JP4519532B2 - LIGHT EMITTING DEVICE AND ELECTRONIC DEVICE USING LIGHT EMITTING DEVICE - Google Patents

Description

  The present invention relates to a light emitting device in which a light emitting element and a means for supplying current to the light emitting element are provided in each of a plurality of pixels, and a method for manufacturing the light emitting device.

  Since the light emitting element emits light by itself, the visibility is high, a backlight necessary for a liquid crystal display (LCD) is not necessary, and it is optimal for thinning, and the viewing angle is not limited. For this reason, a light emitting device using a light emitting element has attracted attention as a display device that replaces a CRT or LCD, and has recently been put into practical use such as being mounted on an electronic device such as a mobile phone or a digital still camera.

  The light-emitting element has an anode, a cathode, and an electroluminescent layer sandwiched between these two electrodes. Of these two electrodes, one electrode whose potential is controlled in accordance with a video signal (hereinafter, referred to as a video signal) , Called pixel electrodes) are separated from each other for each pixel. In addition, the other electrode (hereinafter referred to as a counter electrode) to which a common potential is applied is not realistic to separate for each pixel like a pixel electrode, and is usually common to all pixels. In this way, it is solid or common to each RGB. The potential is supplied to the counter electrode through a connection terminal provided at the end of the panel. Specifically, a contact between the counter electrode and a wiring for routing (hereinafter referred to as a routing wiring) is formed, and the counter electrode and the connection terminal are electrically connected through the routing wiring. The contact is formed in a region different from the region avoiding the region where the electroluminescent layer of the pixel portion is formed.

  By the way, when the area of the pixel portion is increased as the screen size is increased, the potential drop due to the resistance of the counter electrode tends to become remarkable. A pixel having a more significant potential drop at the counter electrode has a smaller absolute value of the voltage Vel applied between the electrodes of the light emitting element. Therefore, a situation in which a luminance gradient is visually recognized when viewed in the entire pixel portion may occur. . Therefore, in order to avoid the above problem, Patent Document 1 below describes an auxiliary material formed of a material having a low resistivity in order to equalize the potential in the surface of the counter electrode after the light emitting element is formed. A technique for forming an electrode (auxiliary electrode) so as to be connected to a counter electrode is described.

Japanese Patent Laid-Open No. 2002-033198

  As described above, the auxiliary electrode is formed when the resistivity of the material forming the counter electrode is high or the resistance of the counter electrode must be increased by increasing the area of the pixel portion. This is a very effective means for equalizing the potential in the plane of the counter electrode. However, in the case of a light emitting device of a type (upper surface light emitting type) in which light emitted from the electroluminescent layer is extracted from the counter electrode side by using a counter electrode having translucency, the light from the light emitting element is not blocked as much as possible. It is necessary to lay out the electrodes. However, even if the auxiliary electrode is formed only in a region that does not overlap with the pixel portion, the effect of equalizing the potential in the plane of the counter electrode is hardly obtained. Therefore, an auxiliary electrode is formed on the counter electrode in a region where light emission is not actually obtained, such as between the light emitting elements of adjacent pixels.

  However, when the definition of a pixel is increased in addition to the enlargement of the screen and the size of the pixel is reduced, the width between the light emitting elements of adjacent pixels is cut by 20 μm. For this reason, it is necessary to lay out the auxiliary electrode so as to be within the above-mentioned width, and it is difficult to form the auxiliary electrode on the counter electrode by a vapor deposition method using a metal mask that cannot form a very precise pattern. is there. In addition, when an auxiliary electrode is formed on a counter electrode by using a photolithography method, a pattern can be formed with an accuracy of μm or less. However, in a series of processes such as exposure, development, and removal of a photoresist, light and moisture The deterioration of the light emitting element may be accelerated by the influence of the above, which is not preferable. Although the auxiliary electrode can be formed by a printing method typified by an ink jet method or the like, the number of steps increases due to the formation of the auxiliary electrode, which is not desirable. This is also true for vapor deposition and lithography.

  In view of the above problems, the present invention can prevent the luminance gradient due to the potential drop of the counter electrode from being visually recognized even when the definition of the light-emitting device is increased, and the auxiliary electrode without increasing the number of steps. It is an object to provide a method for manufacturing a light-emitting device and a light-emitting device capable of forming the light-emitting device.

  In the present invention, the auxiliary electrode is not formed after the light emitting element is formed, but is formed before the electroluminescent layer of the light emitting element is formed. By forming the auxiliary electrode before forming the electroluminescent layer, the auxiliary electrode can be formed using a photolithography method. Then, a precise pattern can be formed by using a photolithography method. Therefore, even if the width between the light emitting elements is reduced to less than 20 μm due to high definition, an assist is made so that the width falls within the width. An electrode can be formed. In the present invention, the auxiliary electrode is formed without increasing the number of steps by forming the auxiliary electrode using a photolithographic method together with the wiring of the pixel portion and the gate electrode formed of a conductive film. Can do.

  The auxiliary electrode can suppress the potential drop of the counter electrode and can prevent the luminance gradient from being visually recognized in the pixel portion. The present invention is particularly effective in a top emission type light emitting device in which it is difficult to form a solid auxiliary electrode on a counter electrode.

  In the present invention, the auxiliary electrode forms a contact with the counter electrode of the light emitting element in the pixel portion, but usually an electroluminescent layer is formed between the counter electrode and the pixel electrode in the pixel portion. The electroluminescent layer includes a hole injection layer, a hole transport layer, a light emitting layer, an electron injection layer, an electron transport layer, and the like. In particular, the light emitting layer has a significantly higher resistance than the auxiliary electrode and the counter electrode. Therefore, in the present invention, since the thickness of the auxiliary electrode is larger than the thickness of the light emitting layer, the contact of the fact that the step coverage (step coverage) of the light emitting layer is inferior at the end of the auxiliary electrode is reversed. Is formed. That is, since the step coverage is inferior, the auxiliary electrode and the counter electrode are electrically connected through a region not covered with the light emitting layer. Note that a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, and the like formed of a material having a relatively low resistance compared to the light emitting layer are used to electrically connect the auxiliary electrode and the counter electrode. It may be provided between the auxiliary electrode and the counter electrode. Also, increase the thickness of the auxiliary electrode relative to the entire thickness of the electroluminescent layer to reduce the coverage of the electroluminescent layer at the end of the auxiliary electrode, and connect the counter electrode and the auxiliary electrode directly. Also good.

  In the present invention, the connection between the auxiliary electrode and the counter electrode is not limited to the method using the above-described step coverage. In the present invention, when the light emitting layer is formed by vapor deposition using a metal mask, a region where the light emitting layer is not formed may be formed, and the auxiliary electrode and the counter electrode may be electrically connected in the region. . In the case of a full-color display light-emitting device manufactured by separately coating the light-emitting layers corresponding to the three primary colors using a metal mask, a region where the light-emitting layer is not formed can be formed using the metal mask. By using the above method, it is not necessary to increase the number of steps even if the contact is formed.

  Note that in this specification, a light-emitting device includes a panel in which a light-emitting element is sealed, and a module in which an IC or the like including a controller is mounted on the panel.

  In addition, the single layer or the plurality of layers included in the electroluminescent layer may contain an inorganic compound. Luminescence in the electroluminescent layer includes light emission (fluorescence) when returning from the singlet excited state to the ground state and light emission (phosphorescence) when returning from the triplet excited state to the ground state.

  In the present invention, the auxiliary electrode can be formed using a photolithography method by forming the auxiliary electrode before forming the light emitting element. Then, a precise pattern can be formed by using a photolithography method. Therefore, even if the width between the light emitting elements is reduced to less than 20 μm due to high definition, an assist is made so that the width falls within the width. An electrode can be formed. In the present invention, the auxiliary electrode is formed without increasing the number of steps by forming the auxiliary electrode using a photolithographic method together with the wiring of the pixel portion and the gate electrode formed of a conductive film. Can do. Then, the potential drop of the counter electrode can be suppressed by the auxiliary electrode, and the luminance gradient can be prevented from being visually recognized in the pixel portion. The present invention is particularly effective in a top emission type light emitting device in which it is difficult to form a solid auxiliary electrode on a counter electrode.

  Hereinafter, embodiments 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)
A structure of a pixel portion included in the light-emitting device of this embodiment will be described with reference to FIG. FIG. 1 shows a top view of the pixel portion and a top view of the routing wiring. Reference numeral 301 denotes a connection terminal, and 302a, 302b, and 302c correspond to routing wires. An electrode 303 formed in the pixel portion corresponds to an auxiliary electrode, and is connected to the connection terminal 301 through routing wirings 302a, 302b, and 302c. In FIG. 1, the connection terminal 301 and the auxiliary electrode 303 are electrically connected using three lead wirings 302a, 302b, and 302c. However, the form of the lead wiring is limited to the configuration shown in FIG. Any connection may be employed as long as the connection terminal 301 and the auxiliary electrode 303 can be electrically connected. The connection terminal, the lead wiring, and the auxiliary electrode may all be formed of one conductive film.

  A plurality of wirings are laid out in the pixel portion. Specifically, in this embodiment mode, a scanning line 306 for selecting a pixel, a signal line 304 for supplying a video signal to the selected pixel, And a power supply line 305 for supplying a current to the light emitting element. Note that the wiring provided in the pixel portion of the present invention is not limited to these three wirings. Depending on the configuration of the pixel, another wiring may be provided in addition to the above wiring.

  In this embodiment mode, the auxiliary electrode 303 is also formed in the step of patterning one conductive film to form the signal line 304 and the power supply line 305. With the above structure, it is not necessary to increase the number of steps for forming the auxiliary electrode 303. Note that the auxiliary electrode 303 is not necessarily formed by patterning the same conductive film as the signal line 304 and the power supply line 305. It may be formed in the step of forming wirings other than the signal line 304 and the power supply line 305, for example, the scanning line 306.

