and an insulating film is formed on the first electrode . At least one spacer layer is formed on the insulating film.
To form a photosensitive layer having photosensitivity on this spacer layer
And, at the same time or after the patterning this photosensitive layer
The spacer layer is removed by etching to form a spacer.
Form, the spacer layer photosensitive During this etching is removed
Over-etch to be smaller than layer pattern
To form a photosensitive overhang, and an organic electroluminescent element is placed between the spacers.
After forming the film that composes the
From the organic layer or the second electrode constituting the sensation element,
Fewer metals or insulating films stable in oxygen, moisture and organic solvents
The protection layer formed on the other hand is formed by forming the second electrode.
The organic layer and the second electrode are entirely formed at this time.
Organic film characterized by being formed so as not to touch the outside air
A method for manufacturing an electroluminescence display device.