JP5004430B2 - Method for manufacturing light emitting device - Google Patents

Description

  The present invention relates to a light emitting device manufactured using a large substrate and a method for manufacturing the light emitting device.

  A light-emitting device using light emitted from an electroluminescence element (light-emitting element) has been attracting attention as a display device with a high viewing angle and low power consumption, and has recently been developed for mass production of light-emitting devices. It is being advanced.

  One of the challenges in mass production of light emitting devices is the development of manufacturing technology for light emitting devices using large substrates. By using a large substrate, it is possible to produce a large television receiver and the like, and it is possible to produce a large number of small light emitting devices mounted on a small electronic device such as a cellular phone on a single substrate.

  However, in manufacturing a light-emitting device using a large substrate, it is necessary to process the substrate using a large processing apparatus, and thus it is difficult to process the entire surface of the substrate under uniform conditions. However, when a substrate made of a material that is easily charged, such as glass, is used, charges are likely to accumulate in a part of the substrate when plasma processing is performed unless the entire surface of the substrate is processed under uniform conditions. When the accumulated electric charge moves through the element being manufactured, a large current flows through the part that becomes the movement path, and as a result, the element may be damaged.

  In order to reduce the damage caused by static electricity as described above, for example, a contrivance is provided such as providing a short ring in which an input terminal for sending a signal to the display unit is connected by a conductive film. Patent Document 1 proposes a method of providing an electrostatic absorption pattern or capacitance made of a wiring layer film in order to reduce damage caused by static electricity.

  However, when a short ring is used, it is difficult to suppress damage to the element due to static electricity that may occur in the process until the short ring is formed. Further, in the method disclosed in Patent Document 1, a portion that becomes unnecessary after device fabrication occurs, and the substrate surface cannot be used effectively.

JP-A-6-75246

  It is an object of the present invention to provide a method for manufacturing a light-emitting device that can reduce element damage due to static electricity that may occur when the light-emitting device is manufactured. It is another object of the present invention to provide a light-emitting device in which defects due to element damage caused by static electricity are reduced.

  The manufacturing method of a light emitting device of the present invention includes a step of manufacturing a planar type transistor for driving a light emitting element, particularly a top gate type transistor. When forming a semiconductor layer functioning as an active layer in a process for manufacturing a transistor, a lattice-shaped first semiconductor layer extending in a row direction and a column direction is formed over a substrate, and the first A plurality of second semiconductor layers separated into island shapes are formed between the semiconductor layers. Here, the second semiconductor layer is a layer functioning as an active layer of the transistor.

  The method for manufacturing a light emitting device of the present invention includes a step of manufacturing a transistor for driving a light emitting element. Here, the transistor is formed by sequentially stacking a semiconductor layer, an insulating layer, and a conductive layer. When forming a semiconductor layer functioning as an active layer in a process for manufacturing a transistor, a lattice-shaped first semiconductor layer extending in a row direction and a column direction is formed over a substrate, and the first A plurality of second semiconductor layers separated into island shapes are formed between the semiconductor layers. Here, the second semiconductor layer is a layer functioning as an active layer of the transistor.

  The manufacturing method of a light emitting device of the present invention includes a step of manufacturing a planar type transistor for driving a light emitting element, particularly a top gate type transistor. In the process of manufacturing the transistor, when forming the semiconductor layer functioning as the active layer, a plurality of groups formed of a plurality of first semiconductor layers separated into island shapes are formed on one substrate, and the group A lattice-shaped second semiconductor layer extending in the row direction and the column direction is formed so as to surround each of them. Here, the first semiconductor layer is a layer functioning as an active layer of the transistor.

  The method for manufacturing a light emitting device of the present invention includes a step of manufacturing a transistor for driving a light emitting element. Here, the transistor is formed by sequentially stacking a semiconductor layer, an insulating layer, and a conductive layer. In the process of manufacturing the transistor, when forming the semiconductor layer functioning as the active layer, a plurality of groups each including a plurality of first semiconductor layers separated into island shapes are formed over one substrate, and A lattice-shaped second semiconductor layer extending in the row direction and the column direction is formed so as to surround each of them. Here, the second semiconductor layer is a layer functioning as an active layer of the transistor.

  In the method for manufacturing a light-emitting device of the present invention described above, a top-gate transistor refers to a transistor manufactured so that a gate electrode is formed after an active layer of the transistor is formed. Moreover, in the manufacturing method of the light-emitting device of this invention shown above, the process of adding an impurity to the said 1st semiconductor layer may be further included. One or both of n-type and p-type may be added.

  The light-emitting device of the present invention includes a first substrate having an element group including a light-emitting element and a transistor, and a second substrate bonded to the first substrate with a sealant so as to enclose the element group. A substrate. In the first substrate, the element group is covered with an insulating layer having an opening, the opening is provided above a semiconductor layer surrounding the element group, and the sealing material fills the opening. It is characterized by being provided.

  The light-emitting device of the present invention includes a first substrate having an element group including a light-emitting element and a transistor, and a second substrate bonded to the first substrate with a sealant so as to enclose the element group. A substrate. In the first substrate, the element group is covered with an insulating layer having an opening provided so that a conductive layer overlapping the semiconductor layer is exposed above a semiconductor layer surrounding the element group, The sealing material is provided so as to fill the opening.

  The light-emitting device of the present invention includes a first substrate having an element group including a light-emitting element and a transistor, and a second substrate bonded to the first substrate with a sealant so as to enclose the element group. A substrate. In the first substrate, the element group is surrounded by a semiconductor layer and covered with an insulating layer, and a conductive layer overlapping the semiconductor layer is exposed from an end of the insulating layer, and the sealing material is The conductive layer is provided so as to cover the end portion of the insulating layer.

  In the light-emitting device of the present invention described above, it is preferable that one or both of n-type and p-type impurities be added to the semiconductor layer. The insulating layer is a layer having a flat surface, such as acrylic, siloxane (a substance having a skeletal structure composed of a bond of silicon (Si) and oxygen (O) and containing at least hydrogen in an organic group), polyimide, or the like. A layer formed by forming a layer made of a substance having self-flatness or a layer made of silicon oxide or the like and then flattening by a CMP (Chemical and Mechanical Polishing) method or the like is preferable. The sealing material is bisphenol A type liquid resin, bisphenol A type solid resin, bromine-containing epoxy resin, bisphenol F type resin, bisphenol AD type resin, phenol type resin, cresol type resin, novolak type resin, cyclic aliphatic epoxy. It is preferable to include a material having low moisture permeability such as an epoxy resin such as a resin, an epibis type epoxy resin, a glycidyl ester resin, a glycidylamine resin, a heterocyclic epoxy resin, and a modified epoxy resin.

