JP6865249B2 - Manufacturing method of organic EL display device and organic EL display device - Google Patents

Description

The present invention relates to an organic EL display device and a method for manufacturing an organic EL display device.

In recent years, an organic EL display device that has been increasingly applied to television receivers and the like includes an organic light emitting element formed for each pixel and a drive circuit that causes the organic light emitting element to emit light with a desired current. In an active matrix type organic EL display device, a thin film transistor constituting a drive circuit is formed on a surface such as a glass substrate for each pixel provided in a matrix, and an organic light emitting element is placed on an insulating film covering the thin film transistor. It is formed. Patent Document 1 discloses that a thin film transistor having a multilayer structure is formed in order to reduce the area occupied by the thin film transistor with respect to the pixels in such an active matrix type display.

JP-A-2017-11173

In an organic EL display device, since the organic light emitting element is a current drive type light emitting element, the drive circuit is required to have a higher current supply capacity (drive capacity) than that of the liquid crystal display device. Although the driving ability can be increased by forming the thin film transistor in a laminated structure as in Patent Document 1, the manufacturing cost inevitably increases. However, in order to further popularize the organic EL display panel in large-sized televisions and the like, it is desired to further improve the driving capacity of the drive circuit and significantly reduce the manufacturing cost. Further, if brightness unevenness or color unevenness (hereinafter, "brightness unevenness and / or color unevenness" is collectively referred to as "display unevenness") occurs in the organic EL display panel, the product value thereof is lowered. Such display unevenness becomes more noticeable as the screen becomes larger, which may hinder the spread of the organic EL display panel. Compensation circuits for display unevenness are provided, and correction means for correcting the drive current of the organic light emitting element after observing the initial display state are provided, but such measures also increase the size or cost. ..

Therefore, the present invention has an organic EL display device capable of enhancing the capacity of the drive circuit with a structure capable of realizing cost reduction, and having less display unevenness, and a drive circuit having such excellent drive capacity. An object of the present invention is to provide a manufacturing method capable of appropriately manufacturing an organic EL display device having less display unevenness.

The organic EL display device of the first embodiment of the present invention includes a substrate having a surface on which a drive circuit including a thin film transistor is formed, a flattening film that flattens the surface of the substrate by covering the drive circuit, and a flattening film. An organic light emitting element formed on a surface of the flattening film facing in the direction opposite to the drive circuit and electrically connected to the drive circuit is provided, and the surface of the flattening film is 50 nm or less. A semiconductor having an arithmetic average roughness, wherein the thin film transistor includes a gate electrode, a drain electrode, a source electrode, and a region serving as a channel of the thin film transistor, and is partially overlapped with the source electrode and the drain electrode. A part of the first conductor film having a layer and forming the drain electrode and a part of each of the second conductor film forming the source electrode are alternately arranged along a predetermined direction, and the region serving as the channel is a region. , Is sandwiched between the part of the first conductor film and the part of the second conductor film.

The method for manufacturing the organic EL display device according to the second embodiment of the present invention includes a step of forming a drive circuit including a thin film transistor on a substrate, and a first inorganic insulating film, an organic insulating film, and a first organic insulating film on the surface of the drive circuit. 2. A step of forming the inorganic insulating film, a step of polishing the surface of the second inorganic insulating film, and contact holes reaching the thin film transistor in the second inorganic insulating film, the organic insulating film, and the first inorganic insulating film. A step of forming a first electrode in a predetermined region while embedding a metal in the contact hole, a step of forming an organic light emitting layer on the first electrode, and the organic light emitting layer. The thin film transistor includes a step of forming a second electrode on the surface, the thin film transistor includes a gate electrode, a gate insulating film, a semiconductor layer including a region to be a channel, and a first conductor film and a source electrode constituting a drain electrode. The first conductor film and the second conductor film are formed in a laminated structure with the second conductor film constituting the above, and a part of each of the first conductor film and the second conductor film is formed so as to be alternately arranged along a predetermined direction. The region is sandwiched between the part of the first conductor film and the part of the second conductor film.

According to the first embodiment of the present invention, in the organic EL display device, the capacity of the drive circuit can be enhanced by a structure capable of realizing cost reduction, and display unevenness can be reduced. Further, according to the second embodiment of the present invention, it is possible to appropriately manufacture an organic EL display device having such a drive circuit having excellent driving ability and having less display unevenness.

It is a figure which shows typically an example of the drive circuit of the organic EL display device of one Embodiment of this invention. It is sectional drawing which shows typically an example of the organic light emitting element and the thin film transistor in the organic EL display device of one Embodiment of this invention. It is sectional drawing which shows typically the other example of the thin film transistor in the organic EL display device of one Embodiment of this invention. It is sectional drawing which shows typically the other example of the thin film transistor in the organic EL display device of one Embodiment of this invention. It is a top view which shows an example of each electrode of the thin film transistor in the organic EL display device of one Embodiment of this invention. It is a top view which shows the other example of each electrode of the thin film transistor in the organic EL display device of one Embodiment of this invention. It is a top view which shows the other example of each electrode of the thin film transistor in the organic EL display device of one Embodiment of this invention. It is a figure which shows an example of the cross section of the thin film transistor in the organic EL display device of one Embodiment of this invention. It is a figure which shows another example of the cross section of the thin film transistor in the organic EL display device of one Embodiment of this invention. It is a flowchart of the manufacturing method of the organic EL display device of one Embodiment of this invention. It is a flowchart about the formation process of the drive circuit in FIG. 5A. It is sectional drawing which shows the manufacturing method of the organic EL display device of one Embodiment of this invention. It is sectional drawing which shows the manufacturing method of the organic EL display device of one Embodiment of this invention. It is sectional drawing which shows the manufacturing method of the organic EL display device of one Embodiment of this invention. It is sectional drawing which shows the manufacturing method of the organic EL display device of one Embodiment of this invention. It is sectional drawing which shows the manufacturing method of the organic EL display device of one Embodiment of this invention. It is sectional drawing which shows the manufacturing method of the organic EL display device of one Embodiment of this invention. It is sectional drawing which shows the manufacturing method of the organic EL display device of one Embodiment of this invention.

The present inventors have made extensive studies in order to enhance the driving ability of the driving circuit. Then, the present inventors can significantly enhance the driving ability by forming the drain electrode and the source electrode of the thin film transistor constituting the driving circuit so that a part of each is arranged along a predetermined direction. Moreover, it has been found that the drive circuit can be formed in the region of one pixel of the organic EL display device. That is, by forming the drain electrode and the source electrode in this way, the length of the portions facing each other in both electrodes (the length of the portions facing each other without increasing the distance (channel length (L)) between the drain electrode and the source electrode ( The channel width (W)) can be increased. Therefore, the ratio (W / L) of the channel width to the channel length can be significantly increased and efficiently within a predetermined section, and as a result, one drive circuit having a significantly increased drive capacity can be obtained. It can be laid out in pixels.

