JP2007103033A - Light emitting device and method of manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device having long service life and high display quality which comprises an organic functional layer with uniform film thickness in an opening sectioned by a bank, and to provide a method of manufacturing the light emitting device. <P>SOLUTION: In the method of manufacturing the light emitting device, a functional layer 140 including a light emitting layer 140B is arranged in the opening 151 sectioned by a barrier rib 150a composed of an organic material BB. The barrier rib 150a is formed on a substrate P, the fluorine content in the top layer of the upper surface of the barrier rib 150a is higher than that in the top layer of the inner surface of the opening 151, and the functional layer 140 is arranged in the opening 151 sectioned by the barrier rib 150a. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a light emitting device and a method for manufacturing the light emitting device.

  In recent years, a technique for forming an organic functional layer including a light emitting layer in an organic EL (electroluminescence) device by an inkjet method is known (for example, see Patent Document 1). Thus, when forming an organic functional layer using the inkjet method, after discharging the functional material made into an ink from an inkjet head into the opening parted with the partition called a bank, a drying process is performed and the light emitting layer is formed. Forming.

Incidentally, the wettability of the inner surface of the opening to the functional material may affect the film formation state of the light emitting layer.
Therefore, when the ink jet method is used, a process of performing a liquid repellent treatment on the surface of the bank (partition wall) is generally essential. For example, as such a liquid repellent treatment, a plasma treatment using CF ₄ gas is performed.
JP 2003-249375 A

However, since the plasma treatment using CF ₄ gas as described above is isotropic, not only the upper surface of the bank but also the inner surface of the opening becomes liquid repellent.
When the inner surface of the opening is made liquid repellent, the functional material is repelled on the inner surface of the opening, so that the thickness of the liquid layer of the functional material is thick near the center of the opening. In the vicinity, the film thickness becomes thin. As described above, the light emitting layer formed by drying the functional material having a variation in film thickness has low flatness, and the thin film portion is deteriorated faster than the thick film portion. The life of the layer is shortened. Further, for example, between the electrodes provided with the light emitting layer interposed therebetween, there is a possibility that the electrodes are short-circuited at the light emitting layer portion having a small thickness. Furthermore, since the organic EL device having a light emitting layer with low flatness causes display unevenness, the display quality is lowered and the reliability as the light emitting device is low.

  The present invention has been made in view of such circumstances, and includes a light emitting device having a long life and high display quality, including an organic functional layer having a uniform film thickness in an opening partitioned by a bank, and a light emitting device. An object is to provide a manufacturing method.

  A method for manufacturing a light emitting device according to the present invention is the method for manufacturing a light emitting device in which a functional layer including a light emitting layer is disposed in an opening partitioned by a partition made of an organic material. A step of making the fluorine content in the surface layer on the upper surface of the partition wall higher than the fluorine content in the surface layer on the inner surface of the opening, and a step of arranging the functional layer in the opening partitioned by the partition. It is characterized by having.

According to the method for manufacturing a light emitting device of the present invention, the fluorine content in the surface layer on the upper surface of the partition wall is higher than the fluorine content in the surface layer on the side surface. Here, for example, when the surface layer on the upper surface has a fluorine content that is liquid repellent with respect to the functional liquid serving as the functional layer, the fluorine content in the surface layer on the inner surface of the opening is the upper surface. Therefore, the inner surface of the opening is relatively lyophilic with respect to the functional liquid. Therefore, when a functional liquid that is a precursor of a functional layer is ejected to the opening partitioned by such a partition wall, for example, by an ink jet method, the functional liquid disposed in the opening becomes relatively lyophilic. It is in a state of being in good contact with the inner side surface of the opening, and thus a liquid layer having a uniform and flat film thickness.
A functional layer having a uniform film thickness can be formed by drying the functional liquid that is in good contact with the inner surface of the opening and is maintained at a uniform film thickness. Therefore, according to the functional layer obtained by this structure, since a thin part does not arise in the inner surface of an opening part, the short circuit between the electrodes provided, for example on both sides of the said functional layer is prevented. In addition, since the flat functional layer is unlikely to deteriorate, the lifetime of the light emitting device can be extended. Furthermore, it is possible to manufacture a highly reliable liquid layer device that has, for example, a light emitting layer as a functional layer having a flat film thickness, has high display characteristics, and prevents display unevenness.

In the method for manufacturing the light emitting device, it is preferable that the inner surface of the opening provided in the partition wall is tapered with respect to the upper surface of the substrate.
In this way, the contact area between the inner surface of the opening having a low fluorine content and relatively lyophilic properties and the functional liquid can be increased. Therefore, it is possible to satisfactorily arrange the functional liquid in the openings defined by the partition walls and obtain a functional layer having a uniform thickness.

Alternatively, in the method for manufacturing the light emitting device, it is preferable to perform an anisotropic plasma treatment using a reaction gas containing fluorine when forming the partition.
In this way, by applying anisotropic plasma treatment, fluorine is selectively applied only to the surface layer on the upper surface of the partition wall. Therefore, by selectively increasing the fluorine content on the upper surface of the partition wall, Liquid repellency is imparted to the upper surface. Therefore, since the inner side surface of the opening has low liquid repellency and becomes relatively lyophilic, the functional liquid can be well placed in the opening partitioned by the partition wall, and thereby the functional layer having a uniform thickness Can be obtained.

In the method of manufacturing the light emitting device, in the step of forming the partition wall, a partition wall forming material is provided on the base, and fluorine ions are implanted into the surface layer on the upper surface of the partition wall forming material, and then the partition wall forming material is used. Patterning is preferred.
In this way, since fluorine ions are selectively implanted only in the surface layer on the upper surface of the partition wall, liquid repellency can be imparted only on the upper surface of the partition wall. Therefore, the inner surface of the opening has a low liquid repellency and is relatively lyophilic, so that the functional liquid can be satisfactorily disposed in the opening partitioned by the partition wall, thereby forming a functional layer having a uniform thickness. I can get it.