  According to the present invention, it is possible to obtain a manufacturing technique of a light-emitting device that can reduce defects caused by static electricity and that can effectively utilize a substrate surface. In addition, according to the present invention, a non-defective light emitting device in which defects due to static electricity are reduced can be obtained.

  Hereinafter, one embodiment of the present invention will be described. 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 the embodiment.

(Embodiment 1)
In this embodiment, after manufacturing a plurality of light-emitting devices over one substrate, the substrate is cut (that is, divided), and a method for manufacturing a light-emitting device using each light-emitting device is described.

  FIG. 1A is a top view for explaining the light-emitting device of the present invention, and FIGS. 2 and 3 are cross-sectional views for explaining a method for manufacturing the light-emitting device of the present invention. FIG. 2A is a cross-sectional view taken along broken line A-A ′ in FIG.

  First, as shown in FIG. 1A, a lattice-shaped first semiconductor layer 102 extending in a row direction and a column direction is formed over a substrate 101. In addition to the formation of the first semiconductor layer 102, a plurality of second semiconductor layers 103 separated in an island shape are formed in a region 130 surrounded by the first semiconductor layer 102 as shown in FIG. To do. Here, the second semiconductor layer 103 is a layer formed in order to manufacture a transistor. Then, a plurality of light-emitting devices each including the region 130 surrounded by the first semiconductor layer 102 as a unit are formed on the substrate 201 through a process described later. Note that in this embodiment mode, the pixel portion 131, the drive circuit portions 132a and 132b, and the like are formed in the region 130, and therefore each portion is schematically illustrated in the cross-sectional views of FIGS.

  Here, the substrate 101 is not particularly limited, but a substrate made of glass, quartz, or the like can be used. Further, an insulating layer 104 that covers the substrate 101 may be formed over the substrate 101. The insulating layer 104 may be either a single layer or a plurality of layers. Note that when the insulating layer 104 includes a layer formed using silicon nitride (which may contain several percent of oxygen), diffusion of impurities from the substrate 101 to a transistor formed in a later step can be prevented.

  The first semiconductor layer 102 and the second semiconductor layer 103 may be formed by forming a semiconductor layer that covers the substrate 101 and then processing the semiconductor layer by etching. Here, there is no particular limitation on the semiconductor layer, and the semiconductor layer can be formed using silicon or the like. There is no particular limitation on the crystallinity of the semiconductor layer, and a semiconductor layer containing a crystalline component can be used.

  Next, an insulating layer 105 that covers the first semiconductor layer 102 and the second semiconductor layer 103 is formed. Note that the insulating layer 105 may be either a single layer or a plurality of layers, and can be formed using, for example, silicon oxide or silicon nitride.

  Note that an n-type or p-type impurity may be added to the second semiconductor layer 103 in order to adjust the threshold value of the transistor before or after the insulating layer 105 is formed. For example, phosphorus or the like can be used as the n-type impurity, and boron or the like can be used as the p-type impurity, for example. Further, when an impurity is added to the second semiconductor layer 103, the impurity may also be added to the first semiconductor layer 102.

  Next, a conductive layer 106 that functions as a gate electrode is formed over the insulating layer 105 and above a portion where the second semiconductor layer 103 and the insulating layer 105 overlap with each other. The conductive layer 106 may be formed by first forming a conductive layer so as to cover the insulating layer 105 and then processing the conductive layer by etching. At this time, the entire substrate 101 is maintained at substantially the same potential because the first semiconductor layer 102 is formed. Therefore, even when an etching method using plasma excitation such as dry etching is used, the potential in the substrate is less likely to be biased and the element is less likely to be damaged due to static electricity. Here, the conductive layer 106 may be either a single layer or a plurality of layers. For example, a conductive layer having good adhesion with the insulating layer 105 is provided so as to be in contact with the insulating layer 105, and the conductive layer 106 is formed on the conductive layer. Alternatively, a conductive layer having a low resistance may be stacked. There is no particular limitation on the shape of the conductive layer 106, and for example, a shape having an inclined side wall may be used.

  Next, an impurity is added to the second semiconductor layer 103 using the conductive layer 106 as a mask. Here, an n-type transistor such as phosphorus may be added when an n-type transistor is manufactured, and a p-type impurity such as boron may be added when a p-type transistor is manufactured. Good. In addition, when an n-type impurity is added, a semiconductor layer which is a component of the p-type transistor may be protected using a mask such as a resist so that the impurity is not added. Even when a p-type impurity is added, the semiconductor layer which is a constituent element of the n-type transistor may be protected by using a mask such as a resist so that the impurity is not added. Further, for example, after adding an n-type impurity to all the semiconductor layers on the substrate 101 without using a mask such as a resist, the addition amount is adjusted so that the n-type can be canceled and a p-type can be imparted. A p-type impurity may be added to the semiconductor layer which is a component of the transistor.

  Here, the method for adding impurities is not particularly limited, and for example, a doping method or the like can be used. Further, impurities may be added to the second semiconductor layer 103 and impurities may be added to the first semiconductor layer 102. By adding an impurity also to the first semiconductor layer 102, the effect of keeping the entire surface of the substrate 101 to be equipotential is further increased.

  Through the above steps, transistors 121a, 121b, 121c, and 121d each including a semiconductor layer, an insulating layer, and a conductive layer can be manufactured. Here, the transistors 121a and 121b are included in the pixel portion 131 and connected to the light emitting element. The transistor 121c is included in the drive circuit portion 132a, and the transistor 121d is included in the drive circuit portion 132b. Further, the pixel portion 131 and the drive circuit portions 132a and 132b may include transistors other than the transistors 121a, 121b, 121c, and 121d, respectively. Note that there is no particular limitation on the structure of the transistors 121a, 121b, 121c, and 121d, which may be any structure such as a single drain structure or an LDD structure, or an LDD structure in which an LDD and a conductive layer functioning as a gate electrode overlap. There may be. Further, there is no particular limitation on a process for manufacturing the transistors 121a, 121b, 121c, and 121d as long as the first semiconductor layer 102 is provided, and the transistors 121a, 121b, 121c, and 121d having a desired structure are not limited. The process may be determined as appropriate so that can be formed. Further, it is not necessary to manufacture all the transistors provided in the light-emitting device with the same structure, and they may be appropriately formed depending on the use of the transistor.