Further, by using such a structure for the thin film transistor, the present inventors have made the semiconductor layer which becomes the channel of the thin film transistor constituting the drive circuit of the organic EL display device polysilicon (specifically, low temperature polysilicon: LTPS). It was found that amorphous silicon can also be formed instead. That is, conventionally, LTPS having excellent carrier mobility has been used for the semiconductor layer of such a thin film transistor. However, the present inventors have found that by applying the above-mentioned configuration of each electrode, even a semiconductor layer made of amorphous silicon can sufficiently function in a drive circuit of an organic EL display device.

LTPS is obtained by forming a semiconductor layer of amorphous silicon and then annealing the amorphous silicon by irradiation with an excimer laser to polycrystallize the amorphous silicon. Therefore, the manufacturing process becomes complicated, and this annealing process hinders the reduction of the manufacturing cost of the organic EL display panel. In addition, the equipment required for excimer laser irradiation is extremely expensive, and the feasibility of equipment applicable to mother substrates exceeding the 10th generation, which has already been introduced in the production line of liquid crystal display devices. Is not foreseen. Further, it is extremely difficult to evenly irradiate the entire surface of the substrate on which the drive circuit is formed with the excimer laser. Therefore, it is easy and easy between each of the plurality of LTPSs that are polycrystalline in each predetermined section on the substrate. There is a large variation in carrier mobility, and as a result, variations in the gate threshold voltage and the like can easily occur between the thin film transistors. As the size of the mother substrate increases, it becomes more difficult to evenly irradiate the mother substrate with the excimer laser. The present inventors have found that the semiconductor layer of the thin film transistor in the drive circuit of the organic EL display panel can be formed of amorphous silicon that does not require annealing by using the structure of the thin film transistor described above.

Furthermore, the present inventors further cause variations in the film thickness of the organic film in the organic light emitting element due to the unevenness of the surface of the drive circuit formed on the surface of the substrate, resulting in uneven brightness and uneven color. We also found that it could occur. More specifically, an insulating film is provided between the drive circuit and the organic light emitting element as described above, and the insulating film electrically separates the two and blocks moisture and the like, and flattens the base of the organic light emitting element. Is being planned. However, the present inventors have found that this flattening is not always sufficient from the viewpoint of obtaining excellent display quality. If the surface of such an insulating film (flattening film) is not sufficiently flat, the thickness of the organic film formed on the insulating film (flattening film) varies with each other, resulting in uneven brightness or peak intensity of emitted light. The indicated direction deviates from the normal direction of the display surface, causing display unevenness. The present inventors have found that the occurrence of display unevenness can be suppressed by further flattening the surface of the flattening film that is the base of the organic light emitting element. Further, by further flattening the surface of the flattening film in this way, even when a thin film transistor having the above-mentioned structure is formed in the lower layer of the light emitting region of the organic light emitting element, display unevenness that may occur due to the unevenness of the surface is generated. It is suppressed.

Hereinafter, the organic EL display device and the method for manufacturing the organic EL display device according to the embodiment of the present invention will be described with reference to the drawings. The materials, shapes, and relative positional relationships of the components in the embodiments described below are merely examples. The organic EL display device and the method for manufacturing the organic EL display device of the present invention are not limitedly interpreted by these.

[Organic EL display device]
FIG. 1 shows an example of the configuration of the drive circuit 2 in the organic EL display device 1 of the first embodiment together with the organic EL display panel 3, the data line driver 1d, and the scanning line driver 1g, which are schematically shown, respectively. Has been done. The organic EL display panel 3 has a plurality of pixels 3a arranged in a matrix, and each pixel 3a is provided with an organic light emitting element 40 and a drive circuit 2. In the example of FIG. 1, the drive circuit 2 has a drive TFT 20 that switches the energization state of the organic light emitting element 40, a switching TFT 2a that switches the drive TFT 20 on / off, and a holding capacity 2b that holds the gate-source voltage of the drive TFT 20. Includes. The drain of the drive TFT 20 is connected to the power supply line 2p, the source is connected to the anode of the organic light emitting element 40, and the gate is connected to the source of the switching TFT 2a, and the cathode of the organic light emitting element 40 is connected to the ground via the cathode wiring 27. It is connected.

A gate signal is sent from the scanning line driver 1g to each switching TFT 2a, and a data signal of a display image is applied from the data line driver 1d to the gate of each driving TFT 20 via each switching TFT 2a. A current based on the voltage of the data signal flows through the organic light emitting element 40, and the organic light emitting element 40 emits light with a predetermined brightness during one frame period due to the action of the holding capacitance 2b. Hereinafter, the organic EL display device 1 of the present embodiment will be described with reference to FIGS. 2A to 2C showing a cross section of the organic EL display panel 3 including one pixel 3a. In the following description, the driving TFT 20 is simply referred to as a "thin film transistor 20 (TFT20)". Further, the "pixel" referred to in the above and the following description and each drawing is the minimum component (unit element) of the display screen and is more accurately a "sub-pixel", but for the sake of brevity of the description, the "pixel" is used. Also called. Further, in the following description, the “surface” is a surface facing the opposite direction to the substrate 10 in each component other than the substrate 10 (see FIG. 2A) constituting the organic EL display device 1 unless the distinction is described in particular. Means. Further, with respect to the substrate 10, the “surface” means a surface facing the organic light emitting element 40 unless the distinction is described.

The structure of the TFT 20 in the drive circuit 2 of the organic EL display device 1 of the present embodiment will be described with reference to FIGS. 2A to 2C and FIGS. 3A to 3C. 2A to 2C show an enlarged cross section of the organic EL display panel 3, and in particular, an example of a cross section of the TFT 20 and the organic light emitting element 40 is shown. 3A to 3C show a plan view of a specific example of the TFT 20 (the drain electrode 26 and the source electrode 25 are hatched). In addition, in FIGS. 2A to 2C, as the TFT 20, one cross section (of both electrodes) of a plurality of portions in which a part of the source electrode 25 and a part of the drain electrode 26 face each other in each of FIGS. 3A to 3C. Opposing directions, for example, cross sections by cutting lines along the Y direction in FIG. 3A) are shown. Further, in FIGS. 2A to 2C, the gate electrode 23 and the semiconductor layer 21 are shown to be formed only on the facing portions of the source electrode 25 and the drain electrode 26, but as in the example of FIGS. 3A, the gate is formed. The electrode 23 may be formed so as to cover the entire plurality of facing portions of the source electrode 25 and the drain electrode 26.