  Note that in the case where the signal line 304 and the power supply line 305 are formed using the same conductive film as the routing wiring 302c as in this embodiment mode, the signal line 304 and the power supply line 305 are arranged so as to dive under the routing wiring 302c. By connecting to the wiring 315 formed in another layer, the signal line 304 and the power supply line 305 can be crossed so as not to contact the wiring 302c.

  In FIG. 1, reference numeral 307 corresponds to a pixel electrode (first electrode), which is separated for each pixel. Electroluminescent layers corresponding to the respective colors are formed in a plurality of regions indicated by broken lines 309. Further, a counter electrode (second electrode) is formed in a region indicated by a broken line 310, and an electroluminescent layer 309 is sandwiched between the pixel electrode 307 and the counter electrode 310. Note that although an example in which the anode is used as the pixel electrode and the cathode is used as the counter electrode is described in this embodiment mode, the present invention is not limited to this structure. The cathode may be used as a pixel electrode and the anode may be used as a counter electrode.

   In FIG. 1, the lead wiring 302 a is connected to one end of a resistor 334 formed of a semiconductor film, and the other end of the resistor 334 is electrically connected to the connection terminal 330 through the wiring 331. Yes. By providing the resistor 334, noise of a signal input to the connection terminal 301 can be reduced, or a subsequent circuit element can be prevented from being damaged due to static electricity or the like.

  1A is a cross-sectional view taken along the line AA ′ of FIG. 1, FIG. 2B is a cross-sectional view taken along the line BB ′ of FIG. 1, and FIG. 2B is a cross-sectional view taken along the line CC ′ of FIG. C). As shown in FIG. 2A, a wiring (hereinafter referred to as a connection wiring) 311 for applying a potential to the pixel electrode 307 in accordance with a video signal input to the pixel, together with the signal line 304, the power supply line 305, and the auxiliary electrode 303, The pixel electrode 307 is formed on and in contact with the connection wiring 311. The pixel electrode 307 is provided on the first interlayer insulating film (first insulating film) 312. Further, the counter electrode 310 is formed using a light-transmitting electrode, and light generated in the electroluminescent layer 309 is reflected by the connection wiring 311 and thus can be extracted from the counter electrode 310 side.

  In the case of a top emission light-emitting device as in this embodiment mode, a light-transmitting cathode is used as the counter electrode 310. Specifically, an electrode having a thickness that is thin enough to extract light generated in the electroluminescent layer is used. Preferably, the film thickness is about 5 nm to 30 nm. In this embodiment, a transparent conductive film 316 having a light-transmitting property is formed so as to cover the counter electrode 310. Although the transparent conductive film 316 is not necessarily provided, even when the resistance of the counter electrode 310 itself is increased by reducing the film thickness, the potential drop can be suppressed.

  Note that although a structure in which light emitted from the electroluminescent layer is extracted from the counter electrode side has been described in this embodiment mode, the present invention is not limited to this structure. A type that extracts light from the pixel electrode side (bottom emission type) or a type that extracts light from both the counter electrode and the pixel electrode (double-sided emission type) may be used.

  A second interlayer insulating film (second insulating film) 313 includes an end portion of the pixel electrode 307, a signal line 304, a power supply line 305, an end portion of the routing wiring 302 c, and an end portion of the auxiliary electrode 303. It is formed on the first interlayer insulating film 312 so as to cover it. The second interlayer insulating film 313 has openings 308a and 308b. In the openings 308a and 308b, a part of the pixel electrode 307, a part of the lead wiring 302c, and a part of the auxiliary electrode 303 are formed. Is exposed. In the opening 308a, the pixel electrode 307, the electroluminescent layer 309, and the counter electrode 310 overlap with each other to form a light emitting element 314.

  Note that in this embodiment, when an electroluminescent layer corresponding to each of the three primary colors is formed by vapor deposition using a metal mask, a region where the electroluminescent layer is not formed is formed, and the auxiliary electrode is opposed to the region. The electrode is electrically connected. Specifically, the opening 308b and the region where the electroluminescent layer 309 is formed are not completely or partially overlapped. That is, the counter electrode 310 is formed in a state where the auxiliary electrode 303 is completely or partially exposed in the opening 308b. With the above structure, the auxiliary electrode 303 can be connected to the counter electrode 310 in the opening 308b. Further, as in this embodiment, by forming the transparent conductive film 316 so as to cover the counter electrode 310, electrical connection between the counter electrode 310 and the auxiliary electrode 303 can be further ensured. . With the above structure, the auxiliary electrode 303 and the counter electrode 310 can be electrically connected in the pixel portion.

  On the other hand, the electroluminescent layer 309 is not formed between the routing wiring 302c and the counter electrode 310. Therefore, as shown in FIG. 2B, the lead wiring 302c and the counter electrode 310 are connected in the opening 308b. Then, the power supply potential supplied from the connection terminal 301 is supplied to the auxiliary electrode 303 and the counter electrode 310 through the lead wiring 302c. By using the auxiliary electrode 303, a potential drop of the counter electrode 310 can be suppressed, and a luminance gradient can be prevented from being visually recognized in the pixel portion. The present invention is particularly effective in a top emission type light emitting device in which it is difficult to form a solid auxiliary electrode on a counter electrode.

  In the present invention, the auxiliary electrode can be formed using a photolithography method by forming the auxiliary electrode before forming the light emitting element. Then, a precise pattern can be formed by using a photolithography method. Therefore, even if the width between the light emitting elements is reduced to less than 20 μm due to high definition, an assist is made so that the width falls within the width. An electrode can be formed. In the present invention, the auxiliary electrode is formed without increasing the number of steps by forming the auxiliary electrode using a photolithographic method together with the wiring of the pixel portion and the gate electrode formed of a conductive film. Can do.

   Note that in this embodiment mode, the routing wiring 302c and the auxiliary electrode 303 are connected to the counter electrode 310 in one opening portion 308b, but the shape of the opening portion is not limited to this embodiment mode. The opening that exposes the routing wirings 302a, 302b, and 302c may be separated from the opening that exposes the auxiliary electrode 303, or a plurality of openings that expose the auxiliary electrode 303 may be provided.

  In this embodiment mode, the case where the electroluminescent layer is separated for each color has been described. However, it is sufficient that at least the light emitting layer is separated, and a hole formed of a material having a relatively low resistance compared to the light emitting layer. The injection layer, hole transport layer, electron injection layer, electron transport layer, and the like do not have to be separated. In this case, the auxiliary electrode and the counter electrode can be electrically connected through the hole injection layer, the hole transport layer, the electron injection layer, or the electron transport layer.

  In the case of a full-color display light-emitting device manufactured by separately coating a light-emitting layer with a metal mask as in this embodiment, a region where the light-emitting layer is not formed can be formed using the metal mask. By using the above method, it is not necessary to increase the number of steps even if the contact is formed. Note that the electroluminescent layer formed in the opening is selectively removed by plasma etching using a metal mask using one or more gases selected from Ar, H, F, or O as an etching gas. Anyway.

(Embodiment 2)
In this embodiment, one embodiment of the shape of the opening, which is different from that in Embodiment 1, is described.

  FIG. 3 is a top view of the pixel portion in this embodiment mode. Reference numeral 403 corresponds to an opening, and the counter electrode 404 and the auxiliary electrode 401 are electrically connected in the opening 403. In this embodiment mode, when the electroluminescent layer 405 is formed so that the auxiliary electrode 401 is directly or electrically connected to the counter electrode 404 in the opening 403, the electroluminescent layer 405 is opened using the metal mask. Do not completely cover 403. In this case, the end portion of the auxiliary electrode may be exposed in the opening, or may be covered with the second interlayer insulating film.

  Note that the end of the auxiliary electrode 401 is exposed in the opening 403, and a portion that is not covered with the electroluminescent layer 405 is intentionally formed at the end using the coverage, and the counter electrode 404 and the auxiliary electrode 401 are formed. May be connected.

  The lead wiring 406 is partially exposed in the opening 402. Since the opening 402 does not overlap with the electroluminescent layer 405, the lead wiring 406 and the counter electrode 404 are connected in the opening 402.

  Reference numeral 407 corresponds to a pixel electrode provided in each pixel. In the opening 408, the pixel electrode 407, the electroluminescent layer 405, and the counter electrode 404 overlap with each other to form a light emitting element.

  As shown in FIG. 3, the openings 403 are arranged at the four corners of the openings 408 in which the light emitting elements are formed, so that the openings 408 are accompanied with the displacement of the mask when the openings 403 and 408 are formed. Can be short-circuited with other adjacent wiring.

(Embodiment 3)
In this embodiment mode, a mode in which the structure of the connection portion between the auxiliary electrode and the counter electrode is different from that in Embodiment Mode 1 will be described.

  The structure of the pixel portion included in the light-emitting device of this embodiment will be described with reference to FIG. FIG. 9 shows a top view of the pixel portion and a top view of the routing wiring. 101 is a connection terminal, 102a, 102b and 102c are routing wires, and 103 is an auxiliary electrode. As in FIG. 1, the auxiliary electrode 103 is electrically connected to the connection terminal 101 via the lead wirings 102a, 102b, and 102c.

  As in Embodiment Mode 1, a scanning line 106, a signal line 104, and a power supply line 105 are provided in the pixel portion. Wirings provided in the pixel portion of the present invention are not limited to these three wirings. Depending on the configuration of the pixel, another wiring may be provided in addition to the above wiring. As in the first embodiment, also in this embodiment, the auxiliary electrode 103 is formed in the process of patterning one conductive film to form the signal line 104 and the power supply line 105. With the above structure, it is not necessary to increase the number of steps for forming the auxiliary electrode 103. Note that the auxiliary electrode 103 is not necessarily formed by patterning the same conductive film as the signal line 104 and the power supply line 105. It may be formed in the step of forming wirings other than the signal lines 104 and the power supply lines 105, for example, scanning lines.

  In FIG. 9, reference numeral 107 corresponds to a pixel electrode. In this embodiment mode, an electroluminescent layer is formed in a region indicated by a broken line 109. Further, a counter electrode is formed in a region indicated by a broken line 110, and the electroluminescent layer 109 is sandwiched between the pixel electrode 107 and the counter electrode 110.