In the method for manufacturing a light emitting device, the partition is formed by laminating a first organic material and a second organic material in this order, and a fluorine-containing material is used as the second organic material. Is preferred.
In this case, the fluorine content in the second organic material becomes the fluorine content in the surface layer on the upper surface of the partition wall, and the average fluorine content of the second organic material and the first organic material is within the opening. This is the fluorine content in the side surface layer. Therefore, the upper surface of the partition wall having a relatively high fluorine content becomes liquid repellent, and the inner side surface of the opening having a low fluorine content is relatively lyophilic with respect to the functional liquid. Therefore, the functional liquid can be satisfactorily disposed in the opening section defined by the partition walls, whereby a functional layer having a uniform film thickness can be obtained.

In the method for manufacturing a light emitting device, a fluorine-containing material is used as the first organic material, and the fluorine content in the first organic material is lower than the fluorine content in the second organic material. It is preferable to do this.
Here, the fluorine content in the inner surface of the opening that is the average of the fluorine content of the second organic material and the first organic material is the fluorine content of the second organic material constituting the upper surface of the partition wall. Lower than. Accordingly, the functional liquid can be satisfactorily disposed in the opening defined by the partition wall, and a functional layer having a uniform thickness can be obtained.

In the method for manufacturing the light emitting device, it is preferable that the thickness of the second organic material is smaller than the thickness of the first organic material.
Thus, by reducing the thickness of the second organic material having a high fluorine content, the weighted average value of the fluorine content on the inner surface of the opening is reduced, and as a result, the fluorine content on the inner surface is reduced. descend. Therefore, the upper surface of the partition wall becomes liquid repellent, and a functional layer having a uniform thickness can be formed in the opening section partitioned by the partition wall as described above.

  The light-emitting device of the present invention is a light-emitting device having a functional layer including a light-emitting layer in an opening partitioned by a partition made of an organic material, wherein the fluorine content in the surface layer on the upper surface of the partition is It is characterized by being higher than the fluorine content in the side surface layer.

According to the light emitting device of the present invention, the fluorine content in the surface layer on the upper surface of the partition wall is higher than the fluorine content in the surface layer on the side surface. Here, for example, when the surface layer on the upper surface has a fluorine content that is liquid repellent with respect to the functional liquid serving as the functional layer, the fluorine content in the surface layer on the inner surface of the opening is the partition wall. The inner surface of the opening is relatively lyophilic with respect to the functional liquid. When a functional liquid serving as a precursor of a functional layer is ejected to the opening section partitioned by such a partition wall, for example, by an inkjet method, the functional liquid disposed in the opening section is relatively lyophilic. It is in a state of being in good contact with the inner surface of the opening, and thus a liquid layer having a uniform and flat film thickness.
A functional layer having a uniform film thickness is obtained by drying the functional liquid that is in good contact with the inner surface of the opening and is maintained at a uniform film thickness. Therefore, according to the light emitting device of this configuration, the short circuit between the electrodes provided with the functional layer having a uniform thickness on the inner side surface of the opening is prevented, and the functional layer having a flat thickness is not easily deteriorated. For this reason, the life of the light emitting device is extended. Furthermore, as a functional layer having a flat film thickness, for example, a light-emitting device including the functional layer can prevent display unevenness, has high reliability, and high display characteristics.

  Embodiments of a light emitting device and a method for manufacturing the light emitting device of the present invention will be described below with reference to the drawings.

(Method for manufacturing light emitting device)
First, a process for manufacturing an organic EL device (light emitting device) will be described as an embodiment of a method for manufacturing a light emitting device.
The method for producing an organic EL device (light-emitting device) of the present invention comprises forming an organic bank (partition) on a substrate (base) and determining the fluorine content in the surface layer on the top surface of the organic bank. And a step of disposing an organic functional layer (functional layer) in the opening defined by the organic bank. In the present embodiment, an embodiment in which an organic functional layer in an organic EL device (light emitting device) is manufactured by using a droplet discharge method, for example, an inkjet method will be described. In addition, the procedure shown below and the material structure of a liquid material are examples, and are not limited to this.

(First embodiment)
First, a first embodiment of a method for manufacturing an organic EL device will be described.
In this embodiment, the organic bank (partition) is formed by laminating the first organic material and the second organic material in this order. Further, a fluorine-containing material is used as the second organic material.

1 and 2 are diagrams showing a manufacturing process of the organic EL device 70 of the present embodiment.
First, as shown in FIG. 1A, a driving TFT 143, a first interlayer insulating film 230, a second interlayer insulating film 240, and a pixel electrode 141 are formed on a substrate (base) P made of, for example, glass. These can be formed by a known method. Note that the pixel electrode 141 is formed of a light-transmitting conductive material such as ITO in the case of the bottom emission type. In the case of the top emission type, in addition to a light-transmitting conductive material, it is formed of an opaque or light-reflective conductive material such as aluminum, silver, gold, or platinum. Moreover, it is good also as a laminated film of ITO / Al.

  Next, as shown in FIG. 1B, an inorganic bank 149 made of an inorganic insulating material such as silicon oxide is formed so as to partially overlap the peripheral edge of the pixel electrode 141 in a planar manner. Specifically, after a silicon oxide film is formed so as to cover the pixel electrode 141 and the planarization insulating film 240, the silicon oxide film is patterned using a known photolithography technique, and the surface of the pixel electrode 141 is partially covered. Open to form.