As shown in FIGS. 2A to 2C, the organic EL display device 1 of the present embodiment has a substrate 10 having a surface on which a drive circuit 2 including a TFT 20 is formed, and a surface of the substrate 10 by covering the drive circuit 2. The flattening film 30 is provided with an organic light emitting element 40 formed on a surface of the flattening film 30 facing in the direction opposite to the drive circuit 2 and electrically connected to the drive circuit 2. .. The TFT 20 has a semiconductor layer 21 including a gate electrode 23, a drain electrode 26, a source electrode 25, and a region 21c serving as a channel of the TFT 20. The semiconductor layer 21 is partially overlapped with the drain electrode 26 and the source electrode 25. In the example of FIG. 2A, a second semiconductor layer 211 made of a semiconductor having a high impurity concentration is provided between the drain electrode 26 and the source electrode 25 and the semiconductor layer 21. A channel is formed by applying a predetermined voltage to the gate electrode 23 in the region 21c of the semiconductor layer 21 which is mainly between the drain electrode 26 and the source electrode 25 and overlaps with the gate electrode 23.

FIG. 2A shows an example of a bottom gate structure (inverted stagger structure) in which a gate electrode 23 is arranged between the semiconductor layer 21 and the substrate 10, and FIG. 2B shows an example of a top gate structure (stagger structure). ing. 2A and 2B show an example in which the semiconductor layer 21 is made of amorphous silicon. Further, FIG. 2C is an example of a TFT 20 having a top gate structure similar to the example of FIG. 2B. The structure illustrated in FIG. 2C is mainly used when the region 21c serving as a channel of the semiconductor layer 21 is composed of LTPS. The drive circuit 2 of the organic EL display device 1 of the present embodiment is suitable when the semiconductor layer 21 of the TFT 20 is made of amorphous silicon, but the region 21c serving as the channel of the semiconductor layer 21 may be formed by LTPS. ..

In the example of FIG. 2A, the gate electrode 23 is formed on the substrate 10 via the base coat layer 11, and the gate insulating film 22 and the semiconductor layer 21 are laminated so as to cover the gate electrode 23. The two semiconductor layers 211 are formed, and the drain electrode 26 and the source electrode 25 are laminated on the second semiconductor layer 211. The cathode wiring 27 and the second electrode 44 of the organic light emitting element 40 are connected via the cathode contact 44a. In the example of FIG. 2B, the drain electrode 26 and the source electrode 25 are formed on the base coat layer 11, and between the drain electrode 26 and the source electrode 25 so as to overlap a part of each of the drain electrode 26 and the source electrode 25. The semiconductor layer 21 is laminated on the base coat layer 11, the gate insulating film 22 is further laminated on the semiconductor layer 21, and the gate electrode 23 is formed on the gate insulating film 22.

In the example of FIG. 2C, a semiconductor layer 21 having a region 21c and a drain 21d as a channel composed of a source 21s and LTPS is formed on the base coat layer 11, and a gate insulating film 22 is laminated so as to cover the semiconductor layer 21. Has been done. The gate electrode 23 is formed on the gate insulating film 22, the interlayer insulating film 24 is laminated so as to cover the gate electrode 23, and the source electrode 25 and the drain electrode 26 are formed on the interlayer insulating layer 24. The source electrode 25 and the drain electrode 26 are connected to the source 21s and the drain 21d of the semiconductor layer 21 through the contact holes 24a, respectively. The cathode contact 44a is composed of a first contact 28 penetrating the gate insulating film 22 and the interlayer insulating film 24, and a second contact 45 penetrating the flattening film 30. In the examples shown in FIGS. 2A to 2C, the structures of the TFTs 20 (mainly the vertical relationship of the layers of the components of the TFT 20) are different from each other. In FIGS. 2A-2C, components having similar functions are designated by the same reference numerals, and duplicate description thereof will be omitted.

The organic light emitting element 40 is a top emission type (TE type) organic light emitting diode (OLED) in the examples of FIGS. 2A to 2C, and the first electrode (for example, anode) 41 formed on the flattening film 30 is the first electrode (for example, the anode) 41. It has an insulating bank 42 surrounding one electrode 41, an organic light emitting layer 43 formed in the insulating bank 42, and a second electrode (for example, a cathode) 44 formed on the entire substrate 10 including the organic light emitting layer 43. .. In the examples of FIGS. 2A to 2C, the source electrode 25 of the TFT 20 is connected to the first electrode 41 of the organic light emitting element 40.

When the organic light emitting element 40 is of the TE type as in the examples of FIGS. 2A to 2C, the TFT 20 is the lower layer (with the first electrode 41) of the light emitting region of the organic light emitting element 40, that is, the region where the organic light emitting layer 43 is formed. It may be formed so as to overlap a part or all of the light emitting region (between the substrate 10). In that case, a TFT 20 capable of passing a large current can be formed.

As shown in FIGS. 3A to 3C, the drain electrode 26 and the source electrode 25 are made of a conductor film made of titanium, aluminum, or the like, and form the first conductor film 26a and the source electrode 25 constituting the drain electrode 26. A part of each of the second conductor films 25a is arranged alternately along a predetermined direction. In the example of FIG. 3A, a part of each conductor film is alternately arranged along the vertical direction (Y direction) of FIG. 3A. The region 21c serving as a channel is a region sandwiched between a part of the first conductor film 26a and a part of the second conductor film 25a in the semiconductor layer 21. As described above, a channel is formed in the region 21c by applying a predetermined voltage to the gate electrode 23, and the drain electrode 26 and the source electrode 25 are made conductive.

In this way, a part of the first conductor film 26a and a part of the second conductor film 25a are alternately arranged along a predetermined direction (Y direction in FIG. 3A), and therefore have a predetermined size. It is possible to obtain a drain electrode 26 and a source electrode 25 having long portions facing each other in the region. Therefore, a channel having a long channel width (W) can be formed. On the other hand, the channel length L is the distance between the first conductor film 26a and the second conductor film 25a, and is associated with the fact that a part of the first conductor film 26a and a part of the second conductor film 25a are alternately arranged. Does not increase. Therefore, it is possible to effectively utilize the limited region to form a channel having a large ratio (W / L) of the channel width (W) to the channel length L, that is, a channel capable of passing a large current. Therefore, for example, a TFT 20 having a large driving ability can be formed in one pixel, and a driving circuit having a large driving ability can be formed for each pixel.