   In FIG. 9, the routing wiring 102 a is connected to one end of the resistor 134 formed of a semiconductor film, and the other end of the resistance 134 is electrically connected to the connection terminal 130 through the wiring 131. Yes. By providing the resistor 134, noise of a signal input to the connection terminal 101 can be reduced, or the subsequent circuit element can be prevented from being destroyed due to static electricity or the like.

  9A is a cross-sectional view taken along A-A ′ in FIG. 9, and FIG. 10B is a cross-sectional view taken along B-B ′ in FIG. 9. As shown in FIG. 10A, as in Embodiment Mode 1, the connection wiring 111 is provided over the first interlayer insulating film 112 together with the signal line 104, the power supply line 105, and the auxiliary electrode 103. The electrode 107 is formed in contact with the connection wiring 111. Further, the counter electrode 110 is formed using a light-transmitting electrode, and light generated in the electroluminescent layer 109 is reflected by the connection wiring 111 and thus can be extracted from the counter electrode 110 side.

  A second interlayer insulating film 113 is formed on the first interlayer insulating film 112 so as to cover the end of the pixel electrode 107, the signal line 104, and the power supply line 105. The second interlayer insulating film 113 has openings 108a and 108b. In the openings 108a and 108b, a part of the pixel electrode 107, a part of the routing wiring 102, and the auxiliary electrode 103 are exposed. Yes. In the opening 108a, the pixel electrode 107, the electroluminescent layer 109, and the counter electrode 110 overlap with each other to form a light emitting element 114. In FIG. 9, the end portion of the auxiliary electrode 103 is not exposed in the opening 108b and is covered with the second interlayer insulating film 113; however, this embodiment is not limited to this structure. The end of the auxiliary electrode 103 may be exposed.

  In the opening 108 b, the electroluminescent layer 109 is formed in a state where the end of the auxiliary electrode 103 is exposed without being covered with the second interlayer insulating film 113. Therefore, when the electroluminescent layer 109 is formed by a vapor deposition method, the auxiliary electrode 103 is not completely covered but partially covered by the electroluminescent layer 109, and the uncovered portion is connected to the counter electrode 110.

  FIG. 11 is an enlarged view of a portion where the auxiliary electrode 103 and the counter electrode 110 are connected. As shown in FIG. 11, in this embodiment mode, when the electroluminescent layer 109 is formed by vapor deposition, the auxiliary electrode 103 is formed not to be completely covered but partially covered. Subsequently, by forming the counter electrode 110, the exposed end portion of the auxiliary electrode 103 and the counter electrode 110 are connected as shown by a portion 120 surrounded by a broken line. Further, as in this embodiment, the transparent conductive film 116 is formed so as to cover the counter electrode 110, so that the electrical connection between the counter electrode 110 and the auxiliary electrode 103 can be made more reliable. . With the above structure, the auxiliary electrode 103 and the counter electrode 110 can be electrically connected in the pixel portion.

  Note that although an example in which the anode is used as the pixel electrode and the cathode is used as the counter electrode is described in this embodiment mode, the present invention is not limited to this structure. The cathode may be used as a pixel electrode and the anode may be used as a counter electrode. In this embodiment mode, a top-emission light-emitting device is used. As in Embodiment Mode 1, a light-transmitting electrode is used as the counter electrode 110 so that the counter electrode 110 is covered. A film 116 is formed. Although the transparent conductive film 116 is not necessarily provided, even if the resistance of the counter electrode 110 itself is increased by reducing the film thickness, the potential drop can be suppressed.

  In this embodiment mode, the structure in which light emitted from the electroluminescent layer is extracted from the counter electrode side is described; however, the present invention is not limited to this structure. A type that extracts light from the pixel electrode side (bottom emission type) or a type that extracts light from both the counter electrode and the pixel electrode (double-sided emission type) may be used.

  On the other hand, the electroluminescent layer 109 is not formed between the routing wiring 102 and the counter electrode 110. Therefore, as shown in FIG. 10B, the lead wiring 102 and the counter electrode 110 are connected in the opening 108b. Then, the power supply potential supplied from the connection terminal 101 is supplied to the auxiliary electrode 103 and the counter electrode 110 via the lead wiring 102. By using the auxiliary electrode 103, a potential drop of the counter electrode 110 can be suppressed, and a luminance gradient can be prevented from being visually recognized in the pixel portion. The present invention is particularly effective in a top emission type light emitting device in which it is difficult to form a solid auxiliary electrode on a counter electrode.

  In this embodiment, the coverage characteristics of the electroluminescent layer are reversed, and the auxiliary electrode is partially exposed to connect the auxiliary electrode and the counter electrode. However, the present invention is not limited to this. A region where the electroluminescent layer is not partially formed may be formed in the pixel portion, and a contact between the auxiliary electrode and the counter electrode may be formed in the region. In this embodiment mode, the case where all the electroluminescent layers are formed by a vapor deposition method has been described. However, at least the light emitting layer may be formed by a vapor deposition method, and it is formed of a material having a relatively low resistance compared to the light emitting layer. The hole injection layer, hole transport layer, electron injection layer, electron transport layer, and the like thus formed may be formed by a coating method without being limited to the vapor deposition method. In this case, the auxiliary electrode and the counter electrode are electrically connected through the hole injection layer, the hole transport layer, the electron injection layer, or the electron transport layer in the region where the light emitting layer at the end of the auxiliary electrode is not formed. be able to.

  In the present invention, the auxiliary electrode can be formed using a photolithography method by forming the auxiliary electrode before forming the light emitting element. Then, a precise pattern can be formed by using a photolithography method. Therefore, even if the width between the light emitting elements is reduced to less than 20 μm due to high definition, an assist is made so that the width falls within the width. An electrode can be formed. In the present invention, the auxiliary electrode is formed without increasing the number of steps by forming the auxiliary electrode using a photolithographic method together with the wiring of the pixel portion and the gate electrode formed of a conductive film. Can do.

  Note that in this embodiment mode, the routing wiring 102 and the auxiliary electrode 103 are connected to the counter electrode 110 in one opening portion 108b, but the shape of the opening portion is not limited to this embodiment mode. The opening for exposing the routing wiring 102 and the opening for exposing the auxiliary electrode may be separated, or a plurality of openings for exposing the auxiliary electrode may be provided.

(Embodiment 4)
In this embodiment, one embodiment of a light-emitting element included in the light-emitting device of the present invention will be described. FIG. 4A is a cross-sectional view of a pixel of this embodiment mode. FIG. 4B is an enlarged view of a portion surrounded by a broken line 570 in FIG. 4A, and FIG. 4C is an enlarged view of a portion surrounded by a broken line 571.

  4A, a base film 501 is formed over a substrate 500, and a transistor (a driving transistor) 502 that controls supply of current to the light-emitting element is formed over the base film 501. In FIG. The driving transistor 502 includes an active layer 503, a gate electrode 505, and a gate insulating film 504 sandwiched between the active layer 503 and the gate electrode 505.

  The active layer 503 is preferably a polycrystalline semiconductor film, and the polycrystalline semiconductor film can be formed by crystallizing an amorphous silicon film by a known technique. Known crystallization methods include a thermal crystallization method using an electric furnace, a laser annealing crystallization method using laser light, and a lamp annealing crystallization method using infrared light. In this embodiment mode, crystallization is performed using excimer laser light using XeCl gas. In addition, a pulse oscillation type excimer laser beam processed into a linear shape is used, but a rectangular shape, a continuous oscillation type argon laser beam, or a continuous oscillation type excimer laser beam can also be used. Alternatively, a polycrystalline semiconductor film can also be formed by a crystallization method using a catalytic element in accordance with the technique disclosed in Japanese Patent Laid-Open No. 7-130652. Further, a polycrystalline semiconductor film formed by a sputtering method, a plasma CVD method, a thermal CVD method, or the like may be used.

  The active layer may be made of silicon germanium as well as silicon. When silicon germanium is used, the concentration of germanium is preferably about 0.01 to 4.5 atomic%. Further, silicon to which carbon nitride is added may be used.

The gate insulating film 504 can be formed using silicon oxide, silicon nitride, or silicon oxynitride. A film in which these layers are stacked, for example, a film in which SiN is stacked on SiO ₂ may be used as the gate insulating film. SiO ₂ is a plasma CVD method in which TEOS (Tetraethyl Orthosilicate) and O ₂ are mixed, the reaction pressure is 40 Pa, the substrate temperature is 300 to 400 ° C., the high frequency (13.56 MHz), and the power density is 0.5 to 0.8 W. A silicon oxide film was formed by discharging at / cm ² . The silicon oxide film thus manufactured can obtain good characteristics as a gate insulating film by subsequent thermal annealing at 400 to 500 ° C. Aluminum nitride can be used as the gate insulating film. Aluminum nitride has a relatively high thermal conductivity and can effectively diffuse the heat generated in the TFT. In addition, after forming silicon oxide or silicon oxynitride which does not contain aluminum, a laminate of aluminum nitride may be used as the gate insulating film. Further, SiO ₂ formed by RF sputtering using Si as a target may be used as the gate insulating film.

  The gate electrode 505 is formed using an element selected from Ta, W, Ti, Mo, Al, and Cu, or an alloy material or a compound material containing the element as a main component. Alternatively, a semiconductor film typified by a polycrystalline silicon film doped with an impurity element such as phosphorus may be used. Further, instead of a single conductive film, a conductive film composed of a plurality of layers may be stacked.

  For example, a combination of forming the first conductive film with tantalum nitride (TaN) and the second conductive film with W, forming the first conductive film with tantalum nitride (TaN), and forming the second conductive film with Ti A combination in which the first conductive film is formed of tantalum nitride (TaN), the second conductive film is formed of Al, the first conductive film is formed of tantalum nitride (TaN), and the second conductive film is formed. It is preferable to form a combination of Cu. Alternatively, a semiconductor film typified by a polycrystalline silicon film doped with an impurity element such as phosphorus, or an AgPdCu alloy may be used as the first conductive film and the second conductive film.

