JP2006210224A - Light emitting device, manufacturing method of light emitting device, and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device, a manufacturing method of the light emitting device, and an electronic equipment wherein high reliability can be secured even when a dielectric multilayer film is formed between the layer of a substrate and a self-luminous element. <P>SOLUTION: As for an organic EL device 1, on a transparent substrate 2, a second TFT90, an interlayer-insulating film 5, a source-drain electrode 11 connected to the second TFT90 via a first contact hole 51 of this interlayer-insulating film 5, an insulation-protecting film 20, a pixel electrode 4 connected to the source-drain electrode 11 via a second contact hole 21 of this insulation-protecting film 20, a positive hole transport layer 63 of the organic EL element, a light emitting layer 65, and a counter electrode 7 (cathode) provided with reflectivity are formed in this order. Between layers of the second TFT90 and the transparent substrate 2, a dielectric multilayer film 30 for constituting a light resonance device 3 is formed, and between the layers of dielectric multilayer film 30 and the pixel electrode 4, the interlayer-insulating film 5 at an area flatly superposed on the light emitting layer 65, a gate-insulating film 92, and the insulation-protecting film 20 are removed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light emitting device having a self-luminous element that emits predetermined color light on a substrate, a method for manufacturing the light emitting device, and an electronic apparatus.

  As a next-generation display device, a light-emitting device such as an organic EL device having a plurality of electroluminescence (EL / Electro Luminescence) elements as a self-light-emitting element on a transparent substrate is expected. In this organic EL device, the EL element has a configuration in which an organic functional layer including a light emitting layer is sandwiched between an anode and a cathode, and holes injected from the anode side and electrons injected from the cathode side are light emitting layers. Recombine in the light and emits light when it leaves the excited state.

  With respect to such an organic EL device, an optical resonator is formed by forming a dielectric multilayer film as a chromaticity correction layer in a region overlapping with the light emitting layer in a plane, and the optical length of the optical resonator is an integer having a half wavelength. A technique for improving the chromaticity of light corresponding to double has been proposed (see, for example, Patent Document 1).

In the technique disclosed in Patent Document 1, a TFT (Thin Film Transistor / Thin Film Transistor) as a switching element, an interlayer insulating film, and a contact hole formed in the interlayer insulating film are electrically connected to the drain region of the TFT. A transparent electrode, a light emitting layer of a self-luminous element, a counter electrode, and a dielectric multilayer film are formed in this order from the substrate side to the upper layer side. However, when a dielectric multilayer film is formed on the substrate side, Further, as shown in FIG. 9, a source / drain electrode made of a conductive film connected to a source / drain region 91 of the TFT 90 through a contact hole 51 formed in the TFT 90, the interlayer insulating film 5, and the interlayer insulating film 5. 11. Dielectric multilayer film 30a, and source / drain through contact holes 39a formed in the dielectric multilayer film 30a The transparent electrode 4 connected to the electrode 11, the hole transport layer 63 of the organic EL element, the light emitting layer 65 of the organic EL element, and the counter electrode 7 having reflectivity are arranged in this order from the transparent substrate 2 side to the upper layer side. The formed structure is employed, and an optical resonator 3a is formed between the dielectric multilayer film 30a and the counter electrode 7. Various wirings (not shown) are formed below the dielectric multilayer film 30a. In addition, a base protective film 29 made of a silicon nitride film is formed between the TFT 90 and the transparent substrate 2 in order to prevent impurities from entering the TFT 90 from the transparent substrate 2.
JP 2004-79428 A

  However, when the structure shown in FIG. 9 is adopted, since the transparent electrode 4 is connected to the source / drain electrode 11 through the contact hole 39a of the dielectric multilayer film 30a, the reliability of the light emitting device is low. There is a problem. That is, the dielectric multilayer film 30a has, for example, a structure in which the silicon nitride films 31 and the silicon oxide films 32 are alternately stacked, and the etching rate is different for each layer. In addition, a defective shape of the contact hole 39a occurs, and the reliability of the electrical connection portion decreases. Further, as in the structure shown in FIG. 9, when the dielectric multilayer film 30a is formed on the upper layer side of the TFT 90, the dielectric multilayer film 30a is formed on the upper layer side of the wiring with respect to the TFT 90. As stress is applied to the wiring, migration tends to occur in the wiring. Furthermore, when the dielectric multilayer film 30a is formed on the upper side of the unevenness generated by the formation of the TFT 90 or the like, a large stress is applied to the transparent substrate 2, so that the transparent substrate 2 is likely to be warped. The warp causes a transport failure when transporting the transparent substrate 2 and decreases the reliability of the organic EL device.

  In view of the above problems, a light emitting device capable of ensuring high reliability even when a dielectric multilayer film is formed between the substrate and the self light emitting element, a method for manufacturing the light emitting device, and the light emitting device are provided. The object is to provide an electronic device equipped.

  In order to solve the above problems, in the present invention, at least a switching element, an interlayer insulating film, a transparent electrode electrically connected to the switching element through a first contact hole formed in the interlayer insulating film, In the light emitting device in which the light emitting layer of the self light emitting element and the counter electrode are formed in this order from the substrate side toward the upper layer, a dielectric multilayer film is formed between the switching element and the substrate, and In the interlayer between the dielectric multilayer film and the transparent electrode, the interlayer insulating film in a region overlapping with the light emitting layer in a plane is removed.