Next, a step of forming the organic bank 150 on the substrate P is performed.
Specifically, as shown in FIG. 1C, after applying the first organic material B1 on the inorganic bank 149 provided on the substrate P, the first organic material B1 is dried ( Temporary drying). Subsequently, the second organic material B2 is applied on the first organic material B1, and the second organic material B2 is dried (temporarily dried). Thus, after laminating | stacking 1st organic material B1 and 2nd organic material B2 in order, the organic bank 150 which divides the opening part 151 is formed by performing patterning. Various methods such as spray coating, roll coating, die coating, and dip coating can be applied as a method for applying the first and second organic materials B1 and B2.
In addition, the first organic material B1 and the second organic material B2 are each made of a photosensitive material. In addition, as the first organic material B1, a material having lyophilicity with respect to a liquid material ejected by an ink jet process described later is employed, and an organic insulating material such as acrylic or polyimide is used. On the other hand, as the second organic material B2, a material having liquid repellency with respect to the liquid material, that is, a fluorine-containing material is used.

  Here, the organic material that is lyophilic with respect to the liquid material is not limited to a material that does not contain fluorine at all, and a fluorine-containing material may be used as the first organic material B1. Good. That is, the first organic material B1 may be composed of a material containing fluorine that does not exhibit liquid repellency with respect to the functional liquid. In this case, the first organic material B1 The fluorine content is assumed to be lower than the fluorine content in the second organic material B2.

By the way, as the fluorine content rate at which the bank exhibits liquid repellency with respect to the liquid material, the fluorine content rate of the surface layer of the bank, for example, the fluorine content rate from the surface to a depth of about 100 nm is the ion concentration of fluorine. It is generally considered to be 1 × 10 ²⁰ pieces / cm ³ or more. Therefore, in the present embodiment, as the second organic material B2, a material having a fluorine content, that is, a fluorine ion concentration of 1 × 10 ²⁰ ions / cm ³ or more is used.

  Then, by using a known photolithography technique and etching technique, the stacked body of the first organic material B1 and the second organic material B2 is patterned, and the organic bank 150 having the opening 151 is formed. Therefore, the organic bank 150 is configured by laminating the first bank layer 150a composed of the first organic material B1 and the second bank layer 150b composed of the second organic material B2. It has become.

  It is desirable that the thickness of the second organic material B2 is smaller than the thickness of the first organic material B1. Thus, by reducing the thickness of the second organic material having a high fluorine content, the proportion of the second organic material B2 having a high fluorine content in the surface layer on the inner surface of the opening 151 is increased. That is, the weighted average value of the fluorine content on the inner surface of the opening 151 is reduced. In this way, the fluorine content on the inner surface of the opening 151 is lower than the fluorine content on the inner surface of the upper surface of the organic bank 150 due to the decrease in the fluorine content on the inner surface.

  The height of the organic bank 150 is set to about 1 to 2 μm, for example, and functions as a partition member for the organic EL element 200 on the substrate P. Based on such a configuration, the opening formed of a sufficiently high step between the formation site of the hole injection layer and the light emitting layer, that is, the application position of these forming materials and the surrounding organic bank 150. 151 is formed. The opening 151 of the organic bank 150 and the opening 149b of the inorganic bank 149 communicate with each other, and the pixel electrode 141 is exposed in these openings.

After forming the organic bank 150, as shown in FIG. 1D, a surface treatment is performed on the region on the substrate P including the organic bank 150 and the pixel electrode 141.
Specifically, a plasma treatment (O ₂ plasma treatment) using oxygen as a reactive gas under atmospheric pressure is performed on the substrate P as a lyophilic step. By this lyophilic treatment, the lyophilicity on the pixel electrode 141 and the first bank layer 150a can be further improved.

  Next, the organic bank 150 can be stabilized by performing heat treatment, and the liquid repellency of the second bank layer 150a can be further improved. The organic bank 150 may be partially softened by controlling the heat treatment conditions so that the inner surface of the opening 151 has a tapered shape with an inclined surface that forms an acute angle with respect to the upper surface of the substrate P. . The provision of such a tapered shape prevents the organic functional layer disposed in the opening 151 from being thinned around the organic bank 150 by a process described later.

  Next, as shown in FIG. 2A, a liquid material 114a containing a hole injection layer forming material with the upper surface of the substrate P facing upward is coated with an organic bank 150 surrounded by an organic bank 150 (see FIG. Apply selectively to the openings 151). The liquid material (functional liquid) 114a for forming the hole injection layer includes a hole injection layer forming material (charge transport layer forming material) and a solvent.

  As the hole injection layer forming material, polyphenylene vinylene whose polymer precursor is polytetrahydrothiophenylphenylene, 1,1-bis- (4-N, N-ditolylaminophenyl) cyclohexane, tris (8-hydroxyquinolinol) Examples thereof include aluminum, polystyrene sulfonic acid, a mixture of polyethylene dioxythiophene and polystyrene sulfonic acid (PEDOT / PSS), and the like. Examples of the solvent include polar solvents such as isopropyl alcohol, N-methylpyrrolidone, and 1,3-dimethyl-imidazolinone.

  When the liquid material 114a containing the hole injection layer forming material described above is ejected from the inkjet head 1 onto the substrate P, it tends to spread in the horizontal direction due to its high fluidity. However, the organic bank surrounds the applied position. Since 150 is formed, the liquid material 114a does not extend beyond the organic bank 150 to the outside.

At this time, the film formation state of the hole injection layer is affected by the wettability of the organic bank 150 with respect to the liquid material 114a.
Therefore, in the present embodiment, as described above, the upper surface of the organic bank 150 having a relatively high fluorine content is made liquid repellent, and the inner surface of the opening 151 defined by the organic bank 150 having a low fluorine content is defined as the above-described inner surface. It is relatively lyophilic with respect to the liquid material 114a.

  When the liquid material 114a serving as the precursor of the hole injection layer (organic functional layer) is ejected to the opening 151 partitioned by the organic bank 150 by an inkjet method, the liquid material 114a disposed in the opening 151 is discharged. Since the inner surface of the opening 151 is lyophilic as described above, the liquid material 114a is in good contact with the inner surface of the opening 151, and thus the film thickness is uniform and flat. It becomes a liquid layer.