  Next, an insulating layer 107 that covers the conductive layer 106 and the like is formed. The insulating layer 107 may be either a single layer or a plurality of layers. In this embodiment mode, the insulating layer 107 includes two layers, an insulating layer 107a and an insulating layer 107b. First, after the insulating layer 107a is formed, heat treatment is performed, and an insulating layer 107b that covers the insulating layer 107a is formed. Although there is no particular limitation on the insulating layer 107a, a substance having heat resistance of 350 ° C. or higher, for example, an inorganic substance such as silicon oxide, silicon nitride, silicon nitride containing several percent oxygen, or silicon oxide containing several percent nitrogen Preferably it consists of. Although there is no particular limitation on the insulating layer 107b, a CMP (Chemical and Chemical) layer is formed after forming a layer having a flat surface, for example, a layer made of a material having self-flatness such as acrylic, siloxane, or polyimide, or a layer made of silicon oxide or the like. A layer formed by planarization by a mechanical polishing method or the like is preferable. Note that although there are no particular limitations on the heat treatment conditions, it is preferably performed in an atmosphere filled with a gas such as nitrogen or hydrogen at a temperature of 350 to 600 ° C. Further, there is no particular limitation on the process part of the heat treatment, which may be performed after the formation of the first insulating layer 107a as in this embodiment, or after the formation of the second insulating layer 107b or after the formation of the insulating layer 107a. And after the formation of the insulating layer 107b.

  Next, a contact hole that penetrates the insulating layer 107 and reaches the second semiconductor layer is formed. The contact hole may be formed by etching the insulating layer 107. At this time, as the etching, either dry etching or wet etching may be used, or both may be used in combination. For example, the contact hole may be formed by opening the insulating layer 107b by dry etching and then opening the insulating layer 107a by wet etching. Further, both of the insulating layers 107a and 107b may be opened by dry etching.

  Note that when the contact hole is formed, the substrate 101 is maintained at substantially the same potential because the first semiconductor layer 102 is formed. Therefore, even when the contact hole is opened using an etching method using plasma excitation such as dry etching, the potential in the substrate is less likely to be biased, and the element is less likely to be damaged due to static electricity.

  Next, wirings 108 and 109 are formed. The wirings 108 and 109 may be formed by forming a conductive layer and then processing the conductive layer by etching. In addition, there is no limitation in particular about an electroconductive layer, You may consist of either a single layer or several layers. However, it is preferably formed so as to include a layer made of a low resistance material such as aluminum. Note that when the wirings 108 and 109 have a stacked structure in which a layer made of aluminum is sandwiched between layers made of titanium nitride or the like, the second semiconductor layer 103 and the layer made of aluminum are formed in a portion in contact with the second semiconductor layer 103. It is possible to prevent contact, and it is possible to prevent the layer made of aluminum from being corroded when an acidic solution is used to form an electrode of a light emitting element in a later step. As in this embodiment, when the wiring 108 and the first semiconductor layer 102 overlap each other and the wiring 108 and the first semiconductor layer 102 are in contact with each other, the first semiconductor layer is etched in the step of etching the wiring 108. 102 may also be etched. Note that the wiring 108 is a wiring for supplying a current to the light emitting element. As in this embodiment mode, the upper portion of the first semiconductor layer 102 can be effectively used as a region for routing the wiring 109. Note that the wiring 108 and the first semiconductor layer 102 are not necessarily in contact with each other as in this embodiment mode, and an insulating layer may be interposed therebetween. The wiring 108 is a wiring for transmitting a signal to each transistor in the region 130 surrounded by the first semiconductor layer 102. The wiring 108 is connected to the second semiconductor layer 103 through the previously formed contact hole.

  In addition, when the insulating layer 107 is formed using a highly moisture-permeable material, it is preferable to form the wirings 108 and 109 and provide a conductive layer that covers the sidewall of the insulating layer 107. Accordingly, moisture can be prevented from entering the light emitting element from the outside of the light emitting device through the insulating layer 107.

  Next, the electrode 110 of the light emitting element is formed. At this time, by forming part of the electrode 110 of the light-emitting element so as to overlap with at least part of the wiring 109, the electrode 110 of the light-emitting element and the wiring 109 can be electrically connected. There is no particular limitation on the electrode 110 of the light-emitting element, and for example, a conductive layer can be formed using a conductive material that can transmit visible light, and then the conductive layer can be etched and processed. Further, there is no particular limitation on the conductive material that can transmit visible light, but indium tin oxide (ITO), ITO containing silicon oxide, IZO formed by mixing indium oxide with 2 to 20% zinc oxide (ZnO). (Indium Zinc Oxide) or the like can be used. Etching may be performed using either wet etching or dry etching. For example, a weakly acidic solution may be used for etching ITO or the like. In addition to a conductive material that can transmit visible light, aluminum or the like can be used. Aluminum may contain an alkali metal such as lithium (Li) or an alkaline earth metal such as magnesium.

  Next, a partition layer 111 having an opening is formed. The partition layer 111 is preferably formed so as to have a shape in which the radius of curvature continuously changes. Further, the electrode 110 of the light emitting element is exposed from the opening. Note that there is no particular limitation on the substance forming the partition layer 111. For example, acrylic, polyimide, siloxane (an organic substance in which a skeleton structure is formed by a bond of silicon (Si) and oxygen (O), and a substituent includes at least hydrogen) ), A resist or the like can be used. Here, the acrylic, polyimide, and resist may have photosensitivity. Note that the partition wall layer 111 does not necessarily cover the sidewall of the insulating layer 107.

  Next, the light emitting layer 112 is formed so as to cover the electrode 110 of the light emitting element. There is no particular limitation on the light-emitting layer 112, and any layer containing a light-emitting substance may be used. For example, it may be a single layer made of a substance having a high light-emitting property and a high carrier-transport property, or a single layer or a plurality of layers containing a material having a high light-emitting property and a substance having a high carrier-transport property. Also good. There is no particular limitation on a substance included in the light-emitting layer 112, and either one or both of an organic substance and an inorganic substance can be used.

  Next, an electrode 113 of the light emitting element is formed. There is no particular limitation on the electrode 113 of the light-emitting element, and the electrode 113 can be formed using aluminum or a conductive material that can transmit visible light as described above. Note that aluminum may contain an alkali metal such as lithium (Li) or magnesium or an alkaline earth metal.

  Note that it is preferable to adjust the film thickness, material, stacked structure, and the like so that at least one of the electrodes 110 and 113 of the light-emitting element can transmit visible light.

  Through the above-described process, the light-emitting element 114 in which the light-emitting layer 112 is sandwiched between the electrode 110 of the light-emitting element and the electrode 113 of the light-emitting element is manufactured.

  After the light-emitting element 114 is manufactured, a protective layer 115 may be provided to prevent moisture or the like from entering the light-emitting element. The protective layer 115 may be formed of either a single layer or a plurality of layers, and can be formed of silicon nitride or the like.