  The structure is not limited to the two-layer structure, and for example, a three-layer structure in which a tungsten film, an aluminum-silicon alloy (Al-Si) film, and a titanium nitride film are sequentially stacked may be employed. In the case of a three-layer structure, tungsten nitride may be used instead of tungsten, or an aluminum / titanium alloy film (Al—Ti) is used instead of an aluminum / silicon alloy film (Al—Si) film. Alternatively, a titanium film may be used instead of the titanium nitride film. Note that it is important to select an optimum etching method and etchant type depending on the material of the conductive film.

  The driving transistor 502 is covered with a first interlayer insulating film 507, and a passivation film 508 is stacked on the first interlayer insulating film 507.

  As the first interlayer insulating film 507, non-photosensitive acrylic, an oxide film, a silicon nitride oxide film, or the like can be used. As the passivation film 508, a film that hardly transmits a substance that causes deterioration of the light-emitting element such as moisture or oxygen as compared with other insulating films is used. Typically, it is desirable to use, for example, a DLC film, a carbon nitride film, a silicon nitride film formed by an RF sputtering method, or the like. Further, the passivation film 508 can prevent the alkali metal, the alkaline earth metal, or the transition metal contained in the electron injection layer 513 from leaking out of the panel.

  A connection wiring 506 is formed over the passivation film 508, and the driving transistor 502 is connected to the connection wiring 506 through a contact hole. On the passivation film 508, an auxiliary electrode 520 obtained by patterning a conductive film common to the connection wiring 506 is formed.

  510 is a pixel electrode, 511 is a hole injection layer, 512 is a light emitting layer, and 513 is an electron injection layer. The pixel electrode 510 is formed in contact with the connection wiring 506, and openings 521 and 522 for exposing a part of the pixel electrode 510 and a part of the auxiliary electrode 520 are formed on the passivation film 508. A second interlayer insulating film 523 is formed. A hole injection layer 511, a light emitting layer 512, and an electron injection layer 513 are sequentially formed so as to cover the passivation film 508 and the opening 521.

  In this embodiment mode, the pixel electrode 510, the hole injection layer 511, the light emitting layer 512, and the electron injection layer 513 overlap in the opening 521, and the overlapping portion corresponds to the light emitting element 514. . Note that the light-emitting layer 512 is formed using the metal mask 572 so that the opening 522 is not completely covered and the auxiliary electrode 520 is partially exposed. Therefore, in the opening 522, the hole injection layer 511 and the electron injection layer 513 are sequentially stacked on the auxiliary electrode 520. A portion where the pixel electrode 510, the hole injection layer 511, the light emitting layer 512, and the electron injection layer 513 overlap corresponds to the light emitting element 514.

  In this embodiment mode, for example, a polyethylenedioxythiophene / polystyrene sulfonic acid (PEDOT / PSS) thin film can be formed as the hole injection layer 511 by a coating method.

  In this embodiment mode, as the electron injection layer, a benzoxazole derivative which is an electron transporting material and any one of an alkali metal, an alkaline earth metal, and a transition metal (for example, Li, Mg, Cs, and the like) are set to 0. An electron injecting composition contained at 1 to 10 (molar ratio) is used. Then, the electron injection layer 513 having the above structure is used instead of the counter electrode. Note that in this embodiment mode, the film is formed by a co-evaporation method with a thickness of 20 nm so that the molar ratio of the benzoxazole derivative represented by the following structural formula (1) and the alkali metal Li is 2.

  A protective film 524 is formed on the electron injection layer 513. Like the passivation film 508, the protective film 524 is a film that hardly transmits a substance that causes deterioration of the light-emitting element such as moisture or oxygen as compared with other insulating films. Typically, it is desirable to use, for example, a DLC film, a carbon nitride film, a silicon nitride film formed by an RF sputtering method, or the like. In addition, the above-described film that hardly transmits a substance such as moisture or oxygen and a film that easily allows a substance such as moisture or oxygen to pass through can be stacked to be used as a protective film.

Note that the second interlayer insulating film 523 is formed in a vacuum atmosphere in order to remove adsorbed moisture, oxygen, and the like before the hole injection layer 511, the light emitting layer 512, and the electron injection layer 513 are formed. Keep it heated. Specifically, heat treatment is performed in a vacuum atmosphere at 100 ° C. to 200 ° C. for about 0.5 to 1 hour. Desirably, it is 3 × 10 ⁻⁷ Torr or less, and if possible, it is most desirably 3 × 10 ⁻⁸ Torr or less. In the case where the hole injection layer 511, the light emitting layer 512, and the electron injection layer 513 are formed after the second interlayer insulating film 523 is subjected to heat treatment in a vacuum atmosphere, the vacuum injection is performed until just before the film formation. By maintaining the above, reliability can be further increased.

  In addition, the end portion of the opening 521 of the second interlayer insulating film 523 has a light emitting layer 512 formed so as to partially overlap the second interlayer insulating film 523 so that there is no hole in the end portion. It is desirable to make it round. Specifically, it is desirable that the radius of curvature of the curve drawn by the cross section of the second interlayer insulating film in the opening is about 0.2 to 2 μm.

  With the above structure, the coverage of the hole injection layer 511, the light emitting layer 512, and the electron injection layer 513 to be formed later can be improved, and the hole in which the pixel electrode 510 and the electron injection layer 513 are formed in the light emitting layer 512 is achieved. Can be prevented from short-circuiting. Further, by relaxing the stress of the light emitting layer 512, a defect called “shrink” in which a light emitting region decreases can be reduced, and reliability can be improved.

  Note that FIG. 4 shows an example in which a positive photosensitive acrylic resin is used as the second interlayer insulating film 523. The photosensitive organic resin includes a positive type in which a portion exposed to energy rays such as light, electrons, and ions is removed, and a negative type in which the exposed portion remains. In the present invention, a negative organic resin film may be used. Alternatively, the second interlayer insulating film 523 may be formed using photosensitive polyimide. In the case where the second interlayer insulating film 523 is formed using negative acrylic, the end portion of the opening 521 has an S-shaped cross-sectional shape. At this time, it is desirable that the radius of curvature at the upper end and the lower end of the opening is 0.2 to 2 μm.

  Note that the first interlayer insulating film 507 or the second interlayer insulating film 523 may be formed using a photosensitive organic resin used for a photoresist. In this case, for example, a solution obtained by dissolving cresol resin, which is one of photosensitive organic resins, in propylene glycol monomethyl ether acetate (PGMEA) is applied onto a substrate and baked. Next, since the cresol resin is a positive photosensitive organic resin, a portion where an opening is to be formed is exposed using a photomask. And after developing with a developing solution, an opening part can be formed by drying a board | substrate and baking for about 1 hour at 120 to 250 degreeC (for example, 125 degreeC). Note that before baking after development, baking as a pre-bake may be performed at a temperature slightly lower than the baking temperature (for example, about 100 ° C.). By using a photosensitive organic resin as the first interlayer insulating film 507, the aspect ratio can be increased so that the diameter of the contact hole provided when the connection wiring 506 is formed becomes smaller with respect to the depth. In addition, when the cresol resin is used as the first interlayer insulating film 507, it is possible to suppress moisture from being released from the first interlayer insulating film 507. Therefore, the passivation film 508 is used for the purpose of suppressing deterioration of the light emitting element 514. There is no need to provide. Therefore, dust is generated from the silicon nitride film used as the passivation film 508, and the pixel electrode and the counter electrode can be prevented from being short-circuited by the dust.

  Note that the second interlayer insulating film is not limited to the organic resin film described above, and may be an inorganic insulating film such as silicon oxide.

  The pixel electrode 510 can be made of ITO, IZO, ITSO, or a transparent conductive film in which indium oxide is mixed with 2 to 20% zinc oxide (ZnO). In addition to the transparent conductive film, a titanium nitride film or a titanium film may be used as the pixel electrode 510. In FIG. 4, ITO is used as the pixel electrode 510. The pixel electrode 510 may be polished and polished with a CMP method or a polyvinyl alcohol-based porous material so that the surface thereof is planarized. Further, after polishing using the CMP method, the surface of the pixel electrode 510 may be subjected to ultraviolet irradiation, oxygen plasma treatment, or the like.

  Note that FIG. 4 illustrates a structure in which light emitted from the light-emitting element is emitted to the substrate 500 side; however, a light-emitting element having a structure in which light is directed to the side opposite to the substrate may be used.

  In actuality, when completed up to FIG. 4, packaging with a protective film (laminate film, UV curable resin film, etc.) or a translucent cover material with high air tightness and low outgassing so as not to be exposed to the outside air ( (Encapsulation) is preferable. At that time, if the inside of the cover material is made an inert atmosphere or a hygroscopic material (for example, barium oxide) is arranged inside, the reliability of the OLED is improved.

  Note that the present invention is not limited to the manufacturing method described above, and can be manufactured using a known method.

  Note that in the light-emitting device illustrated in FIG. 4, the protective film 524 may have a stacked structure of an inorganic insulating film and an organic resin film. 4B, the structure in the case where the protective film 524 has a stacked structure is shown in FIG. 22A, and the structure in the case where the protective film 524 has a stacked structure in FIG. 4C. Is shown in FIG. 22A and 22B, an inorganic insulating film 524a is formed so as to be in contact with the electron injection layer 513, and an organic resin film 524b and an inorganic insulating film 524c are formed over the inorganic insulating film 524a. They are stacked in order. By using silicon nitride, silicon nitride oxide, aluminum oxide, aluminum nitride, aluminum nitride oxide, or aluminum oxynitride as the inorganic insulating films 524a and 524c, a substance that promotes deterioration of moisture, oxygen, or the like to the light-emitting element 514 is used. Intrusion can be prevented. Further, by providing the organic resin film 524b whose internal stress is smaller than that of the inorganic insulating films 524a and 524c between the inorganic insulating films 524a and 524c, the protective film 524 can be prevented from being peeled off due to the stress. As the organic resin film 524b, polyimide, acrylic, polyamide, polyimide amide, benzocyclobutene, or an epoxy resin can be used.