  Further, since the inner side surface of the opening 151 provided in the organic bank 150 is tapered with respect to the upper surface of the substrate P, the inner side surface of the opening 151 that is lyophilic with respect to the liquid material 114a and the liquid The contact area with the material 114a is increased.

Subsequently, the solvent of the liquid material 114 a is evaporated by heating or light irradiation to form a solid hole injection layer 140 A on the pixel electrode 141. Alternatively, firing may be performed at a predetermined temperature and time (for example, 200 ° C., 10 minutes) in an air environment or a nitrogen gas atmosphere.
Or you may make it remove a solvent by arrange | positioning in the pressure environment (under pressure reduction environment) lower than atmospheric pressure.
At this time, the liquid layer made of the liquid material 114a is heat-treated in a state in which the liquid layer 114a is in good contact with the inner surface of the opening 151 and is maintained in a uniform film thickness, and thus becomes a hole injection layer 140A. A hole injection layer 140A having a film thickness is obtained.

  Subsequently, as shown in FIG. 2B, a liquid material (functional liquid) 114 b containing a light emitting layer forming material and a solvent is transferred from the inkjet head 1 in the organic bank 150 with the upper surface of the substrate P facing upward. It selectively coats on the hole injection layer 140A.

  As this light emitting layer forming material, polyfluorene derivatives (PF), polyparaphenylene vinylene derivatives (PPV), polyphenylene derivatives (PP), polyphenylene derivatives (PF), which are known polymer light emitting materials capable of emitting fluorescence or phosphorescence. Polysilanes such as paraphenylene derivatives (PPP), polyvinylcarbazole (PVK), polythiophene derivatives, polydialkylfluorene (PDAF), polyfluorenebenzothiadiazole (PFBT), polyalkylthiophene (PAT), and polymethylphenylsilane (PMPS) Etc. can be used suitably. In addition, these light-emitting materials include polymer materials such as perylene dyes, coumarin dyes, rhodamine dyes, rubrene, perylene, 9,10-diphenylanthracene, tetraphenylbutadiene, Nile red, coumarin 6, quinacridone, and the like. It is also possible to use a low molecular weight material doped.

  The light emitting layer forming material is preferably dissolved or dispersed in a polar solvent to form a liquid material, and this liquid material is preferably discharged from the inkjet head 1. The polar solvent can easily dissolve or uniformly disperse the light emitting material and the like, thereby preventing the solid component in the light emitting layer forming material from adhering to the nozzle holes of the inkjet head 1 and causing clogging. can do.

  Specific examples of such a polar solvent include water, alcohols compatible with water such as methanol and ethanol, N, N-dimethylformamide (DMF), N-methylpyrrolidone (NMP), dimethylimidazoline (DMI), Examples include organic solvents or inorganic solvents such as dimethyl sulfoxide (DMSO), xylene, cyclohexylbenzene, and 2,3-dihydrobenzofuran, and two or more of these solvents may be appropriately mixed.

  The formation of the light emitting layer by ejecting the liquid material 114b from the inkjet head 1 includes a liquid material including a light emitting layer forming material that emits red colored light, a liquid material including a light emitting layer forming material that emits green colored light, A liquid material containing a light emitting layer forming material that emits blue colored light is discharged and applied to the corresponding pixel (opening 151). Note that the pixels corresponding to each color are determined in advance so that they are regularly arranged.

  When the liquid material 114b containing the light emitting layer forming material of each color is discharged and applied in this manner, the solvent in the liquid material 114b is evaporated. By this step, as shown in FIG. 2C, a solid light emitting layer 140B is formed on the hole injection layer 140A, and thereby an organic functional layer 140 composed of the hole injection layer 140A and the light emitting layer 140B is obtained. . Here, regarding the evaporation of the solvent in the liquid material 114b containing the light emitting layer forming material, treatment such as heating or decompression is performed as necessary. However, the light emitting layer forming material usually has a good drying property and a fast drying property. Therefore, the light emitting layer 140B of each color can be formed in the order of application by sequentially discharging and applying the light emitting layer forming material of each color without performing such a process.

  Further, as described above, the organic bank 150 has a liquid-repellent top surface and a lyophilic side surface (inner side surface of the opening 151), and thus a light emitting layer formed on the hole injection layer 140A. 140B is also in good contact with the contact surface with the organic bank 150 and is formed with good flatness. Therefore, the light emitting layer 140B having uniform and good light emission characteristics and reliability can be manufactured.

  Thereafter, as shown in FIG. 2C, a common electrode 154 made of ITO or the like is formed on the entire surface of the substrate P or in a stripe shape. Note that an electrode protective layer for preventing entry of oxygen or the like may be provided over the common electrode 154. In this way, the organic EL element 200 can be manufactured.

Finally, the substrate P provided with the organic EL element 200 is bonded to a sealing substrate (not shown). Here, first, the sealing resin layer 30 is disposed on the surface of the common electrode 154 formed on the substrate P so as to cover the common electrode 154, and then the sealing substrate 40 is sealed in the reduced pressure atmosphere. An organic EL device 70 as shown in FIG. 3 is obtained by performing the above arrangement by adhering.
In this way, by performing adhesion in a reduced-pressure atmosphere, it is possible to prevent bubbles from entering between the sealing resin layer 30 and the substrate P or between the sealing resin layer 30 and the sealing substrate 40. For this reason, it is prevented that oxygen and moisture enter the light emitting layer 140B through the bubbles, and the light emission characteristics and life of the light emitting layer 140B can be prevented from decreasing. Through the above steps, the organic EL device 70 can be manufactured.

