JP2005242338A - Light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an active matrix type light emitting device that can reduce reflection of light caused while the light is guided out of the light emitting device and sufficiently stop impurity diffusion from a substrate to a transistor. <P>SOLUTION: The light emitting device is provided with the substrate, a 1st insulating layer provided on the substrate, the transistor provided on the 1st insulating layer, and a 2nd insulating layer having a 1st opening provided so that the transistor is covered and the substrate is exposed, a light emitting element being provided inside the 1st opening. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an active matrix light-emitting device, and more particularly to a structure of a portion from which light emission is extracted.

  A light-emitting device using light emission from an electroluminescence element (light-emitting element) is a device that has attracted attention as a display device with a high viewing angle and low power consumption.

  There are an active matrix type and a passive matrix type as a driving method of a light-emitting device mainly used for display. An active matrix light-emitting device with a driving method can control light emission and non-light emission for each light-emitting element. Therefore, it can be driven with lower power consumption than a passive matrix light-emitting device, and is suitable not only as a display portion of a small electrical appliance such as a mobile phone but also as a display portion of a large-sized television receiver or the like. .

  In an active matrix light-emitting device, a transistor for controlling driving of each light-emitting element is provided for each light-emitting element. The transistor and the light emitting element are respectively disposed on the substrate so that the extraction of emitted light to the outside is not hindered by the transistor (see, for example, Patent Documents 1 and 2). The light-emitting element has a structure in which a light-emitting layer is sandwiched between a pair of electrodes, and emits light in the light-emitting layer. Here, light emission / non-light emission is controlled by a signal from the transistor.

  Light emission is extracted to the outside through a transparent electrode made of indium tin oxide (ITO) or a substrate made of quartz like the light emitting devices of Patent Documents 1 and 2. At this time, since the refractive index of the material, ITO, and quartz constituting the light emitting layer is different, a part of light emission is reflected at the interface between the light emitting layer and the transparent electrode and the interface between the transparent electrode and the substrate. Such reflection of light emission becomes a factor of lowering the extraction efficiency of light emission to the outside of the light emitting device.

Further, in recent years, an active matrix light emitting device using a substrate made of glass or plastic instead of quartz has been developed with the aim of reducing the weight of the light emitting device. However, the substrate made of glass contains impurities such as alkali metals. Further, in the case of a substrate made of plastic, when an impurity made of alkali metal or the like adheres to the substrate made of plastic, the impurity is easily diffused. There is concern that when this impurity is mixed in the transistor, the transistor does not operate normally. Therefore, an insulating layer for preventing impurity diffusion is provided between the substrate and the transistor. However, when an insulating layer for preventing diffusion of impurities is provided in this way, light emission is reflected at the interface between the insulating layer and the transparent electrode or the insulating layer and the substrate, and the light emission efficiency as described above is improved. There is a concern about the decline.
Japanese Patent Application No. 8-330600 Japanese Patent Application No. 10-254383

  The present invention provides an active matrix light-emitting device that can reduce reflection of light emitted in the process of extracting light emitted from the light-emitting device and can sufficiently prevent impurity diffusion from a substrate to a transistor. Is an issue.

  The light emitting device of the present invention includes a substrate, a first insulating layer provided on the substrate, a transistor provided on the first insulating layer, and an opening of the second insulating layer covering the transistor. A light emitting element provided on the first insulating layer, and the first insulating layer can prevent impurity diffusion and has a refractive index smaller than that of the first electrode and a refractive index higher than that of the substrate. Is characterized by a high layer.

  The light-emitting device of the present invention includes a substrate, a first insulating layer provided on the substrate, a transistor provided on the first insulating layer, a cover for the transistor, and the first insulating layer. A second insulating layer having a first opening provided so as to be exposed, a first electrode provided to overlap the first insulating layer in the first opening, A partition layer that covers the second insulating layer and has a second opening provided so as to expose the first electrode, and overlaps the first electrode in the second opening. And the second electrode provided so as to overlap with the light emitting layer in the second opening, and the first insulating layer can prevent impurity diffusion. A layer having a refractive index smaller than that of the first electrode and higher than that of the substrate. It is characterized in that.

  Here, it is preferable that the first insulating layer is made of silicon nitride containing oxygen, and in particular, 5-6% of oxygen element is contained when analyzed by Rutherford backscattering method / hydrogen forward scattering method (RBS / HFS). It is preferably made of silicon nitride containing.

  The first electrode, the second electrode, and the light emitting layer sandwiched between these electrodes constitute a light emitting element. The transistor is provided to drive the light emitting element and is electrically connected to the first electrode through a connection portion.

  Note that an insulating layer having a small stress difference from the semiconductor layer which is a component of the transistor may be provided between the first insulating layer and the transistor. Such an insulating layer is preferably made of, for example, silicon oxide.

  In the light-emitting device of the present invention, the refractive index between the first insulating layer and the first electrode is lower than that of the first electrode, and is the same as the first insulating layer or the first electrode. An insulating layer having a refractive index smaller than that of the insulating layer may be provided. The insulating layer is preferably made of silicon nitride containing oxygen. Further, in the case where the second insulating layer is formed of a highly moisture permeable material, the side wall of the second insulating layer is formed of silicon nitride containing oxygen in the second opening. Preferably it is covered with a layer.

  According to the present invention, it is possible to obtain a light-emitting device that can reduce reflection of light emitted in the process of extracting light emitted from the light-emitting device and can sufficiently prevent impurity diffusion from the substrate to the transistor.

  Further, according to the present invention, it is possible to obtain a light emitting device that can reduce an emission spectrum change depending on an angle at which a light emission extraction surface is viewed and obtain an image with good visibility.

  Hereinafter, one embodiment of the present invention will be described with reference to the drawings. However, the present invention can be implemented in many different modes, and those skilled in the art can easily understand that the modes and details can be variously changed without departing from the spirit and scope of the present invention. Is done. Therefore, the present invention is not construed as being limited to the description of this embodiment mode.

(Embodiment 1)
The light-emitting device of the present invention will be described with reference to FIG.

  On the substrate 11, an insulating layer 12 including two layers of an insulating layer 12a and an insulating layer 12b is provided. A staggered transistor 17 including a semiconductor layer 14, a gate insulating layer 15, and a gate electrode 16 is provided on the insulating layer 12b.

  The transistor 17 is covered with an insulating layer 18 having a first opening. The first opening also penetrates the gate insulating layer 15 and the insulating layer 12b and reaches the insulating layer 12a. Therefore, a part of the insulating layer 12a is exposed from the first opening.

  The insulating layer 18 and the first opening are covered with the insulating layer 19, and the insulating layer 19 and the insulating layer 12a overlap each other inside the first opening.

  The light emitting element 25 is formed on the insulating layer 19 with the light emitting layer 23 sandwiched between the first electrode 21 and the second electrode 24. The first electrode 21 and the insulating layer 19 overlap each other.

  The transistor 17 and the light emitting element 25 are electrically connected via a connecting portion 20a made of a conductor. The connecting portion 20 a is provided on the insulating layer 19 and reaches the semiconductor layer 14 through a contact hole penetrating the insulating layers 18 and 19. Further, a part of the connection portion 20 a is in contact with the first electrode 21, whereby the connection portion 20 a and the first electrode 21 are electrically connected.

  The connecting portion 20a, the wiring 20b, the insulating layer 19 and the like are covered with a partition layer 22 having a second opening provided so that a part of the first electrode 21 is exposed. In the second opening, a light emitting layer 23 is provided on the first electrode 21, and a second electrode 24 is provided on the light emitting layer 23. Thus, the portion where the first electrode 21, the light emitting layer 23, and the second electrode 24 are stacked functions as the light emitting element 25. Note that the light emitting layer 23 includes a light emitting substance and is a layer formed of a single layer or multiple layers.

  In this embodiment, the substrate 11 is made of a material that can transmit visible light such as glass. Further, a flexible resin such as plastic may be used as the substrate 11. In addition, any substrate that has a light-transmitting property and functions as a support for supporting the transistor 17 and the light-emitting element 25 can be used as the substrate 11.