  In this embodiment mode, the electron injection layer 513 is covered with the protective film 524 as shown in FIG. 4, but the present invention is not limited to this. FIG. 5 shows an example in which a transparent conductive film is formed between the electron injection layer 513 and the protective film 524 in the light emitting device shown in FIG. In FIG. 5, the same reference numerals are given to those already shown in FIG. Reference numeral 580 corresponds to a transparent conductive film. By forming the transparent conductive film 580 so as to be in contact with the electron injection layer 513, a potential drop can be suppressed even when the resistance of the electron injection layer 513 itself functioning as the counter electrode increases.

  In the light emitting device shown in FIGS. 4, 5, 22, and 23, the electron injection layer is composed of a plurality of layers, and the uppermost electron injection layer has the highest concentration of alkali metal, alkaline earth metal, Alternatively, any one of transition metals is added. FIG. 24 shows a connection configuration between the auxiliary electrode and the hole transport layer in the case where two electron injection layers are provided in the light emitting device shown in FIG. In FIG. 24, 659 corresponds to an opening for connecting the auxiliary electrode 660 and the hole transport layer 654. Then, two electron injection layers 657 and 658 are formed on the hole transport layer 654 so as to be sequentially stacked. Reference numeral 663 corresponds to a protective film. In FIG. 24, any one of an alkali metal, an alkaline earth metal, and a transition metal is added to the electron injection layer 658 formed in the uppermost layer at a concentration higher than that of the electron injection layer 657. Note that the electron transporting materials of the electron injection layers 657 and 658 may be the same or different.

(Embodiment 5)
In this embodiment mode, an example in which the hole injection layer is partially removed by plasma etching in the light-emitting device shown in FIG. 4 will be described. FIG. 6A is a cross-sectional view of a pixel of this embodiment mode. FIG. 6B is an enlarged view of a portion surrounded by a broken line 601 in FIG. 6A, and FIG. 6C is an enlarged view of a portion surrounded by a broken line 602.

  In this embodiment mode, the structure of the light emitting element itself is the same as that shown in FIG. Specifically, a part of the pixel electrode 603 is exposed in the opening 605 formed in the second interlayer insulating film 604, and the hole injection layer is formed on the pixel electrode 603 so as to cover the opening 605. 606, the light emitting layer 607, the electron injection layer 608, and the protective film 613 are laminated | stacked in order. Note that the protective film 613 is not necessarily provided, but the provision of the protective film 613 can suppress deterioration of the light-emitting element. In the opening 605, a portion where the pixel electrode 603, the hole injection layer 606, the light emitting layer 607, and the electron injection layer 608 overlap corresponds to the light emitting element 611.

  In the second interlayer insulating film 604, an opening 609 for exposing a part of the auxiliary electrode 610 is formed in addition to the opening 605. In this embodiment mode, at least part of the auxiliary electrode 610 is exposed so that the hole injection layer 606 and the light emitting layer 607 do not completely cover the opening 609. Specifically, after the hole injection layer 606 and the light emitting layer 607 are formed, the auxiliary electrode 610 can be exposed by selective etching by plasma etching using the metal mask 612. Note that the light-emitting layer 607 may be selectively formed by an evaporation method, and the hole injection layer 606 may be selectively etched by plasma etching.

  With the above structure, in the opening 609, the auxiliary electrode 610 and the electron injection layer 608 functioning as a counter electrode can be connected.

  Note that in the light-emitting device illustrated in FIG. 6, the protective film 613 may have a stacked structure of an inorganic insulating film and an organic resin film. 6B, the structure in the case where the protective film 613 has a stacked structure is shown in FIG. 23A, and the structure in the case where the protective film 613 has a stacked structure in FIG. 6C. Is shown in FIG. In FIGS. 23A and 23B, an inorganic insulating film 613a is formed so as to be in contact with the electron injection layer 608, and an organic resin film 613b and an inorganic insulating film 613c are formed over the inorganic insulating film 613a. They are stacked in order. By using silicon nitride, silicon nitride oxide, aluminum oxide, aluminum nitride, aluminum nitride oxide, or aluminum oxynitride as the inorganic insulating films 613a and 613c, a substance that promotes deterioration of moisture, oxygen, or the like to the light-emitting element 611 is used. Intrusion can be prevented. Further, by providing the organic resin film 613b having an internal stress smaller than that of the inorganic insulating films 613a and 613c between the inorganic insulating films 613a and 613c, the passivation film 613 can be prevented from being peeled off due to the stress. As the organic resin film 613b, polyimide, acrylic, polyamide, polyimide amide, benzocyclobutene, or an epoxy resin can be used.

  In this embodiment mode, the electron injection layer 608 is covered with the protective film 613 as shown in FIG. 6, but the present invention is not limited to this. FIG. 7 shows an example in which a transparent conductive film is formed between the electron injection layer 608 and the protective film 613 in the light emitting device shown in FIG. In FIG. 7, the same reference numerals are given to those already shown in FIG. 614 corresponds to a transparent conductive film. By forming the transparent conductive film 614 so as to be in contact with the electron injection layer 608, a potential drop can be suppressed even when the resistance of the electron injection layer 608 itself that functions as a counter electrode increases.

  In the light-emitting device illustrated in FIG. 7, the opening 609 is not necessarily covered with the electron injection layer 608. FIG. 8 shows an example in which a transparent conductive film is formed between the auxiliary electrode 610 and the protective film 613 in the light emitting device shown in FIG. In FIG. 8, the same reference numerals are given to those already shown in FIG. As shown in FIG. 8, the transparent conductive film 614 and the auxiliary electrode 610 are directly connected to each other in the opening 609 by not covering the opening 609 with the electron injection layer 608.

  6, 7, and 8, the electron injecting layer is composed of a plurality of layers as in the light emitting device shown in FIG. 24, and the uppermost electron injecting layer has the highest concentration. Any one of alkali metals, alkaline earth metals, and transition metals may be added.

(Embodiment 6)
In this embodiment mode, a connection relation between each element provided in a pixel and an auxiliary electrode will be described.

  FIG. 12 is a top view of a panel included in the light-emitting device of the present invention. In FIG. 12, reference numeral 700 denotes a substrate. A signal line driver circuit 701, a scanning line driver circuit 702, and a pixel portion 703 are provided over the substrate 700. In the pixel portion 703, an auxiliary electrode 705, a signal line 706, a scanning line 707, and a power supply line 708 are provided. A video signal is supplied to the signal line 706 from the signal line driver circuit 701, and the potential of the scanning line 707 is controlled by the scanning line driver circuit 702.

  A plurality of connection terminals 704 are provided at an end portion of the substrate 700, and various signals and potentials are supplied to the panel through the connection terminals 704. The potential applied to each of the auxiliary electrode 705 and the power supply line 708 is also applied from the connection terminal 704 through the lead wiring 709.

  Next, FIG. 13A shows a circuit diagram of one pixel provided in the pixel portion 703. FIG. 13B illustrates part of a pixel portion 703 in which the pixels illustrated in FIG. 13A are provided in a matrix.

  A pixel illustrated in FIG. 13A includes two transistors 801 and 802, a light-emitting element 803, and a capacitor 804. Further, it has a signal line S, a scanning line G, a power supply line V, and an auxiliary electrode W. Reference numeral 801 corresponds to a transistor (switching transistor) for controlling input of a video signal to the pixel, and reference numeral 802 corresponds to a transistor (drive transistor) for controlling a current supplied to the light emitting element 803. Note that the capacitor 804 has a function of holding the potential of the gate electrode of the driving transistor 802 when the switching transistor 801 is off, and is not necessarily provided.

  Specifically, the switching transistor 801 has a gate electrode connected to the scanning line G, a source and a drain, one connected to the signal line S, and the other connected to the gate electrode of the driving transistor 802. The driving transistor 802 has a source connected to the power supply line V and a drain connected to the pixel electrode of the light emitting element 803. The counter electrode of the light emitting element 803 is connected to the auxiliary electrode W. One of the two electrodes of the capacitor 804 is connected to the gate of the driving transistor 802 and the other is connected to the power supply line V.

  FIG. 13B shows an example in which the auxiliary electrode W is shared in pixels that share the signal line S and the power supply line V. In the case of FIG. 13B, the auxiliary electrode W can be formed of the same conductive film as the signal line S and the power supply line V.

  FIG. 14 shows an example in which the auxiliary electrode W is shared in the pixels sharing the scanning line G. In the case of FIG. 14, the auxiliary electrode W can be formed from the same conductive film as the scanning line G.

  Note that the pixel illustrated in FIG. 13A is merely an embodiment of a pixel included in the light-emitting device of the present invention, and the light-emitting device of the present invention is not limited to the pixel described in this embodiment.

  In this embodiment, the layout of the routing wiring, the auxiliary electrode, the signal line, and the power supply line will be described.

  FIG. 15 shows a top view of a connection portion between the lead wiring and the auxiliary electrode. Reference numeral 1201 denotes a connection terminal, which is connected to the wiring 1203 through the wiring 1202. The wiring 1203 is connected to the wiring 1205 through the wiring 1204. The wiring 1205 is connected to the auxiliary electrode 1206, and more specifically, is formed of one conductive film that is continuous with the auxiliary electrode 1206. Accordingly, in the case of FIG. 15, the lead wirings that connect the connection terminals 1201 and the auxiliary electrodes 1206 correspond to the wirings 1202, 1203, 1204, and 1205.

  Reference numeral 1207 corresponds to a signal line driver circuit, which supplies a video signal to the signal line 1209 through the wiring 1208. The power supply lines 1210r, 1210g, and 1210b corresponding to the respective colors are connected to the wirings 1212r, 1212g, and 1212b through the wirings 1211r, 1211g, and 1211b, respectively. Note that the wiring 1212 b is further connected to the wiring 1214 through the wiring 1213. The wirings 1212r, 1212g, and 1214 are connected to connection terminals 1215r, 1215g, and 1215b, respectively.