As described above, in the method of manufacturing the organic EL device 70 according to the present embodiment, the upper surface of the organic bank 150 is made lyophobic and the inner surface of the opening 151 is made lyophilic as described above. It becomes possible to arrange the liquid materials 114 a and 114 b to be the layer 140 in a state of being in good contact with the inner surface of the opening 151. Therefore, the hole injection layer 140A and the light emitting layer 140B having a flat film thickness can be formed in the opening 151.
In addition, since a thin portion does not occur in the organic functional layer 140 including the hole injection layer 140A and the light emitting layer 140B formed on the inner surface of the opening 151, the organic functional layer 140 is sandwiched therebetween. A short circuit can be prevented from occurring between the pixel electrode 141 and the common electrode 154 provided. Further, since the flat organic functional layer 140 is provided, it is possible to prevent a problem that the deterioration is accelerated, and thus the life of the organic EL device 70 can be extended. Further, the organic EL device 70 including the light emitting layer 140B having a flat film thickness prevents display unevenness, and thus has high display characteristics and high reliability.

  The organic EL device 70 according to the present embodiment employs a structure in which the pixel electrode 141 is an anode and the common electrode 154 is a cathode. On the contrary, the pixel electrode 141 is a cathode and the common electrode 154 is an anode. It is also possible to adopt a structure that does this. In this case, an electron injection layer is formed as the charge transport layer disposed between the pixel electrode and the light emitting layer.

(Light emitting device)
Next, as an embodiment of the light emitting device, a configuration of the organic EL device 70 manufactured by the above-described method for manufacturing an organic EL device will be described with reference to the drawings.
FIG. 3 is a side sectional view of the organic EL device according to the present embodiment. Reference numeral 70 in the drawing is the organic EL device.
The organic EL device includes an organic functional layer 140 in an opening 151 partitioned by an organic bank 150 provided on a substrate P.

  As the substrate P, in the case of a so-called bottom emission type organic EL device, since the light is extracted from the substrate P side, a transparent substrate such as glass is used. On the other hand, in the case of a so-called top emission type organic EL device, light is extracted from the side on which the organic EL element 200 is disposed. Therefore, in addition to a transparent substrate such as glass, an opaque substrate can be used. Examples of opaque substrates include ceramics such as alumina, metal sheets such as stainless steel that have been subjected to insulation treatment such as surface oxidation, thermosetting resins and thermoplastic resins, and films thereof (plastic films). It is done.

  A driving TFT 143 is provided on the substrate P. As shown in FIG. 3, the driving TFT 143 includes a source region 143a, a drain region 143b, a channel region 143c formed in the semiconductor film 210, and a semiconductor layer. The gate electrode 143A facing the channel region 143c is mainly formed through the gate insulating film 220 formed on the surface.

  A first interlayer insulating film 230 is formed to cover the semiconductor film 210 and the gate insulating film 220. The drain electrodes 236 are respectively formed in the contact holes 232 and 234 that penetrate the first interlayer insulating film 230 and reach the semiconductor film 210. The source electrode 238 is buried, and each electrode is conductively connected to the drain region 143b and the source region 143a. A second interlayer insulating film 240 is formed in the first interlayer insulating film 230, and a part of the pixel electrode 141 is embedded in a contact hole penetrating through the second interlayer insulating film 240.

  The pixel electrode 141 and the drain electrode 236 are conductively connected, so that the driving TFT 143 and the pixel electrode 141 (organic EL element 200) are electrically connected. An inorganic bank 149 made of an inorganic insulating material is formed so as to partially run on the peripheral edge of the pixel electrode 141, and an organic bank 150 made of an organic material is laminated on the inorganic bank 149 to constitute a partition member. ing.

  In the present embodiment, the organic bank 150 includes a first bank layer 150a made of the first organic material B1, and a second bank made of the second organic material B2 having a thickness smaller than that of the first bank layer 150a. The bank layer 150b is laminated and configured. As described above, the first organic material B1 is made of a material that is lyophilic with respect to the liquid material that becomes the organic functional layer 140, and the second organic material B2 is repellent to the liquid material. It is composed of a fluorine-containing material that exhibits liquidity, and the fluorine content in the surface layer on the upper surface of the organic bank 150 is higher than the fluorine content in the surface layer on the inner surface of the opening 151.

  An organic functional layer 140 including a hole injection layer 140 </ b> A and a light emitting layer 140 </ b> B as a charge transport layer is provided on the pixel electrode 141 and the opening 151 partitioned by the organic bank 150. The organic functional layer 140 is formed by the above-described ink jet process, is formed in close contact with the inner surface of the opening 151, and has a uniform and flat film thickness. A common electrode 154 is formed to cover the light emitting layer 140 </ b> B and the organic bank 150, thereby configuring the organic EL element 200.

  According to such a configuration, since a thin portion does not occur on the inner side surface of the opening 151, a short circuit between the electrodes (the pixel electrode 141 and the common electrode 154) provided with the organic functional layer 140 interposed therebetween is prevented. Is prevented. Further, since the organic functional layer 140 having a flat film thickness is unlikely to deteriorate, the organic EL device 70 including the organic functional layer 140 has a long life. Further, the organic EL device 70 including the light emitting layer 140B having a flat film thickness prevents display unevenness, and has high reliability and high display characteristics.

  The hole injection layer 140A is formed so as to cover the pixel electrode 141, and the peripheral end portion of the inorganic bank 149 provided on the lower layer side of the organic bank 150 is from the organic bank 150 to the center side of the pixel electrode 141. A portion that protrudes from the cover is also covered.

  The pixel electrode 141 is formed of a light-transmitting conductive material such as ITO (indium tin oxide) in the case of the bottom emission type that extracts light through the substrate P, but in the case of the top emission type, the pixel electrode 141 is transparent. It does not need to be light, and can be formed of an appropriate conductive material such as a metal material.