  The insulating layer 12a and the insulating layer 12b are layers made of a material that can prevent diffusion of impurities from the substrate 11. In particular, the insulating layer 12a preferably has a function of preventing the diffusion of impurities, and is formed of a material having a refractive index higher than that of the substrate 11 and lower than that of the first electrode 21. An example of such a substance is silicon nitride containing oxygen. The insulating layer 12b preferably has a function of preventing impurity diffusion and has a small stress difference from the semiconductor layer 14. An example of such a layer is a layer made of silicon oxide. Note that the layer made of silicon oxide may contain several percent or less of nitrogen. Note that the insulating layer 12b is not necessarily provided between the semiconductor layer 14 and the insulating layer 12a in the case where impurity diffusion from the substrate 11 can be prevented only by the insulating layer 12a.

  Furthermore, the insulating layer 19 is preferably formed of a material having low moisture permeability, a refractive index higher than that of the substrate 11 and a refractive index lower than that of the first electrode 21. The insulating layer 12a preferably has a refractive index smaller than that of the insulating layer 19 or the same refractive index. Note that the insulating layer 12a and the insulating layer 19 may be formed of the same material.

  The first electrode 21 is made of indium tin oxide (ITO), ITO containing silicon oxide, IZO (Indium Zinc Oxide) in which indium oxide is mixed with 2 to 20% zinc oxide (ZnO). ) Or the like, and a conductive material that can transmit visible light may be used.

  When the first electrode 21 is formed of the conductive material, the insulating layer 12a contains 5 to 6% oxygen element when analyzed by Rutherford backscattering method / hydrogen forward scattering method (RBS / HFS). It is preferably formed using silicon nitride. The insulating layer 19 is also formed using silicon nitride containing 5 to 6% oxygen element when analyzed by Rutherford backscattering method / hydrogen forward scattering method (RBS / HFS), as with the insulating layer 12a. Is preferred.

  The insulating layer 18 may be a multilayer or a single layer. The insulating layer 18 may be made of any inorganic material such as silicon oxide, siloxane, or silicon nitride, or an organic material such as acrylic or polyimide, or may include both an inorganic material and an organic material. Good. In any case, an insulator may be used. Note that the insulating layer 18 preferably includes a layer made of a self-flattening material such as siloxane or acrylic so that the surface of the insulating layer 18 is flat. In the case where the insulating layer 18 contains a highly moisture permeable material such as siloxane or acrylic, the insulating layer 18 is covered with the insulating layer 19 as in the light emitting device of this embodiment, so that the light emitting element 25 through the insulating layer 18 is covered. It is possible to prevent moisture from spreading into the water. However, the planarization of the surface of the insulating layer 18 is not limited to using a substance having self-flatness, and may be performed by a polishing method.

  Moreover, the light emitting layer 23 may be made of either an organic material or an inorganic material, or may include both an inorganic material and an organic material.

  Note that there is no particular limitation on the structure of the transistor 17 in the light-emitting device of the present invention. A single gate type or a multi-gate type may be used. Further, a single drain structure, an LDD (Lightly Doped Drain) structure, or a structure in which an LDD region and a gate electrode overlap each other may be used.

  FIG. 2 is a top view of the light emitting device of the present invention. In FIG. 2, a partial cross section of the portion represented by the broken line A-A ′ is represented by the cross sectional view of FIG. 1. Accordingly, components corresponding to those shown in FIG. 1 are denoted by the same reference numerals as those in FIG. That is, 14 is a semiconductor layer, 16 is a gate electrode, 20b is a wiring, and 20a is a connection portion. Reference numeral 21 denotes a first electrode, and reference numeral 22 denotes a partition layer. Furthermore, although not shown in FIG. 1, 20c, 29a, and 29b are wirings, and 27 and 28 are transistors.

  In the light emitting device, light emitted from the light emitting element 25 is emitted to the outside through the first electrode 21, the insulating layer 19, the insulating layer 12a, and the substrate 11 in this order.

  In the light emitting device of the present invention described above, reflection of light emission generated in the process of taking out light emitted from the light emitting device is reduced, and impurity diffusion from the substrate to the transistor can be sufficiently prevented. Furthermore, in the light emitting device of the present invention, the reflection of light emission generated in the process of extracting light emission from the light emitting device is reduced, so that multiple interference due to the reflected light is suppressed. As a result of the suppression of the multiple interference, the change in the emission spectrum depending on the angle at which the emission extraction surface is viewed is reduced, and the visibility of the image displayed on the light emitting device is improved.

(Embodiment 2)
In this embodiment mode, a method for manufacturing the light-emitting device of the present invention shown in FIGS. 1 and 2 will be described with reference to FIGS.

After the insulating layers 12a and 12b are sequentially stacked on the substrate 11, the semiconductor layer 14 is further stacked on the insulating layer 12b. Note that the insulating layer 12a is preferably formed using silicon nitride containing oxygen. Further, the insulating layer 12a is more preferably a layer made of silicon nitride containing 5 to 6% oxygen element when analyzed by Rutherford backscattering method / hydrogen forward scattering method (RBS / HFS). The layer made of silicon nitride containing 5 to 6% oxygen element contains, for example, monosilane (SiH ₄ ), ammonia (NH ₃ ), nitrous oxide (N ₂ O), and hydrogen (H ₂ ) at 1:10 each. : The gas mixed so as to have a flow rate ratio of 2:40 can be used as a raw material, and can be formed using a plasma CVD method. The insulating layer 12b is preferably formed using silicon oxide.

  Next, the semiconductor layer 14 is processed into a desired shape. Note that the processing may be performed by etching the semiconductor layer 14 using a resist mask. The semiconductor layer 14 may be formed using silicon, silicon germanium, or the like. However, other materials may be used.

  Next, a gate insulating layer 15 that covers the semiconductor layer 14, the insulating layer 12 b, and the like is formed, and a conductive layer is stacked over the gate insulating layer 15. The gate insulating layer 15 may be formed using silicon oxide or the like. However, other materials may be used. Further, the gate insulating layer 15 may be a single layer or may be a multilayer in which a plurality of different insulators are stacked.

  Next, the conductive layer is processed into a desired shape, and the gate electrode 16 is formed. Here, wirings 29a and 29b (FIG. 2) are also formed together with the gate electrode 16. Note that the processing may be performed by etching the conductive layer using a resist mask. Note that the gate electrode may be formed using tungsten (W), aluminum, or the like. Further, the gate electrode 16 may be a single layer or may be a multilayer in which a plurality of layers made of different conductive materials are stacked. For example, a layer in which titanium nitride and tungsten are stacked may be used.

  Next, a high concentration impurity is added to the semiconductor layer 14 using the gate electrode 16 as a mask. Thus, the transistor 17 including the semiconductor layer 14, the gate insulating layer 15, and the gate electrode 16 is manufactured.

  Note that a manufacturing process of the transistor 17 is not particularly limited, and may be changed as appropriate so that a transistor having a desired structure can be manufactured.

  Next, an insulating layer 18 that covers the gate electrode 16, the wirings 29a and 29b, the gate insulating layer 15 and the like is formed. In this embodiment, the insulating layer 18 is formed using an inorganic material having self-flatness such as siloxane. However, the present invention is not limited to this, and an organic material having self-flatness may be used. The insulating layer 18 does not necessarily need to be formed of a substance having self-flatness, and may be made of only a substance having no self-flatness. Furthermore, the insulating layer 18 may be a layer having a multilayer structure formed by combining a layer made of a substance having self-flatness and a layer made of a substance not having self-flatness.

  Next, a part of the insulating layer 18 is opened to form the insulating layer 18 having the first opening. Note that the first opening is formed so as to penetrate the gate insulating layer 15 and the insulating layer 12b and reach the insulating layer 12a. Therefore, the insulating layer 12a is exposed from the first opening. The first opening is preferably formed so that the side wall of the insulating layer 18 has an inclination angle of 30 ° to 60 °. By inclining the side wall of the insulating layer 18, when a layer made of a conductive material or an insulating material is formed on the side wall of the insulating layer 18, the layer easily covers the side wall of the insulating layer 18.

  Next, the insulating layer 19 is formed so as to cover the insulating layer 18 and the first opening. As a result, the insulating layer 12 a exposed at the side wall and the first opening of the insulating layer 18 is covered with the insulating layer 19. Note that the insulating layer 19 is preferably formed using silicon nitride containing oxygen.