Further, if a part of the first conductor film 26a and a part of the second conductor film 25a are alternately arranged in this way, a channel having a large W / L ratio is formed in a region having a predetermined size. It is also possible to form the semiconductor layer 21 with amorphous silicon instead of the above-mentioned LTPS. More specifically, the electron mobility of LTPS is ^{about 100 cm 2} / Vs, and the electron mobility of amorphous silicon is about ^{0.5 cm 2 / Vs.} Therefore, when amorphous silicon is used, it is simply necessary to increase the W / L ratio of the channel by LTPS, which is currently in practical use, by about 200 times (for example, about 2.5). However, the electron mobility of the semiconductor layer actually required to drive the organic light emitting element of the organic EL display device ^{is about 10 cm 2} / Vs in the case of the W / L ratio in the current LTPS described above. Therefore, for example, if the W / L ratio is increased by about 20 times the current W / L ratio, amorphous silicon can be used for the semiconductor layer 21 of the TFT 20 in the drive circuit 2. Therefore, for example, amorphous silicon is formed on the semiconductor layer 21 by alternately arranging a part of the first conductor film 26a and a part of the second conductor film 25a so that channels having a W / L ratio of 50 or more are formed. It can be used, and the annealing step for obtaining the above-mentioned LTPS becomes unnecessary. That is, it may be possible to form the TFT 20 of the drive circuit 2 easily, inexpensively, without using expensive equipment, and by a method capable of following the increase in size of the mother substrate. Further, since amorphous silicon has a small variation in carrier mobility, it is possible to reduce the occurrence of display unevenness and eliminate the need for a display unevenness compensation circuit. It can contribute to the improvement of display quality.

In the example of FIG. 3A, the first conductor film 26a and the second conductor film 25a are each formed in a planar shape and in a comb shape. Then, the comb tooth portions of the first conductor film 26a (first portions 26a1 to 26a4 in the example of FIG. 3A) and the comb tooth portions of the second conductor film 25a (second portions 25a1 to 25a4 in the example of FIG. 3A) mesh with each other. Is formed in. The gate electrode 23 shown by the broken line in FIGS. 3A to 3C is below the first conductor film 26a and the second conductor film 25a (gate insulating film) in the bottom gate type TFT 20 as in the example of FIG. 2A. It is formed between 22 and the substrate 10 (see FIG. 4A). Further, in the top gate type TFT 20 as in the example of FIG. 2B, the gate electrode 23 is formed on the upper side (on the gate insulating film 22) of the first conductor film 26a and the second conductor film 25a (see FIG. 4B). .. The gate electrode 23 is formed so as to overlap the facing portions (all of the facing portions in the example of FIG. 3A) between the first portions 26a1 to 26a4 and the second portions 25a1 to 25a4.

The gate electrode 23 has a range of length Wa of the first portions 26a1 to 26a4 which are a part of the first conductor film 26a and the second portions 25a1 to 25a4 which are a part of the second conductor film 25a and which face each other. It is formed all over. Therefore, channels are formed from the first portions 26a1 to 26a4 and the tips of the second portions 25a1 to 25a4 between the second portions 25a1 to 25a4 or the first portions 26a1 to 26a4 facing each other in the Y direction. Further, in the example of FIG. 3A, the gate electrode 23 is a portion between the tip of the first portion 26a1 to 26a4 and the second conductive film 25 facing in the direction orthogonal to the Y direction (X direction in FIG. 3A). The tips of the second portions 25a1 to 25a4 are formed so as to overlap the portions between the second portions 25a1 to 25a4 and the first conductive film 26 facing each other in the X direction. Therefore, the channel is formed in the entire region 21c between the first conductor film 26a and the second conductor film 25a, and the region 21c serving as this channel has a zigzag shape. Therefore, for example, by effectively using the limited region exactly shown in FIG. 3A, a channel having a long channel width (W), that is, a channel capable of passing a large current can be formed.

In the region 21c serving as a channel, the first portions 26a1 to 26a4 of the first conductor film 26a and the second portions 25a1 to 25a4 of the second conductor film 25a are alternately arranged in a predetermined direction (Y direction in FIG. 3A). Therefore, there are a plurality of them in the Y direction. Specifically, in the semiconductor layer 21, a region sandwiched between the second portion 25a1 and the first portion 26a1, a region sandwiched between the first portion 26a1 and the second portion 25a2, and a second portion. It exists in a region sandwiched between 25a2 and the first portion 26a2, and the like. In an example such as FIG. 3A, the channel region 21c is an integral (continuous) region having a zigzag shape, and the channel formed in the channel region 21c has a W / L ratio of 50 or more. It is preferable to have. However, at the tip portions of the first portion 26a1 to 26a4 and the second portion 25a1 to 25a4, the channel length changes at the corner portion.

Therefore, the channel width (W) used in the calculation of the W / L ratio is a part (first portion 26a1 to) of the first conductor film 26a in each of the regions 21c in which a plurality of (for example, n) channels exist in the Y direction. It is preferable that the sum (Wa × n) of the lengths Wa of any of 26a4) and a part of the second conductor film 25a (any of the second portions 25a1 to 25a4) facing each other. Then, the channel width (W = Wa × n) and the first conductor film 26a and the second conductor film 25a in the portion where a part of the first conductor film 26a and a part of the second conductor film 25a face each other. The ratio (W / L) to the interval (channel length L) is preferably 50 or more. By providing the first conductor film 26a and the second conductor film 25a in this way, the tip of a part of the first conductor film 26a or a part of the second conductor film 25a and the tip of each of the second conductor film 25a or the first conductor film 25a are provided. Even if the channel width with and from 26a is ignored, a preferable W / L ratio can be surely obtained. The length Wa is a portion of both conductor films facing each other in a direction (Y direction) orthogonal to a part of the first conductor film 26a and a part of the second conductor film 25a alternately arranged (Y direction). Is the length of. Further, the total length Wa is the sum of the length Wa for all the regions 21c which are a plurality of channels existing in the Y direction, as indicated by Wa × n.

The W / L ratio of the channel of the TFT 20 is preferably as large as possible from the viewpoint of driving ability, but it may be preferable that the ratio is not larger than necessary from the viewpoint of the size of the thin film transistor 20. For example, as described above, since the electron mobility of amorphous silicon is about 1/200 of the electron mobility of LTPS, it is composed of LTPS even when the same driving ability as that of the current semiconductor layer made of LTPS is obtained. It suffices to have a W / L ratio that is 200 times the W / L ratio of the channel (for example, about 2.5). Therefore, the total length Wa of a part of the first conductor film 26a and a part of the second conductor film 25a facing each other in the region 21c to be a channel, and the first conductor film 26a and the second conductor The ratio (W / L) with the distance L from the film 25a is preferably 50 or more and 500 or less.

Also in the example of FIG. 3B, the first conductor film 26a and the second conductor film 25a are each formed in a planar shape and in a comb shape. In the example of FIG. 3B, the length Wc of the comb tooth portion (first portion 26a1 to 26a3) of the first conductor film 26a and the comb tooth portion (second portion 25a1 to 25a3) of the second conductor film 25a is the comb tooth portion. It is longer than the length Lc of the connecting portion that connects the two. Further, in FIG. 3B, the light emitting region 43a of the organic light emitting element 40 (see FIG. 2A) is shown by a two-dot chain line, and the light emitting region 43a is formed in a rectangular shape. The opposite portions of the first portions 26a1 to 26a3, which are a part of the first conductor film 26a, and the second portions 25a1 to 25a3, which are a part of the second conductor film 25a, are the long sides of the rectangular shape of the light emitting region 43a. It is formed along.