  In the present invention, since the dielectric multilayer film is formed between the switching element and the substrate, it is not necessary to form a contact hole in the dielectric multilayer film when the transparent electrode is electrically connected to the switching element. For this reason, the malfunction resulting from forming a contact hole in a dielectric multilayer film does not occur. That is, when the dielectric multilayer film has a structure in which, for example, a silicon oxide film and a silicon nitride film are alternately laminated, a contact hole is formed even if the etching rate is performed between the silicon oxide film and the silicon nitride film. Etching defects and contact hole shape defects do not occur. In addition, since the dielectric multilayer film is formed on the lower layer side of the switching element, stress at the time of forming the dielectric multilayer film is not applied to the wiring, so that the problem of migration occurring in the wiring can be avoided. Further, even when the surface has irregularities due to the formation of switching elements, the dielectric multilayer film is formed on the flat surface on the lower layer side, so that a large stress is not applied to the substrate. Therefore, since the substrate is not warped due to such stress, problems such as poor substrate transport and reduced reliability due to the warp of the substrate can be avoided. Furthermore, since the dielectric multilayer film is formed between the switching element and the substrate, the dielectric multilayer film functions as a base protective film, so that the step of forming the base protective film can be omitted. In addition, when a dielectric multilayer film is formed between the switching element and the substrate, an interlayer insulating film is interposed between the dielectric multilayer film and the transparent electrode, and an optical resonator is configured including the interlayer insulating film. In the present invention, since the interlayer insulating film in a region overlapping the light emitting layer in a plane is removed between the dielectric multilayer film and the transparent electrode in the present invention, the switching element and the substrate Even when a dielectric multilayer film is disposed between these layers, an ideal optical resonator can be configured.

  In the present invention, a conductive film connected to the switching element through the first contact hole of the interlayer insulating film and an insulating protective film are formed in this order between the interlayer insulating film and the transparent electrode. The transparent electrode is connected to the conductive film through a second contact hole formed in the insulating protective film, and is planar with the light emitting layer between the dielectric multilayer film and the transparent electrode. It is preferable that the insulating protective film in a region overlapping with the substrate is removed. When a conductive film is formed on the upper side of the interlayer insulating film and an insulating protective film is formed on the upper layer of the conductive film, the insulating protective film is interposed between the dielectric multilayer film and the transparent electrode and includes the insulating protective film. However, in the present invention, the insulating protective film in a region overlapping the light emitting layer in a plane is removed between the dielectric multilayer film and the transparent electrode in the present invention. Therefore, even when a dielectric multilayer film is arranged between the switching element and the substrate, an ideal optical resonator can be configured.

  In the present invention, at least a switching element, an interlayer insulating film, a transparent electrode electrically connected to the switching element through a first contact hole formed in the interlayer insulating film, a light emitting layer of a self-luminous element, and In the method of manufacturing a light emitting device in which the counter electrode is formed in this order from the substrate side to the upper layer, the method includes a dielectric multilayer film forming step of forming a dielectric multilayer film on the substrate, and the dielectric multilayer film forming step After performing, at least the switching element forming step, the interlayer insulating film forming step, the transparent electrode forming step, the light emitting layer forming step, and the counter electrode forming step are performed in this order. In the step of forming an insulating film, when the first contact hole is formed, the interlayer insulating film in a region overlapping with the light emitting layer in a plane is removed.

  In the present invention, when the transparent electrode is electrically connected to the switching element, it is not necessary to form a contact hole in the dielectric multilayer film, so that a problem caused by forming the contact hole in the dielectric multilayer film occurs. do not do. In addition, since the dielectric multilayer film is formed on the lower layer side of the switching element, stress caused by the dielectric multilayer film is not applied to the wiring, so that the problem of migration occurring in the wiring can also be avoided. Further, since the dielectric multilayer film is formed on the flat surface before forming the switching element or the like, a large stress is not applied to the substrate. Therefore, since the substrate is not warped due to such stress, problems such as poor substrate transport and reduced reliability due to the warp of the substrate can be avoided. Further, when forming the interlayer insulating film, the first contact hole is formed in the interlayer insulating film, and at the same time, the interlayer insulating film in the region overlapping with the light emitting layer is removed, so that the region overlapping with the light emitting layer is removed. No interlayer insulating film is interposed between the dielectric multilayer film and the transparent electrode. Therefore, unnecessary interference due to the interlayer insulating film does not occur, so that an ideal optical resonator can be configured. In addition, since the removal of the interlayer insulating film is performed simultaneously with the formation of the first contact hole, no additional process is required.

  In the present invention, in the step of forming the light emitting layer, after discharging droplets of a liquid material for forming a light emitting layer into a recess formed by removing the interlayer insulating film in a region overlapping with the light emitting layer, The light emitting layer is preferably formed by solidifying the light emitting layer forming liquid. That is, when a light emitting layer is formed by discharging liquid droplets for forming a light emitting layer, a partition (bank) may be formed of a photosensitive resin so that the liquid droplets do not flow out to an unnecessary region. However, in the present invention, since the recess is formed by partial removal of the interlayer insulating film, if the droplet of the liquid material for forming the light emitting layer is ejected into the recess, the droplet can be formed even if the formation of the partition is omitted. Does not flow into unnecessary areas. Therefore, the process for forming the partition can be omitted, so that productivity is improved.