  Next, a contact hole that penetrates the insulating layers 18 and 19 and reaches the semiconductor layer 14 is formed. Note that the contact hole also penetrates the gate insulating layer 15.

  Next, after forming the conductive layer 20 that covers the insulating layer 19 and the like, the conductive layer 20 is processed into a desired shape to form the connection portion 20a, the wirings 20b and 20c, and the like. At this time, the insulating layer 19 is exposed in the first opening. The conductive layer 20 may be formed using a conductive material with low resistance such as aluminum. The conductive layer 20 may be a single layer or a multi-layered structure in which a plurality of layers made of different conductive materials are stacked. For example, titanium nitride, aluminum, and titanium nitride may be sequentially stacked.

  Next, after covering the connection portion 20a and the like and forming a conductive layer made of ITO or the like as described in the first embodiment, the conductive layer is processed to form the first electrode 21. Here, the first electrode 21 is formed on the insulating layer 19 overlapping the insulating layer 12a inside the first opening. A part of the first electrode 21 is provided so as to be in contact with the connection portion 20a. In the present embodiment, the first electrode 21 is in contact with the connection portion 20 a on the insulating layer 19. Thus, the transistor 17 and the first electrode 21 are electrically connected via the connection portion 20a.

  Note that a process such as a hydrogenation process or an impurity activation process using heat may be provided as necessary between the manufacturing of the transistor 17 and the process described above.

  Next, a partition wall layer 22 having a second opening so as to expose a part of the first electrode 21 and covering the connection portion 20a, the insulating layer 19, and the like is formed. Here, the partition wall layer 22 may be formed by processing a photosensitive resin material into a desired shape by exposure / development, or after forming a layer made of an inorganic or organic material having no photosensitivity. It may be formed by etching into a desired shape. The partition layer 22 is preferably formed so that the edge portion has a shape having a curvature.

  Next, a light emitting layer 23 is formed to cover the first electrode 21 exposed from the partition wall layer 22. The light emitting layer 23 may be formed by any method such as a vapor deposition method, an ink jet method, or a spin coating method. In the case where irregularities are formed on the insulating layer 12a, a layer made of a polymer material in which polystyrene sulfonic acid (PSS) and polyethylene dioxythiophene (PEDOT) are mixed is provided in a part of the light emitting layer 23. Therefore, the unevenness can be relaxed.

  Next, a second electrode 24 that covers the light emitting layer 23 is formed. Thus, a light emitting element 25 including the first electrode 21, the light emitting layer 23, and the second electrode 24 can be manufactured. Note that the second electrode 24 may be one that transmits visible light like the first electrode 21, or may be an electrode that is formed using aluminum or the like and does not transmit visible light. .

  As described above, the light-emitting device of the present invention as shown in FIG. 1 can be manufactured.

(Embodiment 3)
In this embodiment mode, a light-emitting device of the present invention which is different in structure and manufacturing method from the light-emitting devices in Embodiment Modes 1 and 2 will be described with reference to FIGS.

After the insulating layers 52a and 52b are sequentially stacked on the substrate 51, the semiconductor layer 53 is further stacked on the insulating layer 52b. Note that the insulating layer 52a is preferably formed using silicon nitride containing oxygen. The insulating layer 52a is more preferably a layer made of silicon nitride containing 5 to 6% oxygen element when analyzed by Rutherford backscattering method / hydrogen forward scattering method (RBS / HFS). The layer made of silicon nitride containing 5 to 6% oxygen element contains, for example, monosilane (SiH ₄ ), ammonia (NH ₃ ), nitrous oxide (N ₂ O), and hydrogen (H ₂ ) at 1:10 each. : The gas mixed so as to have a flow rate ratio of 2:40 can be used as a raw material, and can be formed using a plasma CVD method. The insulating layer 52b is preferably formed using silicon oxide.

  Next, the semiconductor layer 53 is processed into a desired shape. Note that the processing may be performed by etching the semiconductor layer 53 using a resist mask. The semiconductor layer 53 may be formed using silicon, silicon germanium, or the like. However, other materials may be used.

  Following the processing of the semiconductor layer 53, the insulating layer 52b is also etched and processed. At this time, the resist mask used for processing the semiconductor layer 53 may be used as it is.

  Next, a gate insulating layer 54 that covers the semiconductor layer 53, the insulating layer 52a, and the like is formed, and a conductive layer is stacked over the gate insulating layer 54. The gate insulating layer 54 may be formed using silicon oxide or the like. However, other materials may be used. Further, the gate insulating layer 54 may be a single layer or may be a multilayer in which a plurality of different insulators are stacked.

  Next, the conductive layer is processed into a desired shape to form the gate electrode 55. Here, wiring and the like are also formed together with the gate electrode 55. Note that the processing may be performed by etching the conductive layer using a resist mask. Note that the gate electrode may be formed using tungsten (W), aluminum, or the like. In addition, the gate electrode 55 may be a single layer or a multilayer in which a plurality of layers made of different conductive materials are stacked. For example, a layer in which titanium nitride and tungsten are stacked may be used.

  Next, a high concentration impurity is added to the semiconductor layer 53 using the gate electrode 55 as a mask. Thus, the transistor 56 including the semiconductor layer 53, the gate insulating layer 54, and the gate electrode 55 is manufactured.

  Note that the manufacturing process of the transistor 56 is not particularly limited, and may be changed as appropriate so that a transistor having a desired structure can be manufactured.

  Next, an insulating layer 57 is formed to cover the gate electrode 55, the wiring, the gate insulating layer 54, and the like. In this embodiment mode, the insulating layer 57 is formed using an inorganic material having self-flatness such as siloxane. However, the present invention is not limited to this, and an organic material having self-flatness may be used. The insulating layer 57 is not necessarily formed of a substance having self-flatness, and may be made of only a substance having no self-flatness. Furthermore, the insulating layer 57 may be a layer having a multilayer structure formed by combining a layer made of a substance having self-flatness and a layer made of a substance not having self-flatness.

  Next, a part of the insulating layer 57 is opened, and the insulating layer 57 having a first opening is formed. Note that the first opening is formed so as to penetrate the gate insulating layer 54 and reach the insulating layer 52a. Therefore, the insulating layer 52a is exposed from the first opening. The first opening is preferably formed so that the sidewall of the insulating layer 57 has an inclination angle of 30 ° to 60 °. By inclining the side wall of the insulating layer 57, when a layer made of a conductive material or an insulating material is formed on the side wall of the insulating layer 57, the layer easily covers the side wall of the insulating layer 57.

  In addition, a first opening is formed, and a contact hole that penetrates the insulating layer 57 and the gate insulating layer 54 and reaches the semiconductor layer 53 is formed.

  Next, after forming a conductive layer 58 that covers the insulating layer 57 and the like, the conductive layer 58 is processed into a desired shape to form a connection portion 58a, a wiring 58b, and the like. At this time, the insulating layer 52a is exposed in the first opening. The conductive layer 58 may be formed using a conductive material with low resistance such as aluminum. Note that the conductive layer 58 may be a single layer or a multi-layered structure in which a plurality of layers made of different conductive materials are stacked. For example, titanium nitride, aluminum, and titanium nitride may be sequentially stacked.

  Next, a conductive layer made of a conductive material that transmits visible light and covering the connection portion 58a and the like is formed, and then the conductive layer is processed to form the first electrode 59. Here, the first electrode 59 is formed so as to be laminated with the insulating layer 52a inside the first opening. A part of the first electrode 59 is provided in contact with the connection portion 58a. In this embodiment mode, the first electrode 59 is in contact with the connection portion 58 a over the insulating layer 57. Accordingly, the transistor 56 and the first electrode 59 are electrically connected through the connection portion 58a. As the conductive material that transmits visible light, ITO or the like may be used as described in the first embodiment.

  Note that a process such as a hydrogenation process or an impurity activation process using heat may be provided as necessary between the manufacturing process of the transistor 56 and the process described above.