By forming the facing portions of the first conductor film 26a and the second conductor film 25a as shown in the example of FIG. 3B, the length of the facing portion included in the channel width (W) in the calculation of the W / L ratio described above. Wa can be lengthened. Further, between the tip of a part of the first conductor film 26a or a part of the second conductor film 25a and the tip of each of the second conductor film 25a or the first conductor film 26a, which are not included in the calculation of the W / L ratio. The number of parts can be reduced. It is considered that the easily calculateable current allowance of the channel can be brought close to the actual current allowance, and therefore the TFT 20 can be appropriately designed. The example of FIG. 3B is considered to be suitable when the TFT 20 is formed so as to fit within a pixel that occupies most of the light emitting region 43a having a rectangular shape.

FIG. 3C shows still other examples of the first conductor film 26a and the second conductor film 25a. In the example of FIG. 3C, the first conductor film 26a is formed so as to have a zigzag planar shape in which the first portions 26a1 to 26a6, which are a part thereof, are alternately connected at different ends. The second conductor film 25a is formed around the first conductor film 26a, and the second portions 25a1 to 25a6, which are a part thereof, are formed in the zigzag planar recesses of the first conductor film 26a, respectively. It has been inserted. Unlike the example of FIG. 3C, the second conductor film 25a may be formed in a zigzag planar shape, and a part of the first conductor film 26a may be inserted into a recess in the planar shape of the second conductor film 25a. As illustrated in FIG. 3C, the first conductor film 26a and the second conductor film 25a do not necessarily have to be formed in a comb-teeth shape as in the examples of FIGS. 3A and 3B. Further, the number of the first portion of the first conductor film 26a and the second portion of the second conductor film 25a is not limited to the examples of FIGS. 3A to 3C, and any number of the first portion and the second portion are provided. Can be. Except for the planar shapes of the first and second conductor films 26a and 25a, the TFT 20 shown in FIGS. 3B and 3C is the same as the TFT 20 shown in FIG. 3A, and redundant description is omitted.

4A and 4B are cross-sectional views taken along a cutting line parallel to the X direction through the first portion 26a1 of the first conductor film 26a shown in FIG. 3A. In addition, in FIGS. 4A and 4B, unlike the example of FIG. 3A, the width of the gate electrode 23 is shorter than the length Wa of the portion of the gate electrode 23 facing the part of the first conductor film 26a and the part of the second conductor film 25a. This is an example provided in. FIG. 4A is an example in which the TFT 20 is a bottom gate type, and FIG. 4B is an example in which the TFT 20 is a top gate type. That is, in FIGS. 4A and 4B, the gate electrode 23, the gate insulating film 22, the semiconductor layer 21, and the first conductor film 26a, which are laminated on the substrate 10 via the base coat layer 11, are in the reverse order of each other. It is laminated which is formed by. In both FIGS. 4A and 4B, the tip of the first portion 26a1 of the first conductor film 26a and the second conductor film 25a are separated by a distance Lx. The distance Lx is, for example, the first conductor facing each other along the direction in which a part of the first conductor film 26a and a part of the second conductor film 25a are alternately arranged (Y direction shown in FIG. 3A). It is substantially equal to the distance between the film 26a and the second conductor film 25a.

The components other than the TFT 20 in the organic EL display device 1 will be described again with reference to FIGS. 2A to 2C. The flattening film 30 is laminated on the first inorganic insulating film 31 laminated on the drive circuit 2, the organic insulating film 32 laminated on the first inorganic insulating film 31, and the organic insulating film 32. It also contains a second inorganic insulating film 33. The surface of the flattening film 30 facing in the opposite direction to the drive circuit 2 (the surface of the second inorganic insulating film 33 facing in the opposite direction to the organic insulating film 32) has an arithmetic mean roughness of 50 nm or less. That is, in the organic EL display device 1 of the present embodiment, the surface of the substrate 10 having irregularities is covered with the flattening film 30 by forming the drive circuit 2, and the surface is set to 50 nm or less in arithmetic average roughness (Ra). ing. For example, the flattening film 30 can have an arithmetic mean roughness of 50 nm or less by polishing after laminating each insulating film.

As described above, as a result of investigating the cause of display unevenness in the organic EL display device, the present inventors have found that the surface of the organic light emitting layer in the organic light emitting element is not a completely flat surface but contains fine irregularities, and is microscopic. I found that there is a part that is tilted. When the surface of the organic light emitting layer is tilted, its normal direction is tilted with respect to the normal direction of the display surface in the organic EL display device, and the light emitted obliquely from such an organic light emitting layer is emitted. It becomes difficult to recognize from the front of the display surface. Therefore, the brightness is lowered or the chromaticity is changed, which is determined by the light intensity of each of the R, G, and B colors.

Conventionally, as a countermeasure against display unevenness, for example, a circuit for compensating for variation in the characteristics of the TFT and / or OLED has been added to each drive circuit provided for each pixel. However, such measures do not effectively function as measures against display unevenness found by the present inventors, but rather may increase the unevenness of the surface of the substrate due to the increase in the components of the drive circuit. It was. In addition, the current flowing through each organic light emitting element may be controlled based on the brightness distribution grasped in the inspection process of the organic EL display device. However, these measures have increased the cost and size as the number of components of the drive circuit increases, the manufacturing process of the organic EL display device becomes complicated, and complicated control is required. ..

On the other hand, in the present embodiment, as described above, the surface of the flattening film 30 has an arithmetic mean roughness of 50 nm or less in order to eliminate the newly found cause of display unevenness. Further, the organic light emitting layer 43 is formed so as to avoid directly above the contact hole 30a described later. By doing so, it is possible to obtain a display image with extremely little display unevenness. The smaller the surface roughness of the flattening film 30, the more preferable it is, but it is not always necessary to obtain the arithmetic mean roughness of, for example, less than 20 nm, which is the target in the polishing process of the semiconductor process. That is, from the viewpoint of suppressing display unevenness of the organic EL display device 1, the surface of the flattening film 30 may have an arithmetic mean roughness of 50 nm or less, and in that case, display unevenness that can be perceived by humans is almost present. The present inventors have found that it does not occur. It was also found that an arithmetic mean roughness of 20 nm or more is preferable in terms of ease of realization. That is, the surface of the flattening film 30 having an arithmetic mean roughness of 20 nm or more and 50 nm or less is compatible with effective suppression of display unevenness that may affect display quality and simple production. Is preferable.

