JP2007227127A - Light-emitting device and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting device in which the fluctuations of intra-pixel and inter-pixel thickness of organic functional layer can be suppressed, even when the discharge rate of a liquid composition from a nozzle opening fluctuates, and to provide a manufacturing method of the light emitting device. <P>SOLUTION: In the light-emitting device, in which a plurality of pixels 115 provided with an organic electroluminescent elements 110 are formed in linear shape on a substrate with respect to respective corresponding colors (R), (G), and (B), a first barrier rib 105a, continuously extending along a first boundary region 116a between the pixels of different corresponding colors is formed; and in a second boundary region 116b between the pixels of the same corresponding color, a second barrier rib 105b for partly partitioning between the pixels is formed. In forming the organic functional layer of the organic electroluminescent element 110, the liquid composition is filled into a recess part 150, formed by the first barrier rib 105a and the second barrier rib 105b, and is solidified. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a light emitting device including an organic electroluminescence element and a method for manufacturing the same.

  In the organic electroluminescence device, pixels including an organic electroluminescence element in which a first electrode layer, an organic functional layer, and a second electrode layer are stacked in this order are formed in a matrix on a substrate. In producing such an organic electroluminescence device, the organic functional layer is formed by discharging a liquid composition obtained by dissolving or dispersing an organic functional material made of a polymer material in a solvent (including a dispersion medium). There has been proposed a method of fixing an organic functional material on a substrate by discharging a liquid film from a nozzle opening of a head onto a substrate to dispose a liquid film and then drying the solvent from the liquid film (for example, Patent Documents). 1).

In manufacturing a light emitting device by such a method, conventionally, after forming a pixel driving thin film transistor and a pixel electrode (anode layer) as a first electrode layer, partition walls are formed along a boundary region between adjacent pixels. Then, the liquid composition is discharged into a recess completely surrounded by the partition wall. Here, while imparting lyophilicity to the pixel electrode and imparting water repellency to the partition walls, the liquid composition is prevented from protruding from the recess.
JP 2000-323276 A

  However, in the method in which the liquid composition is filled in the recess completely surrounded by the partition walls, when the amount of droplets discharged from the nozzle openings of the droplet discharge head varies, the variation amount remains as it is between pixels. In addition, there is a problem that the thickness of the organic functional layer in the pixel varies and luminance variation occurs between pixels.

  In view of the above problems, an object of the present invention is to provide light emission that can suppress variation in the thickness of the organic functional layer between pixels and within the pixels even when the discharge amount of the liquid composition from the nozzle openings varies. An object of the present invention is to provide a device and a method for manufacturing a light emitting device.

  In order to solve the above-described problem, in the present invention, a plurality of pixels including an organic electroluminescence element in which a first electrode layer, an organic functional layer, and a second electrode layer are sequentially stacked are linearly provided for each corresponding color. In a light emitting device arranged on a substrate, a first partition wall extending continuously along the first boundary region is formed in a first boundary region between pixels having different colors corresponding to the first boundary region. In the second boundary region between pixels having the same color, a second partition that partially partitions the pixels is formed, and the organic functional layer is formed by the first partition and the second partition. In the second boundary region, the organic functional layers formed in adjacent pixels are connected to each other in a region where the second partition wall is not formed. .

  In the present invention, a plurality of pixels including an organic electroluminescence element in which a first electrode layer, an organic functional layer, and a second electrode layer are sequentially stacked are linearly arranged on the substrate for each corresponding color. In the method for manufacturing a light emitting device, after forming the first electrode layer and before forming the organic functional layer, a first boundary region between pixels having different colors is included in the first boundary region. Forming a first partition wall that extends continuously along the line, and forming a second partition wall that separates the pixels in a second boundary region between pixels having the same color corresponding to each other. And a step of discharging a liquid composition into a recess formed by the first partition and the second partition from a nozzle opening of a droplet discharge head, and then solidifying the liquid composition to form the organic functional layer. An organic functional layer forming step to form And wherein the door.

  In the present invention, since the second partition formed in the second boundary region between pixels having the same corresponding color partially partitions the pixels, between the pixels sandwiching the second boundary region, The liquid composition for forming the organic functional layer filled in the recesses is connected in the non-formation region of the second partition, and leveling occurs between the pixels. For this reason, even if there is a difference in the amount of the liquid composition filled in the pixels sandwiching the second boundary region, there is no variation in the thickness of the organic functional layer between the pixels. In the second boundary region, even if the organic functional layers formed in adjacent pixels are connected to each other, they are only connected in the region where the second partition wall is not formed. Crosstalk between pixels is not a problem.

  In the light emitting device according to the present invention, it is preferable that the first partition and the second partition are made of the same material. That is, in the method for manufacturing a light emitting device according to the present invention, it is preferable that in the partition formation step, the first partition and the second partition are simultaneously formed of the same material.

  In the light emitting device according to the present invention, the second partition wall itself has a discontinuous portion or a structure formed at a predetermined distance from the first partition wall. be able to. Of these configurations, in the latter case, the non-formation region of the second partition wall is located at the corner of the recess, so that the leveling of the liquid composition between the pixels is performed via the corner of the recess. This can be performed, and variations in the thickness of the organic functional layer between pixels and within the pixels can be effectively suppressed. In the present invention, from the viewpoint of effectively leveling the liquid composition between the pixels through the non-formation region of the second partition, the separation distance between the first partition and the second partition. Is preferably 15 μm or more.