  Next, a partition layer 60 having an opening so as to expose a part of the first electrode 59 and covering the connection portion 58a, the insulating layer 57, and the like is formed. Here, the partition wall layer 60 may be formed by processing a photosensitive resin material into a desired shape by exposure / development, or after forming a layer made of an inorganic or organic material having no photosensitivity. It may be formed by etching into a desired shape.

  Next, a light emitting layer 61 is formed to cover the first electrode 59 exposed from the partition wall layer 60. The light emitting layer 61 may be formed using any method such as a vapor deposition method, an ink jet method, or a spin coating method. Note that in the case where unevenness is formed on the insulating layer 52a, the unevenness can be reduced by providing a layer made of a polymer material such as PEDOT in part of the light-emitting layer 61.

  Next, a second electrode 62 covering the light emitting layer 61 is formed. Thus, a light emitting element 63 including the first electrode 59, the light emitting layer 61, and the second electrode 62 can be manufactured.

  As described above, the light-emitting device of the present invention can also be manufactured by a manufacturing method in which the insulating layer 52a is processed in succession to the processing of the semiconductor layer 53.

  Note that in the light-emitting device in FIG. 6B, unlike the light-emitting device in FIG. 1, an insulating layer (corresponding to the insulating layer 19 in FIG. 1) that covers the side wall of the insulating layer having the first opening is formed. Not. In the case where moisture mixing into the light-emitting element through the insulating layer covering the transistor is sufficiently suppressed, insulation that covers the side wall of the insulating layer having the first opening as in the light-emitting device in FIG. It is not necessary to provide a layer.

  In addition, the first electrode does not need to cover the entire first opening, and may have a structure that covers only a part of the first opening as in the light emitting device of FIG. 6B, for example. Absent.

(Embodiment 4)
In this embodiment mode, a light-emitting device of the present invention having a structure different from that shown in Embodiment Modes 1 to 3 will be described with reference to FIGS.

  In the light-emitting device illustrated in FIG. 7, the connection portion 20 a for connecting the transistor 17 and the first electrode 21 covers a part of the sidewall of the insulating layer 18 and overlaps with the first electrode 21 in the portion. Yes. Other configurations are the same as those shown in FIG.

  Thus, the connection means between the transistor 17 and the first electrode 21 is not limited to that shown in FIG. 1, but may be as shown in FIG.

(Embodiment 5)
In this embodiment mode, a light-emitting device of the present invention having a structure different from that shown in Embodiment Modes 1 to 4 will be described with reference to FIGS.

  In the light-emitting device illustrated in FIG. 8, the connection portion 58a for connecting the transistor 56 and the first electrode 59 overlaps so that the first electrode 59 is in a lower layer than the connection portion 58a. Other configurations are the same as those shown in FIG.

  Note that the light-emitting device as illustrated in FIG. 8 is manufactured by reversing the process order of the first electrode 59, the connection portion 58a, the wiring 58b, and the like in the method for manufacturing the light-emitting device described in Embodiment 3. can do.

  Thus, the connection means between the transistor 56 and the first electrode 59 is not limited to that shown in FIG. 6B, and may be as shown in FIG. Further, the connecting means as shown in FIG. 8 may be applied to FIG.

(Embodiment 6)
In this embodiment mode, a light-emitting device of the present invention which is different from those described in Embodiment Modes 1 to 5 will be described with reference to FIGS.

  In the light-emitting device shown in FIG. 9, the connection portion 58a for connecting the transistor 56 and the first electrode 59 which is a constituent element of the light-emitting element 63 covers the entire side wall of the insulating layer 57, and a part thereof is the first portion. The electrode 59 overlaps the other electrode 59. Other configurations are the same as those shown in FIG.

  In the light-emitting device of this embodiment, the first electrode 59 and the second electrode 62 both transmit visible light.

  Further, FIG. 10 is a top view of the light emitting device of the present invention shown in FIG. In FIG. 10, a partial cross section of the portion represented by the broken line A-A ′ is represented by the cross sectional view of FIG. 9. Accordingly, components corresponding to those shown in FIG. 9 are denoted by the same reference numerals as those in FIG. That is, 53 is a semiconductor layer, 55 is a gate electrode, 58b is a wiring, and 58a is a connection portion. Reference numeral 59 denotes a first electrode, and reference numeral 60 denotes a partition layer. Furthermore, although not shown in FIG. 9, 58c, 65a, and 65b are wirings, and 66 and 67 are transistors.

  As can be seen from FIGS. 9 and 10, the connecting portion 58 a is provided so as to cover the entire side wall of the insulating layer 57. Thus, the entire side wall of the insulating layer 57 may be covered with the connection portion 58a, or may be covered with a conductive layer or the like provided in the same layer as the connection portion 58a.

  In a light-emitting device in which both electrodes constituting the light-emitting element can transmit visible light, part of light emitted from one electrode may be reflected in the process of taking it out of the light-emitting device and return to the other electrode side. Then, the returned light emission interferes with the light emission from the light emitting layer, and may cause a spectrum change of the light emission extracted from the other electrode side. However, since the light-emitting device of the present invention can suppress the reflection, it is also effective when both the first electrode 59 and the second electrode 62 can transmit visible light.

(Embodiment 7)
In this embodiment mode, a light-emitting device of the present invention which is different in structure and manufacturing method from the light-emitting devices in Embodiment Modes 1, 2, and 3 will be described with reference to FIGS.

After the insulating layers 102a and 102b are sequentially stacked over the substrate 101, the semiconductor layer 103 is further stacked over the insulating layer 102b. Note that the insulating layer 102a is preferably formed using silicon nitride containing oxygen. Further, the insulating layer 102a is more preferably a layer made of silicon nitride containing 5 to 6% oxygen element when analyzed by Rutherford backscattering method / hydrogen forward scattering method (RBS / HFS). The layer made of silicon nitride containing 5 to 6% oxygen element contains, for example, monosilane (SiH ₄ ), ammonia (NH ₃ ), nitrous oxide (N ₂ O), and hydrogen (H ₂ ) at 1:10 each. : The gas mixed so as to have a flow rate ratio of 2:40 can be used as a raw material, and can be formed using a plasma CVD method. The insulating layer 102b is preferably formed using silicon oxide.

  Next, the semiconductor layer 103 is processed into a desired shape. Note that the processing may be performed by etching the semiconductor layer 103 using a resist mask. The semiconductor layer 103 may be formed using silicon, silicon germanium, or the like. However, other materials may be used.

  Next, a gate insulating layer 104 that covers the semiconductor layer 103, the insulating layer 102b, and the like is formed, and a conductive layer is stacked over the gate insulating layer 104. The gate insulating layer 104 may be formed using silicon oxide or the like. However, other materials may be used. The gate insulating layer 104 may be a single layer or a multilayer in which a plurality of different insulators are stacked.

  Next, the conductive layer is processed into a desired shape, so that the gate electrode 105 is formed. Here, wirings and the like are formed together with the gate electrode 105. Note that the processing may be performed by etching the conductive layer using a resist mask. Note that the gate electrode 105 may be formed using tungsten (W), aluminum, or the like. In addition, the gate electrode 105 may be a single layer or a multilayer in which a plurality of layers made of different conductive materials are stacked. For example, a layer in which titanium nitride and tungsten are stacked may be used.

  Next, a high concentration impurity is added to the semiconductor layer 103 using the gate electrode 105 as a mask. Thus, the transistor 106 including the semiconductor layer 103, the gate insulating layer 104, and the gate electrode 105 is manufactured.

  Note that the manufacturing process of the transistor 106 is not particularly limited, and may be changed as appropriate so that a transistor having a desired structure can be manufactured.

  Next, part of the gate insulating layer 104 and the insulating layer 102b is etched to form an opening from which part of the insulating layer 102a is exposed. Note that the opening is provided in a portion where the light-emitting element is formed in a later step.