A glass substrate, a polyimide film, or the like is mainly used for the substrate 10. When the organic EL display device 1 is a bottom emission type (BE type) unlike the examples of FIGS. 2A to 2C, a translucent material, that is, a glass substrate, a transparent polyimide film, or the like is used. A base coat layer 11 is formed as a barrier film on the surface of the substrate 10 on which the TFT 20 is formed. For example, by a plasma CVD method, mainly basecoat having a lower layer consisting of SiN _X film of about 500nm thickness of about SiO ₂ film and the 50nm thick and a top layer mainly consisting of SiO ₂ film of about 250nm thick Layer 11 is formed.

A drive circuit 2 including a TFT 20 is formed on the base coat layer 11. The cathode wiring 27 is also formed on the base coat layer 11. Although omitted in FIG. 2A and the like, wirings for scanning lines and data lines are also formed in the same manner as the cathode wiring 27. Further, in FIG. 2A and the like, only the TFT 20 that drives the light emitting element 40 is shown, but the switching TFT 2a described above is also formed on the base coat layer 11, and other TFTs may be formed. When the organic EL display device 1 is of the TE type as in the example of FIG. 2A, the drive circuit 2 can be formed over the entire surface below the light emitting region of the organic light emitting element 40. On the other hand, in the BE type, since the TFT 20 or the like cannot be formed below the light emitting region of the organic light emitting element 40, the TFT 20 or the like is formed on the peripheral edge of the portion that overlaps the light emitting region in a plane. However, even in this case, a flattening film 30 having a flatness on the surface thereof that does not cause display unevenness is required.

The gate insulating film 22 of the TFT 20 is mainly composed of SiO ₂ or the like having a thickness of about 50 nm, and the gate electrode 23 is formed by patterning or the like after film formation of a film such as Mo having a thickness of about 250 nm.

TFT20 and the first inorganic insulating film 31 made of 200nm thickness of about SiN _X as a barrier layer is formed on the surface of the driving circuit 2 including, an organic insulating film 32 is formed on the first inorganic insulating film 31 Further, a second inorganic insulating film 33 is formed. The flattening film 30 is formed with contact holes 30a that collectively penetrate the first inorganic insulating film 31, the organic insulating film 32, and the second inorganic insulating film 33. As will be described later, a metal such as indium tin oxide (ITO) and silver (Ag) or APC (silver + palladium + copper) is embedded in the contact hole 30a, and the drive circuit 2 passes through the metal. And the organic light emitting element 40 are connected.

The organic insulating film 32 has a thickness of, for example, 1 μm or more and 2 μm or less. The organic insulating film 32 significantly reduces the unevenness of the surface of the substrate 10 due to the formation of the drive circuit 2. The organic insulating film 32 is formed by using, for example, a polyimide resin or an acrylic resin. Further, the organic insulating film 32 contains 0.5% by mass or more and 5.0% by mass or less of an additive (leveling improving agent) for improving the flatness of the surface of the organic insulating film 32 facing the second inorganic insulating film 33. It is preferable that the content is contained. Examples of such leveling improvers include silicone-based, hydrocarbon-based, and fluorine-based surfactants. Further, the organic insulating film 32 may be formed by using a photosensitive resin, but since the photopolymerization initiator may weaken the effect of the leveling improver or the like, the organic insulating film 32 is photopolymerized. It is preferable to use a material that does not contain a photoconductor such as an initiator.

Acrylic resin is preferable as a material for the organic insulating film 32 because it has high purity, is well compatible with surfactants and the like, and has high flatness. On the other hand, when the manufacturing process of the organic EL display device 1 includes a high temperature process of 200 ° C. or higher, a polyimide resin having high heat resistance is preferable. Therefore, the organic insulating film 32 is preferably an acrylic resin that does not contain a photopolymer such as a photopolymerization initiator, or a polyimide resin that does not contain a photopolymer.

As described above, the second inorganic insulating film 33 has an arithmetic mean roughness of 50 nm or less on the surface facing the opposite direction to the organic insulating film 32, and therefore display unevenness of the organic EL display device 1 is suppressed. .. The second inorganic insulating film 33 is formed of, for example, SiN _X or SiO _{2 , but SiN X} is preferable from the viewpoint of moisture blocking property. That is, the second inorganic insulating layer 33 enhances the barrier performance against moisture in the flattening film 30.

The second inorganic insulating film 33 may have a moisture blocking action not only when the organic EL display device 1 is used but also when it is manufactured. That is, as will be described later, the surface of the flattening film 30 may be polished in the manufacturing process so as to have a surface roughness of 50 nm or less, and after polishing, cleaning may be performed to remove the abrasive and the like. .. When the second inorganic insulating film 33 is not formed, the surface of the organic insulating film 32 is polished and further exposed to a cleaning agent. In that case, this cleaning agent may permeate into the organic insulating film 32 and remain as it is, causing deterioration of the TFT 20 and the like. However, the formation of the second inorganic insulating film 33 prevents the permeation of the cleaning agent into the organic insulating film 32 and the deterioration of the TFT 20.

The second inorganic insulating film 33 is formed to have a thickness of, for example, 100 nm or more and 600 nm or less. However, the thickness of the second inorganic insulating film 33 varies based on the unevenness of the surface of the organic insulating film 32 facing the second inorganic insulating film 33. The second inorganic insulating layer 33 has, for example, 3 of the maximum height difference DT in the surface irregularities of the organic insulating film 32 so that the irregularities on the surface of the organic insulating film 32 can be sufficiently embedded in the second inorganic insulating layer 33. It is preferably formed to be at least twice as thick. Then, if necessary, it is preferable to polish the surface of the second inorganic insulating film 33 by a length (thickness) of not more than the maximum height difference DT and less than twice the maximum height difference DT. By doing so, the convex portion of the surface of the second inorganic insulating film 33 based on the convex portion of the surface of the organic insulating film 32 can be scraped off without exposing the organic insulating film 32, and the surface of the flattening film 30 is omitted. The arithmetic mean roughness of 50 nm or less can be surely obtained. In that case, the second inorganic insulating film 33 may have a thickness of 1 time or more and 3 times or less of the maximum height difference DT of the unevenness of the surface on the entire surface of the organic insulating film 32. For example, in FIG. 2A, the maximum thickness TL of the second inorganic insulating film 33 is twice or more and three times or less the maximum height difference DT of the unevenness of the organic insulating film 32, and is the minimum of the second inorganic insulating film 33. The thickness TM of the organic insulating film 32 is 1 times or more and 2 times or less of the maximum height difference DT of the unevenness of the organic insulating film 32. In particular, in the example of FIG. 2A, the maximum thickness TL of the second inorganic insulating film 33 is approximately twice the maximum height difference DT of the unevenness of the organic insulating film 32, and the minimum thickness TM is the organic insulating film. It is substantially the same as the maximum height difference DT of 32 irregularities.

