JP2010118198A - Manufacturing method of organic light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an organic light-emitting device of excellent emission characteristics by effectively removing decomposed water generated at a manufacturing process. <P>SOLUTION: In the manufacturing method of the organic light-emitting device 1 having an organic light-emitting element part pinched by an anode 12 and a cathode 17 and composed of an organic compound layer including a hole transport layer 13 and a light-emitting layer 14 in that order, pixel separation films 18, and a flattened film (an inter-layer insulation film 11) provided on a substrate 10, with a constituent material of either the pixel separation films or the flattened film made of an organic material, a process of forming the anode 12, the pixel separation films 18, and the flattened film on the substrate 10, a UV-ray irradiating process of irradiating UV rays on the substrate 10 while guiding in/exhausting gas containing at least oxygen, a heating treatment process of the substrate 10, and an organic compound layer forming process of forming an organic compound layer on the anode 12 are included. The UV-ray irradiating process and the substrate heating treatment process are carried out at the same time, and the UV-ray irradiating process is carried out under a pressure atmosphere of less than an ambient pressure. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an organic light emitting device.

In 1987, Tang et al. Proposed an organic light-emitting device in which organic compounds having different carrier transport properties were stacked and holes and electrons could be injected from the anode and the cathode in a balanced manner. Specifically, a thin film made of an organic compound is formed between the anode and the cathode with a film thickness of 200 nm or less. The manufactured device emitted light with a luminance of 1000 cd / m ² when a voltage of 10 V was applied, and achieved luminous efficiency and luminance that were not found in the past. Since then, research and development have been carried out to obtain high luminance light emission and high driving life at a lower voltage.

  Patent Document 1 proposes that the steps from forming the anode on the substrate to forming the organic compound layer and forming the cathode are consistently performed under reduced pressure. That is, after the anode is patterned on the substrate by dry etching without providing a pixel separation film, the UV ozone treatment step, the oxygen plasma treatment step, and the organic compound layer formation step are performed consistently and continuously under reduced pressure. It is a method. According to Patent Document 1, not only the anode surface can be cleaned by this method, but also the anode surface is appropriately oxidized, so that the hole injection property is improved, the emission is uniformized, the voltage is reduced, and the length is increased. It is shown that the lifetime is improved.

  In Patent Document 2, after irradiating UV light (ultraviolet rays) having directivity under a reduced pressure of 0.0001 Pa to 0.1 Pa, the substrate is transported to an organic compound layer forming chamber having a pressure condition higher than this pressure range. It is shown that an organic compound layer is formed. Further, according to Patent Document 2, it is shown that contaminants in the organic compound layer forming treatment chamber are not attached to the substrate by irradiation with UV light in advance.

  Further, Patent Document 3 shows that UV light emission is performed while heating the substrate with an anode at 145 ° C. or higher. According to Patent Document 3, by performing UV light irradiation while heating the substrate, the carbonyl compound that can be present on the surface of the anode (ITO, etc.) that was difficult to decompose by UV light irradiation at room temperature is decomposed, Since it can be removed, it is disclosed that the device itself has a long lifetime.

JP-A-10-302965 Japanese Patent Application Laid-Open No. 9-232075 JP 2004-139746 A

  However, regarding the organic light-emitting device in which the constituent material of either the pixel separation film or the planarization film is an organic material, there is a problem described later when the techniques of Patent Documents 1 to 3 are used. That is, in a step of irradiating UV light in a gas atmosphere containing at least oxygen (hereinafter referred to as a UV ozone treatment step), a part of the pixel separation film and the planarization film is decomposed, and the decomposition product causes the anode Could be contaminated.

  Furthermore, there is a problem that decomposed water is generated during the decomposition process, and this decomposed water is inherent in the pixel separation film and the flattening film. This decomposed water has been a cause of peripheral luminance deterioration of the organic light emitting element pixel portion when the organic light emitting device is used.

  Accordingly, an object of the present invention is to provide a method for manufacturing an organic light-emitting device capable of effectively removing decomposed water generated in the manufacturing process and obtaining good light-emitting characteristics.

The organic light-emitting device manufacturing method of the present invention comprises an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode and including at least a hole transport layer and a light-emitting layer in this order. A light emitting element portion;
A pixel separation film;
A planarization film;
In a method for manufacturing an organic light-emitting device in which any of the constituent materials of the pixel separation film and the planarization film is an organic material,
Forming each of the anode, the pixel isolation film, and the planarizing film on the substrate;
A UV light irradiation step of irradiating the substrate with UV light while introducing and exhausting a gas containing at least oxygen;
A substrate heat treatment step for heating the substrate;
An organic compound layer forming step of forming the organic compound layer on the anode,
Performing the UV light irradiation step and the substrate heat treatment step simultaneously;
The UV light irradiation step is performed under a pressure atmosphere less than atmospheric pressure.

  According to the present invention, it is possible to provide a method for manufacturing an organic light-emitting device capable of effectively removing decomposed water generated in the manufacturing process and obtaining good light-emitting characteristics.

  The manufacturing method of the organic light emitting device of the present invention is a method of manufacturing an organic light emitting device including an organic light emitting element portion, a pixel separation film, and a planarizing film on a substrate. Note that the organic light emitting element portion includes an anode, a cathode, and an organic compound layer sandwiched between the anode and the cathode and including at least a hole transport layer and a light emitting layer in this order. In the organic light emitting device manufactured by the manufacturing method of the present invention, any constituent material of the pixel separation film and the planarization film is an organic material.

  First, an organic light-emitting device manufactured by the manufacturing method of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view showing an organic light-emitting device manufactured by the manufacturing method of the present invention.