  Through the above steps, as shown in FIG. 1B, the pixel portion 131, the driver circuit portions 132a, 132b, and 133, the wiring 109 provided around the pixel portion and the driver circuit portion, and connection terminals A plurality of light emitting devices including 134 and the like are manufactured over the substrate 101. In the pixel portion 131, a plurality of pixels each including a transistor and a light emitting element are arranged in the row direction and the column direction. Note that in FIG. 1B, components included in the light-emitting device (the pixel portion 131, the driver circuit portions 132a, 132b, and 133, the wiring 108 provided around the pixel portion and the driver circuit portion, the connection terminal 134, and the like) In order to show the positional relationship between the first semiconductor layer 102 and the first semiconductor layer 102, the first semiconductor layer 102 is also illustrated. Further, FIG. 1B illustrates one pixel including two transistors and a light-emitting element; however, the structure of the pixel is not limited to this.

  Note that in the method for manufacturing a light-emitting device as described above, a short ring may be used in order to reduce element damage due to static electricity that may occur after the wirings 108 and 109 are formed.

  Next, the substrate 101 is cut (that is, divided) for each light emitting device. At this time, it is preferable that no layer is stacked on the substrate where the cut is made, and it is particularly preferable that a conductive layer, a layer made of an organic material, or the like is not stacked.

  Next, the divided substrate 101 and the substrate 140 are bonded using a sealant 141 and sealed so that the light emitting layer is confined inside. At this time, it is preferable that the sealant 141 further covers the wiring 108 covering the insulating layer 107. The sealing material 141 is, for example, a bisphenol A liquid resin, a bisphenol A solid resin, a bromine-containing epoxy resin, a bisphenol F resin, a bisphenol AD resin, a phenol resin, a cresol resin, a novolac resin, a cyclic aliphatic. It is preferable to include a material having low moisture permeability such as an epoxy resin such as an epoxy resin, an epibis type epoxy resin, a glycidyl ester resin, a glycidylamine resin, a heterocyclic epoxy resin, or a modified epoxy resin. Accordingly, moisture can be prevented from diffusing into the light-emitting element through the insulating layer 107 when the insulating layer 107 or the partition wall layer 111 is formed using a highly moisture-permeable material. Note that the inside of the light emitting device after sealing, that is, the inside surrounded by the substrate 101, the substrate 140, and the sealant 141 may be filled with an inert gas such as nitrogen or a resin material with low moisture permeability. Or it may be in a vacuum. Alternatively, a hygroscopic substance may be fixed inside the light-emitting device after sealing so that moisture mixed in the inside can be absorbed, and the light-emitting element can be prevented from being deteriorated by moisture or the like. There is no particular limitation on the hygroscopic substance, and for example, calcium oxide can be used. There is no particular limitation on the method for fixing the substance. For example, a recess is provided in a part of the substrate 140, and a composition containing granular calcium oxide and a fixing agent is injected into the recess, and then the composition is solidified. Can be fixed. The fixing agent is not particularly limited, and for example, ester acrylate can be used. The substrate 140 is not particularly limited, and a substrate made of glass, quartz, plastic, or the like can be used.

  The light-emitting device manufactured as described above has a lattice shape extending in the row direction and the column direction over the substrate 101 from the time of manufacturing the transistors 121a, 121b, 121c, and 121d to the formation of the wirings 108 and 109. The first semiconductor layer 102 is included, and the substrate 101 is manufactured so as to be at an equipotential. Therefore, in the light-emitting device, damage to elements due to static electricity that easily occurs in processing using plasma excitation or the like is reduced. Note that the present invention is very effective when a plurality of light-emitting devices are formed from one substrate using a large substrate, particularly a large substrate of 600 mm × 720 mm or more.

(Embodiment 2)
In this embodiment mode, the manufacturing method described in Embodiment Mode 1 and aspects of the present invention will be described with reference to FIGS.

  First, in the same manner as the first semiconductor layer 102 described in Embodiment Mode 1, a lattice-shaped first semiconductor layer 202 extending in the row direction and the column direction is formed over the substrate 201. In addition to the formation of the first semiconductor layer 202, the region 230 surrounded by the first semiconductor layer 202 is separated into island shapes in the same manner as the second semiconductor layer 103 described in Embodiment 1. A plurality of second semiconductor layers 203 are formed. Here, the second semiconductor layer 203 is a layer formed in order to manufacture a transistor. Then, a plurality of light-emitting devices each including the region 230 surrounded by the first semiconductor layer 202 as a unit are formed on the substrate 201 through a process described later. Note that in this embodiment mode, the pixel portion 231, the driver circuit portions 232 a and 232 b, and the like are formed in the region 230, and thus each portion is schematically illustrated in the cross-sectional views of FIGS.

  Here, there is no particular limitation on the substrate 201, and a substrate similar to the substrate 101 described in Embodiment 1 can be used. An insulating layer 204 that covers the substrate 201 may be formed over the substrate 201. There is no particular limitation on the insulating layer 204, and the same material as the insulating layer 104 described in Embodiment 1 may be used.

  The first semiconductor layer 202 and the second semiconductor layer 203 may be formed by forming a semiconductor layer that covers the substrate 201 and then processing the semiconductor layer by etching. There is no particular limitation on the semiconductor layer, and the semiconductor layer can be formed using silicon or the like. There is no particular limitation on the crystallinity of the semiconductor layer, and a semiconductor layer containing a crystalline component can be used.

  Next, an insulating layer 205 that covers the first semiconductor layer 202 and the second semiconductor layer 203 is formed. The insulating layer 205 is not particularly limited and may be formed in a manner similar to that of the insulating layer 105 described in Embodiment 1.

  Note that an n-type or p-type impurity may be added to the second semiconductor layer 203 in order to adjust the threshold value of the transistor before or after the insulating layer 205 is formed. For example, phosphorus or the like can be used as the n-type impurity, and boron or the like can be used as the p-type impurity, for example. Further, when an impurity is added to the second semiconductor layer 203, the impurity may be added to the first semiconductor layer 202.

  Next, a conductive layer 206 serving as a gate electrode is formed over the insulating layer 205 and above a portion where the second semiconductor layer 203 and the insulating layer 205 overlap with each other. The conductive layer 206 may be formed by first forming a conductive layer so as to cover the insulating layer 205 and then processing the conductive layer by etching. At this time, the entire surface of the substrate 201 is maintained at substantially the same potential because the first semiconductor layer 202 is formed. Therefore, even when an etching method using plasma excitation such as dry etching is used, the potential in the substrate is less likely to be biased and the element is less likely to be damaged due to static electricity. Here, the conductive layer 206 may be either a single layer or a plurality of layers. For example, a conductive layer having good adhesion with the insulating layer 205 is provided so as to be in contact with the insulating layer 205, and the conductive layer 206 is formed on the conductive layer. Alternatively, a conductive layer having a low resistance may be stacked. The shape of the conductive layer 206 is not particularly limited, and may be a shape having an inclination on the side wall, for example.