  Reference numeral 1216 corresponds to an opening formed in the second interlayer insulating film. In the opening 1216, the wiring 1205 and the counter electrode (not shown) are directly or electrically connected.

  In this embodiment, variations of the pixel of the present invention will be described.

  FIG. 16A illustrates one mode of a pixel of this example. A pixel shown in FIG. 16A includes a light-emitting element 901, a switching transistor 902 used as a switching element for controlling input of a video signal to the pixel, and a driving transistor for controlling a current value flowing through the light-emitting element 901. 903 and a current control transistor 904 for selecting whether or not to supply current to the light emitting element 901. Further, as in this embodiment, a capacitor 905 for holding the potential of the gate of the transistor 904 may be provided in the pixel.

  The switching transistor 902 may be either n-type or p-type. The driving transistor 903 and the current control transistor 904 may be either n-type or p-type, but both have the same polarity. Then, the driving transistor 903 is operated in the saturation region, and the current control transistor 904 is operated in the linear region. As the driving transistor 903, an enhancement type transistor or a depletion type transistor may be used.

  Further, L of the driving transistor 903 may be longer than W, and L of the current control transistor 904 may be equal to or shorter than W. More preferably, the ratio of L to W of the driving transistor 903 is 5 or more. With the above structure, variation in luminance of the light-emitting element 901 between pixels due to a difference in characteristics of the driving transistor 903 can be further suppressed. When the channel length of the driving transistor is L1, the channel width is W1, the channel length of the current control transistor is L2, and the channel width is W2, X is 5 when L1 / W1: L2 / W2 = X: 1. It is desirable to set it to 6000 or more. For example, when X = 6000, it is desirable that L1 / W1 = 500 μm / 3 μm and L2 / W2 = 3 μm / 100 μm.

  The gate electrode of the switching transistor 902 is connected to the scanning line G. One of the source and the drain of the switching transistor 902 is connected to the signal line S, and the other is connected to the gate electrode of the current control transistor 904. The gate electrode of the driving transistor 903 is connected to the second power supply line Vb. The driving transistor 903 and the current control transistor 904 are supplied so that the current supplied from the first power supply line Va is supplied to the light emitting element 901 as the drain current of the driving transistor 903 and the current control transistor 904. The first power supply line Va and the light emitting element 901 are connected. In this embodiment, the source of the current control transistor 904 is connected to the first power supply line Va, and the drain of the driving transistor 903 is connected to the pixel electrode of the light emitting element 901.

  Note that the source of the driving transistor 903 may be connected to the first power supply line Va, and the drain of the current control transistor 904 may be connected to the pixel electrode of the light emitting element 901.

  The light-emitting element 901 includes an anode, a cathode, and an electroluminescent layer provided between the anode and the cathode. As shown in FIG. 16A, when the anode is connected to the driving transistor 903, the anode is a pixel electrode and the cathode is a counter electrode. A potential difference is provided between the counter electrode of the light emitting element 901 and the first power supply line Va so that a current in the forward bias direction is supplied to the light emitting element 901. The counter electrode of the light emitting element 901 is connected to the auxiliary electrode W.

  One of the two electrodes of the capacitor 905 is connected to the first power supply line Va, and the other is connected to the gate electrode of the current control transistor 904. The capacitor 905 is provided to hold a potential difference between the electrodes of the capacitor 905 when the switching transistor 902 is in a non-selected state (off state). Note that FIG. 16A illustrates a structure in which the capacitor 905 is provided; however, the pixel illustrated in FIG. 16A is not limited to this structure, and the capacitor 905 may not be provided.

  In FIG. 16A, the driving transistor 903 and the current control transistor 904 are p-type, and the drain of the driving transistor 903 and the anode of the light-emitting element 901 are connected. Conversely, if the driving transistor 903 and the current control transistor 904 are n-type, the source of the driving transistor 903 and the cathode of the light emitting element 901 are connected. In this case, the cathode of the light emitting element 901 is a pixel electrode, and the anode is a counter electrode.

  Next, FIG. 16B shows a circuit diagram of a pixel in which a transistor (erase transistor) 906 for forcibly turning off the current control transistor 904 is provided in the pixel shown in FIG. . Note that in FIG. 16B, the elements already described in FIG. 16A are denoted by the same reference numerals. Note that the first scan line is indicated by Ga and the second scan line is indicated by Gb in order to be distinguished from the second scan line. The erasing transistor 906 has a gate electrode connected to the second scanning line Gb, one of a source and a drain connected to the gate electrode of the current control transistor 904 and the other connected to the first power supply line Va. Yes. The erasing transistor 906 may be either n-type or p-type.

  Next, FIG. 16C illustrates a pixel circuit in which the gate electrode of the driving transistor 903 is connected to one power supply line V together with the source of the current control transistor 904 in the pixel illustrated in FIG. The figure is shown. Note that in FIG. 16C, elements already described in FIG. 16A are denoted by the same reference numerals. As shown in FIG. 16C, when the source of the current control transistor 904 and the gate electrode of the driving transistor 903 are connected to a common power supply line V, a depletion type transistor is used as the driving transistor 903. Transistors other than the driving transistor 903 are normal enhancement type transistors.

  Next, FIG. 16D shows a circuit diagram of a pixel provided with a transistor (erase transistor) 906 for forcibly turning off the current control transistor 904 in the pixel shown in FIG. . Note that in FIG. 16D, elements already described in FIGS. 16A to 16C are denoted by the same reference numerals. The erasing transistor 906 has a gate electrode connected to the second scanning line Gb, one of the source and the drain connected to the gate electrode of the current control transistor 904 and the other connected to the power supply line V. The erasing transistor 906 may be either n-type or p-type.

  Next, FIG. 17A is a circuit diagram of a pixel in which the gate electrode of the driving transistor 903 is connected to the second scanning line Gb in the pixel shown in FIG. Note that in FIG. 17A, elements already described in FIG. 16A are denoted by the same reference numerals. As shown in FIG. 17A, by switching the potential applied to the gate electrode of the driving transistor 903, light emission of the light-emitting element 901 can be forcibly terminated regardless of information included in the video signal. As the driving transistor 903, an enhancement type transistor or a depletion type transistor may be used.

  Next, FIG. 17B is a circuit diagram of a pixel provided with a transistor (erase transistor) 906 for forcibly turning off the current control transistor 904 in the pixel shown in FIG. . Note that in FIG. 17B, elements already described in FIGS. 16A to 16D and 17A are denoted by the same reference numerals. The erasing transistor 906 has a gate electrode connected to the second scanning line Gb, one of the source and the drain connected to the gate electrode of the current control transistor 904 and the other connected to the power supply line V. The erasing transistor 906 may be either n-type or p-type.

  Next, FIG. 17C is a circuit diagram of a pixel in which the gate electrode of the driving transistor 903 and the gate electrode of the current control transistor 904 are connected in the pixel illustrated in FIG. . Note that in FIG. 17C, elements already described in FIG. 16A are denoted by the same reference numerals. As shown in FIG. 17C, in the case where the gate electrode of the current control transistor 904 and the gate electrode of the driving transistor 903 are connected, a depletion type transistor is used as the driving transistor 903, and other than the driving transistor 903. This transistor is a normal enhancement type transistor.

  Next, FIG. 17D illustrates a pixel configuration in which a current control transistor is not provided. In FIG. 17D, 911 corresponds to a light emitting element, 912 corresponds to a switching transistor, 913 corresponds to a driving transistor, 915 corresponds to a capacitor element, and 916 corresponds to an erasing transistor. The switching transistor 912 has a gate electrode connected to the first scanning line Ga, a source and a drain, one connected to the signal line S, and the other connected to the gate electrode of the driving transistor 913. The driving transistor 913 has a source connected to the power supply line V and a drain connected to the pixel electrode of the light emitting element 911. The counter electrode of the light emitting element 911 is connected to the auxiliary electrode W. The erasing transistor 916 has a gate electrode connected to the second scanning line Gb, one source and drain connected to the gate electrode of the driving transistor 913, and the other connected to the power supply line V.

  Note that the structure of the pixel included in the light-emitting device of the present invention is not limited to the structure shown in this embodiment.

  In this example, an example of a top view of the pixel illustrated in FIG. 16A will be described. FIG. 18 shows a top view of the pixel of this embodiment.

Reference numeral 8001 denotes a signal line, 8002 denotes a first power supply line, 8003 denotes a second power supply line, 8004 denotes a first scanning line, 8005 denotes a second scanning line, and 8006 denotes an auxiliary electrode. In this embodiment, the signal line 8001, the first power supply line 8002, the second power supply line 8003, and the auxiliary electrode 8006 are formed of the same conductive film, and the first scan line 8004 and the second scan line are formed. 8005 is formed of the same conductive film.
Reference numeral 8007 denotes a switching transistor, and part of the first scan line 8004 functions as a gate electrode. Reference numeral 8008 denotes an erasing transistor, and a part of the second scanning line 8005 functions as a gate electrode thereof. Reference numeral 8009 denotes a current control transistor 8009 which corresponds to a driving transistor. The active layer of the driving transistor 8010 is winding so that L / W is larger than that of the current control transistor 8009. Reference numeral 8011 corresponds to a pixel electrode, which overlaps with an electroluminescent layer and a counter electrode (both not shown) so as to be in contact with each other at an opening 8012. The auxiliary electrode 8006 is connected to the counter electrode at the opening 8013. Reference numeral 8014 denotes a capacitor means, which is formed by a gate insulating film between the second power supply line 8003 and the current control transistor 8009.

  It should be noted that the top view of the present invention is an example, and the present invention is not limited thereto.

  The transistor that can be used in the present invention may be formed of amorphous silicon. When a transistor is formed using amorphous silicon, it is not necessary to provide a crystallization process, so that a manufacturing method can be simplified and cost can be reduced. However, a transistor formed using amorphous silicon has higher mobility in the n-type than in the p-type, and is more suitable for use in a pixel of a light-emitting device. In this embodiment, a cross-sectional structure of a pixel in the case where an n-type driving transistor is described.