  In the organic light emitting device 1 of FIG. 1, a TFT (thin film transistor, not shown), an interlayer insulating film 11, and an anode 12 are provided on a substrate 10 in this order. Here, the interlayer insulating film 11 functions as a planarizing film that fills the unevenness generated when the TFT is provided and planarizes the surface. On the anode 12, a pixel separation layer 18 is formed in a desired pattern. In a region where the surface of the anode 12 is exposed without the pixel separation layer 18 being formed, an organic compound layer (to be described later) and a cathode 17 are sequentially formed to constitute a pixel region.

  In the organic light emitting device 1 of FIG. 1, a hole transport layer 13, a light emitting layer 14, an electron transport layer 15 and an electron injection layer 16 are laminated in this order in the pixel region. Here, the hole transport layer 13, the light-emitting layer 14, the electron transport layer 15 and the electron injection layer 16 shown in FIG. 1 constitute an organic compound layer. However, the layers constituting the organic compound layer are not limited to this combination. It is sufficient that at least the hole transport layer and the light emitting layer are included, and a layer not shown in FIG. 1 may be interposed.

  In the organic light emitting device 1 of FIG. 1, a cathode 17 is provided on the electron injection layer 16 so as to cover the electron injection layer 16 and the pixel separation film 18. Here, in the organic light emitting device 1 of FIG. 1, the anode 12, the hole transport layer 13, the light emitting layer 14, the electron transport layer 15, the electron injection layer 16, and the cathode 17 constitute an organic light emitting element unit.

  Although not shown in FIG. 1, a transparent protective film made of an inorganic material film such as silicon oxide or silicon nitride or a polymer film may be provided in order to prevent moisture permeation into the organic compound layer. . Moreover, you may seal with cap materials, such as a glass plate. Furthermore, sealing may be performed using the protective film and the cap material in combination.

  Next, the manufacturing method of the organic light emitting device of the present invention will be specifically described. The manufacturing method of the organic light-emitting device of this invention has process (i)-(iv) shown below.

(I) Step of forming an anode, a pixel separation film, and a planarization film on the substrate (anode / pixel separation film / planarization film formation step)
(Ii) A step of irradiating the substrate with UV light while introducing / exhausting a gas containing at least oxygen (UV light irradiation step)
(Iii) A step of heating the substrate (substrate heating treatment step)
(Iv) Step of forming an organic compound layer on the anode (organic compound layer forming step)
In addition, the manufacturing method of the organic light-emitting device of this invention needs to perform a UV light irradiation process and this board | substrate heat processing process simultaneously. In addition, in the method for manufacturing an organic light emitting device of the present invention, it is necessary to perform the UV light irradiation step in a pressure atmosphere less than atmospheric pressure.

  In the steps (i) to (iv), the anode surface can be efficiently cleaned by performing the steps (ii) and (iii). Further, by heating the substrate simultaneously with the UV light irradiation, the decomposed water that can be generated from either the pixel separation film or the planarization layer during the UV light irradiation can be more effectively diffused and removed. For this reason, it is possible to prevent luminance degradation of the element due to the decomposed water. Further, by performing the step (ii) and the step (iii), it is possible to remove contaminants generated on the anode surface after the UV light irradiation step. For this reason, it is possible to suppress a decrease in the light emission lifetime of the device caused by this contaminant.

  Hereinafter, each of the steps (i) to (iv) will be described in detail.

  First, step (i) will be described. The substrate 10 including the anode 12, the pixel separation film 18, and the planarization film has a TFT for driving the organic light emitting device formed on the surface thereof.

  Here, when forming the anode 12 or an organic compound layer to be described later, it is necessary to fill the unevenness of the TFT wiring portion and flatten the film surface. Therefore, preferably, an interlayer insulating film 11 that functions as a planarization film is provided on the substrate 10. Here, an organic material such as an acrylic resin film is usually used as a constituent material of the interlayer insulating film 11. However, an inorganic material may be used as a constituent material of the interlayer insulating film 11. Further, when the interlayer insulating film 11 is provided, the film thickness is preferably several μm to several tens of μm.

  The interlayer insulating film 11 is provided with a connection hole (not shown) at a predetermined position for electrically connecting the TFT wiring portion and the anode 12. As a method of providing the connection hole, a known method such as etching can be used.

  An anode 12 that is electrically connected to the TFT wiring portion through the connection hole is formed on the interlayer insulating film 11. When forming the anode, the anode may be formed so as to cover the entire surface of the interlayer insulating film 11 as in the organic light emitting device of FIG. 1, or a pattern may be formed corresponding to each pixel region.

  In the case of manufacturing a top emission type organic light emitting device, a material having a high reflectance such as a simple metal such as Cr, Ag, Al or an alloy obtained by combining a plurality of these simple metals can be used as a constituent material of the anode 12. . In order to increase charge injection efficiency, a film made of a conductive oxide such as ITO or IZO can be further stacked. On the other hand, when a bottom emission type organic light emitting device is manufactured, a conductive oxide having transparency such as ITO and IZO can be used as a constituent material of the anode 12.

  After the anode 12 is formed, a pixel isolation film 18 for partitioning the anode 12 in units of pixels is provided on the interlayer insulating film 11 or the anode 12. Further, by providing the pixel separation film 18, the periphery of the anode 12 is covered with the pixel separation film 18. The pixel isolation film 18 is formed in a desired pattern so as to expose only the portion of the anode surface corresponding to the pixel region. As a pattern forming method, a known method such as photolithography can be used. Further, by forming the pixel isolation film 18, an opening that becomes a pixel region is formed in a desired pattern.

  The constituent material of the pixel separation film 18 is preferably an organic material such as photosensitive polyimide or acrylic resin. However, inorganic materials such as silicon oxide (for example, SiO) and silicon nitride (for example, SiN) can also be used.