  Next, an impurity is added to the second semiconductor layer 203 using the conductive layer 206 as a mask. Here, an n-type transistor such as phosphorus may be added when an n-type transistor is manufactured, and a p-type impurity such as boron may be added when a p-type transistor is manufactured. Good. In addition, when an n-type impurity is added, a semiconductor layer which is a component of the p-type transistor may be protected using a mask such as a resist so that the impurity is not added. Even when a p-type impurity is added, the semiconductor layer which is a constituent element of the n-type transistor may be protected by using a mask such as a resist so that the impurity is not added. Further, for example, after adding an n-type impurity to all the semiconductor layers on the substrate 201 without using a mask such as a resist, the addition amount is adjusted so that the n-type can be canceled and a p-type can be imparted. A p-type impurity may be added to the semiconductor layer which is a component of the transistor.

  Here, the method for adding impurities is not particularly limited, and for example, a doping method or the like can be used. Further, an impurity may be added to the second semiconductor layer 203 and an impurity may be added to the first semiconductor layer 202 as well. By adding an impurity also to the first semiconductor layer 202, the effect of keeping the substrate 201 at an equipotential is further increased.

  Through the above steps, the transistors 221a, 221b, 221c, and 221d in which the semiconductor layer, the insulating layer, and the conductive layer are stacked can be manufactured. Here, the transistors 221a and 221b are included in the pixel portion 231 and connected to the light emitting element. The transistor 221c is included in the driver circuit portion 232a, and the transistor 221d is included in the driver circuit portion 232b. Further, the pixel portion 231 and the driver circuit portions 232a and 232b may include transistors other than the transistors 221a, 221b, 221c, and 221d, respectively. Note that there is no particular limitation on the structure of the transistors 221a, 221b, 221c, and 221d, which may be any structure such as a single drain structure or an LDD structure, or an LDD structure in which an LDD and a conductive layer functioning as a gate electrode overlap. There may be. Further, there is no particular limitation on a process for manufacturing the transistors 221a, 221b, 221c, and 221d as long as the first semiconductor layer 202 is provided, and the transistors 221a, 221b, 221c, and 221d having a desired structure are not particularly limited. The process may be determined as appropriate so that can be formed. Further, it is not necessary to manufacture all the transistors provided in the light-emitting device with the same structure, and they may be appropriately formed depending on the use of the transistor.

  Next, an insulating layer 207 is formed to cover the conductive layer 206 and the like. The insulating layer 207 may be a single layer or a plurality of layers. In this embodiment mode, the insulating layer 207 is formed of two layers of an insulating layer 207a and an insulating layer 207b. First, after the insulating layer 207a is formed, an insulating layer 207b that covers the insulating layer 207a is formed, and then heat treatment is performed. There is no particular limitation on the insulating layers 207a and 207b, but a material having heat resistance of 350 ° C. or higher, such as silicon oxide, silicon nitride, silicon nitride containing several percent oxygen, or silicon oxide containing several percent nitrogen, etc. It is preferable to consist of these inorganic substances. Note that although there are no particular limitations on the heat treatment conditions, it is preferably performed in an atmosphere filled with a gas such as nitrogen or hydrogen at a temperature of 350 to 600 ° C. Further, there is no particular limitation on the process part of the heat treatment, which may be performed after the formation of the first insulating layer 207a as in this embodiment, or after the formation of the second insulating layer 207b or after the formation of the insulating layer 207a. And after the formation of the insulating layer 207b.

  Next, a contact hole that penetrates the insulating layer 207 and reaches the second semiconductor layer 203 is formed. The contact hole may be formed by etching the insulating layer 207. At this time, as the etching, either dry etching or wet etching may be used, or both may be used in combination. For example, the insulating layer 207b may be opened by wet etching, and then the insulating layer 207a may be dry-etched to form a contact hole. Further, both of the insulating layers 207a and 207b may be opened by dry etching.

  Note that when the contact hole is formed, the entire surface of the substrate 201 is kept substantially equipotential because the first semiconductor layer 202 is formed. Therefore, even when the contact hole is opened using an etching method utilizing plasma excitation such as dry etching, the potential in the substrate surface is less likely to be biased, and the element is not easily damaged due to static electricity.

  Next, wirings 208, 209 and the like are formed. The wirings 208 and 209 may be formed by forming a conductive layer and then processing the conductive layer by etching. Note that after the conductive layer is formed, heat treatment may be performed for sintering. There is no particular limitation on the conductive layer, and it may be a single layer or a plurality of layers. However, it is preferably formed so as to include a layer made of a low resistance material such as aluminum. Note that when the wirings 208 and 209 have a stacked structure in which a layer made of aluminum is sandwiched between layers made of titanium nitride or the like, the second semiconductor layer 203 and the layer made of aluminum are formed in a portion in contact with the second semiconductor layer 203. It is possible to prevent contact, and it is possible to prevent the layer made of aluminum from being corroded when an acidic solution is used to form an electrode of a light emitting element in a later step. Note that the wiring 208 is a wiring for supplying current to the light-emitting element. The wiring 208 and the first semiconductor layer 202 overlap with each other. As described above, the region above the first semiconductor layer 202 can be effectively used as a region for routing the wiring 208. Note that the wiring 209 is a wiring for transmitting a signal to each transistor in the region 230 surrounded by the first semiconductor layer 202. The wiring 209 is connected to the second semiconductor layer 203 through the contact hole formed earlier.

  Next, an insulating layer 210 that covers the wiring 209 is formed. There is no particular limitation on the insulating layer 210, but a CMP (Chemical and Mechanical Polishing) layer is formed after forming a layer having a flat surface, for example, a layer made of a material having self-flatness such as acrylic, siloxane, or polyimide, or a layer made of silicon oxide or the like. It is preferable that the layer be flattened by a method or the like. In the case where the insulating layer 210 is made of siloxane, heat treatment for baking the insulating layer 210 may be performed.

  Next, a contact hole that penetrates the insulating layer 210 and reaches the wiring 209 is formed. In addition, a contact hole is formed and an opening is formed so that a part of the wiring 208 is exposed. Contact holes and the like may be formed by etching the insulating layer 210. At this time, as the etching, either dry etching or wet etching may be used, or both may be used in combination.