  In the light emitting device according to the present invention, the organic functional layer may employ a configuration including at least a hole injection layer and a light emitting layer laminated on the hole injection layer. In this case, in the method for manufacturing a light emitting device, in the organic functional layer forming step, at least a hole injection layer forming step for forming a hole injection layer included in the organic functional layer, and a light emission included in the organic functional layer A light emitting layer forming step of laminating a layer on the hole injection layer, and in the light emitting layer forming step, a solvent insoluble in the hole injection layer (a solvent having low solubility in the hole injection layer) It is preferable to use a liquid composition in which the light emitting layer forming material is blended. If comprised in this way, when forming a light emitting layer after forming a hole injection layer, it can prevent that a hole injection layer deteriorates with the solvent of the liquid composition for forming a light emitting layer. However, in this case, since the hole injection layer has low lyophilicity with respect to the liquid composition for forming the light emitting layer, the wettability of the liquid composition to the base is poor. Then, in the second boundary region, the liquid composition is leveled between the pixels by the non-formation region of the second partition, and the liquid composition is discharged to or near the non-formation region of the second partition. As a result, the liquid composition is leveled in the pixel, so that variations in the thickness of the light emitting layer can be prevented.

  In the method for manufacturing a light emitting device according to the present invention, it is preferable that the surfaces of the first partition and the second partition have liquid repellency with respect to the liquid composition. If comprised in this way, it can prevent that a liquid composition protrudes outside the recessed part.

  In this case, when discharging the liquid composition, it is preferable to discharge a part of the liquid composition to a position overlapping with an end of the second partition wall. With this configuration, since the liquid composition is discharged in the vicinity of the non-formation region of the second partition wall, the liquid composition is effectively leveled between the pixels through the non-formation region of the second partition wall. be able to.

  In the present invention, when discharging the liquid composition, it is preferable to discharge a part of the liquid composition to a position overlapping with an end of the first partition wall. If comprised in this way, since a liquid composition can be discharged to the corner part of a recessed part, the film thickness variation of the organic functional layer in a pixel can be suppressed effectively.

  In the present invention, when a plurality of nozzle openings are aligned to form a nozzle row on the nozzle forming surface of the droplet discharge head, in the organic functional layer forming step, an array of pixels having the same opposing color is arranged. It is preferable to move the droplet discharge head relative to the substrate in a direction perpendicular to the arrangement direction in a state where the nozzle row is directed in a direction or an oblique direction with respect to the arrangement direction.

  The light-emitting device according to the present invention can be used as a full-color display device in electronic devices such as a mobile phone, a television, a vehicle-mounted panel, a personal computer, and a PDA.

  Embodiments of the present invention will be described below with reference to the drawings. In each drawing used in the following description, the scales are different for each layer and each member so that each layer and each member can be recognized on the drawing. In addition, components that are not directly related to the present invention, such as thin-film transistors and wiring, are easily recognized on the drawings by shifting their formation positions.

(Whole structure of light emitting device)
FIG. 1 is a block diagram showing an electrical configuration of a light emitting device to which the present invention is applied. In FIG. 1, whether each pixel corresponds to red (R), green (G), or blue (B) is represented by adding (R), (G), or (B). .

  A light-emitting device 100 shown in FIG. 1 is a device that drives and controls an organic electroluminescence element that emits light when a driving current flows, and in this type of light-emitting device 100, the organic electroluminescence element self-emits. There are advantages such as not requiring a light and less viewing angle dependency.

  In the light emitting device 100 of this embodiment, a plurality of scanning lines 163, a plurality of data lines 164 extending in a direction intersecting with the extending direction of the scanning lines 163, and a plurality of data lines 164 arranged in parallel with these data lines 164. The common power supply line 165 and the pixel 115 corresponding to the intersection of the data line 164 and the scanning line 163 are configured, and the pixels 115 are arranged in a matrix in the image display area. For the data line 164, a data line driving circuit 151 including a shift register, a level shifter, a video line, and an analog switch is configured. A scanning line driving circuit 154 including a shift register and a level shifter is configured for the scanning line 163. Each of the plurality of pixels 115 receives a pixel switching thin film transistor 106 to which a scanning signal is supplied to the gate electrode through the scanning line 163 and an image signal supplied from the data line 164 through the thin film transistor 106. Common when a storage capacitor 133 to be held, a current control thin film transistor 107 to which an image signal held by the storage capacitor 133 is supplied to the gate electrode, and the common power supply line 165 through the thin film transistor 107 are electrically connected An organic electroluminescence element 110 into which a driving current flows from the feeder line 165 is configured.

(Pixel configuration)
FIG. 2 is a plan view of a plurality of pixels of a light emitting device to which the present invention is applied. 3A and 3B are a plan view and a cross-sectional view, respectively, for one pixel of a light emitting device to which the present invention is applied. FIG. 4 is a cross-sectional view of three pixels (one dot) corresponding to each color of the light emitting device to which the present invention is applied.

  As shown in FIGS. 1 and 2, since the light emitting device 100 of this embodiment is a color display device, each pixel 115 corresponds to red (R), green (G), and blue (B). In the embodiment, a stripe arrangement in which a plurality of pixels 115 are linearly arranged for the corresponding colors (R), (G), and (B) is employed.

As shown in FIG. 2, FIG. 3A, FIG. 3B, and FIG. 4, in constructing the light emitting device 100 of this embodiment, more specifically, a substrate 120 (including a glass substrate constituting an element substrate). A base protective film (not shown) made of a silicon oxide film is formed on the substrate for the light emitting device, and a semiconductor film 109a made of a polysilicon film for forming the thin film transistor 107 and the like is formed in an island shape on the base protective film. Is formed. Source / drain regions 109b and 109c are formed in the semiconductor film 109a by introducing impurities, and a portion where no impurities are introduced becomes a channel region 109d. A gate insulating film 121 is formed on an upper layer side of the base protective film and the semiconductor film 109a. On the gate insulating film 121, aluminum (Al), molybdenum (Mo), tantalum (Ta), titanium (Ti), tungsten (W A scanning line 163 and a gate electrode 143 are formed. On the upper layer side of the scanning line 163, the gate electrode 143, and the gate insulating film 121, a first interlayer insulating film 122 and a second interlayer insulating film 123 are stacked in this order. Here, the first interlayer insulating film 122 and the second interlayer insulating film 123 are made of an inorganic insulating film such as silicon oxide (SiO ₂ ) or titanium oxide (TiO ₂ ).