The common electrode 154 is formed on the substrate P so as to cover the upper surfaces of the light emitting layer 140B and the organic bank 150 and further the inner surface of the opening 151. As a material for forming the common electrode 154, in the case of the top emission type, a transparent conductive material is used. ITO is suitable as the transparent conductive material, but other translucent conductive materials may be used. In the case of the bottom emission type, in addition to the transparent conductive material, an opaque or light reflective conductive material such as aluminum can be used. Note that an electrode protective layer for preventing oxygen or the like from entering the common electrode 154 made of an inorganic oxide may be provided on the upper side of the common electrode 154.
A sealing resin layer 30 is provided on the common electrode, and the sealing substrate 40 is bonded to the common electrode via the sealing resin layer 30.

FIG. 4 is a diagram illustrating a circuit configuration of the organic EL device 70.
As shown in FIG. 4, the organic EL device 70 includes a plurality of scanning lines (wirings, power conduction units) 131 and a plurality of signals extending in a direction intersecting the scanning lines 131 on a substrate made of glass or the like. A line (wiring, power conduction unit) 132 and a plurality of common power supply lines (wiring, power conduction unit) 133 extending in parallel to the signal lines 132 are respectively wired. A pixel (pixel region) 71 is provided for each intersection.

  For the signal line 132, a data side driving circuit 72 including a shift register, a level shifter, a video line, an analog switch, and the like is provided. On the other hand, the scanning line 131 is provided with a scanning side drive circuit 73 including a shift register, a level shifter, and the like. Further, each of the pixel regions 71 is supplied from a switching TFT (thin film transistor) 142 to which a scanning signal is supplied to the gate electrode through the scanning line 131 and from the signal line 132 through the switching TFT (thin film transistor) 142. A storage capacitor cap that holds the image signal (power) to be generated, the driving TFT 143 that supplies the image signal held by the storage capacitor cap to the gate electrode, and the common feeding line 133 via the driving TFT 143. A pixel electrode 141 into which a driving current flows from the common power supply line 133 when connected to the pixel electrode 141 and an organic functional layer 140 sandwiched between the pixel electrode 141 and the common electrode 154 are provided.

  Under such a configuration, when the scanning line 131 is driven and the switching TFT 142 is turned on, the potential of the signal line 132 at that time is held in the holding capacitor cap, and depending on the state of the holding capacitor cap, The on / off state of the driving TFT 143 is determined. Then, a current flows from the common power supply line 133 to the pixel electrode 141 through the channel of the driving TFT 143, and further a current flows to the common electrode 154 through the light emitting layer 140B, whereby the organic EL element 200 emits light according to the amount of current. It is like that.

  According to the organic EL device 70 of the present embodiment, since the organic functional layer 140 having a uniform film thickness is provided in the opening 151, the electrodes (the pixel electrode 141 and the common electrode) provided with the organic functional layer 140 interposed therebetween. 154) is prevented, and the functional layer having a flat film thickness is not easily deteriorated. Therefore, the organic EL device 70 has a long life. Furthermore, the organic EL device 70 provided with the light emitting layer 140B having a flat film thickness prevents display unevenness, and has high reliability and high display characteristics.

(Second Embodiment)
Next, a method for manufacturing an organic EL device and a second embodiment of the organic EL device will be described.
In the manufacturing method of the organic EL device of the present embodiment, as described later, when forming the organic bank, the fluorine content in the surface layer on the upper surface of the organic bank is determined from the fluorine content in the surface layer on the inner side surface of the opening. The step of increasing is performed by anisotropic plasma treatment using a reactive gas containing fluorine.

  In the first embodiment described above, the upper part of the two-layer organic bank is formed of a material having a high fluorine content (second organic material B2), but in this embodiment, plasma processing is used. The method differs in that the fluorine content in the surface layer on the upper surface of the organic bank is made higher than the fluorine content in the surface layer on the side surface. Therefore, in the following description, an anisotropic plasma treatment process using a reaction gas containing fluorine will be described, and description of other manufacturing processes will be omitted. Moreover, the same code | symbol is attached | subjected about the thing of the same structure.

FIG. 5 is a diagram showing a process of forming an organic bank in the organic EL device of this embodiment.
As shown in FIG. 5A, the driving TFT 143 and the pixel electrode 141 are formed on the substrate P, and the inorganic bank 149 is partially overlapped with the peripheral edge of the pixel electrode 141 in a plane. Is formed.

First, the bank forming material BB made of an organic insulating material such as acrylic or polyimide is applied on the inorganic bank 149 by various methods such as spray coating, roll coating, die coating, dip coating, and the like.
Then, by using a known photolithography technique and etching technique, the bank forming material BB is patterned to form an organic bank 150A provided with an opening 151. The opening 151 of the organic bank 150A and the opening 149b of the inorganic bank 149 communicate with each other, and the pixel electrode 141 is exposed in these openings.

  Subsequently, before the liquid material 114a containing the hole injection layer forming material is discharged into the opening 151 provided in the organic bank 150A by the ink jet head, as shown in FIG. Surface treatment is performed on the region on the substrate P including the pixel electrode 141.

In the present embodiment, anisotropic plasma treatment is performed using a fluoride compound such as CF ₄ , SF ₆ , and CHF ₃ as a reactive gas containing fluorine. Specifically, ICP (inductively coupled plasma) that can individually control the bias to the substrate and the excitation energy of the plasma is suitably used as the plasma. Then, anisotropic plasma treatment is performed by applying a high substrate bias in a low-pressure atmosphere (for example, 10 Pa or less).
At this time, the surface layer on the upper surface of the organic bank 150A, for example, fluorine content between from the surface to 100nm depth of about is, under conditions such that 1 × 10 ²⁰ / cm ³ or more as the ion concentration of fluorine The plasma treatment was performed. Therefore, fluorine ions are introduced only into the surface layer on the upper surface of the organic bank 150A (the surface indicated by the two-dot chain line in FIG. 5B), and the upper surface of the organic bank 150A repels the liquid material.