  Note that when the contact hole is formed, the substrate 201 is maintained at substantially the same potential because the first semiconductor layer 202 is formed. Therefore, even when the contact hole is opened using an etching method using plasma excitation such as dry etching, the potential in the substrate is less likely to be biased, and the element is less likely to be damaged due to static electricity.

  Next, an electrode 211 of the light-emitting element that reaches the wiring 209 through a contact hole that penetrates the insulating layer 210 is formed. There is no particular limitation on the electrode 211 of the light-emitting element, and for example, a conductive layer can be formed using a conductive material that can transmit visible light, and then the conductive layer can be etched and processed. Further, there is no particular limitation on the conductive material that can transmit visible light, but indium tin oxide (ITO), ITO containing silicon oxide, IZO formed by mixing indium oxide with 2 to 20% zinc oxide (ZnO). (Indium Zinc Oxide) or the like can be used. Etching may be performed using either wet etching or dry etching. For example, a weakly acidic solution may be used for etching ITO or the like. In addition to a conductive material that can transmit visible light, aluminum or the like can be used. Aluminum may contain an alkali metal such as lithium (Li) or an alkaline earth metal such as magnesium.

  Next, the partition layer 212 having openings is formed. The partition layer 212 is preferably formed so as to have a shape in which the radius of curvature continuously changes. Further, the electrode 211 of the light emitting element is exposed from the opening. Note that there is no particular limitation on the substance forming the partition layer 212. For example, acrylic, polyimide, siloxane (a substance in which a skeleton structure is formed by a bond of silicon (Si) and oxygen (O), and the substituent includes at least hydrogen) ), A resist or the like can be used. Here, the acrylic, polyimide, and resist may have photosensitivity. Note that as in FIG. 3B, the partition layer 212 may cover a sidewall of the insulating layer 210.

  Next, the light emitting layer 213 is formed so as to cover the electrode 211 of the light emitting element. There is no particular limitation on the light-emitting layer 213, and the light-emitting layer 213 may be the same as the light-emitting layer 112 described in Embodiment 1.

  Next, an electrode 214 of the light emitting element is formed. There is no particular limitation on the electrode 214 of the light-emitting element, and the electrode 214 can be formed using aluminum or a conductive material that transmits visible light as described above. Note that aluminum may contain an alkali metal such as lithium (Li) or magnesium or an alkaline earth metal.

  Note that it is preferable to adjust the film thickness, material, stacked structure, and the like so that at least one of the electrodes 211 and 214 of the light-emitting element can transmit visible light.

  Through the above-described process, the light-emitting element 215 in which the light-emitting layer 213 is sandwiched between the electrode 211 of the light-emitting element and the electrode 214 of the light-emitting element is manufactured.

  After the light-emitting element 215 is manufactured, a protective layer 216 for preventing moisture or the like from entering the light-emitting element may be provided. The protective layer 216 may be either a single layer or a plurality of layers, and can be formed of silicon nitride or the like.

  Through the above steps, a plurality of light-emitting devices including the pixel portion 231, the driver circuit portions 232a and 232b, the wiring 208 provided around the pixel portion and the driver circuit portion, connection terminals, and the like are formed over the substrate 201. Produced. In the pixel portion 231, a plurality of pixels each including a transistor and a light emitting element are arranged in the row direction and the column direction. Note that components included in the light-emitting device (the pixel portion 231, the driver circuit portions 232 a and 232 b, the wiring 208 provided around the pixel portion and the driver circuit portion, connection terminals, and the like) and the first semiconductor layer 202 The positional relationship is the same as that shown in FIG. Note that the structure of the light-emitting device is not limited to that illustrated in FIG.

  Next, the substrate 201 is cut (that is, divided) for each light emitting device. At this time, it is preferable that no layer is stacked on the dividing portion on the substrate, and it is particularly preferable that a conductive layer, a layer made of an organic material, or the like is not stacked.

  Next, the separated substrate 201 and the substrate 240 are attached and sealed using a sealant 241 so that the light emitting layer is confined inside. At this time, the opening formed in the insulating layer 210 is preferably filled with the sealant 241. The sealing material 241 is, for example, a bisphenol A liquid resin, a bisphenol A solid resin, a bromine-containing epoxy resin, a bisphenol F resin, a bisphenol AD resin, a phenol resin, a cresol resin, a novolac resin, or a cyclic aliphatic. It is preferable to include a material having low moisture permeability such as an epoxy resin such as an epoxy resin, an epibis type epoxy resin, a glycidyl ester resin, a glycidylamine resin, a heterocyclic epoxy resin, or a modified epoxy resin. Accordingly, moisture can be prevented from diffusing to the light emitting element 215 through the insulating layer 210 when the insulating layer 210 or the partition wall layer 212 is formed using a highly moisture permeable material. Note that the inside of the light-emitting device after sealing, that is, the inside surrounded by the substrate 201, the substrate 240, and the sealant 241 may be filled with an inert gas such as nitrogen or a resin material with low moisture permeability. Or it may be in a vacuum. Alternatively, a hygroscopic substance may be fixed inside the light-emitting device after sealing so that moisture mixed in the inside can be absorbed, and the light-emitting element can be prevented from being deteriorated by moisture or the like. There is no particular limitation on the hygroscopic substance, and for example, calcium oxide can be used. Also, there is no particular limitation on the fixing method of the substance. For example, a recess is provided in a part of the substrate 240, and a composition containing granular calcium oxide and a fixing agent is injected into the recess, and then the composition is solidified. Can be fixed. The fixing agent is not particularly limited, and for example, ester acrylate can be used. The substrate 240 is not particularly limited, and a substrate made of glass, quartz, plastic, or the like can be used.

  The light-emitting device manufactured as described above includes the first semiconductor layer 202 in a lattice shape extending in the row direction and the column direction on the substrate 201 during manufacturing of the light-emitting device, and the substrate 201 becomes equipotential. It is produced in such a state. Therefore, in the light-emitting device, damage to elements due to static electricity that easily occurs in processing using plasma excitation or the like is reduced. Note that the present invention is very effective when a plurality of light-emitting devices are formed from one substrate using a large substrate, particularly a large substrate of 600 mm × 720 mm or more.

(Embodiment 3)
In this embodiment mode, a light-emitting device manufactured by applying the present invention as shown in Embodiment Modes 1 and 2 will be described.

  In this embodiment mode, a mode of 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 mode.