  A source / drain electrode 126 and a common feed line 165 are connected to the source / drain regions 109b and 109c through contact holes of the first interlayer insulating film 122 and the gate insulating film 121, respectively, on the first interlayer insulating film 122. Is formed. A data line 164 is also formed in the upper layer of the first interlayer insulating film 122.

  A light transmissive pixel electrode 111 made of an ITO (Indium Tin Oxide / Indium Tin Oxide) layer is formed on the second interlayer insulating film 123, and the pixel electrode 111 is a contact hole of the second interlayer insulating film 123. The electrode is electrically connected to the source / drain electrode 126. Accordingly, when the pixel electrode 111 is electrically connected to the common power supply line 165 via the thin film transistor 107, a drive current flows from the common power supply line 165.

  In each pixel 115, an organic electroluminescence element in which a pixel electrode 111 as an anode layer (first electrode layer), an organic functional layer 113, and a counter electrode 112 as a cathode layer (second electrode layer) are laminated in this order. 110 is formed. The organic functional layer 113 includes a hole injection layer 113a stacked on the pixel electrode 111 and a light emitting layer 113b formed on the upper layer side of the hole injection layer 113a. The light emitting layer 113b functions as a region that emits light by combining holes injected from the hole injection layer 113a and electrons injected from the counter electrode 112 side. Whether the color corresponds to red (R), green (G), or blue (B) is defined by the type of the organic material constituting the light emitting layer 113b. The film thickness of the light emitting layer 113b is, for example, about 80 to 150 nm. In this embodiment, the hole injection layer 113a also functions as a hole transport layer that transports holes to the light emitting layer 113b, and the thickness of the hole injection layer 113a is, for example, about 10 to 100 nm.

  Note that each pixel 115 corresponds to red (R), green (G), and blue (B), but only the composition of the light emitting layer 113b constituting the organic electroluminescence element 110 is different in each color pixel 115. Other configurations are common.

  The light emitting device 100 of this embodiment is a bottom emission type that emits display light toward the substrate side, and the counter electrode 112 is formed of a light reflective conductive film such as a thin calcium layer or an aluminum film. When the light emitting device 100 is a top emission type that emits display light toward the side opposite to the substrate, the counter electrode 112 includes, for example, a thin calcium layer and a light-transmitting cathode layer made of an ITO layer or the like. A light reflection layer made of an aluminum film or the like is formed on the lower layer side of the pixel electrode 111 so as to overlap substantially the entire pixel electrode 111. Note that a sealing resin (not shown) that prevents oxidation of the cathode layer or the functional layer by preventing intrusion of water or oxygen is formed on the element forming surface side of the substrate 120, and further, a sealing substrate (see FIG. (Not shown) may be affixed.

(Structure of the partition wall)
In this embodiment, a partition made of a photosensitive resin (a region indicated by a diagonal line rising to the right in FIGS. 2 and 3A) is provided in a boundary region between adjacent pixels 115 so as to surround a peripheral portion of the pixel electrode 111. In the first boundary region 116a between the formed pixels having different colors, a first partition wall 105a extending along the first boundary region 116a is formed, and the corresponding color is the same pixel. A second partition wall 105b extending along the second boundary region 116b is formed in the second boundary region 116b therebetween.

  The first partition 105a and the second partition 105b are both formed of the same material. In this embodiment, the first partition 105a and the second partition 105b are formed of a photosensitive acrylic resin.

  Here, the first partition wall 105a continuously extends along the first boundary region 116a. On the other hand, the second partition wall 105b is formed so that both ends thereof are interposed between the first partition wall 105a and a gap 105c (a region where the second partition wall 105b is not formed). The intervening pixels 115 are partially partitioned. In this embodiment, the dimension Lb of the gap 105c (the separation distance between the first partition wall 105a and the second partition wall 105b) is set to 15 μm or more.

  The first partition wall 105a and the second partition wall 105b configured as described above are applied when the ink jet method (liquid ejection method) is used to form the organic functional layer 113 (the hole injection layer 113a and the light emitting layer 113b). The organic functional layer 113 is formed in a recess 150 formed by the first partition wall 105a and the second partition wall 105b.

  However, in this embodiment, since there is a gap 105c between the first partition 105a and the second partition 105b, the organic functional layers 113 formed in the pixels 115 sandwiching the second partition 105b are separated by a gap 105c. It is connected.

  Further, both the first partition wall 105a and the second partition wall 105b are provided with liquid repellency to the liquid composition used when forming the organic functional layer 113 on the surface, and the surface tension of the liquid composition The organic functional layer 113 is prevented from protruding from the recess 150 to the outside, and variations in the film thickness of the organic functional layer 113 are prevented. As will be described later, an ink jet type droplet discharge device uses a piezoelectric jet droplet discharge device that discharges a liquid composition by volume change of a piezoelectric vibrator, or an electrothermal transducer as an energy generating element. A droplet discharge device or the like is employed. Here, it does not matter whether the liquid composition is aqueous or oily. Moreover, about a liquid composition, it is enough if it has fluidity | liquidity, and even if a solid substance is mixed, it should just be a fluid as a whole. In addition, the solid material contained in the liquid material may be dissolved by being heated to a temperature higher than the melting point, or may be dispersed as fine particles in a solvent, and a dye, pigment or other functional material added in addition to the solvent It may be.