  In the present invention, after the step of forming the interlayer insulating film, and before the step of forming the transparent electrode, a step of forming a conductive film connected to the switching element through the first contact hole of the interlayer insulating film, And forming the insulating protective film in this order. In the insulating protective film forming step, after forming the insulating protective film on the substrate, the insulating protective film is partially etched to form the insulating film on the conductive film. When forming the second contact hole to which the transparent electrode is connected, it is preferable to remove the insulating protective film in a region overlapping the light emitting layer in a plane. When forming the second contact hole in the step of forming the insulating protective film, the insulating protective film in the region overlapping with the light emitting layer is removed, so that the region overlapping the light emitting layer in the region overlapping with the dielectric multilayer film and There is no insulating protective film between the layers with the transparent electrode. Therefore, since unnecessary interference due to the insulating protective film does not occur, an ideal optical resonator can be configured. In addition, since the insulation protective film is removed at the same time as the formation of the second contact hole, no additional process is required.

  When configured in this manner, in the step of forming the light emitting layer, the light emitting layer forming liquid is formed in the recess formed by removing the interlayer insulating film and removing the insulating protective film in a region overlapping the light emitting layer in a planar manner. It is preferable that the light emitting layer is formed by solidifying the liquid material for forming the light emitting layer after discharging the droplets of the material. In the case of forming a light emitting layer by discharging liquid droplets for forming a light emitting layer, a partition wall (bank) may be formed of a photosensitive resin so that the liquid droplets do not flow into an unnecessary region. In the present invention, since the concave portion is formed by partial removal of the interlayer insulating film and the insulating protective film, even if the droplets of the liquid material for forming the light emitting layer are discharged into the concave portion, the formation of the partition is omitted. Droplet does not flow out to unnecessary area. Therefore, the process for forming the partition can be omitted, so that productivity is improved.

  The organic EL device according to the present invention is used as an electronic apparatus such as a mobile phone, a mobile computer, a direct-view display device, and various color light sources. In particular, if the organic EL device according to the present invention is used as a display device for an electronic device, the color range of the electronic device can be expanded.

  Hereinafter, an embodiment of an organic EL device according to the present invention, a manufacturing method thereof, and an electronic device will be described with reference to the drawings. In the following description, parts having common functions are denoted by the same reference numerals so as to clarify the opposition to the components shown in FIG. Further, in each drawing to be referred to, the scale may be different for each layer or each member in order to make the size recognizable on the drawing.

[Embodiment 1]
(overall structure)
FIG. 1 is an equivalent circuit diagram showing an electrical configuration of an active matrix organic EL device (light emitting device). FIG. 2 is a plan view showing an example of the pixel configuration of the organic EL device.

  As shown in FIG. 1, in the organic EL device 1 of the present embodiment, a plurality of scanning lines 131, a plurality of signal lines 132 extending in a direction intersecting with the scanning lines 131, and the signal lines are formed on the substrate. A plurality of common power supply lines 133 extending in parallel with each other 132 are wired, and pixels (pixel area elements) 100 are configured in a matrix at each intersection of the scanning lines 131 and the signal lines 132.

  A data line driver circuit 390 including a shift register, a level shifter, a video line, and an analog switch is provided for the signal line 132. On the other hand, a scanning line driving circuit 380 including a shift register and a level shifter is provided for the scanning line 131. Each pixel region 100 holds a first TFT 80 to which a scanning signal is supplied to the gate electrode via the scanning line 131 and an image signal supplied from the signal line 132 via the first TFT 80. Holding capacitor 110, the second TFT 90 to which the image signal held by the holding capacitor 110 is supplied to the gate electrode, and the common supply line 133 when electrically connected to the common power supply line 133 via the second TFT 90. A pixel electrode (anode) 4 into which a drive current flows from the electric wire 133 and a light emitting layer 65 sandwiched between the pixel electrode 4 and the counter electrode (cathode) 7 are provided. The pixel electrode 4, the counter electrode 7, and the light emitting layer are provided. 65 constitutes an EL element (self-luminous element).

  In configuring such an organic EL device 1, the planar structure of each pixel 100 is such that the four sides of the pixel electrode 4 having a rectangular planar shape are the signal line 132, the common power supply line 133, the scanning line 131, and other pixels not shown. The arrangement is surrounded by scanning lines for electrodes. As the planar shape of the pixel region 100, an arbitrary shape such as a circle or an oval is applied in addition to the rectangle shown in the figure. Note that the electrical connection between the pixel electrode 4 and the second TFT 90, the connection between the common power supply line 133 and the second TFT 90, and the like are performed by using a contact hole formed in an interlayer insulating film or the like, as will be described later. It is done using.

  Here, the pixel 100 is used as a sub-pixel that forms one dot with three colors of red (R), green (G), and blue (B), and the corresponding color of such a pixel 100 is , And is defined by the material constituting the light emitting layer 65.

  Under such a configuration, when the scanning line 131 is driven and the first TFT 80 is turned on, the potential of the signal line 132 at that time is held in the holding capacitor 110, and depending on the state of the holding capacitor 110. The conduction state of the second TFT 90 is determined. Then, a current flows from the common power supply line 133 to the pixel electrode 4 through the channel of the second TFT 90, and further a current flows to the counter electrode 7 through the light emitting layer 65, so that the light emitting layer 65 corresponds to the amount of current flowing therethrough. Will start to emit light.