Next, an insulating layer 107 is formed to cover the opening, the gate electrode 105, the wiring, the gate insulating layer 104, and the like. In this embodiment mode, the insulating layer 107 has an insulating layer 107a in a lower layer and an insulating layer 107b in an upper layer, and is composed of two layers. In this embodiment mode, the insulating layer 102a is preferably formed using silicon nitride containing oxygen. Further, the insulating layer 102a is more preferably a layer made of silicon nitride containing 5 to 6% oxygen element when analyzed by Rutherford backscattering method / hydrogen forward scattering method (RBS / HFS). The layer made of silicon nitride containing 5 to 6% oxygen element contains, for example, monosilane (SiH ₄ ), ammonia (NH ₃ ), nitrous oxide (N ₂ O), and hydrogen (H ₂ ) at 1:10 each. : The gas mixed so as to have a flow rate ratio of 2:40 can be used as a raw material, and can be formed using a plasma CVD method. The layer thus formed contains hydrogen. Then, the hydrogen can be used for hydrogenation for improving the interface state between the semiconductor layer 103 and the gate insulating layer 104. In this embodiment mode, the insulating layer 107b is formed using an inorganic material having self-flatness such as siloxane. However, the present invention is not limited to this, and an organic material having self-flatness may be used. In addition, the insulating layer 107b is not necessarily formed of a substance having self-flatness, and may be made of only a substance having no self-flatness. Further, the insulating layer 107b may be a layer having a multilayer structure formed by combining a layer made of a substance having self-flatness and a layer made of a substance not having self-flatness.

  Next, part of the insulating layer 107b is opened to form the insulating layer 107b having a first opening. Note that the first opening is provided inside the opening that penetrates the gate insulating layer 104 and the insulating layer 102b. Therefore, the insulating layer 107a is exposed from the first opening. The first opening is preferably formed so that the sidewall of the insulating layer 107b has an inclination angle of 30 ° to 60 °. By inclining the side wall of the insulating layer 107b, when a layer made of a conductive material or an insulating material is formed on the side wall of the insulating layer 107b, the layer easily covers the side wall of the insulating layer 107b.

  In addition, after the first opening is formed, a contact hole that penetrates the insulating layer 107 and the gate insulating layer 104 and reaches the semiconductor layer 103 is formed.

  Next, after the conductive layer 108 that covers the insulating layer 107 and the like is formed, the conductive layer 108 is processed into a desired shape, so that the connection portion 108a, the wiring 108b, and the like are formed. At this time, the insulating layer 107b is exposed in the first opening. The conductive layer 108 may be formed using a conductive material with low resistance such as aluminum. Note that the conductive layer 108 may be a single layer or a multilayer in which a plurality of layers made of different conductive materials are stacked. For example, titanium nitride, aluminum, and titanium nitride may be sequentially stacked.

  Next, a conductive layer made of a conductive material that transmits visible light is formed so as to cover the connection portion 108a and the like, and then the conductive layer is processed to form the first electrode 109. Here, the first electrode 109 is formed so as to be stacked with the insulating layer 107b inside the first opening. Further, part of the first electrode 109 is provided in contact with the connection portion 108a. In this embodiment mode, the first electrode 109 is in contact with the connection portion 108a over the insulating layer 107b. Accordingly, the transistor 106 and the first electrode 109 are electrically connected through the connection portion 108a. As the conductive material that transmits visible light, ITO or the like may be used as described in the first embodiment.

  Note that a process such as a hydrogenation process or an impurity activation process using heat may be provided as necessary between the manufacturing process of the transistor 106 and the process described above.

  Next, a partition layer 110 having an opening so that part of the first electrode 109 is exposed and covering the connection portion 108a, the insulating layer 107, and the like is formed. Here, the partition wall layer 110 may be formed by processing a photosensitive resin material into a desired shape by exposure and development, or after forming a layer made of an inorganic or organic material having no photosensitivity. It may be formed by etching into a desired shape.

  Next, a light-emitting layer 111 that covers the first electrode 109 exposed from the partition wall layer 110 is formed. The light emitting layer 111 may be formed by any method such as an evaporation method, an ink jet method, a spin coating method, or the like. Note that in the case where unevenness is formed over the insulating layer 107a, the unevenness can be reduced by providing a layer of a polymer material such as PEDOT in part of the light-emitting layer 111.

  Next, a second electrode 112 that covers the light-emitting layer 111 is formed. Thus, a light-emitting element 113 including the first electrode 109, the light-emitting layer 111, and the second electrode 112 can be manufactured.

  The light emitting device of the present invention can also be manufactured by the manufacturing method as described above. Further, the means shown in Embodiment Mode 4 or Embodiment Mode 5 may be applied to the connection between the first electrode and the transistor.

(Embodiment 8)
In Embodiments 1 to 7, a light-emitting device having a structure in which a transistor and a first electrode of a light-emitting element are electrically connected to each other through a connection portion is described. However, the light-emitting device is not limited to such a structure, and the first electrode and the connection portion of the light-emitting element are provided in different layers via an insulating layer, and the light-emitting element is connected via a contact hole penetrating the insulating layer. A light emitting device having a configuration in which the first electrode and the connection portion are connected may be used.

  In this example, a light-emitting device to which the present invention is applied will be described. However, the structure of the light-emitting device of the present invention and the substances constituting the light-emitting device are not limited to those shown in this embodiment.

  An embodiment of the present invention shown in FIG. 1 will be described.

  In the present embodiment, the light emitting layer 23 which is a constituent element of the light emitting element 25 includes a plurality of layers. The plurality of layers are formed by combining layers made of a substance selected from a substance having a high carrier transporting property and a substance having a high carrier injecting property, and partly contains a substance having a high light emitting property. The substance constituting the light emitting layer 23 may be inorganic or organic. In the case of an organic substance, it may be a low molecule or a polymer.

Here, as the light-emitting substance, 4- (dicyanomethylene) -2-methyl-6- [2- (1,1,7,7-tetramethyljulolidin-9-yl) ethenyl] -4H-pyran (abbreviation: DCJT), 4- (dicyanomethylene) -2-tert-butyl-6- [2- (1,1,7,7-tetramethyljulolidin-9-yl) ethenyl] -4H-pyran (abbreviation: DCJTB) , Periflanthene, 2,5-dicyano-1,4-bis [2- (10-methoxy-1,1,7,7-tetramethyljulolidin-9-yl) ethenyl] benzene, N, N′-dimethylquinacridone (abbreviation: DMQd), coumarin 6, coumarin 545T, tris (8-quinolinolato) aluminum (abbreviation: Alq _3), 9,9'-bianthryl, 9,10-diphenyl anthracene (abbreviation : DPA) and 9,10-bis (2-naphthyl) anthracene (abbreviation: DNA), or the like can be used. Other substances may also be used.

  In addition to the singlet excited luminescent material as described above, a triplet excited luminescent material containing a metal complex or the like may be used. For example, among red light emitting pixels, green light emitting pixels, and blue light emitting pixels, a red light emitting pixel having a relatively short luminance half time is formed of a triplet excitation light emitting material, and the other It is formed of a singlet excited luminescent material. A triplet excited luminescent substance has a feature that it has a high luminous efficiency, so that less power is required to obtain the same luminance. That is, when applied to a red pixel, the amount of current flowing through the light emitting element can be reduced, so that reliability can be improved. As a reduction in power consumption, a red light-emitting pixel and a green light-emitting pixel may be formed using a triplet excitation light-emitting material, and a blue light-emitting pixel may be formed using a singlet excitation light-emitting material. By forming a green light-emitting element having high human visibility with a triplet-excited light-emitting substance, power consumption can be further reduced.

  Examples of triplet excited luminescent materials include those using metal complexes as dopants, and metal complexes having a third transition series element platinum as the central metal and metal complexes having iridium as the central metal are known. Yes. The triplet excited light-emitting substance is not limited to these compounds, and it is also possible to use a compound having the above structure and having an element belonging to Group 8 to 10 in the periodic table as a central metal.