(Operation of Light Emitting Device 100)
In the light emitting device 100 configured as described above, when the scanning line 163 is driven and the thin film transistor 106 is turned on, the potential of the signal line 164 at that time is held in the holding capacitor 133, and according to the state of the holding capacitor 133. The conduction state of the thin film transistor 107 is controlled. Further, when the thin film transistor 107 is turned on, a current flows from the common power supply line 165 to the pixel electrode 111 through the thin film transistor 107, and in the organic electroluminescence element 110, a current flows to the counter electrode 112 through the organic functional layer 113. The light emitting layer 113b emits light according to the amount of current at this time. As a result, in the case of the bottom emission type, the light emitted from the light emitting layer 113b toward the pixel electrode 111 and the substrate 120 is emitted through the pixel electrode 111 and the substrate 120, while the light directed toward the counter electrode 112 is emitted. After being reflected by the counter electrode 112, the light passes through the pixel electrode 111 and the substrate 120 and is emitted. On the other hand, in the case of the top emission type, the light emitted from the light emitting layer 113b toward the substrate 120 is formed in the lower layer of the pixel electrode 111 while being transmitted through the counter electrode 112 and emitted to the observer side. The light is reflected by the light reflecting layer, passes through the counter electrode 112, and is emitted to the observer side.

(Configuration of droplet discharge head)
5A to 5D are explanatory diagrams of the nozzle formation surface of the droplet discharge head used when manufacturing the light emitting device 100 of this embodiment, respectively, and an explanation schematically showing the internal structure of the droplet discharge head. FIG. 6 is an explanatory diagram of a pressure generating element used in a droplet discharge head, and an explanatory diagram of another pressure generating element.

  As shown in FIG. 5A, the droplet discharge head 22 includes a nozzle row 28 formed by arranging a plurality of nozzle openings 27 in a row on the nozzle forming surface 271 thereof. The number of nozzle openings 27 is, for example, 180, the hole diameter of the nozzle openings 27 is, for example, 28 μm, and the nozzle pitch between the nozzle openings 27 is, for example, 141 μm. The main scanning direction X and the sub-scanning direction Y perpendicular to the substrate of the droplet discharge head 22 are as illustrated. That is, the droplet discharge head 22 is positioned so that the nozzle row 28 extends in a direction (sub-scanning direction Y) intersecting the main scanning direction X, and the liquid composition is moved while moving in parallel in the main scanning direction X. By selectively ejecting objects from the plurality of nozzle openings 27, droplets are landed at predetermined positions in the substrate. Further, the droplet discharge head 22 can be moved in parallel in the sub-scanning direction Y by a predetermined distance, so that the main scanning position by the droplet discharge head 22 can be shifted at a predetermined interval.

  As shown in FIGS. 5B and 5C, the droplet discharge head 22 includes, for example, a stainless steel nozzle plate 29, a diaphragm 31 facing the nozzle plate 29, and a plurality of partition members 32 that join them together. have. A plurality of pressure generating chambers 33 and liquid reservoirs 34 are formed between the nozzle plate 29 and the diaphragm 31 by the partition member 32. The plurality of pressure generating chambers 33 and the liquid reservoir 34 communicate with each other through a passage 38. A liquid composition supply hole 36 is formed at an appropriate position of the diaphragm 31, and a liquid composition supply device 37 is connected to the liquid composition supply hole 36. The liquid composition supply device 37 supplies the liquid composition M to be discharged to the liquid composition supply hole 36. The supplied liquid composition M fills the liquid reservoir 34 and further fills the pressure generating chamber 33 through the passage 38.

  The nozzle plate 29 is provided with a nozzle opening 27 for discharging the liquid composition M from the pressure generating chamber 33 in the form of a jet (droplet M0), and the nozzle forming surface 271 on which the nozzle opening 27 is open. Is a flat surface. A piezoelectric vibrator 39 (pressure generating element) is attached to the back surface of the surface of the vibration plate 31 forming the pressure generating chamber 33 so as to correspond to the pressure generating chamber 33. The piezoelectric vibrator 39 includes, for example, a piezoelectric element 41 and a pair of electrodes 42a and 42b that sandwich the piezoelectric element 41. The piezoelectric element 41 is bent and deformed so as to protrude outward as indicated by an arrow C by energization of the electrodes 42a and 42b, thereby increasing the volume of the pressure generating chamber 33. Then, the liquid composition M corresponding to the increased volume flows from the liquid reservoir 34 through the passage 38 into the pressure generating chamber 33.

  Next, when energization to the piezoelectric element 41 is released, both the piezoelectric element 41 and the diaphragm 31 return to their original shapes. As a result, the pressure generating chamber 33 also returns to its original volume, so that the pressure of the liquid composition M inside the pressure generating chamber 33 rises, and the liquid composition M drops from the nozzle opening 27 toward the substrate 120. And erupts.

  As shown in FIG. 5D, as the piezoelectric vibrator 39, a longitudinal vibration mode piezoelectric element may be used. The piezoelectric vibrator 39 in the longitudinal vibration mode is configured by alternately laminating piezoelectric materials and conductive materials in parallel to the extension direction, and the tip is fixed to the vibration plate 31 and the other end is fixed to the base 20. Has been. Such a piezoelectric vibrator 39 contracts in a direction perpendicular to the stacking direction of the conductive layers in a charged state, and extends in a direction perpendicular to the conductive layers when the charged state is released.

  Any of the piezoelectric vibrators 39 is deformed by a drive signal applied between the electrodes, and the pressure generating chamber 33 is expanded and contracted. In addition, a liquid repellent composition layer 43 made of, for example, a Ni-tetrafluoroethylene eutectoid plating layer is provided around the nozzle opening 27 in order to prevent the flying of the droplet M0 and the clogging of the nozzle opening 27. Provided.

(Method for manufacturing light emitting device)
6-8 is process sectional drawing which shows the method of manufacturing the light-emitting device 100 of this form. 9, FIG. 10 and FIG. 11 are respectively a plan view showing a state where up to pixel electrodes are formed, a plan view showing a state where barrier ribs are formed, and an organic functional layer in the manufacturing process of the light emitting device 100 of this embodiment. It is a top view which shows the method to do.