At this time, the surface of the pixel electrode 141 made of an inorganic material such as an ITO film or a metal film and the surface of the inorganic bank 149 made of an inorganic material such as silicon oxide are less liable to be lyophobic than the surface of the organic bank 150A made of an organic material. Therefore, fluorine ions are not introduced into the surface of the pixel electrode 141 and the surface of the inorganic bank 149 exposed in the opening 151 provided in the organic bank 150A, and the liquid material has lyophilicity. Will remain held.
As described above, only the upper surface of the organic bank 150A can be selectively made liquid-repellent by the above-described plasma treatment process, and the fluorine content in the surface layer on the upper surface of the organic bank 150A is determined by the side surface of the organic bank 150A. It is relatively higher than the fluorine content in the surface layer.

Next, as shown in FIG. 5C, the liquid material 114a containing the material for forming the hole injection layer (organic functional layer) is discharged to the opening 151 of the organic bank 150A by the inkjet head.
In the present embodiment, the upper surface of the organic bank 150A having a relatively high fluorine content exhibits liquid repellency, and the inner surface of the opening 151 defined by the organic bank 150A having a low fluorine content is relative to the liquid material 114a. It is lyophilic.
Therefore, when the liquid material 114a is ejected into the opening 151 by the ink jet method, the liquid material 114a is in good contact with the inner surface of the opening 151, and a liquid layer having a uniform film thickness is obtained.

  Subsequently, as in the first embodiment, the liquid material 114a is in good contact with the inner surface of the opening 151, and is heated to maintain a uniform film thickness, thereby forming a uniform film thickness. A hole injection layer 140A is formed. Then, a liquid material 114b containing a light emitting layer forming material and a solvent is selectively applied from the inkjet head onto the hole injection layer 140A in the organic bank 150A.

  Further, as described above, the organic bank 150A has a liquid-repellent top surface and a lyophilic side surface (inner side surface of the opening 151), and thus a light emitting layer formed on the hole injection layer 140A. 140B is also formed in contact with the organic bank 150A, so that the film thickness is uniform. Therefore, the light emitting layer 140B having uniform and good light emission characteristics and reliability can be manufactured. After that, as shown in FIG. 5D, the organic EL element 200 can be formed by forming the common electrode 154 made of ITO or the like on the entire surface of the substrate P or in a stripe shape. Finally, the organic EL device of this embodiment is obtained by bonding the substrate P provided with the organic EL element 200 and the sealing substrate through a sealing resin layer.

  Note that the organic EL device formed by the method of manufacturing the organic EL device of the present embodiment has a configuration other than that in which the organic bank 150A has a single-layer structure, and the organic EL device 70 in the first embodiment. Since it is the same as that, its description is omitted.

Thus, according to the manufacturing method of the organic EL device in the present embodiment, as described above, the upper surface of the organic bank 150A is made liquid-repellent, and the side surface (the inner surface of the opening 151) of the organic bank 150A is a lyophilic solution. Thus, the hole injection layer 140 </ b> A and the light emitting layer 140 </ b> B having a flat film thickness can be formed in the opening 151, and high display characteristics and reliability in which display unevenness is prevented are provided.
Therefore, as in the first embodiment, by preventing a short circuit between the pixel electrode 141 and the common electrode 154, an organic EL device having a long lifetime can be obtained.

(Third embodiment)
Next, a third embodiment of the method for manufacturing an organic EL device will be described.
In the present embodiment, as will be described later, an organic bank (partition) is provided on the substrate with an organic bank forming material (partition forming material), and fluorine ions are implanted into the surface layer on the upper surface of the organic bank forming material. The organic bank forming material is formed by patterning openings.

  In the present embodiment, ion implantation is used as a method for increasing the fluorine content in the surface layer on the upper surface of the organic bank in the second embodiment described above than the fluorine content in the surface layer on the inner surface of the opening. The steps for manufacturing the organic EL device are the same except for the differences. Therefore, in the following description, only the process of forming the organic bank of this embodiment will be described in detail, and the description of other manufacturing processes will be omitted. In addition, the same structure is described with the same reference numeral.

  FIG. 6 is a diagram schematically showing a process of forming an organic bank in the organic EL device 70 of the present embodiment. Therefore, in FIG. 6, illustration of the driving TFT 143, the pixel electrode 141, and the inorganic bank 149 provided on the pixel electrode 141 provided on the substrate P is omitted.

  In this embodiment, as shown in FIG. 6A, a bank forming material (partition wall formation) made of an organic insulating material such as acrylic or polyimide is a photosensitive material on a substrate P provided with an inorganic bank or the like. Material) BB is applied by various methods such as spray coating, roll coating, die coating, and dip coating.

Subsequently, fluorine ions are implanted from the upper surface side of the bank forming material BB by using an ion implantation method such as ion doping or ion implantation. At this time, the surface layer on the upper surface of the organic bank 150A, for example, under the condition that the fluorine content between the surface and the depth of about 100 nm is 1 × 10 ²⁰ ions / cm ³ or more as the ion concentration of fluorine. The ion implantation process was performed. The ion implantation amount can be controlled by adjusting the ion current when ionizing by generating plasma by gas discharge and the implantation time into the sample (bank forming material BB).

In the present embodiment, fluorine ions are implanted by implanting, for example, BF ₃ under an acceleration voltage of about 2 to 50 KV. The dose is about 1.5 × 10 ¹⁶ / cm ² . Then, as shown in FIG. 6B, a fluorine implantation region FA in which fluorine ions are implanted into a surface layer on the upper surface of the bank forming material BB, specifically, a region having a depth of about 100 nm from the upper surface is formed. . Here, in the fluorine implantation region FA, that is, the surface layer on the upper surface of the bank forming material BB, fluorine ions are implanted to a depth of about 100 nm at a dose of 1.5 × 10 ¹⁶ / cm ² as described above. The fluorine ion concentration is 1 × 10 ²¹ ions / cm ³ . Therefore, since the surface layer on the upper surface of the bank forming material BB has a fluorine content of 1 × 10 ²⁰ pieces / cm ³ or more, it repels liquid material discharged into the opening 151 in a later step. Become liquid.