Among substances having a high carrier transport property, a substance having a particularly high electron transport property includes, for example, tris (8-quinolinolato) aluminum (abbreviation: Alq ₃ ), tris (5-methyl-8-quinolinolato) aluminum (abbreviation: Almq _3). ), Bis (10-hydroxybenzo [h] -quinolinato) beryllium (abbreviation: BeBq ₂ ), bis (2-methyl-8-quinolinolato) -4-phenylphenolato-aluminum (abbreviation: BAlq), or the like, And metal complexes having a benzoquinoline skeleton. As a substance having a high hole-transport property, for example, 4,4′-bis [N- (1-naphthyl) -N-phenyl-amino] -biphenyl (abbreviation: α-NPD), 4,4′-bis [ N- (3-methylphenyl) -N-phenyl-amino] -biphenyl (abbreviation: TPD) or 4,4 ′, 4 ″ -tris (N, N-diphenyl-amino) -triphenylamine (abbreviation: TDATA) ), 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenyl-amino] -triphenylamine (abbreviation: MTDATA) (ie, benzene ring-nitrogen) And a compound having a bond of In addition, among substances having a high carrier-injecting property, substances having a particularly high electron-injecting property include alkali metals or alkalis such as lithium fluoride (LiF), cesium fluoride (CsF), and calcium fluoride (CaF ₂ ). Examples include earth metal compounds. In addition, a mixture of a substance having a high electron transport property such as Alq ₃ and an alkaline earth metal such as magnesium (Mg) may be used. Examples of the material having a high hole injection property include molybdenum oxide (MoOx), vanadium oxide (VOx), ruthenium oxide (RuOx), tungsten oxide (WOx), and manganese oxide (MnOx). A metal oxide is mentioned. In addition, phthalocyanine compounds such as phthalocyanine (abbreviation: H ₂ Pc) and copper phthalocyanine (CuPC) can be given.

  The transistor 17 is a staggered type, but may be an inverted staggered type. Further, in the case of an inverted staggered type, a so-called channel protective type having a protective layer on a semiconductor layer may be used, or a so-called channel etched type in which a part of the semiconductor layer is etched.

  The semiconductor layer 14 may be either crystalline or non-crystalline. Moreover, a semi-amorphous etc. may be sufficient.

The semi-amorphous semiconductor is as follows. A semiconductor having an intermediate structure between amorphous and crystalline (including single crystal and polycrystal) and having a third state that is stable in terms of free energy, has a short-range order, and has a lattice distortion. It contains a crystalline region. Further, at least a part of the region in the film contains crystal grains of 0.5 to 20 nm. The Raman spectrum is shifted to the lower wavenumber side than 520 cm ⁻¹ . In X-ray diffraction, diffraction peaks of (111) and (220) that are derived from the Si crystal lattice are observed. In order to terminate dangling bonds (dangling bonds), hydrogen or halogen is contained at least 1 atomic% or more. It is also called a so-called microcrystalline semiconductor (microcrystal semiconductor). A silicide gas is formed by glow discharge decomposition (plasma CVD). As the silicide gas, SiH ₄ , Si ₂ H ₆ , SiH ₂ Cl ₂ , SiHCl ₃ , SiCl ₄ , SiF ₄ or the like can be used. This silicide gas may be diluted with H ₂ , or H ₂ and one or more kinds of rare gas elements selected from He, Ar, Kr, and Ne. The dilution rate is in the range of 2 to 1000 times. The pressure is generally in the range of 0.1 Pa to 133 Pa, and the power supply frequency is 1 MHz to 120 MHz, preferably 13 MHz to 60 MHz. The substrate heating temperature may be 300 ° C. or less, preferably 100 to 250 ° C. As an impurity element in the film, impurities of atmospheric components such as oxygen, nitrogen, and carbon are desirably 1 × 10 ²⁰ / cm ³ or less, and in particular, the oxygen concentration is 5 × 10 ¹⁹ / cm ³ or less, preferably 1 × 10 ¹⁹ / cm ³ or less. Note that the mobility of a TFT (thin film transistor) using a semi-amorphous semiconductor is approximately 1 to 10 m ² / Vsec.

  Further, specific examples of the crystalline semiconductor layer include those made of single crystal or polycrystalline silicon, silicon germanium, or the like. These may be formed by laser crystallization, or may be formed by crystallization by a solid phase growth method using nickel or the like, for example.

  Note that in the case where the semiconductor layer is formed of an amorphous material, for example, amorphous silicon, the transistor 17 and other transistors (transistors constituting a circuit for driving the light-emitting element) are all N-channel transistors. It is preferable that the light-emitting device have a structured circuit. Other than that, a light-emitting device having a circuit including any one of an N-channel transistor and a P-channel transistor, or a light-emitting device including a circuit including both transistors may be used.

  The partition layer 22 preferably has a shape in which the radius of curvature continuously changes at the edge portion as shown in FIG. The partition layer 22 is formed using acryl, siloxane (a substance having a skeleton structure formed of a bond of silicon (Si) and oxygen (O) and containing at least hydrogen as a substituent), a resist, silicon oxide, or the like. . The partition layer 22 may be formed of any one of an inorganic film and an organic film, or may be formed using both.

  The light-emitting element 25 may have a configuration in which the first electrode 21 functions as an anode and the second electrode 24 functions as a cathode, or the first electrode 21 functions as a cathode, The electrode 24 may function as an anode. However, in the former case, the transistor 17 is a P-channel transistor, and in the latter case, the transistor 17 is an N-channel transistor.

The light emitting device of the present invention is formed by arranging a plurality of pixels including the light emitting element 25 and the transistor 17 as described above in a matrix. Note that the light-emitting layer may be configured to perform color display by forming light-emitting layers having different emission wavelength bands for each pixel. Typically, a light emitting layer corresponding to each color of R (red), G (green), and B (blue) is formed. In this case as well, by providing a filter (colored layer) that transmits light in the emission wavelength band on the light emission side of the pixel, the color purity is improved and the pixel portion is mirrored (reflected). Prevention can be achieved. By providing the filter (colored layer), it is possible to omit a circularly polarizing plate that has been conventionally required, and it is possible to eliminate the loss of light emitted from the light emitting layer. Furthermore, a change in color tone that occurs when the pixel portion (display screen) is viewed obliquely can be further reduced.
In addition to providing a light emitting layer corresponding to each color and performing color display as described above, the light emitting layer may be configured to emit monochromatic or white light. In the case of using a white light emitting material, color display can be made possible by providing a filter (colored layer) that transmits light of a specific wavelength on the light emission side of the pixel.
In order to form a light emitting layer that emits white light, for example, Alq _3, partially Alq doped with Nile Red _3, p-EtTAZ, TPD white by sequentially laminated by an evaporation method (aromatic diamine) Can be obtained. Moreover, when forming a light emitting layer by the apply | coating method using spin coating, after apply | coating, it is preferable to bake by vacuum heating. For example, a poly (ethylenedioxythiophene) / poly (styrenesulfonic acid) aqueous solution (PEDOT / PSS) is applied and fired on the entire surface, and then dye (1,1,4,4-tetraphenyl-1,3-butadiene is obtained. (TPB), 4-dicyanomethylene-2-methyl-6- (p-dimethylamino-styryl) -4H-pyran (DCM1), Nile Red, Coumarin 6 etc.) doped polyvinyl carbazole (PVK) solution is applied over the entire surface What is necessary is just to bake.

  The light emitting layer can be formed as a single layer in addition to the multilayer as described above. In this case, a 1,3,4-oxadiazole derivative (PBD) may be dispersed in polyvinyl carbazole (PVK). Further, white light emission can be obtained by dispersing 30 wt% PBD and dispersing an appropriate amount of four kinds of dyes (TPB, coumarin 6, DCM1, Nile red).

  The light emitting element which is a component of the light emitting device of the present invention emits light by being forward biased. A pixel of a display device formed using a light-emitting element can be driven by an active matrix method. In any case, each pixel emits light by applying a forward bias at a specific timing, but is in a non-light emitting state for a certain period. By applying a reverse bias during the non-light emitting state, the reliability of the light emitting element can be improved. The light emitting element has a degradation mode in which the light emission intensity decreases under a constant driving condition and a degradation mode in which the non-light emitting area is enlarged in the pixel and the luminance is apparently decreased. However, alternating current that applies a bias in the forward and reverse directions. By performing a typical drive, the progress of deterioration can be slowed, and the reliability of the light emitting device can be improved.

  Note that the configuration described above is not limited to the light emitting device of the present invention as shown in FIG. 1, and may be applied to other light emitting devices of the present invention such as FIGS.

  In this embodiment, a circuit provided in a pixel portion in order to drive a light emitting element in a light emitting device of the present invention will be described. However, the circuit for driving the light emitting element is not limited to that shown in this embodiment.