  In order to manufacture the light emitting device 100 of this embodiment, first, as shown in FIG. 6A, a substrate 120 (light emitting device substrate) is prepared. Here, when the light emitting device 100 is a bottom emission type, a transparent or translucent material such as glass, quartz, or resin is used as the substrate 120, and glass is particularly preferably used. Further, a color filter film, a color conversion film containing a fluorescent material, or a dielectric reflection film may be disposed on the substrate 120 to control the emission color. On the other hand, when the light emitting device 100 is a top emission type, the substrate 120 may be opaque. In this case, a ceramic sheet such as alumina or a metal sheet such as stainless steel is subjected to an insulation treatment such as surface oxidation. A thermosetting resin, a thermoplastic resin, or the like can be used.

Next, a base protective film (not shown) made of a silicon oxide film having a thickness of about 200 to 500 nm is formed on the substrate 120 by plasma CVD using TEOS (tetraethoxysilane) or oxygen gas as a raw material if necessary. Form. Next, the temperature of the substrate 120 is set to about 350 ° C., and a semiconductor film 109 made of an amorphous silicon film having a thickness of about 30 to 70 nm is formed on the surface of the base protective film by plasma CVD. Next, a crystallization process such as laser annealing or solid phase growth is performed on the semiconductor film 109 to crystallize the semiconductor film 109 into a polysilicon film. In the laser annealing method, for example, a line beam having a long beam length of 400 mm is used with an excimer laser, and the output intensity is set to 200 mJ / cm ² , for example. With respect to the line beam, the line beam is scanned so that a portion corresponding to 90% of the peak value of the laser intensity in the short dimension direction overlaps each region.

  Next, as shown in FIG. 6B, the semiconductor film (polysilicon film) 109 is patterned to form an island-shaped semiconductor film 109a, and the surface is plasma CVD using TEOS, oxygen gas, or the like as a raw material. Thus, a gate insulating film 121 made of a silicon oxide film or a nitride film having a thickness of about 60 to 150 nm is formed. Note that the semiconductor film 109a serves as a channel region and a source / drain region of the thin film transistor 107 shown in FIG. 3, but semiconductor films serving as a channel region and a source / drain region of the thin film transistor 106 are also formed at different cross-sectional positions. ing. That is, in the light emitting device 100, the two types of transistors 106 and 107 are formed in the same layer or in different layers, but are formed in substantially the same procedure. Therefore, in the following description, only the thin film transistor 107 is described. The description of the thin film transistor 106 is omitted.

  Next, as shown in FIG. 6C, a conductive film made of a metal film such as aluminum, tantalum, molybdenum, titanium, or tungsten is formed by sputtering, and then patterned to form a gate electrode 143 or the like. . Next, an impurity such as phosphorus is implanted in this state to form source / drain regions 109b and 109c in the semiconductor film 109a in a self-aligned manner with respect to the gate electrode 143. Note that a portion where no impurity is introduced becomes the channel region 109d.

  Next, as shown in FIG. 6D, after the first interlayer insulating film 122 is formed, contact holes are formed and electrically connected to the source / drain regions 109b and 109c through these contact holes. A source / drain electrode 126 and a common feed line 165 are formed. At that time, a data line 164 and the like are also formed.

Next, as shown in FIG. 6E, after forming a second interlayer insulating film 123 made of an inorganic insulating film such as SiO ₂ or TiO ₂ so as to cover the upper surface of each wiring, the second interlayer insulating film A contact hole is formed at a position corresponding to the source / drain electrode 126 with respect to 123.

  Next, in the pixel electrode forming step, an ITO film is formed on the second interlayer insulating film 123, and then the ITO film is patterned to form data lines 164, scanning lines 163, and common power supply lines as shown in FIG. A pixel electrode 111 is formed at a predetermined position surrounded by 165.

Next, plasma processing (O ₂ plasma processing) using oxygen as a processing gas in an air atmosphere is performed, and a portion of the pixel electrode 111 and the second interlayer insulating film 123 exposed from the pixel electrode 111 is lyophilic. Gives sex.

  Next, in the partition formation step shown in FIG. 6F, the height is increased by a photosensitive acrylic resin so as to surround the formation place of the organic functional layer 113 described with reference to FIGS. For example, a partition wall of 1 to 2 μm is formed. Specifically, as shown in FIG. 10, a first partition wall 105a extending along the first boundary region 116a is formed in the first boundary region 116a between pixels having different colors corresponding to each other, A second partition wall 105b extending along the second boundary region 116b is formed in the second boundary region 116b between pixels having the same corresponding color. At this time, the first partition wall 105a is formed so as to continuously extend along the first boundary region 116a. On the other hand, the second partition wall 105b is formed such that both ends thereof are interposed between the first partition wall 105a and a gap 105c (a region where the second partition wall 105b is not formed), and the second partition wall 105b. Thus, the pixels 115 sandwiching the second partition wall 105b are partially partitioned. At that time, the dimension Lb of the gap 105c (the separation distance between the first partition wall 105a and the second partition wall 105b) is set to 15 μm or more. As a result, a region defined by the first partition wall 105a and the second partition wall 105b becomes a recess 150. Note that the first partition wall 105a and the second partition wall 105b may be formed of an insulating organic material such as polyimide resin in addition to an acrylic resin, or may be formed of an insulating inorganic material such as polysilazane.

Next, the surface of the first partition wall 105a and the second partition wall 105b is subjected to a liquid repellency treatment to form the organic functional layer 113 on the surface of the first partition wall 105a and the second partition wall 105b. Imparts liquid repellency to the liquid composition. In order to impart such liquid repellency, for example, a method of surface-treating the surfaces of the first partition wall 105a and the second partition wall 105b with a fluorine-based compound or the like is employed. Examples of the fluorine compound include CF ₄ , SF ₅ , and CHF _3. Examples of the surface treatment include plasma treatment and UV irradiation treatment.