  FIG. 19A is a cross-sectional view of a pixel in the case where the driving transistor 6001 is n-type and light emitted from the light-emitting element 6002 is emitted to the anode 6005 side. In FIG. 19A, a cathode 6003 of a light-emitting element 6002 and a driving transistor 6001 are electrically connected, and an electroluminescent layer 6004 and an anode 6005 are stacked over the cathode 6003 in this order. A known material can be used for the cathode 6003 as long as it has a small work function and reflects light. For example, Ca, Al, CaF, MgAg, AlLi, etc. are desirable. The electroluminescent layer 6004 may be composed of a single layer or a plurality of layers stacked. In the case of a plurality of layers, an electron injection layer, an electron transport layer, a light emitting layer, a hole transport layer, and a hole injection layer are stacked in this order on the cathode 6003. Note that it is not necessary to provide all of these layers. The anode 6005 is formed using a transparent conductive film that transmits light. For example, in addition to ITO, a transparent conductive film in which 2 to 20% zinc oxide (ZnO) is mixed with indium oxide may be used.

  A portion where the cathode 6003, the electroluminescent layer 6004, and the anode 6005 overlap corresponds to the light emitting element 6002. In the case of the pixel shown in FIG. 19A, light emitted from the light-emitting element 6002 passes to the anode 6005 side as indicated by a hollow arrow.

  In addition, part of the active layer of the driving transistor 6001 functions as the resistor 6009.

  FIG. 19B is a cross-sectional view of a pixel in the case where the driving transistor 6011 is n-type and light emitted from the light-emitting element 6012 is emitted to the cathode 6013 side. In FIG. 19B, a cathode 6013 of a light-emitting element 6012 is formed over a transparent conductive film 6017 electrically connected to a driving transistor 6011. An electroluminescent layer 6014 and an anode 6015 are formed over the cathode 6013. They are stacked in order. A shielding film 6016 for reflecting or shielding light is formed so as to cover the anode 6015. As in the case of FIG. 19A, a known material can be used for the cathode 6013 as long as it is a conductive film having a low work function. However, the film thickness is set so as to transmit light. For example, Al having a thickness of 20 nm can be used as the cathode 6013. Similarly to FIG. 19A, the electroluminescent layer 6014 may be formed of a single layer or a stack of a plurality of layers. The anode 6015 is not required to transmit light, but can be formed using a transparent conductive film as in FIG. The shielding film 6016 can be formed using, for example, a metal that reflects light, but is not limited to a metal film. For example, a resin to which a black pigment is added can also be used.

  A portion where the cathode 6013, the electroluminescent layer 6014, and the anode 6015 overlap corresponds to the light emitting element 6012. In the case of the pixel shown in FIG. 19B, light emitted from the light-emitting element 6012 passes to the cathode 6013 side as indicated by a hollow arrow.

  In addition, part of the active layer of the driving transistor 6011 functions as the resistor 6019.

  In this embodiment, an example in which the driving transistor and the light emitting element are electrically connected is shown. However, even in a configuration in which a current control transistor is connected between the driving transistor and the light emitting element. Good.

  In this embodiment, a cross-sectional structure of a pixel when a driving transistor is a p-type will be described.

  FIG. 20A is a cross-sectional view of a pixel in the case where the driving transistor 6021 is p-type and light emitted from the light-emitting element 6022 is emitted to the anode 6023 side. In FIG. 20A, an anode 6023 of a light-emitting element 6022 and a driving transistor 6021 are electrically connected, and an electroluminescent layer 6024 and a cathode 6025 are stacked over the anode 6023 in this order. A known material can be used for the cathode 6025 as long as it has a low work function and reflects light. For example, Ca, Al, CaF, MgAg, AlLi, etc. are desirable. The electroluminescent layer 6024 may be formed of a single layer or a plurality of layers stacked. In the case of a plurality of layers, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer are stacked in this order on the anode 6023. Note that it is not necessary to provide all of these layers. The anode 6023 is formed using a transparent conductive film that transmits light. For example, in addition to ITO, a transparent conductive film in which 2 to 20% zinc oxide (ZnO) is mixed with indium oxide may be used.

  A portion where the anode 6023, the electroluminescent layer 6024, and the cathode 6025 overlap with each other corresponds to the light-emitting element 6022. In the case of the pixel shown in FIG. 20A, light emitted from the light-emitting element 6022 passes to the anode 6023 side as shown by a hollow arrow.

  In addition, part of the active layer of the driving transistor 6021 functions as the resistor 6029.

  FIG. 20B is a cross-sectional view of a pixel in the case where the driving transistor 6031 is p-type and light emitted from the light-emitting element 6032 is emitted to the cathode 6035 side. In FIG. 20B, the anode 6033 of the light-emitting element 6032 is formed over the wiring 6037 electrically connected to the driving transistor 6031, and the electroluminescent layer 6034 and the cathode 6035 are sequentially stacked over the anode 6033. Has been. With the above structure, even when light is transmitted through the anode 6033, the light is reflected at the wiring 6037. As in the case of FIG. 20A, a known material can be used for the cathode 6035 as long as it is a conductive film having a low work function. However, the film thickness is set so as to transmit light. For example, Al having a thickness of 20 nm can be used as the cathode 6035. As in FIG. 20A, the electroluminescent layer 6034 may be formed of a single layer or a stack of a plurality of layers. The anode 6033 does not need to transmit light, but can be formed using a transparent conductive film as in FIG. The wiring 6037 can be formed using, for example, a metal that reflects light.

  A portion where the anode 6033, the electroluminescent layer 6034, and the cathode 6035 overlap corresponds to the light emitting element 6032. In the case of the pixel shown in FIG. 20B, light emitted from the light-emitting element 6032 passes to the cathode 6035 side as shown by a hollow arrow.

  Further, part of the active layer of the driving transistor 6031 functions as the resistor 6039.

  In this embodiment, an example in which the driving transistor and the light emitting element are electrically connected is shown. However, even in a configuration in which a current control transistor is connected between the driving transistor and the light emitting element. Good.

  A cross-sectional structure of a pixel of the dual emission type light emitting device of the present invention will be described with reference to FIG. FIG. 21 shows a driving transistor 9001 formed over a substrate 9000. The driving transistor 9001 is covered with a first interlayer insulating film 9002, and a wiring 9004 electrically connected to the drain of the driving transistor 9001 through a contact hole is formed over the first interlayer insulating film 9002. Is formed.

  The wiring 9004 is connected to the pixel electrode 9006. A second interlayer insulating film 9005 is formed over the first interlayer insulating film 9002 so as to cover the wiring 9004 and part of the pixel electrode 9006. Note that the first interlayer insulating film 9002 or the second interlayer insulating film 9005 can be formed using a single layer or a stacked layer of silicon oxide, silicon nitride, or silicon oxynitride films by a plasma CVD method or a sputtering method. . The first interlayer insulating film 9002 or the second interlayer insulating film 9005 is a film in which a silicon oxynitride film having a higher oxygen molar ratio than nitrogen is stacked over a silicon oxynitride film having a higher nitrogen molar ratio than oxygen. It may be used as Alternatively, an organic resin film or an organic polysiloxane may be used as the first interlayer insulating film 9002 or the second interlayer insulating film 9005.

  The second interlayer insulating film 9005 has an opening, and a light-emitting element 9011 is formed by overlapping the pixel electrode 9006, the electroluminescent layer 9009, and the cathode 9010 in the opening. In this embodiment, a transparent conductive film 9012 is formed so as to cover the cathode 9010.

  Note that the electroluminescent layer 9009 has a structure in which a light emitting layer alone or a plurality of layers including a light emitting layer are stacked. Further, a protective film may be formed over the transparent conductive film 9012. In this case, the protective film is a film that is less likely to transmit a substance that causes deterioration of the light emitting element such as moisture and oxygen as compared with other insulating films. Typically, it is desirable to use, for example, a DLC film, a carbon nitride film, a silicon nitride film formed by an RF sputtering method, or the like. In addition, the above-described film that hardly transmits a substance such as moisture or oxygen and a film that easily allows a substance such as moisture or oxygen to pass through can be stacked to be used as a protective film.

  A transparent conductive film can be used for the pixel electrode 9006. In addition to ITO, IZO, and ITSO, a transparent conductive film in which indium oxide is mixed with 2 to 20% zinc oxide (ZnO) may be used. In FIG. 21, ITO is used as the pixel electrode 9006. The pixel electrode 9006 may be polished by wiping with a CMP method or a polyvinyl alcohol-based porous material so that the surface thereof is planarized. Further, after polishing using the CMP method, the surface of the pixel electrode 9006 may be subjected to ultraviolet irradiation, oxygen plasma treatment, or the like.

  The cathode 9010 has a thickness enough to transmit light (preferably about 5 nm to 30 nm), and other known materials can be used as long as the conductive film has a low work function. For example, Ca, Al, CaF, MgAg, AlLi, etc. are desirable. In order to obtain light from the cathode side, there is a method of using ITO whose work function is reduced by adding Li in addition to the method of reducing the film thickness. The light-emitting element used in the present invention may be configured so that light is emitted from both the anode side and the cathode side.

  In actuality, when completed up to FIG. 21, packaging with a protective film (laminate film, UV curable resin film, etc.) or a translucent cover material that is highly airtight and less degassed so as not to be exposed to the outside air ( (Encapsulation) is preferable. At that time, if the inside of the cover material is made an inert atmosphere or a hygroscopic material (for example, barium oxide) is arranged inside, the reliability of the OLED is improved. In the present invention, a color filter may be provided on the cover material.

  Note that the present invention is not limited to the manufacturing method described above, and can be manufactured using a known method.

   In this example, the appearance of a panel corresponding to one embodiment of the light-emitting device of the present invention will be described with reference to FIG. FIG. 25 is a top view of a panel in which a transistor and a light-emitting element formed over the first substrate are sealed with a sealant between the second substrate and FIG. 25B. This corresponds to a cross-sectional view taken along line AA ′ in FIG.