  As shown in FIG. 13, a circuit for driving each light emitting element is connected to the light emitting element 301. The circuit includes a driving transistor 321 that determines light emission / non-light emission of the light emitting element 301 based on a video signal, a switching transistor 322 that controls input of the video signal, and a light emitting element 301 regardless of the video signal. And an erasing transistor 323 which is brought into a non-light-emitting state. Here, the source (or drain) of the switching transistor 322 is connected to the source signal line 331, and the source of the driving transistor 321 and the source of the erasing transistor 323 are extended in parallel with the source signal line 331. 332, the gate of the switching transistor 322 is connected to the first scanning line 333, and the gate of the erasing transistor 323 is connected to the second scanning line 334 extending in parallel with the first scanning line 333. Yes. Further, the driving transistor 321 and the light emitting element 301 are connected in series.

  A driving method when the light emitting element 301 emits light will be described. When the first scan line 333 is selected in the writing period, the switching transistor 322 whose gate is connected to the first scan line 333 is turned on. Then, when the video signal input to the source signal line 331 is input to the gate of the driving transistor 321 via the switching transistor 322, a current flows from the current supply line 332 to the light emitting element 301, and emits green light, for example. To do. At this time, the luminance of light emission is determined by the magnitude of the current flowing to the light emitting element 301.

  Note that the light-emitting element 301 corresponds to the light-emitting element 25 in FIG. 1, and the driving transistor 321 corresponds to the transistor 17 in FIG. The erasing transistor 323 corresponds to the transistor 28 in FIG. 2, and the switching transistor 322 corresponds to the transistor 27 in FIG. Further, the source signal line 331 corresponds to the wiring 20c in FIG. 2, the current supply line 332 corresponds to the wiring 20b in FIG. 2, the first scanning line 333 corresponds to the wiring 29a in FIG. A line 334 corresponds to the wiring 29b in FIG.

  In addition, the structure of the circuit connected to each light-emitting element is not limited to that described here, and may be different from the above as illustrated in FIG.

  Next, the circuit shown in FIG. 14 will be described.

  As shown in FIG. 14, a circuit for driving each light emitting element is connected to the light emitting element 801. The circuit includes a driving transistor 821 that determines light emission / non-light emission of the light emitting element 801 according to a video signal, a switching transistor 822 that controls input of the video signal, and a light emitting element 801 that does not emit light regardless of the video signal. It has an erasing transistor 823 for making a state and a current control transistor 824 for controlling the magnitude of the current supplied to the light emitting element 801. Here, the source (or drain) of the switching transistor 822 is connected to the source signal line 831, and the source of the driving transistor 821 and the source of the erasing transistor 823 extend in parallel with the source signal line 831. 832, the gate of the switching transistor 822 is connected to the first scanning line 833, and the gate of the erasing transistor 823 is connected to the second scanning line 834 extending in parallel with the first scanning line 833. Yes. Further, the driving transistor 821 and the light emitting element 801 are connected in series with the current control transistor 824 interposed therebetween. The gate of the current control transistor 824 is connected to the power supply line 835. Note that the current control transistor 824 is configured and controlled so that a current flows in a saturation region in the voltage-current (Vd-Id) characteristics, and thus, a current value flowing through the current control transistor 824 is large. Can be determined.

  A driving method when the light-emitting element 801 emits light will be described. When the first scan line 833 is selected in the writing period, the switching transistor 822 whose gate is connected to the first scan line 833 is turned on. Then, the video signal input to the source signal line 831 is input to the gate of the driving transistor 821 through the switching transistor 822. Further, current flows from the current supply line 832 to the light-emitting element 801 through the driving transistor 821 and the current control transistor 824 that is turned on in response to a signal from the power supply line 835, and thus light emission is performed. At this time, the magnitude of the current flowing to the light emitting element is determined by the current control transistor 824.

  The light emitting device of the present invention can efficiently extract light emitted from the light emitting layer to the outside of the light emission. For this reason, in the electronic device which mounts the light-emitting device of this invention, the power consumption concerning a display function becomes low. In addition, since there is little change in the emission spectrum depending on the angle at which the light emission extraction surface is viewed, an image with good visibility can be obtained in an electronic device in which the light-emitting device of the present invention is mounted. Hereinafter, electronic devices and the like mounted with the light emitting device of the present invention will be described.

  The light emitting device of the present invention is mounted on various electronic devices after mounting and sealing the external input terminal.

  In this example, a light-emitting device of the present invention after sealing and an electronic device in which the light-emitting device is mounted will be described with reference to FIGS. However, what is shown in FIGS. 15, 16, and 17 is one example, and the configuration of the light-emitting device is not limited to this.

  In this example, a method for manufacturing a light-emitting device of the present invention will be described with reference to FIGS. 16 is a cross-sectional view in FIG.

  In FIG. 15, a pixel portion 502, drive circuit portions 503 and 504, and a connection terminal portion 505 are provided over a first substrate 501 made of glass. The drive circuit portions 503 and 504 are arranged along one end of the pixel portion 502, respectively. The connection terminal portion is provided adjacent to the drive circuit portion 503, and is connected to the drive circuit portions 503 and 504 by wiring. In this embodiment, a glass substrate is used as the first substrate 501, but a quartz substrate, a flexible substrate such as plastic, or the like may be used.

  In the pixel portion 502, a light-emitting element and a circuit element for driving the light-emitting element (each unit constituting a circuit, which is a transistor, a resistor, or the like) are provided. FIG. 16 schematically shows a cross-sectional structure of the first substrate 501. The present invention is applied to the pixel portion 502.

  A substance having water absorbability is fixed to the second substrate 511 provided to face the first substrate 501. As shown in FIG. 15, the region 512 to which a substance having water absorption properties is fixed is provided outside the pixel portion 502 along the end portion of the pixel portion 502. In FIG. 15, the region 512 overlaps with the driver circuit portions 503 and 504. In this embodiment, granular calcium oxide is used as a substance having water absorption. Further, a recess is provided in part of the second substrate 511, and ester acrylate is used as a fixing agent, and calcium oxide is fixed to the recess.

  Note that in this embodiment, a glass substrate is used as the second substrate 511. However, in addition to this, a quartz substrate, a flexible substrate such as plastic, or the like may be used. Moreover, you may use substances with high moisture permeability other than ester acrylate as a fixing agent. In addition to the resin, an inorganic substance such as siloxane may be used as a fixing agent. In this embodiment, the fixing agent is solidified by heating. However, the present invention is not limited to this, and a substance that includes a polymerization initiator and has photocurability and high moisture permeability may be used as a fixing agent. In this embodiment, granular calcium oxide is used as the substance having water absorption, but other substances having water absorption may be used. Alternatively, a composition obtained by injecting into a recess a composition in which molecules capable of adsorbing water by chemical adsorption are mixed in an organic solvent may be used.

  The first substrate 501 and the second substrate 511 are attached to each other with a sealant 522 so that the light-emitting element, the transistor 506, and the like are enclosed inside. Further, a driver circuit portion 503 and the like are connected to a flexible printed wiring board (FPC) 523 through a connection terminal portion 505.

  Note that a space surrounded by the first substrate 501, the second substrate 511, and the sealant 522 (inside the light-emitting device) is filled with an inert gas such as nitrogen.

  In the light-emitting device of the present invention described above, since there is nothing to prevent extraction of light emitted from the pixel portion 502 to the outside, the second electrode of the light-emitting element (provided on the side opposite to the substrate with the light-emitting layer as the center) This is effective when light emission is taken out from the electrode). In addition, since a substance having water absorbency is fixed in the region 512, the substance having water absorbency is driven even when pressed to bond the first substrate 501 and the second substrate 511 together with the driver circuit portion 503. , 504, and the drive circuit portions 503 and 504 can be prevented from being damaged by the water-absorbing substance.

  FIG. 17 illustrates an embodiment of an electronic device in which the light-emitting device to which the present invention is applied is mounted.

  FIG. 17A illustrates a personal computer manufactured by applying the present invention, which includes a main body 5521, a housing 5522, a display portion 5523, a keyboard 5524, and the like. The personal computer can be completed by incorporating the light emitting device of the present invention as a display portion.