  Next, an organic functional layer formation process is performed. First, in the hole injection layer forming step, in the discharge step shown in FIG. 7A, the droplet discharge head 22 described with reference to FIG. 5 is used with the upper surface of the substrate 120 facing upward. A droplet Ma of the hole injection layer forming liquid (liquid composition) is discharged into the recess 150 surrounded by the first partition 105a and the second partition 105b. At this time, as shown in FIG. 5 and FIG. 11, when the nozzle row 28 is directed in the arrangement direction of the pixels 115 having the same facing color, the color facing the droplet discharge head 22 with respect to the substrate 120 is changed. Relative movement is performed in a direction (main scanning direction X) orthogonal to the arrangement direction of the same pixels 115. Further, as shown in FIG. 11, a part of the droplet Ma of the hole injection layer forming liquid is discharged to a position overlapping with the end of the second partition wall 105b. Here, the hole injection layer forming liquid ejected on the second partition 105b is repelled by the water repellency applied to the second partition 105b, and is thus filled in the recess 150.

  As a result, the hole injection layer forming liquid discharged into the recess 150 spreads in the recess 150, and leveling occurs in the pixel. Further, in the second boundary region 116b of the pixel 115 corresponding to the same color, there is a gap 105c between the first partition wall 105a and the second partition wall 105b, so that the second boundary region 116b is adjacent to the second boundary region 116b. Between the matching pixels 115, the hole injection layer forming liquid is leveled through the gap 105c.

  Accordingly, as shown in FIG. 7B, a liquid film Fa having a constant film thickness is disposed in the recess 150. As the hole injection layer forming liquid, for example, a solution in which 3,4-polyethylenedioxythiophene (conductive polymer material), which is a polyolefin derivative, and polystyrene sulfonic acid (dopant) are dispersed in a solvent is used. . As such a hole injection layer forming liquid, water alone is used as a solvent and 3,4-polyethylenedioxythiophene and polystyrenesulfonic acid are dispersed in water. However, when it is necessary to adjust the viscosity of the hole injection layer forming liquid in order to discharge the droplet Ma of the hole injection layer forming liquid in a stable state from the nozzle opening, polystyrenesulfonic acid and 3, As a solvent for dispersing 4-polyethylenedioxythiophene, a mixed solvent in which an organic solvent is mixed with water is used, and the properties of the hole injection layer forming liquid are optimized by the organic solvent. Examples of the organic solvent that can be used for such a mixed solvent include alcohols, ethers, glycol monoethers, lactones, oxazolidinones, carbonates, nitriles, amides, sulfones, and the like.

Next, in the present embodiment, in the drying step for the liquid film Fa, drying under reduced pressure is performed in a reduced pressure atmosphere at a pressure equal to or lower than atmospheric pressure, for example, about 10 ⁻⁴ to 10 ⁻⁶ Pascal (Pa). The solvent in the forming material is evaporated. As a result, as shown in FIG. 7C, the hole injection layer 113a is formed on the pixel electrode 111 with a thickness of about 10 to 100 nm. In this drying step, the solvent in the hole transport layer forming liquid may be evaporated by heating at about 40 to 200 ° C.

  Next, in the light emitting layer forming step, first, in the discharge step shown in FIG. 8A, the light emitting layer is formed from the droplet discharge head 22 described with reference to FIG. 5 with the upper surface of the substrate 120 facing upward. A droplet Mb of the forming liquid (liquid composition) is discharged into a recess 150 surrounded by the first partition wall 105a and the second partition wall 105b. At this time, as shown in FIG. 5 and FIG. 11, when the nozzle row 28 is directed in the arrangement direction of the pixels 115 having the same facing color, the color facing the droplet discharge head 22 with respect to the substrate 120 is changed. Relative movement is performed in a direction (main scanning direction X) orthogonal to the arrangement direction of the same pixels 115. In addition, as shown in FIG. 11, a part of the droplet Mb of the light emitting layer forming liquid is discharged to a position overlapping the end of the second partition wall 105b. Here, the light emitting layer forming liquid discharged onto the second partition wall 105b is repelled by the water repellency applied to the second partition wall 105b, so that the recess 150 is filled.

  As a result, the light emitting layer forming liquid discharged into the recess 150 spreads in the recess 150 and leveling occurs in the pixel. Further, in the second boundary region 116b of the pixel 115 corresponding to the same color, there is a gap 105c between the first partition wall 105a and the second partition wall 105b, so that the second boundary region 116b is adjacent to the second boundary region 116b. Between the matching pixels 115, the light emitting layer forming liquid is leveled through the gap 105c.

  Therefore, as shown in FIG. 8B, a liquid film Fb having a constant film thickness is disposed in the recess 150. As the light emitting material, for example, a polymer material having a molecular weight of 1000 or more is used. Specifically, a polyfluorene derivative, a polyphenylene derivative, a polyvinyl carbazole, a polythiophene derivative, or a polymer material thereof, a perylene dye, a coumarin dye, a rhodamine dye such as rubrene, perylene, 9,10-diphenylanthracene, What doped tetraphenyl butadiene, Nile red, coumarin 6, quinacridone, etc. is used. As such a polymer material, a π-conjugated polymer material in which π electrons of a double bond are non-polarized on the polymer chain is also a conductive polymer, and thus has excellent light emitting performance. Used. In particular, a compound having a fluorene skeleton in the molecule, that is, a polyfluorene compound is more preferably used. In addition to such materials, for example, a composition for an organic electroluminescence device disclosed in JP-A-11-40358, that is, a precursor of a conjugated polymer organic compound, and at least one for changing the light emission characteristics A composition for an organic electroluminescence device comprising a seed fluorescent dye can also be used as a light emitting layer forming material.

  As an organic solvent for dissolving or dispersing such a light emitting material, a nonpolar solvent is preferable. In particular, the light emitting layer 113b is formed on the hole injection layer 113a. It is preferable to use an insoluble material. Specifically, xylene, cyclohexylbenzene, dihydrobenzofuran, trimethylbenzene, tetramethylbenzene and the like are preferably used. Note that the formation of the light emitting layer 113b by discharging the light emitting layer forming liquid is performed by forming a light emitting layer 113b (R) that emits red colored light, a material forming a light emitting layer 113b (G) that emits green colored light, A material for forming the light emitting layer 113 (R) that emits blue colored light is discharged and applied to the corresponding pixel 115.