(Pixel configuration)
FIG. 3 is a cross-sectional view showing a pixel configuration of the organic EL device according to Embodiment 1 of the present invention. In FIG. 3, an organic EL device 1 shown here is a so-called “bottom emission type” organic EL device that emits light emitted from a light emitting element (organic EL element) from the transparent substrate 2 side. In any pixel 100, on the surface side of the transparent substrate 2 such as a glass substrate, a thickness of 1 μm configured to cover the second TFT 90, the gate insulating film 92 of the second TFT 90, and the gate electrode 93 is formed. Aluminum connected to the source / drain region 91 of the second TFT 90 through the first contact hole 51 formed in the interlayer insulating film 5 made of a photosensitive resin of a certain degree, the interlayer insulating film 5 and the gate insulating film 92. A source / drain electrode 11 made of a conductive film such as a film, an insulating protective film 20 made of a silicon nitride film, etc., and a second contact hole 21 formed in the insulating protective film 20 are connected to the source / drain electrode 11. Pixel electrode 4 (transparent electrode / anode), hole transport layer 63 of an organic EL element as a self-luminous element, light emitting layer 65 of an organic EL element, and Counter electrode 7 having a reflective (cathode) are formed in this order toward the upper layer side. In each pixel 100, an insulating film 25 made of a silicon nitride film or the like is formed on the pixel electrode 4. The insulating film 25 is removed in a region overlapping the light emitting layer 65 in a plan view, and the pixel electrode 4 and the hole transport layer 63 can be in direct contact.

  On the insulating layer 25, a partition wall 6 is formed by a photosensitive resin so as to surround the formation region of the hole transport layer 63 and the light emitting layer 65 of the organic EL element. As will be described later, the partition wall 6 is used to prevent the liquid material from flowing out to unnecessary regions when the hole transport layer 63 and the light emitting layer 65 are formed by discharging liquid droplets of an organic functional material. It is a bank and also has a function of preventing a short circuit between the pixel electrode 4 and the counter electrode 7. Note that the first TFT 80 shown in FIGS. 1 and 2 is formed between the same layers as the second TFT 90.

  In this embodiment, the hole transport layer 63 and the light emitting layer 65 are formed of an organic functional material described later. A hole injection layer may be formed between the pixel electrode 4 and the light emitting layer 65, and an electron injection layer or an electron transport layer may be formed between the counter electrode 7 and the light emitting layer 65. .

  The pixel electrode 4 is a transparent electrode made of ITO (indium tin oxide) or the like, and has transparency to the light emitted from the light emitting layer 63. The counter electrode 7 is made of a metal such as aluminum (Al), magnesium (Mg), gold (Au), or silver (Ag), and has reflectivity with respect to light emitted from the light emitting layer 65.

  Therefore, when a current flows from the pixel electrode 4 to the counter electrode 7 through the light emitting layer 65, the light emitting layer 65 emits light according to the amount of current flowing through this, and the light is emitted from the transparent substrate 2 side. At that time, the light traveling from the light emitting layer 65 toward the counter electrode 7 is reflected from the counter electrode 7 and then emitted from the transparent substrate 2 side. Here, each pixel 100 corresponds to three colors of red (R), green (G), and blue (B) depending on the material constituting the light emitting layer 65, and emits predetermined color light. A color image is displayed. Therefore, the second TFT 90, the source / drain electrode 11 and the like are not shifted in plane with respect to the pixel electrode 4, the hole transport layer 63 of the organic EL element, and the light emitting layer 65 so as not to prevent light emission. Formed in the region.

(Configuration of optical resonator)
In the organic EL device 1 configured as described above, in this embodiment, the dielectric multilayer film 30 having a thickness of about 500 nm is formed between all the pixels 100 between the second TFT 90 and the transparent substrate 2. The optical resonator 3 is formed between the dielectric multilayer film 30 and the counter electrode 7 in a region overlapping the light emitting layer 65 in a plan view. The dielectric multilayer film 30 has, for example, a structure in which a plurality of silicon nitride films 31 and a plurality of silicon oxide films 32 are alternately stacked. Therefore, in the organic EL device 1 of this embodiment, the chromaticity of light corresponding to an integral multiple of the half wavelength of the optical length of the optical resonator 3 can be improved. In the optical resonator 3, the dielectric multilayer film 30 is common to the pixels 100 facing each color, but the hole transport layer 63 and the light emitting layer 65 have the refractive index and thickness of the material for each corresponding color. Can be different. Therefore, if the optical lengths of the hole transport layer 63 and the light emitting layer 65 are optimized for each pixel 100 corresponding to each color, an optical resonator having an optical length corresponding to the wavelength of light emitted from each pixel 100. 3 can be configured. In addition to the configuration in which the optical length of the optical resonator 3 is optimized for all the pixels 100 corresponding to each color, the optical length of the optical resonator 3 is set only for the pixel 100 corresponding to a specific color. An optimized configuration may be employed.

  In this embodiment, the interlayer insulating film 5 and the gate insulating film 92 in a region overlapping the light emitting layer 65 in a plane are removed between the dielectric multilayer film 30 and the pixel electrode 4, and the light emitting layer 65 is planarly formed. In the overlapping region, the interlayer insulating film 5 and the gate insulating film 92 are not interposed between the dielectric multilayer film 30 and the pixel electrode 4. Further, in the interlayer between the dielectric multilayer film 30 and the pixel electrode 4, the insulating protection film 20 in a region overlapping the light emitting layer 65 in a plane is removed, and in a region overlapping the light emitting layer 65 in a plane, the dielectric multilayer film 30 and The insulating protective film 20 is not interposed between the pixel electrodes 4.