  FIG. 17B illustrates a cellular phone manufactured by applying the present invention. A main body 5552 is provided with a display portion 5551, a sound output portion 5554, a sound input portion 5555, operation switches 5556 and 5557, an antenna 5553, and the like. It has been. The cellular phone can be completed by incorporating the light emitting device of the present invention as a display portion.

  FIG. 17C illustrates a television set manufactured by applying the present invention, which includes a display portion 5531, a housing 5532, a speaker 5533, and the like. The television receiver can be completed by incorporating the light-emitting device of the present invention as a display portion.

  As described above, the light-emitting device of the present invention is very suitable for use as a display portion of various electronic devices.

  Note that although a personal computer or the like is described in this embodiment, a light-emitting device having the light-emitting element of the present invention may be mounted in a car navigation system or a lighting device.

FIG. 14 is a cross-sectional view illustrating a structure of a light-emitting device of the present invention. FIG. 7 is a top view for explaining a structure of a light-emitting device of the present invention. 8A and 8B illustrate a method for manufacturing a light-emitting device of the present invention. 8A and 8B illustrate a method for manufacturing a light-emitting device of the present invention. 8A and 8B illustrate a method for manufacturing a light-emitting device of the present invention. 8A and 8B illustrate a method for manufacturing a light-emitting device of the present invention. FIG. 14 is a cross-sectional view illustrating a structure of a light-emitting device of the present invention. FIG. 14 is a cross-sectional view illustrating a structure of a light-emitting device of the present invention. FIG. 14 is a cross-sectional view illustrating a structure of a light-emitting device of the present invention. FIG. 7 is a top view for explaining a structure of a light-emitting device of the present invention. 8A and 8B illustrate a method for manufacturing a light-emitting device of the present invention. 8A and 8B illustrate a method for manufacturing a light-emitting device of the present invention. 3A and 3B each illustrate a circuit for operating a light-emitting device of the present invention. 3A and 3B each illustrate a circuit for operating a light-emitting device of the present invention. The figure explaining the light-emitting device of this invention after sealing. The figure explaining the light-emitting device of this invention after sealing. 6A and 6B illustrate electronic devices to which the present invention is applied.

Explanation of symbols

11 Substrate 12 Insulating layer 12a Insulating layer 12b Insulating layer 14 Semiconductor layer 15 Gate insulating layer 16 Gate electrode 17 Transistor 18 Insulating layer 19 Insulating layer 19c Wiring 19b Wiring 20 Conductive layer 20a Connection portion 20b Wiring 21 First electrode 22 Partition layer 23 Light emitting layer 24 Second electrode 25 Light emitting element 28 Transistor 27 Transistor 29a Wiring 29b Wiring 51 Substrate 52a Insulating layer 52b Insulating layer 53 Semiconductor layer 54 Gate insulating layer 55 Gate electrode 56 Transistor 57 Insulating layer 58 Conductive layer 58a Connection part 58b Wiring 59 First electrode 60 Partition layer 61 Light emitting layer 62 Second electrode 63 Light emitting element

Claims (19)

A substrate,
A first insulating layer provided on the substrate;
A transistor provided on the first insulating layer;
A second insulating layer covering the transistor and having a first opening provided to expose the first insulating layer;
A first electrode provided so as to overlap with the first insulating layer in the first opening;
A partition layer covering the second insulating layer and having a second opening provided to expose the first electrode;
A light emitting layer provided so as to overlap with the first electrode in the second opening;
A second electrode provided to overlap the light emitting layer in the second opening,
The light emitting device, wherein the first insulating layer is a layer that can prevent impurity diffusion and has a refractive index smaller than that of the first electrode and higher than that of the substrate.   2. The light-emitting device according to claim 1, wherein a refractive index between the first insulating layer and the first electrode is lower than that of the first electrode and is the same as the first insulating layer or the first A light-emitting device, wherein a third insulating layer having a refractive index smaller than that of the first insulating layer is provided.   3. The light emitting device according to claim 2, wherein a side wall of the second insulating layer is covered with the third insulating layer. A substrate,
A first insulating layer provided on the substrate;
A transistor provided on the first insulating layer;
A second insulating layer covering the transistor and having a first opening provided to expose the first insulating layer;
A first electrode provided so as to overlap with the first insulating layer in the first opening;
A partition layer covering the second insulating layer and having a second opening provided to expose the first electrode;
A light emitting layer provided so as to overlap with the first electrode in the second opening;
A second electrode provided to overlap the light emitting layer in the second opening,
The light-emitting device, wherein the first insulating layer is made of silicon nitride containing oxygen.   5. The light-emitting device according to claim 4, wherein a refractive index between the first insulating layer and the first electrode is lower than that of the first electrode and is the same as the first insulating layer or the first A light-emitting device, wherein a third insulating layer having a refractive index smaller than that of the first insulating layer is provided.   5. The light emitting device according to claim 4, wherein a side wall of the second insulating layer is covered with the third insulating layer. A substrate,
A first insulating layer provided on the substrate;
A transistor provided on the first insulating layer;
A light emitting element comprising a light emitting layer sandwiched between a first electrode and a second electrode;
A second insulating layer covering the transistor and having a first opening provided to expose the first insulating layer;
A partition layer that covers the second insulating layer and has a second opening provided inside the first opening;
Have
The first insulating layer is a layer that can prevent impurity diffusion, has a lower refractive index than the first electrode, and a higher refractive index than the substrate;
The light-emitting device, wherein the light-emitting element is provided inside the second opening so that the first insulating layer and the first electrode overlap each other.   The light-emitting device according to claim 7, wherein a third insulating layer is provided between the first insulating layer and the transistor.   9. The light emitting device according to claim 8, wherein the third insulating layer is a layer made of silicon oxide. A substrate,
A first insulating layer provided on the substrate;
A transistor provided on the first insulating layer;
A light emitting element comprising a light emitting layer sandwiched between a first electrode and a second electrode;
A second insulating layer covering the transistor and having a first opening provided to expose the first insulating layer;
A partition layer that covers the second insulating layer and has a second opening provided inside the first opening;
Have
The first insulating layer is made of silicon nitride containing oxygen,
The light-emitting device, wherein the light-emitting element is provided inside the second opening so that the first insulating layer and the first electrode overlap each other.   The light-emitting device according to claim 10, wherein a third insulating layer is provided between the first insulating layer and the transistor.   12. The light emitting device according to claim 11, wherein the third insulating layer is a layer made of silicon oxide. A substrate,
A first insulating layer provided on the substrate;
A transistor provided on the first insulating layer;
A light emitting element comprising a light emitting layer sandwiched between a first electrode and a second electrode;
A second insulating layer covering the transistor and having a first opening provided to expose the first insulating layer;
A third insulating layer covering the second insulating layer and the first insulating layer exposed from the first opening;
A partition layer that covers the third insulating layer and has a second opening provided inside the first opening;
Have
The first insulating layer is a layer that can prevent impurity diffusion, has a lower refractive index than the first electrode, and a higher refractive index than the substrate;
The light emitting device, wherein the light emitting element is provided inside the second opening so that the third insulating layer and the first electrode overlap each other.   14. The light-emitting device according to claim 13, wherein a fourth insulating layer is provided between the first insulating layer and the transistor.   15. The light emitting device according to claim 14, wherein the fourth insulating layer is a layer made of silicon oxide. A substrate,
A first insulating layer provided on the substrate;
A transistor provided on the first insulating layer;
A light emitting element comprising a light emitting layer sandwiched between a first electrode and a second electrode;
A second insulating layer covering the transistor and having a first opening provided to expose the first insulating layer;
A third insulating layer covering the second insulating layer and the first insulating layer exposed from the first opening;
A partition layer that covers the third insulating layer and has a second opening provided inside the first opening;
Have
The first insulating layer is made of silicon nitride containing oxygen,
The light emitting device, wherein the light emitting element is provided inside the second opening so that the third insulating layer and the first electrode overlap each other.   17. The light-emitting device according to claim 16, wherein a fourth insulating layer is provided between the first insulating layer and the transistor.   18. The light emitting device according to claim 17, wherein the fourth insulating layer is a layer made of silicon oxide. An electronic apparatus using the light-emitting device according to claim 1 as a display portion.

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