The first electrode 41 of the organic light emitting element 40 is integrally formed with the metal embedded in the contact hole 30a. That is, for example, ITO and a metal such as Ag or APC and ITO are embedded in the contact hole 30a by sputtering or the like, and the same ITO film, a metal film such as Ag or APC, and an ITO film are also formed on the surface of the flattening film 30. Are formed respectively. The first electrode 41 is formed by patterning them into a predetermined shape. However, as described above, the formation region of the organic light emitting layer 43 is set so as to avoid directly above the contact hole 30a. The first electrode 41 preferably has a work function of about 5 eV in relation to the organic light emitting layer 43, and in the case of the top emission type, ITO and Ag or APC as described above are used. The ITO film is formed to a thickness of about 10 nm, and the Ag or APC film is formed to a thickness of about 100 nm. In the case of the bottom emission type, for example, only an ITO film having a thickness of about 300 nm to 1 μm is formed. The flattening film 30 is also formed with contact holes 30b for forming the cathode contact 44a, and the contact holes 30b also collectively penetrate each insulating film constituting the flattening film 30.

If the contact hole 30a is not completely filled by ITO or the like, a recess as shown in FIG. 2A or the like may occur in the portion of the surface of the first electrode 41 directly above the contact hole 30a. However, in the example of FIG. 2A and the like, the first electrode 41 has a region that does not overlap with the contact hole 30a in a plan view with a size sufficient for forming the organic light emitting layer 43, and the region does not overlap with the contact hole 30a. An organic light emitting layer 43 is formed on the top. Therefore, unevenness in the thickness of the organic light emitting layer 43 and dents on the surface thereof are unlikely to occur, and display unevenness due to the contact hole 30a is unlikely to occur.

An insulating bank 42 is formed on the peripheral edge of the first electrode 41 to partition each pixel and insulate between the first electrode 41 and the second electrode 44. In the example of FIG. 2A and the like, the recess on the surface of the first electrode 41 is covered by the insulating bank 42. The organic light emitting layer 43 is laminated on the first electrode 41 surrounded by the insulating bank 42. The organic light emitting layer 43, which is a light emitting region of the organic light emitting element 40, is preferably formed in a region that does not overlap with the contact hole 30a in a plan view, as in the example of FIG. 2A. In that case, as described above, display unevenness due to the contact hole 30a is unlikely to occur. Although the organic light emitting layer 43 is shown as a single layer in FIG. 1 and the like, the organic light emitting layer 43 is formed by a plurality of organic layers by laminating various materials. The organic light emitting layer 43 is formed by vapor deposition, printing, or the like in which an evaporated or sublimated organic material is selectively attached only to a necessary portion by a mask.

For example, as a layer in contact with the first electrode 41, a hole injection layer made of a material having good ionization energy consistency that improves hole injection is provided. On the hole injection layer, for example, an amine-based material is formed to improve the stable transport of holes and to confine electrons (energy barrier) to the light emitting layer. Further, a light emitting layer selected according to the emission wavelength is formed on the light emitting layer. For example, for red and green, Alq ₃ is doped with a red or green organic fluorescent material. Further, as the blue-based material, a DSA-based organic material is used. Further, on the light emitting layer, an electron transporting layer that improves electron injection and stably transports electrons can be formed by _{Alq 3 or the like.} A laminated film of the organic light emitting layer 43 is formed by laminating each of these layers by about several tens of nm. An electron injection layer for improving the electron injection property such as LiF or Liq may be provided between the organic light emitting layer 43 and the second electrode 44.

The second electrode 44 is formed on the organic light emitting layer 43. In the example of FIGS. 2A to 2C, the second electrode 44 is continuously formed so as to be common over all the pixels, and is connected to the cathode wiring 27 via the cathode contact 44a formed on the flattening film 30. Has been done. The second electrode 44 is formed of a translucent material, for example, a thin Mg-Ag film. A material having a small work function is preferable for the second electrode 44, and an alkali metal, an alkaline earth metal, or the like can be used. Mg is preferable because it has a small work function of 3.6 eV, and Ag having a small work function of about 4.25 eV is co-deposited at a ratio of about 10% by mass in order to impart stability. In the BE type, since the second electrode 44 serves as a reflector, Al is formed thickly as the second electrode 44.

A coating layer (TFE) 46 is formed on the second electrode 44 to prevent moisture from reaching the second electrode 44. Coating layer 46 is, for example SiN _X, an inorganic insulating film such as SiO _2, is formed by depositing single layer, or two or more layers of laminated film. For example, a two-layer laminated film having a thickness of about 0.1 μm to 0.5 μm is formed as the coating layer 46. The coating layer 46 is preferably formed in multiple layers with different materials so that a sufficient barrier property against moisture or the like can be obtained even if pinholes or the like are formed in one layer. The coating layer 46 is formed so as to completely cover the organic light emitting layer 43 and the second electrode 44. The coating layer 46 may include an organic insulating film between the two inorganic insulating films.

[Manufacturing method of organic EL display device]
Next, taking the organic EL display device 1 shown in FIG. 2A as an example, the manufacturing method of the organic EL display device of one embodiment refers to the flowcharts of FIGS. 5A and 5B and the cross-sectional views shown in FIGS. 6A to 6G. In addition, FIG. 3A will be described with reference to the appropriate reference.

As shown in FIG. 6A, a drive circuit 2 including the thin film transistor 20 is formed on the substrate 10 (S1 in FIG. 5A).

When the organic EL display device 1 shown in FIG. 2A is manufactured, the base coat layer 11 is formed on the surface of the substrate 10 by using, for example, a plasma CVD method. Although the base coat layer 11 is indicated by single-layer structure in FIG. 6A, for example, 500nm thickness of about SiO ₂ layer, SiN _X layer of about 50nm thick thereon, further about 250nm thick is formed thereon It is formed by laminating _two layers of SiO.

After that, the gate electrode 23 is formed by forming a metal film such as Mo by sputtering or the like and patterning it (S11 in FIG. 5B). Preferably, the cathode wiring 27 and other wirings (not shown) for scanning lines and data lines are formed together with the gate electrode 23. For example, as shown in FIG. 3A referred to above, in a predetermined direction (Y direction in the example of FIG. 3A) in which a part of the first conductor film 26a and a part of the second conductor film 25a are alternately arranged. An extending gate electrode 23 is formed.

A gate insulating film 22 is formed on the gate electrode 23 (S12 in FIG. 5B). The gate insulating film 22 is formed by depositing, for example, about 50nm using plasma CVD to a thickness of SiO ₂ film or SiN _X film. Further, a semiconductor layer 21 made of amorphous silicon is formed on the gate insulating film 22 so as to cover the gate electrode 23 by using, for example, a plasma CVD method (S13 in FIG. 5B). The semiconductor layer 21 is dehydrogenated by, for example, annealing at a temperature of about 350 ° C. for about 45 minutes. The semiconductor layer 21 is patterned into a desired shape by dry etching or the like. As described above, when the gate electrode 23 extends in a predetermined direction in which a part of the first conductor film 26a and a part of the second conductor film 25a are alternately arranged, the gate electrode 23 is used to cover the entire gate electrode 23. A semiconductor layer 21 extending along a predetermined direction is formed.