  After preparing a substrate provided with an anode, a planarization film, and a pixel separation film in this way, this substrate was subjected to wet cleaning using various solvents, surfactants, pure water, etc., and then 100 ° C. It is desirable to perform a heat dehydration treatment in which the substrate is heated in a range of about ~ 200 ° C.

  Next, process (ii) and process (iii) are demonstrated. After performing the heat dehydration process on the substrate, the substrate is put into a substrate pretreatment apparatus. After the substrate is put into the substrate pretreatment apparatus, UV light is irradiated onto the substrate while introducing and exhausting a gas containing at least oxygen.

  By irradiating UV light in the presence of oxygen in this manner, the residue of the pixel separation film material or resist material and other contaminants that may be generated on the anode surface by performing UV ozone treatment are treated with UV light and UV light. It can be removed by the action of ozone and active oxygen generated by the reaction of oxygen with oxygen.

  In addition, when performing this process (ii), the pressure in a substrate pretreatment apparatus is controlled to less than atmospheric pressure. By reducing the pressure in the substrate pretreatment apparatus to less than atmospheric pressure, resist material residues that can remain on the anode surface, contaminants generated by decomposition from the pixel separation film, and other contaminants are less likely to adhere to the anode surface. At the same time, these contaminants and the like can be effectively removed.

  Even when the pixel separation film contains moisture, a part of the surface of the pixel separation film is decomposed by performing the step (ii), and the moisture contained in the pixel separation film is effective. Thus, it is diffused and removed from the pixel isolation film.

  However, when any of the constituent materials of the pixel separation film and the planarization film is an organic material such as an acrylic resin or a polyimide resin, decomposed water is generated by the decomposition of the organic material during the step (ii). The decomposed water is contained in the pixel separation film and the planarization film. Moreover, the generated decomposed water may not be sufficiently removed even if the substrate pretreatment apparatus is depressurized to less than atmospheric pressure.

  Therefore, in the present invention, step (ii) and step (iii) are performed simultaneously. In this way, even if decomposed water is generated from the pixel separation film or the flattening film, the decomposed water can be efficiently diffused, so that good light emission characteristics can be obtained without deteriorating the light emission lifetime of the device. Obtainable. Further, if the step (ii) and the step (iii) are performed at the same time, the above-described effect of dissipating the decomposed water and the effect of removing the contaminants occur at the same time. Can do.

  Here, when performing step (ii), the pressure in the apparatus is preferably 10 Pa or more and 10,000 Pa or less while introducing a gas containing at least oxygen into the substrate pretreatment apparatus in the range of 0.1 slm to 500 slm. Control to the range. Then, after the pressure in the apparatus is stabilized, the substrate is irradiated with infrared light and UV light for a predetermined time.

  The time for irradiating the UV light must be changed depending on the contamination state of the substrate, but is preferably in the range of 0.5 minutes to 60 minutes.

  When UV light is irradiated, if the pressure in the apparatus is low (the degree of vacuum is high), contaminants present on the exposed anode surface even when oxygen is introduced and exhausted into the apparatus, The amount of ozone and active oxygen necessary to remove decomposition products such as residues is reduced. Here, the low pressure in the device specifically means that the pressure in the device is less than 10 Pa. Therefore, when the pressure in the apparatus is less than 10 Pa, decomposed substances such as contaminants and residues may remain on the anode surface even when UV light is irradiated for a long time. This decomposition product may significantly hinder the carrier injection from the anode to the organic compound layer, and may not satisfy the favorable light emission characteristics that are the object of the present invention.

  On the other hand, when the pressure in the device is greater than 10,000 Pa, more contaminants and residues remain on the anode surface, and these contaminants may reduce the driving durability characteristics of the organic light emitting device. Further, when the pressure in the apparatus is greater than 10,000 Pa, it means that the pressure in the apparatus is close to atmospheric pressure. When the pressure in the apparatus is close to atmospheric pressure, the time for removing the decomposed water tends to be long even if the substrate heat treatment step is performed.

  From the above, when performing step (ii), the pressure in the substrate pretreatment apparatus is preferably in the range of 10 Pa to 10,000 Pa.

  However, even when the pressure in the substrate pretreatment apparatus is controlled to the above-described range when performing the step (ii), the decomposition is performed when the temperature for heating the substrate is less than 100 ° C. in the step (iii) performed simultaneously. Water remains. This decomposed water causes degradation in luminance from the vicinity of the pixel isolation film and the wiring protective film formed simultaneously with the planarization film on the outer periphery of the organic light emitting device when using the organic light emitting device, and appears as a deterioration of the light emitting state around the pixel become.

  In addition, when performing the step (iii), if the substrate is heated in a range exceeding the lower one of the decomposition temperatures of the organic material that is the constituent material of the pixel separation film and the planarization film, the pixel separation film and the planarization film Any one of the constituent materials is excessively decomposed, and the decomposition product contaminates the anode surface. For this reason, it becomes a cause which reduces the drive durability characteristic of an organic light-emitting device. For example, when an acrylic resin is used as a constituent material, the decomposition temperature is about 200 ° C. When the substrate is heated in a range exceeding the decomposition temperature, the decomposition product derived from the acrylic resin is excessively generated as described above, which causes the drive durability characteristics of the organic light-emitting device to deteriorate.

  Hereinafter, the apparatus used when performing process (ii) and process (iii) is demonstrated, referring drawings.