  In the light-emitting device as illustrated in FIG. 3C or FIG. 5C, the light-emitting layer 112 that is a component of the light-emitting element 114 and the light-emitting layer 213 that is a component of the light-emitting element 215 include a plurality of layers. Consists of. 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 112 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-diphenylanthracene (abbreviation: DPA) and 9,10-bis (2- Naf Chill) 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 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, examples of the substance having a particularly high electron transport property include, 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. Alternatively, a polymer material obtained by mixing polystyrene sulfonic acid (PSS) and polyethylenedioxythiophene (PEDOT), which are substances having a high hole injecting property and a high hole transporting property, may be used.

  The high molecular weight organic light emitting material has higher physical strength than the low molecular weight material, and the durability of the device is high. In addition, since the film can be formed by coating, the device can be manufactured relatively easily.

  As a specific example of a semiconductor layer containing a crystalline component that can be used as the second semiconductor layer 103 or the second semiconductor layer 203, a semiconductor layer made of single crystal or polycrystalline silicon, silicon germanium, or the like can be used. Can be mentioned. 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. Further, it may be formed by combining laser crystallization and solid phase growth. In addition, a semi-amorphous semiconductor can also be used as the second semiconductor layer 203.

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 partial region in the film contains crystal grains of 0.5 to 20 nm. The Raman spectrum derived from the L—O phonon 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 atoms / cm ³ or less. In particular, the oxygen concentration is 5 × 10 ¹⁹ atoms / cm ³ or less, preferably 1 × 10 ¹⁹ atoms / 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.

  The light emitting elements 114 and 215 may be configured such that the electrodes 110 and 211 of the light emitting element function as anodes and the electrodes 113 and 214 of the light emitting elements function as cathodes, or the electrodes 110 and 211 of the light emitting elements. May function as the cathode, and the electrodes 113 and 214 of the light-emitting element may function as the anode. However, in the former case, the transistor connected to the light emitting element is a P-channel transistor, and in the latter case, the transistor is an N-channel transistor.

  The pixel portion of the light emitting device of the present invention includes a plurality of pixels including the light emitting elements 114 and 215 and the transistors for driving the light emitting elements 114 and 215 as described above arranged 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 can be configured to emit a single color, for example, 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 to the entire surface and fired, and then a dye (1,1,4,4-tetraphenyl-1,3-butadiene (TPB), 4-dicyanomethylene-2-methyl-6- (p-dimethylamino-styryl) -4H-pyran (DCM1), Nile Red, Coumarin 6 etc.) doped polyvinylcarbazole (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 this non-light emitting time, 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 structure described above is not limited to the light emitting device of the present invention as shown in FIG. 3C or FIG. 5C, and may be applied to other light emitting devices of the present invention. .

(Embodiment 4)
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 device is not limited to that shown in this embodiment.

  As shown in FIG. 6A, the light emitting element 301 is connected to a circuit for driving each light emitting element. 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 a video signal input to the source signal line 331 is input to the gate of the driving transistor 321 through the switching transistor 322, a current flows from the current supply line 332 to the light emitting element 301, and light is emitted. At this time, the luminance of light emission is determined by the magnitude of the current flowing to the light emitting element 301.

  FIG. 9 is a top view of a pixel portion of a light emitting device having a circuit as shown in FIG. The numerical values given in FIG. 9 represent the same as those in FIG. In FIG. 9, the electrode 84 of the light emitting element 301 is illustrated.

  Further, the structure of a circuit connected to each light-emitting element is not limited to that described here, and may be a structure similar to, for example, FIG. 6B or FIG. .

  Next, the circuit shown in FIG. 6B will be described. As shown in FIG. 6B, the light-emitting element 801 is connected to a circuit for driving each light-emitting element. 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. In addition, a current control transistor 824 is sandwiched between the driving transistor 821 and the light emitting element 801 and connected in series. 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 801 is determined by the current control transistor 824.

  FIG. 8 is a top view of a pixel portion of a light emitting device having a circuit as shown in FIG. The numerical value attached | subjected to FIG. 8 represents the same thing as FIG. 6 (B), respectively. In FIG. 8, the light emitting element 801 is not illustrated, and the electrode 94 of the light emitting element 801 is illustrated.

  Next, the circuit shown in FIG. 6C will be described. A circuit for driving each light emitting element is connected to the light emitting element 401. Each of the circuits includes a driving transistor 421 that determines light emission / non-light emission of the light-emitting element 401 based on a video signal, and a switching transistor 422 that controls input of the video signal. Here, the source (or drain) of the switching transistor 422 is connected to the source signal line 431, and the source of the driving transistor 421 is connected to the current supply line 432 extending in parallel with the source signal line 431. The gate of the transistor 422 is connected to the scan line 433. Further, the driving transistor 421 and the light emitting element 401 are connected in series.

  A driving method when the light-emitting element 401 emits light will be described. When the scan line 433 is selected in the writing period, the switching transistor 422 whose gate is connected to the scan line 433 is turned on. Then, when a video signal input to the source signal line 431 is input to the gate of the driving transistor 421 through the switching transistor 422, a current flows from the current supply line 432 to the light emitting element 401, and light is emitted. At this time, the luminance of light emission is determined by the magnitude of the current flowing to the light emitting element 401.

(Embodiment 5)
FIG. 9 is a top view of the light emitting device when the light emitting device manufactured by applying the method for manufacturing the light emitting device of the present invention is sealed and the external input terminal is mounted.

  The first substrate 1001 and the second substrate 1021 are bonded so as to face each other and overlap each other. The first substrate 1001 includes a pixel portion 1011, a drive circuit portion 1012 for driving the first scan line, a drive circuit portion 1013 for driving the second scan line, and a drive for driving the source signal line. A circuit portion 1014 and a connection wiring group 1015 (enclosed by a dotted line) are provided. The driver circuit portions 1012, 1013, and 1014 are provided with shift registers, buffers, switches, and the like. Further, the connection wiring group 1015 and an FPC (flexible printed circuit) 1031 which is an external input terminal are connected by an anisotropic conductive adhesive. In the pixel portion 1011, a plurality of pixels each including a light emitting element and a circuit for driving the light emitting element are arranged. Signals such as a video signal, a clock signal, a start signal, and a reset signal are sent from the controller to the drive circuit units 1012, 1013, and 1014, the current supply line 1016, and the like via the FPC 1031. Then, signals are sent from the drive circuit portions 1012, 1013, and 1014 and the current supply line 1016 to the pixel portion.

  Note that the driver circuit portion is not necessarily provided on the same substrate as the pixel portion 1011 as described above. For example, a driver circuit portion (TCP) mounted on an FPC on which a wiring pattern is formed (TCP) or the like is used. It may be used and provided outside the substrate.