  Subsequently, as shown in FIG. 6C, the bank forming material BB is patterned by performing exposure through the mask M by a photolithography technique and then performing development processing. Then, as shown in FIG. 6D, an organic bank 150B provided with an opening 151 is formed. In the present embodiment, the inner surface of the opening 151 is tapered with respect to the upper surface of the substrate P.

Here, since fluorine ion implantation is performed with the surface of the pixel electrode 141 and the surface of the inorganic bank 149 covered with the bank forming material BB, the inner surface of the opening 151 provided in the organic bank 150B after the ion implantation. Fluorine ions are not introduced into the liquid, so that the liquid material is kept in a lyophilic state.
Thus, by making the surface layer (fluorine region) on the upper surface of the organic bank 150B liquid-repellent by the above-described fluorine ion implantation step, the fluorine content in the upper surface layer can be reduced. It is in a state relatively higher than the fluorine content in the surface layer on the inner side surface.

Next, in the same manner as in the above embodiment, the liquid material 114a containing the hole injection layer forming material is discharged to the opening 151 of the organic bank 150B by the ink jet head.
At this time, similarly to the first and second embodiments, when the liquid material 114a serving as the precursor of the hole injection layer (organic functional layer) is discharged and arranged in the opening 151 by the inkjet method, the liquid material 114a is disposed. Is in good contact with the inner surface of the opening 151 and forms a uniform and flat liquid layer. Subsequently, similarly to the above embodiment, when the heat treatment is performed, the liquid material 114a is held in the opening 151 in a uniform film thickness state, so that the hole injection layer 140A having a uniform film thickness is Become.

  Subsequently, a liquid material 114b containing a light emitting layer forming material and a solvent is selectively applied from the inkjet head onto the hole injection layer 140A in the organic bank 150B, thereby providing uniform and good light emitting characteristics and reliability. The light emitting layer 140B can be manufactured. Thereafter, the common electrode 154 made of ITO or the like is formed on the entire surface of the substrate P or in a stripe shape, and the organic EL element 200 can be manufactured as shown in FIG. Finally, the organic EL device of this embodiment is obtained by bonding the substrate P provided with the organic EL element 200 and the sealing substrate through a sealing resin layer.

  Note that the organic EL device formed by the method of manufacturing the organic EL device of the present embodiment has the same configuration as that of the first embodiment except that the organic bank 150B has a single layer structure. Since it is the same as that, its description is omitted.

Thus, also in the manufacturing method of the organic EL device in the present embodiment, the upper surface of the organic bank 150B is made liquid repellent as described above, and the side surface of the organic bank 150B (the inner side surface of the opening 151) is lyophilic. As a result, the hole injection layer 140A and the light emitting layer 140B having a flat film thickness can be formed in the opening 151, and an organic EL device having high display characteristics in which display unevenness is prevented and reliability can be manufactured. .
Therefore, as in the first and second embodiments, by preventing a short circuit between the pixel electrode 141 and the common electrode 154, an organic EL device having a long lifetime can be obtained.

It is a figure which shows the manufacturing process of an organic electroluminescent apparatus. It is a figure which shows the manufacturing process of the organic electroluminescent apparatus following FIG. It is a figure which shows the side part cross section in the organic electroluminescent apparatus of 1st Embodiment. It is a figure which shows the circuit structure of the organic electroluminescent apparatus of 1st Embodiment. It is a figure which shows the process of forming the organic bank of 2nd Embodiment. It is a figure which shows typically the process of forming the organic bank of 3rd Embodiment.

Explanation of symbols

70 ... Organic EL device (light emitting device), 114a, 114b ... Liquid material (functional liquid), 140 ... Organic functional layer (functional layer), 140A ... Hole injection layer (charge transport layer), 140B ... Light emitting layer, 141 ... Pixel electrode, 149... Inorganic bank, 149 b. Inorganic bank opening, 150... Organic bank (partition), 151... Opening, BB ... Bank formation material (partition formation material), P.

Claims (8)

In the method for manufacturing a light-emitting device, in which a functional layer including a light-emitting layer is disposed in an opening partitioned by a partition made of an organic material,
Forming the partition on the substrate, and making the fluorine content in the surface layer on the upper surface of the partition higher than the fluorine content in the surface layer on the inner surface of the opening;
And a step of disposing the functional layer in an opening defined by the partition wall.   The method for manufacturing a light emitting device according to claim 1, wherein an inner side surface of the opening provided in the partition wall is tapered with respect to an upper surface of the base.   2. The method for manufacturing a light emitting device according to claim 1, wherein an anisotropic plasma treatment using a reactive gas containing fluorine is performed when forming the partition wall.   In the step of forming the partition wall, a partition wall forming material is provided on the substrate, fluorine ions are implanted into a surface layer on the upper surface of the partition wall forming material, and then the partition wall forming material is patterned to form the opening. The method for manufacturing a light-emitting device according to claim 1 or 2.   The partition is formed by laminating a first organic material and a second organic material in this order, and a fluorine-containing material is used as the second organic material. The manufacturing method of the light-emitting device of description.   6. The fluorine-containing material is used as the first organic material, and the fluorine content in the first organic material is lower than the fluorine content in the second organic material. The manufacturing method of the light-emitting device of description.   The method for manufacturing a light-emitting device according to claim 6, wherein a thickness of the second organic material is made thinner than a thickness of the first organic material. In a light emitting device including a functional layer including a light emitting layer in an opening sectioned by a partition made of an organic material,
The light-emitting device according to claim 1, wherein the fluorine content in the surface layer on the upper surface of the partition wall is higher than the fluorine content in the surface layer on the inner surface of the opening.

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