  FIG. 2 is a schematic cross-sectional view showing a substrate pretreatment apparatus that simultaneously performs a UV light irradiation step and a substrate heating treatment step. The substrate pretreatment apparatus 2 of FIG. 2 includes a halogen lamp heater 20, a UV lamp 21, and a substrate holder (not shown) for fixing the substrate 22 in a vacuum chamber 27. 2 includes a mass float controller 23 that adjusts the amount of gas introduced into the apparatus (inside the vacuum chamber 27), and a variable valve 26a that appropriately discharges ozone and the like present in the apparatus. And a decompression pump 26. The decompression pump 26 is electrically connected to a pressure controller 25 that controls the pressure of the vacuum chamber 27 while looking at the vacuum gauge 24 attached to the vacuum chamber 27. The pressure in the apparatus can be adjusted while introducing a gas such as dry air or oxygen into the substrate pretreatment apparatus 2 by the mass float controller 23 and the decompression pump 26 described above. Here, the gas introduced into the substrate pretreatment apparatus 2 is preferably one containing as little moisture as possible, and one having a dew point of −70 ° C. or less can be suitably used.

  As the UV lamp 21 that is an irradiation source of UV light, a low-pressure mercury lamp or an excimer lamp can be used. When irradiating UV light, the distance between the substrate 22 and the UV lamp 21 is preferably 1 mm to 50 mm. Further, it is desirable to swing the substrate 22 or the UV lamp 21 in order to make the irradiation intensity of the UV light uniform.

  On the other hand, as the substrate heating source used in the step (iii), the halogen lamp 20 can be used, but an infrared heater that generates infrared rays may be used. Whichever heating source is used, the temperature of the substrate can be increased by directly or indirectly irradiating the substrate. Here, when heating the substrate, a thermocouple for controlling the output of the substrate heating source must be arranged on the substrate surface or inside the substrate so that the substrate temperature can be controlled to an arbitrary temperature. In addition to the substrate heating source described above, the temperature of the substrate may be increased by bringing a hot plate or the like into contact with the substrate.

  After performing the step (ii) and the step (iii), the substrate is transferred to a film forming apparatus, and an organic compound layer is sequentially formed on the exposed anode by the step (iv) described later. At this time, the temperature of the substrate is controlled so as to be equal to or lower than the glass transition point of the constituent material of the layer in direct contact with the anode surface. If this is not done, the organic compound layer to be formed will crystallize, leading to a decrease in carrier injectability. For this reason, after performing process (ii) and process (iii), when the temperature of a board | substrate is too high, it is necessary to cool a board | substrate once. As a method for cooling the substrate, a heat radiation process performed by evacuating the apparatus or filling the apparatus with an inert gas, a cooling process using a cooling plate, or the like can be considered. However, in any process, while the substrate is cooled, impurities remaining in the apparatus and contaminants on the cooling plate adhere to the substrate during the cooling process. For this reason, the anode surface is contaminated, and there is a high possibility that the driving durability characteristic of the organic light emitting device is deteriorated.

  Accordingly, in performing the step (iii), the substrate heat treatment temperature is controlled to 100 ° C. or higher, and the decomposition temperature of the constituent material of the pixel separation film and the planarization film is controlled to be lower than one of the lower temperatures. It is preferable to do.

  By the way, after performing step (ii) and step (iii), in order to prevent moisture from adhering to the anode, the pixel separation film, etc., preferably, the substrate is not exposed to the outside air or a gas containing moisture. . Further, in order to prevent the anode surface from being contaminated again by a contaminant or the like, preferably, after performing the step (ii) and the step (iii), the substrate is quickly transported to form an organic compound layer. Here, in the case where the organic compound layer is formed by a vacuum deposition method, the environment in which the substrate is placed is preferably maintained at least at a pressure lower than atmospheric pressure.

On the other hand, before performing the step (iv), the introduction of the gas performed when performing the step (ii) is stopped. Then, the inside of the pretreatment apparatus was evacuated to a high vacuum of 10 ⁻³ Pa or less, and the substrate was quickly brought to a high vacuum of 1 × 10 ⁻⁵ to 5 × 10 ⁻⁴ Pa while maintaining the high vacuum. The film is transferred to a film forming apparatus (vacuum evaporation apparatus). After performing step (ii) in this way, the substrate is placed under a high vacuum, whereby the surface of the substrate is cleaned and the pixel isolation film and the planarization film are dehydrated.

  Next, process (iv) is demonstrated. After the substrate is transferred into the film forming apparatus, an organic compound layer is formed mainly by a vacuum heating vapor deposition method.

  As a method for forming the organic compound layer, an EB vapor deposition method, an LB method, a spin coating method, an ink jet method, a thermal transfer method, or the like can be used in addition to the vacuum heating vapor deposition method.

  After forming the organic compound layer, the cathode 17 is provided so as to cover the organic compound layer. The cathode 17 is provided as a single layer on the substrate 11 as an electrode common to each pixel. When the organic light emitting device manufactured here is a top emission type, the cathode 17 needs to be light transmissive. At this time, a conductive oxide having transparency such as ITO or IZO is usually used as a constituent material of the cathode 17. On the other hand, when the organic light emitting device to be manufactured is a bottom emission type, the cathode 17 serves as a reflective electrode, and the constituent material is preferably a single metal such as Al or Ag, or an alloy combining a plurality of these metals. The

  An apparatus for performing the steps (i) to (iv) shown above, particularly the steps (ii) to (iv) in a lump will be described with reference to the drawings. FIG. 3 is a schematic view of an apparatus that collectively performs the steps from step (ii) (UV light irradiation step) to the step of sealing the organic light emitting device.

  In the apparatus shown in FIG. 3, 30a is a first load lock chamber, 31 is a substrate pretreatment chamber, 32 is an organic compound layer deposition chamber, 33 is a cathode deposition chamber, 30b is a second load lock chamber, 34 Indicates a glove box.

  The first load lock chamber 30a shown in FIG. 3 is for carrying a substrate that has been cleaned, dehydrated and dried. At this time, the pressure inside the first load lock chamber 30a may be atmospheric pressure or reduced pressure. Further, the substrate may be dehydrated and dried in the first load lock chamber 30a.