  The light emitting device as described above is manufactured by a manufacturing method capable of reducing defects caused by static electricity and further effectively utilizing the substrate surface. That is, a light emitting device is manufactured at a low manufacturing cost, in which more light emitting devices are manufactured together on one substrate.

  FIG. 10 illustrates an embodiment of an electronic device in which the light-emitting device to which the present invention is applied is mounted. FIG. 10 illustrates a cellular phone manufactured by applying the present invention. The main body 5552 includes a display portion 5551, an audio output portion 5554, an audio input portion 5555, operation switches 5556 and 5557, an antenna 5553, and the like. . By incorporating the light-emitting device of the present invention as a display portion, a display failure due to static electricity generated during the manufacturing process is reduced, and a mobile phone capable of providing a good image can be completed. Moreover, by incorporating the light emitting device of the present invention as a display unit in a digital camera, car navigation device, display device, etc. in addition to a mobile phone, display defects due to static electricity generated during the manufacturing process are reduced, which is favorable. A digital camera, a car navigation device, a display device, or the like that can provide a simple image can be completed.

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

FIG. 6 is a top view for explaining the method for manufacturing the light emitting device of the present invention. Sectional drawing for demonstrating the manufacturing method of the light-emitting device of this invention. Sectional drawing for demonstrating the manufacturing method of the light-emitting device of this invention. Sectional drawing for demonstrating the manufacturing method of the light-emitting device of this invention. Sectional drawing for demonstrating the manufacturing method of the light-emitting device of this invention. FIG. 3 is a circuit diagram for operating a pixel included in the light emitting device of the present invention. FIG. 6 is a top view of a pixel portion of a light emitting device of the present invention. FIG. 6 is a top view of a pixel portion of a light emitting device of the present invention. The top view of the light-emitting device of this invention. The figure of the electronic device to which this invention is applied.

Explanation of symbols

94 electrode 101 substrate 102 first semiconductor layer 103 second semiconductor layer 104 insulating layer 105 insulating layer 106 conductive layer 107 insulating layer 107a insulating layer 107b insulating layer 108 wiring 109 wiring 110 electrode 111 partition layer 112 light emitting layer 113 electrode 114 light emission Element 115 Protective layer 121a Transistor 121b Transistor 121c Transistor 121d Transistor 130 Region 131 Pixel portion 132a Drive circuit portion 132b Drive circuit portion 133 Drive circuit portion 134 Connection terminal 140 Substrate 141 Sealing material 150 Light emitting device 201 Substrate 202 First semiconductor layer 203 First 2 semiconductor layer 204 insulating layer 205 insulating layer 206 conductive layer 207 insulating layer 207a insulating layer 207b insulating layer 208 wiring 209 wiring 210 insulating layer 211 electrode 212 partition wall layer 213 light emitting layer 214 electrode 2 5 Light-Emitting Element 216 Protective Layer 221a Transistor 221b Transistor 221c Transistor 221d Transistor 230 Region 231 Pixel Unit 232a Drive Circuit Unit 232b Drive Circuit Unit 240 Substrate 241 Sealing Material 301 Light-Emitting Element 321 Driving Transistor 322 Switching Transistor 323 Erasing Transistor 331 Source Signal Line 332 Current supply line 333 First scanning line 334 Second scanning line 401 Light emitting element 421 Driving transistor 422 Switching transistor 431 Source signal line 432 Current supply line 433 Scanning line 801 Light emitting element 821 Driving transistor 822 Switching transistor 823 Erase transistor 824 Current control transistor 831 Source signal line 832 Current supply line 833 First scan line 834 Current supply line 835 Power supply line 1001 First substrate 1011 Pixel portion 1012a
1013 Drive circuit portion 1014 Drive circuit portion 1015 Connection wiring group 1021 Second substrate 1031 FPC
5551 Display unit 5552 Main unit 5553 Antenna 5554 Audio output unit 5555 Audio input unit 5556 Operation switch 5557 Operation switch

Claims (4)

In a method for manufacturing a light emitting device in which a plurality of light emitting devices are formed on a substrate,
A transistor forming step of forming a transistor for driving the light emitting element;
The transistor forming step includes
A first step of forming a first semiconductor layer;
A second step of forming a gate insulating layer;
A third step of forming a gate electrode;
A fourth step of forming an interlayer insulating film;
A fifth step of opening a contact hole in the interlayer insulating film;
A sixth step of forming a wiring layer on the interlayer insulating film,
In the first step, a plurality of element groups having the first semiconductor layers separated into island shapes are formed, and a continuous second semiconductor layer is formed so as to surround each of the plurality of element groups.
In the fifth step or the sixth step, an etching method using plasma excitation is used.
In the fifth step, simultaneously with the etching for opening the contact hole, a lattice-like opening is formed on the second semiconductor layer in the interlayer insulating film so as to surround each of the plurality of element groups,
In the sixth step, simultaneously with the etching for forming the wiring layer, the second semiconductor layer is separated so as to surround the plurality of element groups in the lattice-shaped openings,
In the transistor formation step, without forming a short ring,
One of the light emitting devices is formed from one of the element groups by dividing the substrate at the lattice-shaped opening and a region where the second semiconductor layer is separated. Manufacturing method of light-emitting device. In a method for manufacturing a light emitting device in which a plurality of light emitting devices are formed on a substrate,
A transistor forming step of forming a transistor for driving the light emitting element;
The transistor forming step includes
A first step of forming a first semiconductor layer;
A second step of forming a gate insulating layer;
A third step of forming a gate electrode;
A fourth step of forming an interlayer insulating film;
A fifth step of opening a contact hole in the interlayer insulating film;
A sixth step of forming a wiring layer on the interlayer insulating film,
In the first step, a lattice-shaped second semiconductor layer is formed, and a plurality of the first semiconductor layers separated in an island shape are formed in each region surrounded by the second semiconductor layer,
In the fifth step or the sixth step, an etching method using plasma excitation is used.
In the fifth step, simultaneously with the etching for opening the contact hole, a lattice-like opening is formed on the second semiconductor layer in the interlayer insulating film,
In the sixth step, simultaneously with the etching for forming the wiring layer, the second semiconductor layer is separated into a frame shape at the lattice-shaped openings,
In the transistor formation step, without forming a short ring,
One of the light emitting devices is selected from one of the regions surrounded by the second semiconductor layer by dividing the substrate at the lattice-shaped opening and the region where the second semiconductor layer is separated. Forming a light emitting device. In claim 1 or claim 2,
In the sixth step, a wiring for supplying a current to the light emitting element is formed above the second semiconductor layer. In any one of Claim 1 thru | or 3,
The method for manufacturing a light-emitting device, wherein the transistor forming step includes a step of adding an impurity to the second semiconductor layer.

Images