Next, in the drying step for the liquid film Fb, vacuum drying is performed in a reduced-pressure atmosphere at atmospheric pressure or less, for example, about 10 ⁻⁴ to 10 ⁻⁶ Pascal (Pa), and the solvent in the light emitting layer forming material is removed from the liquid film Fb. Evaporate. As a result, as shown in FIG. 8C, a solid light emitting layer 113b is formed over the hole injection layer 113a. Thereby, the organic functional layer 113 composed of the hole injection layer 113a and the light emitting layer 113b is formed. In the drying step, the solvent in the light emitting layer forming liquid may be evaporated by heating at about 40 to 200 ° C.

  Next, as shown in FIGS. 3 and 4, LiF / Al (a laminated film of LiF and Al), MgAg, or LiF / Ca / Al (LiF and Ca) are formed on the entire surface of the substrate 120 or in a stripe shape. A counter electrode 112 is formed by depositing a film of Al and Al) by an evaporation method or the like. Then, after sealing, the light-emitting device 100 provided with the organic electroluminescent element 110 in each pixel 115 can be manufactured by further forming various elements such as wiring.

(Main effects of this form)
As described above, in this embodiment, since the second partition wall 105b formed in the second boundary region 116b between pixels having the same corresponding color partially partitions the pixels, Between the pixels sandwiching the boundary region 116b, the liquid composition (hole injection layer forming liquid and light emitting layer forming liquid) for forming the organic functional layer filled in the recess 150 is not formed in the second partition 105b non-forming region (gap). 105c) and leveling occurs between pixels. For this reason, even if there is a difference in the amount of the liquid composition filled in the pixels 115 sandwiching the second boundary region 116b, there is no variation in the thickness of the organic functional layer between the pixels. Further, even if the organic functional layers 113 formed in the adjacent pixels 115 are connected by the second boundary region 116b, they are only connected by the non-formation region (gap 105c) of the second partition wall 105b. , Crosstalk between pixels having the same corresponding color is not a problem.

  In this embodiment, there is a gap 105c between both ends of the second partition 105b and the first partition 105a, and the gap 105c forms a non-formation region of the second partition 105b. For this reason, since the non-formation region of the second partition wall 105b is located in the corner portion of the recess 150, the liquid composition can be leveled between the pixels through the corner portion of the recess 150, Variations in the thickness of the organic functional layer 113 between and within the pixels can be effectively suppressed.

  Furthermore, in this embodiment, as described with reference to FIG. 11, when the liquid composition (hole injection layer forming liquid and light emitting layer forming liquid) is discharged, a part of the liquid composition is removed from the second partition. It discharges to the position which overlaps with the edge part of 105b. For this reason, the liquid composition is discharged in the vicinity of the non-formation region of the second partition wall 105b. Accordingly, since the liquid composition can be reliably connected between the pixels through the non-formation region of the second partition wall 105, the connection between the pixels can be performed through the non-formation region of the second partition wall 105. Leveling of the liquid composition can be performed effectively.

  In particular, in this embodiment, in the light emitting layer forming step, a light emitting layer forming liquid in which a light emitting layer forming material is blended with a solvent insoluble in the hole injection layer 113a (including a solvent having low solubility in the hole injection layer). Therefore, deterioration of the hole injection layer 113a when forming the light emitting layer 113b can be prevented, while the hole injection layer 113a has low lyophilicity with respect to the light emitting layer forming liquid, and Poor wettability to the ground. Nevertheless, in the present embodiment, in the second boundary region 116b, the liquid composition is leveled between the pixels by the non-formation region of the second partition wall 105b, and through the non-formation region of the second partition wall 105b. Since the light emitting layer forming liquid is leveled, variations in the film thickness of the light emitting layer 113b can be prevented.

[Other embodiments]
In the above embodiment, the liquid composition (the hole injection layer forming liquid and the light emitting layer forming liquid) is discharged to the approximate center of the region sandwiched between the first partition walls 105a, but as shown in FIG. It is preferable to discharge a part of the first partition 105a at a position overlapping with the end of the first partition 105a. With this configuration, the liquid composition discharged onto the first partition wall 105a is repelled by the water repellency imparted to the first partition wall 105a, so that the recess 150 is filled. As a result, the liquid composition spreads to the corners of the recesses 150, so that variations in the film thickness of the organic functional layer 113 (the hole injection layer 113a and the light emitting layer 113b) in the pixel can be effectively suppressed. Also in this case, as shown in FIG. 12, it is preferable to discharge a part of the liquid composition to a position overlapping with the end of the second partition wall 105b.

  The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention, and the specific materials and configurations described in the embodiment. These are merely examples, and can be changed as appropriate. For example, in the above embodiment, 3,4-polyethylenedioxythiophene is used as the hole injection layer 113a, but other polyalkylthiophene derivatives or polypyrrole derivatives may be used. In addition, as the hole injection layer 113a, a layer formed using polytetrahydrothiophenylphenylene, polyphenylene vinylene, 1,1-bis- (4-N, N-ditolylaminophenyl) cyclohexane, or the like as a polymer precursor. The present invention may be applied when used.

  In the above embodiment, the light-emitting layer 113b having a different composition is formed between pixels having different colors, but the light-emitting layer 113b that emits white light is formed for each pixel. The present invention may be applied to a light-emitting device that performs color display by coloring the white light with a color filter. In addition, the present invention is applied to a light emitting device that performs color display by forming a light emitting layer 113b that emits the same color light for any pixel and emitting light of each color through this light. Also good. In any of these cases, if the liquid composition is leveled between pixels having the same corresponding color, variation in the film thickness of the liquid composition can be prevented, and the liquid composition can be partially applied between pixels having the same corresponding color. Therefore, it is possible to prevent the image quality from being deteriorated due to crosstalk.