  The substrate pretreatment chamber 31 shown in FIG. 3 includes a halogen lamp heater 35 and a UV lamp 36, and performs the above-described step (ii) and step (iii). The equipment provided in the substrate pretreatment chamber 31 is the same as that of the substrate pretreatment apparatus shown in FIG.

  The organic compound layer deposition chamber 32 shown in FIG. 3 includes a shutter 37 and a vapor deposition source 38, and performs the above-described step (iv). Here, the shutter 37 is used when the organic compound layer is formed in a predetermined pattern. The vapor deposition source 38 is charged with a constituent material for the organic compound layer.

  The cathode film forming chamber 33 shown in FIG. 3 is for forming a cathode. For example, when the cathode is formed by sputtering, the cathode target 39 shown in FIG. 3 is prepared in advance. The cathode may be formed in a predetermined pattern by preparing the shutter 37.

  The second load lock chamber 30b shown in FIG. 3 is provided to carry the substrate formed up to the cathode into the glove box 34. Here, the pressure in the second load lock chamber 30b may be atmospheric pressure or reduced pressure. However, it is preferable not to expose the organic light emitting device to moisture or oxygen.

  The glove box 34 shown in FIG. 3 is used for sealing the organic light emitting device.

  The manufacturing method of the organic light emitting device of the present invention is not limited to the case of manufacturing a top emission type (top emission) organic light emitting device, but also applied to the case of manufacturing a bottom emission type (bottom emission) organic light emitting device. can do.

  Examples of the present invention will be described below, but the present invention is not limited thereto.

<Example 1>
The organic light emitting device shown in FIG. 1 was manufactured. In this example, Ag alloy and indium zinc oxide (IZO) were used as the constituent material of the anode 11. In addition, indium tin oxide (ITO) was used as a constituent material for the cathode 16 to function as a transparent light emitting electrode. That is, a top emission type organic light emitting device was manufactured.

(1) Anode / flattening film / pixel separation film forming step First, an acrylic resin was formed on the substrate 10 to form an interlayer insulating film 11 (flattening film). At this time, the film thickness of the interlayer insulating film 11 was 2 μm. Next, an Ag alloy film and an IZO film were sequentially formed on the interlayer insulating film 11 by sputtering. At this time, the thickness of the Ag alloy film was 100 nm, and the thickness of the IZO film was 60 nm. Note that the Ag alloy film and the IZO film function as the anode 12.

  Next, an acrylic resin was applied to the entire surface of the anode 12 by a wet process by spin coating. At this time, the film thickness of the acrylic resin was 2 μm. Next, a pixel separation film 18 for partitioning pixels (regions for forming an organic compound layer) was formed by performing pattern exposure and development using an ultraviolet lamp by photolithography.

(2) Substrate cleaning / drying step After the pixel separation film 18 was formed, an organic light-emitting device was fabricated based on the flowchart shown in FIG.

  The substrate 10 formed up to the pixel separation film 18 in the anode / planarization film / pixel separation film formation step was washed with a surfactant aqueous solution, and then rinsed with ion exchange water and ultrasonic waves. Next, the cleaned substrate was placed in a vacuum dryer and vacuum dried for 24 hours while being heated to 150 ° C.

(3) UV light irradiation process / substrate heat treatment process Next, the substrate subjected to the cleaning / drying process is introduced into a vacuum deposition apparatus (manufactured by ULVAC, Inc.) having a pretreatment chamber and a film formation chamber. After that, evacuation was performed until the pressure in the apparatus reached 1 × 10 ⁻⁴ Pa.

  Next, after the substrate is moved to the UV light irradiation apparatus 2 shown in FIG. 2, the anode provided on the substrate faces the UV lamp at a position where the halogen lamp heater 20 and the UV lamp 21 are installed. Then, the substrate was rocked.

  Next, dry air with a dew point of -80 ° C is introduced at 10 slm, the valve with the opening control mechanism is automatically adjusted by the pressure controller, and the exhaust pressure is balanced while continuing to introduce the dry air. The pressure was maintained at 1000 Pa. Next, the halogen lamp heater 20 and the UV lamp 21 were turned on at the same time while swinging the substrate which was performed previously. The substrate temperature was 150 ° C. when the halogen lamp heater was turned on.

After the UV light irradiation and the substrate heat treatment were performed for 10 minutes, the irradiation of the halogen lamp heater 20 and the UV lamp 21 was stopped, the inflow of dry air was stopped, and the exhaust was performed. Next, when the pressure in the apparatus reached 1 × 10 ⁻³ Pa, the substrate was transferred to a film formation chamber maintained at 1 × 10 ^{−5 to} 5 × 10 ⁻⁴ Pa.

(4) Organic Compound Layer Formation Step Next, N, N′-α-dinaphthylbenzidine (α-NPD) was formed on the anode 12 by a vacuum vapor deposition method to form the hole transport layer 13. The hole transport layer 13 was formed immediately after the substrate was transferred into the film formation chamber. The film thickness of the hole transport layer 13 was 40 nm, and the temperature of the substrate was 70 ° C. The set temperature of the substrate is lower than the glass transition point (96 ° C.) of N, N′-α-dinaphthylbenzidine.

Next, coumarin 6 and tris [8-hydroxyquinolinato] aluminum (Alq ₃ ) are formed on the hole transport layer 13 by vacuum deposition, and the coumarin 6 is 1.0 wt% with respect to the entire layer. Thus, the light-emitting layer 14 was formed by co-evaporation. At this time, the thickness of the light emitting layer 14 was set to 30 nm.

Next, tris [8-hydroxyquinolinato] aluminum (Alq ₃ ) was vapor-deposited on the light emitting layer 14 by a vacuum vapor deposition method to form the electron transport layer 15. At this time, the thickness of the electron transport layer 14 was set to 10 nm.