(Effect of this embodiment)
FIG. 4 is a cross-sectional view showing a pixel configuration of an organic EL device according to a comparative example of the present invention. As described above, in this embodiment, the dielectric multilayer film 30 constituting the optical resonator 3 is formed over all the pixels 100. The dielectric multilayer film 30 is formed on the lower layer side of the second TFT 90, that is, The second TFT 90 and the transparent substrate 2 are formed between the layers. Therefore, in this embodiment, when the pixel electrode 4 is electrically connected to the second TFT 90, it is not necessary to form a contact hole in the dielectric multilayer film 30. Therefore, a contact hole is formed in the dielectric multilayer film 30. There is no problem caused by Further, since the dielectric multilayer film 30 is formed on the lower layer side of the second TFT 90, the stress caused by the dielectric multilayer film 30 is not applied to the wiring and the like, so that the problem of migration occurring in the wiring can also be avoided. Furthermore, since the dielectric multilayer film 30 is formed on the flat surface before the second TFT 90 and the like are formed, a large stress is not applied to the transparent substrate 2. Therefore, since the warp of the transparent substrate 2 due to the stress does not occur, problems such as a substrate conveyance failure and a decrease in the reliability of the organic EL device 1 can be avoided even in the manufacturing process due to the warp of the transparent substrate 2. .

  Further, since the dielectric multilayer film 30 including the silicon nitride film 31 is formed between the second TFT 90 and the transparent substrate 2, the dielectric multilayer film 30 functions as a base protection film. The process can be omitted.

  Further, when the dielectric multilayer film 30 is formed between the second TFT 90 and the transparent substrate 2, the interlayer insulating film 5 and the gate insulation are interposed between the dielectric multilayer film 30 and the pixel electrode 4 as shown in FIG. The film 92 is interposed, and the optical resonator 3 is configured including the interlayer insulating film 5 and the gate insulating film 92, and unnecessary interference occurs. Further, when the source / drain electrode 11 is formed on the upper layer side of the interlayer insulating film 5 and the insulating protective film 20 is formed on the upper layer of the source / drain electrode 11, it is formed between the dielectric multilayer film 30 and the pixel electrode 4. The insulating protective film 20 is interposed, and the optical resonator 3 is configured including the insulating protective film 20, and unnecessary interference occurs. However, in this embodiment, the interlayer insulating film 5, the gate insulating film 92, and the insulating protective film 20 in a region overlapping the light emitting layer 65 in a plane are removed between the dielectric multilayer film 30 and the pixel electrode 4. In the region overlapping the layer 65 in a plan view, the interlayer insulating film 5, the gate insulating film 92, and the insulating protective film 20 are not interposed between the dielectric multilayer film 30 and the pixel electrode 4. Therefore, even when the dielectric multilayer film 30 is disposed between the second TFT 90 and the transparent substrate 2, an ideal optical resonator 3 can be configured.

(Production method)
FIG. 5 is a process cross-sectional view illustrating a part of the manufacturing process of the organic EL device according to Embodiment 1 of the present invention. In order to manufacture the organic EL device of this embodiment, as shown in FIGS. 3 and 5A, first, in the dielectric multilayer film forming step, a plurality of silicon nitride films 31 and a plurality of layers are formed by sputtering or the like. The silicon oxide films 32 are alternately stacked to form the dielectric multilayer film 3 having a thickness of about 500 nm.

  Next, a formation process of the TFT 90 is performed using a known semiconductor process.

  Next, as shown in FIG. 5A, in the step of forming the interlayer insulating film 5, the interlayer insulating film 5 having a thickness of about 1 μm is formed by, for example, a photosensitive resin. At this time, the first contact hole 51 is formed, and the interlayer insulating film 5 and the gate insulating film 92 in a region overlapping the light emitting layer 65 in a plan view are simultaneously removed. For example, after applying the photosensitive resin, the photosensitive resin is exposed to light and developed to remove the photosensitive resin (interlayer insulating film 5) corresponding to the first contact hole 51. The photosensitive resin (interlayer insulating film 5) in the overlapping region is also removed. Then, the gate insulating film 92 in the removed portion of the interlayer insulating film 5 is removed using the interlayer insulating film 5 as a mask, and the first contact hole 51 is removed. In the step of forming the interlayer insulating film 5, after forming an insulating film (interlayer insulating film 5) on the entire surface of the transparent substrate 2, a resist mask is formed, and the interlayer insulating film 5 and the gate insulating film 92 are simultaneously etched. The first contact hole 51 may be formed, and the interlayer insulating film 5 and the gate insulating film 92 in a region overlapping the light emitting layer 65 in a plan view may be removed.

  Next, in the step of forming the source / drain electrodes 11, as shown in FIG. 5B, a conductive film such as an aluminum film is formed on the entire surface of the transparent substrate 2 on the interlayer insulating film 5, and then patterned. Source / drain electrodes 11 are formed.

  Next, in the formation process of the insulating protective film 5, after forming an insulating film (insulating protective film 20) made of a silicon nitride film or the like on the entire surface of the transparent substrate 2, a resist mask is formed, and the insulating protective film 20 is partially formed. The second contact hole 21 is formed by etching. At this time, the insulating protective film 20 in a region overlapping the light emitting layer 65 in a plan view is removed.

  Next, in the step of forming the transparent electrode 4, an ITO film or the like is formed on the entire surface of the transparent substrate 2 and then patterned to form the transparent electrode 4.

  Next, in the step of forming the insulating film 25, after forming a silicon nitride film or the like on the entire surface of the transparent substrate 2, the insulating protective film 25 in a region overlapping the light emitting layer 65 in a plane is removed.

  Next, after forming a thick photosensitive resin on the entire surface of the transparent substrate 2, exposure and development are performed, and as shown in FIG. 5C, formation regions of the hole transport layer 63 and the light emitting layer 65 of the organic EL element are formed. A partition wall 6 (bank) is formed so as to surround it.