  A sealant 4005 is provided so as to surround the pixel portion 4002, the signal line driver circuit 4003, and the scan line driver circuit 4004 which are provided over the first substrate 4001. A second substrate 4006 is provided over the pixel portion 4002, the signal line driver circuit 4003, and the scan line driver circuit 4004. Therefore, the pixel portion 4002, the signal line driver circuit 4003, and the scan line driver circuit 4004 are sealed together with the filler 4007 by the first substrate 4001, the sealant 4005, and the second substrate 4006.

   In addition, the pixel portion 4002, the signal line driver circuit 4003, and the scan line driver circuit 4004 provided over the first substrate 4001 include a plurality of transistors. In FIG. 25B, the signal line driver circuit 4003 is provided. The transistors 4008 and 4009 included in the pixel portion and the driving transistor 4010 included in the pixel portion 4002 are illustrated.

  Reference numeral 4011 corresponds to a light-emitting element, and a pixel electrode included in the light-emitting element 4011 is electrically connected to the drain of the driving transistor 4010 through a wiring 4017. In this embodiment, the counter electrode of the light emitting element 4011 and the transparent conductive film 4012 are electrically connected, and the transparent conductive film 4012 is electrically connected to the auxiliary electrode 4013. Although not illustrated in the cross-sectional view in FIG. 25B, the auxiliary electrode 4013 is electrically connected to the connection terminal 4016 through the lead wirings 4014 and 4015.

  In this embodiment, the connection terminal 4016 is formed of the same conductive film as the pixel electrode included in the light emitting element 4011. Further, the lead wiring 4014 is formed of the same conductive film as the wiring 4017. In addition, the lead wiring 4015 is formed using the same conductive film as the gate electrode of each of the driving transistor 4010 and the transistors 4008 and 4009.

  The connection terminal 4016 is electrically connected to a terminal included in the FPC 4018 through an anisotropic conductive film 4019.

  Note that as the first substrate 4001 and the second substrate 4006, glass, metal (typically stainless steel), ceramics, or plastic can be used. As the plastic, an FRP (Fiberglass-Reinforced Plastics) plate, a PVF (polyvinyl fluoride) film, a mylar film, a polyester film, or an acrylic resin film can be used. A sheet having a structure in which an aluminum foil is sandwiched between PVF films or mylar films can also be used.

  However, the second substrate must be transparent to the substrate positioned in the light extraction direction from the light emitting element 4011. In that case, a light-transmitting material such as a glass plate, a plastic plate, a polyester film, or an acrylic film is used.

  As the filler 4007, in addition to an inert gas such as nitrogen or argon, an ultraviolet curable resin or a thermosetting resin can be used. PVC (polyvinyl chloride), acrylic, polyimide, epoxy resin, silicon resin, PVB (Polyvinyl butyral) or EVA (ethylene vinyl acetate) can be used. In this example, nitrogen was used as the filler.

  In order to expose the filler 4007 to a hygroscopic substance (preferably barium oxide) or a substance that can adsorb oxygen, a hygroscopic substance or a substance that can adsorb oxygen may be provided. By providing a hygroscopic substance or a substance that can adsorb oxygen, deterioration of the light-emitting element 4011 can be suppressed.

  Since a light-emitting device using a light-emitting element is a self-luminous type, it has excellent visibility in a bright place and a wide viewing angle compared to a liquid crystal display. Therefore, it can be used for display portions of various electronic devices.

  As an electronic device using the light emitting device of the present invention, a video camera, a digital camera, a goggle type display (head mounted display), a navigation system, a sound reproduction device (car audio, audio component, etc.), a notebook type personal computer, a game device, Play back a recording medium such as a portable information terminal (mobile computer, mobile phone, portable game machine or electronic book), an image playback device (specifically a DVD: Digital Versatile Disc) equipped with a recording medium, A device having a display capable of displaying). In particular, it is desirable to use a light-emitting device for a portable information terminal that often has an opportunity to see a screen from an oblique direction because the wide viewing angle is important. Specific examples of these electronic devices are shown in FIGS.

  FIG. 26A illustrates a portable information terminal including a main body 2001, a display portion 2002, operation keys 2003, a modem 2004, and the like. Although FIG. 26A shows a portable information terminal in which the modem 2004 is removable, the modem may be incorporated in the main body 2001. The light emitting device of the present invention can be used for the display portion 2002.

  FIG. 26B shows a cellular phone, which includes a main body 2101, a display portion 2102, a voice input portion 2103, a voice output portion 2104, operation keys 2105, an external connection port 2106, an antenna 2107, and the like. Note that the display portion 2102 can suppress current consumption of the mobile phone by displaying white characters on a black background. The light emitting device of the present invention can be used for the display portion 2102.

  FIG. 26C illustrates an electronic card, which includes a main body 2201, a display portion 2202, a connection terminal 2203, and the like. The light emitting device of the present invention can be used for the display portion 2202. Note that a contact-type electronic card is illustrated in FIG. 26C; however, the light-emitting device of the present invention is also used for a non-contact type electronic card or an electronic card having both a contact type and a non-contact type function. Can do.

  FIG. 26D shows an electronic book, which includes a main body 2301, a display portion 2302, operation keys 2303, and the like. A modem may be incorporated in the main body 2301. The display portion 2302 uses the light-emitting device of the present invention.

  FIG. 26E shows a sheet-type personal computer, which includes a main body 2401, a display portion 2402, a keyboard 2403, a touch pad 2404, an external connection port 2405, a power plug 2406, and the like. The display portion 2402 uses the light emitting device of the present invention.

  As described above, the applicable range of the present invention is so wide that it can be used for electronic devices in various fields. In addition, the electronic device of this embodiment may use the light emitting device having any configuration shown in Embodiments 1 to 7.

FIG. 6 illustrates a structure of a pixel portion in a light emitting device of the present invention. FIG. 2 is a cross-sectional view of the pixel portion in FIG. 1. FIG. 6 illustrates a structure of a pixel portion in a light emitting device of the present invention. FIG. 4 is a cross-sectional view of a pixel portion in a light emitting device of the present invention. FIG. 4 is a cross-sectional view of a pixel portion in a light emitting device of the present invention. FIG. 4 is a cross-sectional view of a pixel portion in a light emitting device of the present invention. FIG. 4 is a cross-sectional view of a pixel portion in a light emitting device of the present invention. FIG. 4 is a cross-sectional view of a pixel portion in a light emitting device of the present invention. FIG. 6 illustrates a structure of a pixel portion in a light emitting device of the present invention. Sectional drawing of the pixel part of FIG. 4A and 4B illustrate a structure of a connection portion between an auxiliary wiring and a counter electrode in a light-emitting device of the present invention. FIG. 6 illustrates a structure of a light-emitting device of the present invention. FIG. 6 is a circuit diagram of a pixel portion in the light emitting device of the present invention. FIG. 6 is a circuit diagram of a pixel portion in the light emitting device of the present invention. FIG. 6 shows a layout of lead wirings and connection wirings in the light emitting device of the present invention. FIG. 6 is a circuit diagram of a pixel in the light emitting device of the present invention. FIG. 6 is a circuit diagram of a pixel in the light emitting device of the present invention. FIG. 6 is a top view of a pixel in the light-emitting device of the present invention. 4 is a cross-sectional view of a pixel in a light-emitting device of the present invention. FIG. 4 is a cross-sectional view of a pixel in a light-emitting device of the present invention. FIG. 4 is a cross-sectional view of a pixel in a light-emitting device of the present invention. FIG. 4 is a cross-sectional view of a pixel in a light-emitting device of the present invention. FIG. 4 is a cross-sectional view of a pixel in a light-emitting device of the present invention. FIG. 4 is a cross-sectional view of a pixel in a light-emitting device of the present invention. FIG. 2A and 2B are a top view and a cross-sectional view of a light-emitting device of the present invention. FIG. 14 is a diagram of an electronic device using the light-emitting device of the present invention.

Explanation of symbols

Reference numeral 301 Connection terminal 302a Lead wiring 302b Lead wiring 302c Lead wiring 303 Auxiliary electrode 304 Signal line 305 Power supply line 306 Scan line 307 Pixel electrode 308a Opening 308b Opening 309 Electroluminescent layer 310 Counter electrode 311 Connecting wiring 312 First interlayer insulating film 313 Second interlayer insulating film 314 Light emitting element 315 Wiring 316 Transparent conductive film

Claims (14)

A first insulating film;
A first electrode and an auxiliary electrode formed on the first insulating film;
A second insulating film formed so as to cover an end of the first electrode;
Electroluminescence in contact with the first electrode in the first opening formed in the second insulating film and in contact with the upper portion of the auxiliary electrode in the second opening formed in the second insulating film Layers,
A light emitting device comprising: a second electrode in contact with the electroluminescent layer in the first opening and in contact with a side surface of the auxiliary electrode in the second opening. 2. The light emitting device according to claim 1 , wherein the first insulating film is a photosensitive organic resin. 3. The light emitting device according to claim 1 , wherein the second insulating film is a photosensitive organic resin. 4. The light emitting device according to claim 2 , wherein the photosensitive organic resin includes a cresol resin. In any one of claims 1 to 4, the light emitting device characterized by having a transparent conductive film formed to cover the second electrode. In any one of claims 1 to 5, wherein the first electrode, the light emitting device which is a transparent conductive film. It any one of claims 1 to 5, wherein the first electrode, ITO, IZO, the transparent conductive film of zinc oxide is mixed from 2 to 20% of indium oxide, a titanium film or a titanium nitride film, A light emitting device characterized by the above. In any one of claims 1 to 7, wherein the second electrode is light-emitting device characterized by having a light-transmitting property. In any one of claims 1 to 7, wherein the second electrode is light-emitting device according to claim Ca, Al, CaF, that the MgAg or AlLi,. Electronic devices using the light emitting device according to any one of claims 1 to 9. Mobile computer using the light emitting device according to any one of claims 1 to 9. Sound reproducing apparatus using the light emitting device according to any one of claims 1 to 9. Portable game machine using a light-emitting device according to any one of claims 1 to 9. A mobile phone using the light-emitting device according to any one of claims 1 to 9.

Images