Next, cesium carbonate and tris [8-hydroxyquinolinate] aluminum (Alq ₃ ) are deposited on the electron transport layer 15 by vacuum deposition so that the cesium carbonate becomes 0.7% by volume with respect to the entire layer. The electron injection layer 16 was formed by co-evaporation. At this time, the thickness of the electron injection layer 15 was set to 40 nm.

  Next, indium tin oxide (ITO) was formed on the electron injection layer 16 by sputtering to form the cathode 17. At this time, the thickness of the cathode 17 was 220 nm, the pressure in the apparatus was 0.6 Pa, and the flow rate of Ar gas was 100 sccm. The cathode 17 formed in this embodiment is a transparent light emission extraction electrode.

(5) Cathode Formation Step / Sealing Step Next, the substrate formed up to the cathode 17 was transferred to a glove box and sealed with a glass cap containing a desiccant in a nitrogen atmosphere. An organic light emitting device was obtained through the above steps.

(6) Evaluation of characteristics of organic light-emitting device When a constant current having a current value of 100 mA / cm ² was passed through the obtained organic light-emitting device, the organic light-emitting device emitted green light. Moreover, about this apparatus, constant current continuous lighting was performed for 100 hours with an electric current value of 100 mA / cm ² , and the initial luminance and luminance after 100 hours were measured with a luminance meter (Topcon BM-7). Changes in the light emission characteristics of the organic light emitting devices of the examples were evaluated. As a result, the initial luminance L (ini) was 1300 cd / m ² , and L (100h) / L (ini) indicating the luminance change was 95.4%. For this reason, it turned out that it is the outstanding drive life characteristic.

  Furthermore, the organic light-emitting device of this example was put in a thermostatic bath at a temperature of 80 ° C. and a humidity of 30%, and left for 1000 hours to perform a durability test of the organic light-emitting device under high temperature and high humidity. As a result, when the light emitting state of the organic light emitting device after the test was observed, it was found that uniform green light emission was exhibited as before the test, and the deterioration around the pixel was 3 μm or less of the detection limit.

  Therefore, it was shown that the organic light emitting device obtained by this example has good driving life characteristics and light emitting state.

<Example 2>
In Example 1 (1), the pixel separation film 18 was formed by the following method. That is, the acrylic resin used in Example 1 and the photosensitive polyimide resin were sequentially formed on the anode 12. At this time, the film thickness of the acrylic resin was 1 μm, and the film thickness of the photosensitive polyimide resin was 1 μm. After that, the pixel separation film was patterned by the same method as in Example 1.

  In Example 1 (3), the pressure in the apparatus was 10000 Pa, the substrate heating temperature was 170 ° C., and the UV light irradiation and substrate heating treatment time was 5 minutes. Except for these, an organic light emitting device was obtained in the same manner as in Example 1.

The obtained organic light emitting device was evaluated in the same manner as in Example 1. As a result, the organic light emitting device of this example emitted green light, the initial luminance (L (ini)) was 1300 cd / m ² , and L (100h) / L (ini) was 94.2%. It was found to have a long driving life characteristic.

Moreover, the durability test of the organic light-emitting device under high temperature and high humidity was done similarly to Example 1, and evaluated.
As a result, when the light emission state after the test was observed, it was found that uniform green light emission was exhibited as before the test, and the deterioration around the pixel was 3 μm or less of the detection limit.

  Therefore, it was shown that the organic light emitting device obtained by this example has good driving life characteristics and light emitting state.

<Example 3>
In Example 1 (1), the pixel separation film 18 was formed by the following method. That is, the acrylic resin used in Example 1 and the photosensitive polyimide resin were sequentially formed on the anode 12. At this time, the film thickness of the acrylic resin was 1 μm, and the film thickness of the photosensitive polyimide resin was 1 μm. After that, the pixel separation film was patterned by the same method as in Example 1.

  In Example 1 (3), the pressure in the apparatus was 100 Pa, and the heating temperature of the substrate was 120 ° C. Except for these, an organic light emitting device was obtained in the same manner as in Example 1.

The obtained organic light emitting device was evaluated in the same manner as in Example 1. As a result, the organic light emitting device of this example emitted green light, the initial luminance (L (ini)) was 1300 cd / m ² , and L (100h) / L (ini) was 94.3%. It was found to have a long driving life characteristic.

  Moreover, the durability test of the organic light-emitting device under high temperature and high humidity was done similarly to Example 1, and evaluated. As a result, when the light emission state after the test was observed, it was found that uniform green light emission was exhibited as before the test, and the deterioration around the pixel was 3 μm or less of the detection limit.

  Therefore, it was shown that the organic light emitting device obtained by this example has good driving life characteristics and light emitting state.

<Example 4>
In Example 1 (3), the pressure in the apparatus was 10 Pa, and the heating temperature of the substrate was 200 ° C.

Further, in Example 1, after the UV light irradiation process / substrate heating process and before the organic compound layer forming process, in order to release the heat accumulated in the substrate, the inside of the apparatus is evacuated for 5 minutes. Left to stand.

  Except for these, an organic light emitting device was obtained in the same manner as in Example 1.

The obtained organic light emitting device was evaluated in the same manner as in Example 1. As a result, the organic light emitting device of this example emitted green light, the initial luminance (L (ini)) was 1300 cd / m ² , and L (100h) / L (ini) was 92.4%. It was found to have a long driving life characteristic.

  Moreover, the durability test of the organic light-emitting device under high temperature and high humidity was done similarly to Example 1, and evaluated. As a result, when the light emission state after the test was observed, it was found that uniform green light emission was exhibited as before the test, and the deterioration around the pixel was 3 μm or less of the detection limit.