  Next, in the step of forming the hole transport layer 63, liquid droplets of the organic functional material (hole transport layer forming liquid), as indicated by the alternate long and short dash line L 63, in the recesses surrounded by the partition walls 6. Then, the hole transport layer forming liquid is solidified by drying and baking to form the hole transport layer 63. For discharging such droplets, an inkjet droplet discharge head or the like is used. As the ink jet method, a piezo jet method in which a fluid is ejected by a volume change of a piezoelectric element, a method using an electrothermal transducer as an energy generating element, or the like is employed. The droplet discharge device may be a dispenser device. Here, the liquid material refers to a medium having a viscosity that can be discharged from the nozzle of the discharge head. It does not matter whether it is aqueous or oily. It is sufficient if it has fluidity (viscosity) that can be discharged from a nozzle or the like. 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. The hole transport layer 63 is exemplified by, for example, polythiophene, polystyrene sulfonic acid, polypyrrole, polyaniline, and derivatives thereof as polymer materials. In the case of using a low molecular weight material, it is preferable that the hole injection layer and the hole transport layer 63 are stacked. In that case, as a material for forming the hole injection layer, for example, a dispersion liquid in which 3,4-polyethylenediosithiophene / polystyrene sulfonic acid (PEDOT / PSS), which is a polyolefin derivative, is dispersed using an organic solvent as a main solvent. Preferably used. However, the hole injecting material is not limited to those described above, but polyphenylene vinylene whose polymer precursor is polytetrahydrothiophenylphenylene, 1,1-bis- (4-N, N-ditolylaminophenyl) ) Cyclohexane, tris (8-hydroxyquinolinol) aluminum and the like can also be used.

  Next, in the formation process of the light emitting layer 65, as in the formation process of the hole transport layer 63, as shown by a one-dot chain line L 65 in FIG. The light emitting layer 65 is formed by solidifying the light emitting layer forming liquid by drying and firing. As a material for forming the light emitting layer 65, 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 a polymer chain is also a conductive polymer, and thus has excellent light emitting performance. Preferably 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 EL device disclosed in JP-A-11-40358, that is, a precursor of a conjugated polymer organic compound, and at least one kind for changing light emission characteristics A composition for an organic EL device comprising the above 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, since the light emitting layer is formed on the hole transport layer 63, the hole transport layer 63 Insoluble materials are used. Specifically, xylene, cyclohexylbenzene, dihydrobenzofuran, trimethylbenzene, tetramethylbenzene and the like are preferably used. In forming the light emitting layer 65, a light emitting layer forming material that emits red colored light, a light emitting layer forming material that emits green colored light, a light emitting layer forming material that emits blue colored light, This is performed by discharging and applying to the corresponding pixels 100.

  Thereafter, in the step of forming the counter electrode 7 shown in FIG. 3, a metal film such as an aluminum film is formed on the entire surface of the transparent substrate 2 and then patterned to form the counter electrode 7.

  As described above, in this embodiment, when the first contact hole 51 is formed in the step of forming the interlayer insulating film 5, the interlayer insulating film 5 and the gate insulating film 92 in a region overlapping the light emitting layer 6 in a plane are removed. Further, when forming the second contact hole 52 in the step of forming the insulating protective film 20, the insulating protective film 20 in a region overlapping the light emitting layer 6 in a plan view is removed. Accordingly, since the interlayer insulating film 5, the gate insulating film 92, and the insulating protective film 20 are not interposed between the dielectric multilayer film 30 and the pixel electrode 4 in the region overlapping the light emitting layer 65 in a plan view, Even when the dielectric multilayer film 30 is disposed between the transparent substrate 2 and the transparent substrate 2, the ideal optical resonator 3 can be configured. In addition, since the removal of the interlayer insulating film 5, the gate insulating film 92, and the insulating protective film 20 from the region overlapping the light emitting layer 65 in a plane is performed simultaneously with the formation of the contact holes 51, 21, regions other than the contact holes 51, 21 are formed. Even when an insulating film is formed from, no additional process is required.

[Embodiment 2]
FIG. 6 is a cross-sectional view showing a pixel configuration of an organic EL device according to Embodiment 2 of the present invention. FIG. 7 is a process cross-sectional view illustrating a part of the manufacturing process of the organic EL device according to the second embodiment of the present invention. In addition, since the basic structure of the organic EL device of this embodiment is the same as that of Embodiment 1, common portions are denoted by the same reference numerals and detailed description thereof is omitted.

  As in the first embodiment, the organic EL device 1 shown in FIG. 6 is also a so-called “bottom emission type” that emits light emitted from the light emitting element (organic EL element) from the transparent substrate 2 (transparent substrate) side. This is an organic EL device, and on the surface side of the transparent substrate 2 such as a glass substrate, in any pixel 100, the second TFT 90, the gate insulating film 92 of the second TFT 90 and the gate electrode 93 are covered. The interlayer insulating film 5 and the source / drain composed of the conductive film connected to the source / drain region 91 of the second TFT 90 through the first contact hole 51 formed in the interlayer insulating film 5 and the gate insulating film 92. The drain electrode 11, the insulating protective film 20, and the pixel electrode connected to the source / drain electrode 11 through the second contact hole 21 formed in the insulating protective film 20 4 (transparent electrode / anode), a hole transport layer 63 of the organic EL element as a self-luminous element, a light emitting layer 65 of the organic EL element, and a counter electrode 7 (cathode) having reflectivity are directed toward the upper layer side. It is formed in order.