[Application to electronic devices]
The light-emitting device 100 according to the present invention can be used as a full-color display device or various light sources in electronic devices such as a mobile phone, a television, an in-vehicle panel, a personal computer, and a PDA.

It is a block diagram which shows the electrical constitution of the light-emitting device to which this invention is applied. It is a block diagram of a light-emitting device. It is a top view for several pixels of the light-emitting device to which this invention is applied. (A) and (B) are respectively a plan view and a cross-sectional view of one pixel of a light emitting device to which the present invention is applied. It is sectional drawing of three pixels (for 1 dot) corresponding to each color of the light-emitting device to which this invention is applied. 1A to 1D are explanatory diagrams of a nozzle forming surface of a droplet discharge head used in the droplet discharge apparatus shown in FIG. 1, an explanatory diagram schematically showing the internal structure of the droplet discharge head, and droplet discharge It is explanatory drawing of the pressure generating element used for the head, and explanatory drawing of another pressure generating element. It is process sectional drawing which shows the method of forming the thin-film transistor etc. of a light-emitting device by applying this invention. It is process sectional drawing which shows the method of forming the hole injection layer of a light-emitting device by applying this invention. It is process sectional drawing which shows the method of forming the light emitting layer of a light-emitting device by applying this invention. It is a top view which shows the state which formed even the pixel electrode in the manufacturing process of the light-emitting device which concerns on this invention. It is a top view which shows the state in which the partition was formed in the manufacturing process of the light-emitting device which concerns on this invention. It is a top view which shows the method of forming an organic functional layer in the manufacturing process of the light-emitting device which concerns on this invention. It is a top view which shows another method of forming an organic functional layer in the manufacturing process of the light-emitting device which concerns on this invention.

Explanation of symbols

10 .... Droplet ejection device, 12 .... Substrate (light emitting device substrate), 22 .... Droplet ejection head, 27 ... Nozzle opening, 28 ... Nozzle row, 100 ... Light emitting device (light emitting device), 105a ..First partition 105b ..Second partition 110 ..Organic electroluminescence element 111 ..Pixel electrode (first electrode layer) 112 ..Counter electrode (second electrode layer) 113. Organic functional layer, 113a ... hole injection layer, 113b ... light emitting layer, 115 ... pixel, 116a ... first boundary region, 116b ... second boundary region, 120 ... substrate, Fa, Fb ...・ Liquid film, M ・ ・ Liquid composition, M0, Ma, Mb ・ ・ Drop

Claims (12)

In a light emitting device in which a plurality of pixels including an organic electroluminescence element in which a first electrode layer, an organic functional layer, and a second electrode layer are sequentially laminated are arranged on a substrate for each corresponding color,
In the first boundary region between pixels corresponding to different colors, a first partition wall extending continuously along the first boundary region is formed,
In the second boundary region between pixels having the same corresponding color, a second partition that partially partitions the pixels is formed,
The organic functional layer is formed in a recess formed by the first partition and the second partition, and in the second boundary region, the organic functional layers formed in adjacent pixels are A light-emitting device connected by a non-formation region of the second partition.   The light emitting device according to claim 1, wherein the first partition and the second partition are made of the same material.   3. The light emitting device according to claim 1, wherein the second partition is formed at a position spaced apart from the first partition by a predetermined distance.   The light emitting device according to claim 3, wherein a distance between the first partition and the second partition is 15 μm or more.   The light emitting device according to any one of claims 1 to 4, wherein the organic functional layer includes a hole injection layer and a light emitting layer laminated on the hole injection layer. In a method for manufacturing a light emitting device, in which a plurality of pixels including an organic electroluminescence element in which a first electrode layer, an organic functional layer, and a second electrode layer are sequentially stacked are arranged linearly on a substrate for each corresponding color ,
After forming the first electrode layer and before forming the organic functional layer, a first boundary region between pixels corresponding to different colors extends continuously along the first boundary region. A partition formation step of forming a first partition and forming a second partition between the pixels having the same corresponding color in the second boundary region to partition the pixels separately;
An organic material that discharges a liquid composition from a nozzle opening of a droplet discharge head into a recess formed by the first partition and the second partition, and then solidifies the liquid composition to form the organic functional layer. A method for producing a light emitting device, comprising: a functional layer forming step.   The method for manufacturing a light emitting device according to claim 6, wherein in the partition formation step, the first partition and the second partition are simultaneously formed of the same material. In the organic functional layer forming step, at least a hole injection layer forming step for forming a hole injection layer included in the organic functional layer and a light emitting layer included in the organic functional layer are stacked on the hole injection layer. Performing a light emitting layer forming step,
The light emitting device manufacturing method according to claim 6 or 7, wherein in the light emitting layer forming step, a liquid composition in which a light emitting layer forming material is blended in a solvent insoluble in the hole injection layer is used. Method.   The method for manufacturing a light emitting device according to claim 6, wherein surfaces of the first partition and the second partition have liquid repellency with respect to the liquid composition. .   The method for manufacturing a light emitting device according to claim 9, wherein when the liquid composition is discharged, a part of the liquid composition is discharged to a position overlapping with an end of the second partition.   11. The method for manufacturing a light emitting device according to claim 9, wherein when the liquid composition is discharged, a part of the liquid composition is discharged to a position overlapping with an end portion of the first partition. On the nozzle forming surface of the droplet discharge head, a plurality of the nozzle openings are aligned to form a nozzle row,
In the organic functional layer forming step, the liquid droplet ejection heads are arranged with respect to the substrate in a state in which the nozzle rows are directed in the arrangement direction of pixels having the same opposing color or in an oblique direction with respect to the arrangement direction. The method for manufacturing a light-emitting device according to claim 6, wherein the light-emitting device is relatively moved in a direction orthogonal to the direction.

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