  Therefore, it was shown that the organic light emitting device obtained by this example has good driving life characteristics and light emitting state.

<Comparative Example 1>
In Example 1 (3), the organic light emitting device was obtained by the same method as in Example 1 except that the pressure in the device was 100000 Pa (atmospheric pressure) and the substrate was not heated.

The obtained organic light emitting device was evaluated in the same manner as in Example 1. As a result, the organic light emitting device of this comparative example emitted green light, and the initial luminance (L (ini)) was 1300 cd / m ² , but L (100h) / L (ini) was 88.2%. It was found that the drive life characteristics were inferior compared with the above examples.

  Moreover, the durability test of the organic light-emitting device under high temperature and high humidity was done similarly to Example 1, and evaluated. As a result, when the light emitting state after the test was observed, the green light was emitted uniformly as before the test, but the deterioration around the pixel was found to be 163 μm.

  As described above, as in this comparative example, it was found that when the pressure in the apparatus in the UV light irradiation process is greater than 10,000 Pa, more contamination and residue remain on the surface of the pixel electrode, resulting in poor driving durability characteristics. . Furthermore, since the decomposition water could not be removed because the substrate heating step was omitted, it was found that the pixel peripheral deterioration was in a poor state.

<Comparative example 2>
In Example 3, an organic light emitting device was obtained by the same method as Example 3 except that the pressure in the apparatus when performing the UV light irradiation step was set to 100000 Pa (atmospheric pressure).

The obtained organic light emitting device was evaluated in the same manner as in Example 1. As a result, the organic light emitting device of this comparative example emitted green light, and the initial luminance (L (ini)) was 1300 cd / m ² , but L (100h) / L (ini) was 90.2%. It was found that the drive life characteristics were inferior compared with the above examples.

  Moreover, the durability test of the organic light-emitting device under high temperature and high humidity was done similarly to Example 1, and evaluated. As a result, when the light emitting state after the test was observed, the green light was emitted uniformly as before the test, but the deterioration around the pixel was found to be 60 μm.

  As described above, in this comparative example, as in comparative example 1, since the pressure in the apparatus is larger than 10,000 Pa in the UV light irradiation process, more contamination and residue remain on the pixel electrode surface. It was found that the driving durability characteristics were inferior compared. Moreover, in this comparative example, although the heat processing process of the board | substrate was performed, it was shown that the effect of moisture removal is inadequate.

<Comparative Example 3>
In Example 1 (3), an organic light emitting device was obtained by the same method as in Example 1 except that the pressure in the device was 10000 Pa, the heat treatment was omitted, and the UV light irradiation time was 5 minutes. It was.

The obtained organic light emitting device was evaluated in the same manner as in Example 1. As a result, the organic light emitting device of this comparative example emitted green light, the initial luminance (L (ini)) was 1300 cd / m ² , and L (100h) / L (ini) was 94.8%.

  Moreover, the durability test of the organic light-emitting device under high temperature and high humidity was done similarly to Example 1, and evaluated. As a result, when the light emission state after the test was observed, the green light was emitted uniformly as before the test, but the deterioration around the pixel was found to be 33 μm.

  Accordingly, it was found that although the effect of reducing the pressure inside the apparatus appeared, it did not completely remove moisture.

  Thus, even when the pressure in the apparatus is controlled within the range specified in the present invention when performing the UV light irradiation process, the decomposition water is removed unless the substrate heat treatment process is performed simultaneously with the UV light irradiation process. It was found that the pixel periphery deterioration was poor because it could not be exhausted. Moreover, since the irradiation time of UV light was short, the effect of reducing the generation of decomposed water was not observed.

<Example 5>
In Example 1 (1), the pixel separation film 18 was formed by the following method. That is, the acrylic resin used in Example 1 and the photosensitive polyimide resin were sequentially formed on the anode 12. At this time, the film thickness of the acrylic resin was 1 μm, and the film thickness of the photosensitive polyimide resin was 1 μm. After that, the pixel separation film was patterned by the same method as in Example 1.

  In Example 1 (3), the UV light irradiation and the substrate heat treatment time were 3 minutes. Except for these, an organic light emitting device was obtained in the same manner as in Example 1.

The obtained organic light emitting device was evaluated in the same manner as in Example 1. As a result, the organic light emitting device of this example emitted green light, the initial luminance (L (ini)) was 1300 cd / m ² , and L (100h) / L (ini) was 95.2%. It was found to have a long driving life characteristic.

  Moreover, the durability test of the organic light-emitting device under high temperature and high humidity was done similarly to Example 1, and evaluated. As a result, when the light emission state after the test was observed, it was found that uniform green light emission was exhibited as before the test, and the deterioration around the pixel was 3 μm or less of the detection limit.

  Therefore, it was shown that the organic light emitting device obtained by this example has good driving life characteristics and light emitting state. Moreover, even when the time for UV light irradiation and substrate heat treatment was short, the UV light irradiation and substrate heat treatment could be effectively performed.

<Comparative example 4>
In Example 3, an organic light emitting device was obtained by the same method as in Example 3 except that the substrate was heated at 250 ° C. when performing the substrate heat treatment step.

The obtained organic light emitting device was evaluated in the same manner as in Example 1. As a result, the organic light emitting device of this comparative example emitted green light, and the initial luminance (L (ini)) was 1300 cd / m ² , but L (100h) / L (ini) was 90.8%. It was found that the drive life characteristics were inferior compared with the above examples. Further, the pixel separation film after the substrate heat treatment process was turned brown. This is considered that the decomposition of the pixel separation film occurred remarkably because the substrate was heated at a temperature exceeding the decomposition temperature of the pixel separation film.