  Also in this embodiment, the dielectric multilayer film 30 constituting the optical resonator 3 is formed in all the pixels 100 as in the first embodiment. The dielectric multilayer film 30 is formed on the lower layer side of the second TFT 90, That is, since it is formed between the second TFT 90 and the transparent substrate 2, it is not necessary to form a contact hole in the dielectric multilayer film 30 when the pixel electrode 4 is electrically connected to the second TFT 90. . Therefore, there is an effect that a defect caused by forming a contact hole in the dielectric multilayer film 30 does not occur. Similarly to the first embodiment, the interlayer insulating film 5, the gate insulating film 92, and the insulating protective film 20 in a region overlapping the light emitting layer 65 in a plane are removed between the dielectric multilayer film 30 and the pixel electrode 4. In the region overlapping the light emitting layer 65 in a plan view, the interlayer insulating film 5, the gate insulating film 92, and the insulating protective film 20 are not interposed between the dielectric multilayer film 30 and the pixel electrode 4, so that the second TFT 90 Even when the dielectric multilayer film 30 is disposed between the transparent substrate 2 and the transparent substrate 2, an ideal optical resonator 3 can be configured.

  In this embodiment, unlike the first embodiment, the partition wall 6 is not formed in the upper layer of the insulating layer 25. However, in this embodiment, in the region overlapping the light emitting layer 65 in a plane, the interlayer is formed as described below. Since the deep recess 60 is formed by removing the insulating film 5, the gate insulating film 92, and the insulating protective film 20, hole transport is performed by discharging liquid droplets of an organic functional material into the recess 60. A layer 63 and a light emitting layer 65 are formed.

  In order to manufacture the organic EL device 1 of this embodiment, as shown in FIGS. 5 and 7A, first, in the dielectric multilayer film forming step, a plurality of silicon nitride films 31 and a plurality of silicon nitride films 31 are formed by sputtering or the like. The dielectric silicon film 32 having a thickness of about 500 nm is formed by alternately stacking the silicon oxide films 32 as layers.

  Next, a formation process of the TFT 90 is performed using a known semiconductor process. Next, as shown in FIG. 7A, in the step of forming the interlayer insulating film 5, the interlayer insulating film 5 having a thickness of about 1 μm is formed by, for example, a photosensitive resin. At this time, the first contact hole 51 is formed, and the interlayer insulating film 5 in a region overlapping the light emitting layer 65 in a plan view is simultaneously removed. Next, as shown in FIG. 7B, in the step of forming the source / drain electrode 11, the source / drain electrode 11 is formed on the interlayer insulating film 5. Next, in the step of forming the insulating protective film 5, after forming an insulating film (insulating protective film 20) made of a silicon nitride film or the like on the entire surface of the transparent substrate 2, the light emitting layer is formed when the second contact hole 21 is formed. The insulating protective film 20 in a region overlapping with the plane 65 is removed. Next, in the step of forming the transparent electrode 4, an ITO film or an IZO film is formed on the entire surface of the transparent substrate 2 and then patterned to form the transparent electrode 4. Next, in the step of forming the insulating film 25, after forming a silicon nitride film or the like on the entire surface of the transparent substrate 2, the insulating protective film 25 in a region overlapping the light emitting layer 65 in a plane is removed.

  In the state where the above steps are performed, the region where the hole transport layer 63 and the light emitting layer 65 are to be formed has a depth of about 1 μm by removing the interlayer insulating film 5, the gate insulating film 92, and the insulating protective film 20. A recess 60 is formed. Therefore, in this embodiment, in the step of forming the hole transport layer 63, as shown by a one-dot chain line L63 in FIG. Then, the hole transport layer 63 is formed by solidifying the hole transport layer forming liquid by drying and firing. At that time, the inner wall of the recess 60 functions as a bank that prevents liquid droplets from flowing out to an unnecessary region.

  Next, in the formation step of the light emitting layer 65, as in the formation step of the hole transport layer 63, as shown by a one-dot chain line L65 in FIG. 7d), a liquid material of organic functional material (liquid material for forming the hole transport layer) After the liquid droplets are discharged, the light emitting layer forming liquid is solidified by drying and baking to form the light emitting layer 65. At that time, the inner wall of the recess 60 functions as a bank that prevents liquid droplets from flowing out to an unnecessary region.

  Thereafter, in the step of forming the counter electrode 7 shown in FIG. 3, a metal film such as an aluminum film is formed on the entire surface of the transparent substrate 2 and then patterned to form the counter electrode 7.

  As described above, in the present embodiment, as in the first embodiment, when the first contact hole 51 is formed in the step of forming the interlayer insulating film 5, the interlayer insulating film 5 and the gate in a region overlapping the light emitting layer 6 in a plane are formed. The insulating film 92 is removed. Further, when forming the second contact hole 52 in the step of forming the insulating protective film 20, the insulating protective film 20 in a region overlapping the light emitting layer 6 in a plan view is removed. Accordingly, since the interlayer insulating film 5, the gate insulating film 92, and the insulating protective film 20 are not interposed between the dielectric multilayer film 30 and the pixel electrode 4 in the region overlapping the light emitting layer 65 in a plan view, Even when the dielectric multilayer film 30 is disposed between the transparent substrate 2 and the transparent substrate 2, the ideal optical resonator 3 can be configured and the same effects as those of the first embodiment can be obtained.