  Moreover, the durability test of the organic light-emitting device under high temperature and high humidity was done similarly to Example 1, and evaluated. As a result, when the light emission state after the test was observed, it was found that uniform green light emission was exhibited as in the case before the test, and the deterioration around the pixel was 3 μm or less.

  As described above, when the heating temperature exceeds the decomposition temperature of the constituent material of the pixel separation film when the substrate is heated, the pixel periphery does not deteriorate, but the pixel separation film is excessively decomposed, and this decomposition product It has been shown that the drive durability characteristics deteriorate due to contamination of the anode surface.

<Comparative Example 5>
In Example 3, the pressure in the apparatus is set to 1 Pa when performing the UV light irradiation step, the substrate is heated at 80 ° C. when performing the substrate heat treatment step, and the UV light irradiation step and the substrate heat treatment step are performed for 20 minutes. An organic light-emitting device was obtained in the same manner as in Example 3 except that it was performed.

The obtained organic light emitting device was evaluated in the same manner as in Example 1. As a result, the organic light emitting device of this comparative example emitted green light, and the initial luminance (L (ini)) was 1300 cd / m ² , but L (100h) / L (ini) was 20.6%. It was found that the drive life characteristics were inferior compared with the above examples.

  Moreover, the durability test of the organic light-emitting device under high temperature and high humidity was done similarly to Example 1, and evaluated. As a result, when the light emission state after the test was observed, it was found that uniform green light emission was exhibited as in the case before the test, and the deterioration around the pixel was 12 μm.

  For this reason, although the effect of heating the substrate in a reduced pressure environment has appeared, the moisture has not been completely removed.

  Accordingly, in the region where the pressure in the apparatus is lower than the range defined in the present invention (the degree of vacuum is high) when performing the UV light irradiation process, even if oxygen is introduced / exhausted into the apparatus, the organic EL layer is formed from the pixel electrode. The carrier injection into this was significantly hindered, and excellent driving durability characteristics could not be obtained.

  Further, it was shown that even when the heat treatment is performed during the UV ozone treatment, when the heating temperature is less than 100 ° C., the decomposed water remains and the peripheral luminance is deteriorated.

  The conditions and results of each example and each comparative example are shown in Table 1 above.

  As described above, when the organic light-emitting device was produced by the production method of the present invention, the electrode surface was efficiently washed, and the decomposed water generated during washing could be more effectively dehydrated.

  As a result, the organic light-emitting device manufactured according to the present invention can realize a light-emitting device that suppresses a decrease in light emission lifetime and has no luminance deterioration due to moisture.

It is a cross-sectional schematic diagram which shows the organic light-emitting device manufactured by the manufacturing method of this invention. It is a cross-sectional schematic diagram which shows the substrate pretreatment apparatus which performs a UV light irradiation process and a board | substrate heat processing process simultaneously. It is the schematic of the apparatus which performs collectively the process from process (ii) (UV light irradiation process) to the process of sealing an organic light-emitting device. It is a flowchart which shows the process until it forms an organic light-emitting device after forming a pixel separation film.

Explanation of symbols

1 Organic Light-Emitting Device 10 Substrate 11 Interlayer Insulating Film (Planarization Film)
DESCRIPTION OF SYMBOLS 12 Anode 13 Hole transport layer 14 Light emitting layer 15 Electron transport layer 16 Electron injection layer 17 Cathode 18 Pixel separation film 2 Substrate pretreatment device 20 Halogen lamp heater 21 UV lamp 22 Substrate 23 Mass flow controller 24 Vacuum gauge 25 Pressure controller 26 Depressurization pump 26a Variable valve 30a First load lock chamber 30b Second load lock chamber 31 Substrate pretreatment chamber 32 Organic compound layer deposition chamber 33 Cathode deposition chamber 34 Glove box 35 Halogen lamp heater 36 UV lamp 37 Shutter 38 Deposition source 39 Cathode target

Claims (7)

An organic light-emitting element section comprising an anode and a cathode, and an organic compound layer sandwiched between the anode and the cathode and including at least a hole transport layer and a light-emitting layer in this order;
A pixel separation film;
A planarization film;
In a method for manufacturing an organic light-emitting device in which any of the constituent materials of the pixel separation film and the planarization film is an organic material,
Forming each of the anode, the pixel isolation film, and the planarizing film on the substrate;
A UV light irradiation step of irradiating the substrate with UV light while introducing and exhausting a gas containing at least oxygen;
A substrate heat treatment step for heating the substrate;
An organic compound layer forming step of forming the organic compound layer on the anode,
Performing the UV light irradiation step and the substrate heat treatment step simultaneously;
A method for producing an organic light-emitting device, wherein the UV light irradiation step is performed under a pressure atmosphere less than atmospheric pressure.   2. The method of manufacturing an organic light-emitting device according to claim 1, wherein a pressure atmosphere when performing the UV light irradiation step is 10 Pa or more and 10,000 Pa or less.   The method for manufacturing an organic light emitting device according to claim 1, wherein the substrate is heated at 100 ° C. or higher in the substrate heating step.   The heating temperature of the substrate is controlled to be lower than the lower one of the decomposition temperatures of the constituent materials of the pixel separation film and the planarization film in the substrate heating step. A method for producing an organic light-emitting device according to claim 1.   The pressure in the apparatus in which the substrate is placed is controlled to be lower than the atmospheric pressure until the organic compound layer forming step is performed after the UV light irradiation step. 5. The method for producing an organic light-emitting device according to any one of 4 above.   6. The organic light emitting device according to claim 1, wherein, in the organic compound layer forming step, the temperature of the substrate is controlled to be equal to or lower than a glass transition point of a constituent material of the organic compound layer. Production method.   7. The method of manufacturing an organic light emitting device according to claim 1, wherein one of constituent materials of the pixel isolation film and the planarizing film is an acrylic resin or a polyimide resin. 8.

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