  In this embodiment, the deep recess 60 is formed in the region where the hole transport layer 63 and the light emitting layer 65 are to be formed by removing the interlayer insulating film 5, the gate insulating film 92, and the insulating protective film 20. Liquid droplets of organic functional material are discharged into the recess 60. For this reason, even if the partition wall 6 shown in FIGS. 3 and 5 is not formed, the liquid droplet does not flow out to an unnecessary region. Therefore, productivity can be improved as much as the step of forming the partition wall 6 can be omitted.

[Electronics]
Next, an example of an electronic apparatus including the above-described organic EL device will be described. FIG. 8 is a perspective view illustrating a configuration of a mobile personal computer (information processing apparatus) including the display device according to the above-described embodiment. In the figure, a personal computer 1100 is composed of a main body 1104 provided with a keyboard 1102 and a display device unit provided with the organic EL device described above as a display device 1106. For this reason, the electronic device provided with the display part with a wide color specification range can be provided.

  In addition to the above-described examples, other examples include mobile phones, wristwatch-type electronic devices, liquid crystal televisions, viewfinder-type and monitor direct-view video tape recorders, car navigation devices, pagers, electronic notebooks, calculators, word processors, Examples include workstations, videophones, POS terminals, electronic paper, and devices equipped with touch panels. The electro-optical device of the present invention can also be applied as a display unit of such an electronic apparatus.

[Other embodiments]
The preferred embodiments of the organic EL device, the manufacturing method thereof, and the electronic apparatus according to the present invention have been described above with reference to the accompanying drawings. Needless to say, the present invention is not limited to the above embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

FIG. 1 is an equivalent circuit diagram showing an electrical configuration of an active matrix organic EL device (light emitting device). It is a top view which shows an example of the pixel structure of an organic electroluminescent apparatus. It is sectional drawing which shows the pixel structure of the organic EL apparatus which concerns on Embodiment 1 of this invention. It is sectional drawing which shows the pixel structure of the organic electroluminescent apparatus which concerns on the comparative example of this invention. It is process sectional drawing which shows a part of manufacturing process of the organic EL apparatus concerning Embodiment 1 of this invention. It is sectional drawing which shows the pixel structure of the organic electroluminescent apparatus which concerns on Embodiment 2 of this invention. It is process sectional drawing which shows a part of manufacturing process of the organic EL apparatus which concerns on Embodiment 2 of this invention. It is a figure which shows an example of the electronic device provided with the organic EL apparatus of this embodiment. It is sectional drawing which shows the pixel structure of the conventional organic EL apparatus.

Explanation of symbols

1 organic EL device (light emitting device), 2 transparent substrate, 3 optical resonator, 4 pixel electrode (transparent electrode / anode), 5 interlayer insulation film, 6 partition, 7 counter electrode (cathode), 11 source / drain electrode (conductive) Film), 20 insulating protective film, 21 second contact hole, 30 dielectric multilayer film, 51 first contact hole, 60 recess, 63 hole transport layer of organic EL element, 65 light emitting layer of organic EL element, 90 Second TFT (switching element), 92 gate insulating film, 93 gate electrode, 100 pixels

Claims (6)

At least a switching element, an interlayer insulating film, a transparent electrode electrically connected to the switching element through a first contact hole formed in the interlayer insulating film, a light emitting layer of the self-light emitting element, and a counter electrode are substrates In the light emitting device formed in this order from the side toward the upper layer,
A dielectric multilayer film constituting an optical resonator is formed between the switching element and the substrate, and the light emitting layer is planarly overlapped between the dielectric multilayer film and the transparent electrode. A light-emitting device, wherein the interlayer insulating film in a region is removed. 2. The conductive film connected to the switching element through the first contact hole of the interlayer insulating film and the insulating protective film are disposed in this order between the interlayer insulating film and the transparent electrode. Formed,
The transparent electrode is connected to the conductive film through a second contact hole formed in the insulating protective film,
The light-emitting device, wherein the insulating protective film is removed in a region overlapping the light-emitting layer in a plane between the dielectric multilayer film and the transparent electrode. At least a switching element, an interlayer insulating film, a transparent electrode electrically connected to the switching element through a first contact hole formed in the interlayer insulating film, a light emitting layer of the self-light emitting element, and a counter electrode are substrates A method for manufacturing a light emitting device formed in this order from the side toward the upper layer,
A dielectric multilayer film forming step of forming a dielectric multilayer film on the substrate;
After performing the dielectric multilayer film forming step, at least the switching element forming step, the interlayer insulating film forming step, the transparent electrode forming step, the light emitting layer forming step, and the counter electrode forming step In this order, and
In the step of forming the interlayer insulating film, the method of manufacturing a light emitting device is characterized in that, when the first contact hole is formed, the interlayer insulating film in a region overlapping with the light emitting layer in a plane is removed.   In claim 3, in the step of forming the light emitting layer, after discharging droplets of the liquid material for forming the light emitting layer into the recess formed by removing the interlayer insulating film in a region overlapping the light emitting layer in a plane, A method for manufacturing a light emitting device, wherein the light emitting layer is formed by solidifying the light emitting layer forming liquid. 4. The step of forming a conductive film connected to the switching element through the first contact hole of the interlayer insulating film after the step of forming the interlayer insulating film and before the step of forming the transparent electrode. , And the process of forming the insulating protective film in this order,
In the step of forming the insulating protective film, when forming the second contact hole for connecting the transparent electrode to the conductive film, the insulating protective film in a region overlapping the light emitting layer in a plane is removed. A method for manufacturing a light emitting device.   An electronic apparatus comprising the light emitting device according to claim 1.

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