After that, preferably, the second semiconductor layer 211 having a high impurity concentration is formed on the semiconductor layer 21 in the region where the first conductor film 26a or the second conductor film 25a is formed later (S14 in FIG. 5B). That is, interposing the second semiconductor layer 211 having a high impurity concentration between the semiconductor layer 21 and the first conductor film 26a and the second conductor film 25a causes the semiconductor layer 21, the drain electrode 26, and the source electrode 25 to interpose. It is preferable in terms of lowering the contact resistance. The second semiconductor layer 211 may be formed by laminating a semiconductor layer having a higher impurity concentration than the semiconductor layer 21 on the semiconductor layer 21, and by doping a predetermined region of the semiconductor layer 21 with impurities. It may be formed. Examples of impurities include phosphorus and arsenic when the TFT 20 is an Nch field effect transistor, and boron and aluminum when the TFT 20 is a Pch field effect transistor.

A first conductor film 26a forming the drain electrode 26 and a second conductor film 25a forming the source electrode 25 are formed on the semiconductor layer 21 (or the second semiconductor layer 211) and the gate insulating film 22 (S15 in FIG. 5B). ). For example, a titanium film or an aluminum film having a diameter of several hundred nm or a laminated film thereof is formed by using sputtering, and the formed metal film is separated into a first conductor film 26a and a second conductor film 25a by dry etching or the like. At the same time, unnecessary parts are removed. As a result, a plurality of first portions (four first portions 26a1 in the example of FIG. 3A) extending along a direction intersecting a predetermined direction (for example, the Y direction shown in FIG. 3A) (for example, the X direction in FIG. 3A). A first conductor film 26a having ~ 26a4) is formed. At the same time, a second conductor film 25a having a plurality of second portions (four second portions 25a1 to 25a4 in the example of FIG. 3A) extending along a direction intersecting the predetermined direction (Y direction in FIG. 3A) It is formed. The first conductor film 26a and the second conductor film 25a are formed so that a plurality of first portions and a plurality of second portions are alternately arranged along a predetermined direction (Y direction in FIG. 3A). To. As a result, the TFT 20 is formed on the substrate 10. As shown in FIG. 6A, the TFT 20 includes a gate electrode 23, a gate insulating film 22, a semiconductor layer 21, a first conductor film 26a constituting the drain electrode 26, and a second conductor film 25a constituting the source electrode 25. It is formed in a laminated structure with. Further, as illustrated in FIG. 3A, the first conductor film 26 and the second conductor film 25 are formed so that a part thereof is alternately arranged along a predetermined direction. The semiconductor layer 21 includes a region 21c serving as a channel, which is a region sandwiched between a part of the first conductor film 26a and a part of the second conductor film 25a.

The first conductor film 26a and the second conductor film 25a may be formed so as to have a comb-shaped shape as a planar shape as in the example of FIG. 3A. The first and second conductor films 25a and 26a are the comb tooth portions of the first conductor film 26a (first portions 26a1 to 26a4 in the example of FIG. 3A) and the comb tooth portions of the second conductor film 25a (FIG. 3A). The second portions 25a1 to 25a4) of the above example may be formed so as to mesh with each other.

When the top gate type TFT 20 illustrated in FIG. 2B is formed, a method substantially similar to the formation of the bottom gate type TFT 20 illustrated in FIG. 2A is used, but the procedure is substantially the reverse of the procedure. Each component is formed by. That is, first, a plurality of first portions extending along a direction (for example, the X direction in FIG. 3A) intersecting a predetermined direction (for example, the Y direction shown in FIG. 3A) on the substrate 10 (four in the example of FIG. 3A). A first conductor film 26a having two first portions 26a1 to 26a4) is formed. Further, along with the formation of the first conductor film 26a, a plurality of second portions extending along a direction intersecting a predetermined direction (Y direction in FIG. 3A) (four second portions 25a1 to 25a4 in the example of FIG. 3A). The second conductor film 25a having the above is formed. The first conductor film 26a and the second conductor film 25a are formed so that a plurality of first portions and a plurality of second portions are alternately arranged along a predetermined direction (Y direction in FIG. 3A). To.

After that, the amorphous silicon semiconductor layer 21 is formed on the first conductor film 26a and the second conductor film 25a. Preferably, a semiconductor layer 21 extending along a predetermined direction in which a plurality of first portions of the first conductor film 26a and a plurality of second portions of the second conductor film 25a are alternately arranged is formed. Then, the gate insulating film 22 is formed on the semiconductor layer 21, and the portion where the first portion of the first conductor film 26a and the second portion of the second conductor film 25a face each other is covered on the gate insulating film 22. The gate electrode 23 is formed so as to do so. Preferably, a gate electrode 23 extending along a predetermined direction in which a plurality of first portions of the first conductor film 26a and a plurality of second portions of the second conductor film 25a are alternately arranged is formed.

When the top gate type TFT 20 illustrated in FIG. 2C is formed, the semiconductor layer 21, the gate insulating film 22, the gate electrode 23, the interlayer insulating film 24, and the drain electrode 26 (the first) are formed on the substrate 10. The 1 conductor film 26a) and the source electrode 25 (second conductor film 25a) are formed in this order. The semiconductor layer 21 is irradiated with an excimer laser, and the annealing converts amorphous silicon into polysilicon (LTPS). Further, the region of the semiconductor layer 21 that should be the source 21s and the drain 21d is doped with impurity ions. Contact holes 24a are formed in the interlayer insulating film 24 and the gate insulating film 22 by dry etching or the like, and metal is embedded when the drain electrode 26 and the source electrode 25 are formed.

After that, as shown in FIG. 6B, the first inorganic insulating film 31, the organic insulating film 32, and the second inorganic insulating film 33 are formed on the surface of the drive circuit 2 (see FIG. 6A) (S2 in FIG. 5A). The first inorganic insulating film 31 is formed, for example, by forming a film such as SiN _X or SiO ₂ of about 200nm thickness by the plasma CVD method. The organic insulating film 32 is formed by applying a liquid or low-viscosity paste-like resin. Examples of the coating method include a slit coating, a spin coating, and a slit and spin coating method in which both are combined. The organic insulating film 32 is formed to have a thickness of about 1 μm or more and 2 μm or less. As the material of the organic insulating film 32, for example, a polyimide resin or an acrylic resin can be used. A non-photosensitive resin that does not contain a photosensitizer is preferable because it has high purity and high surface smoothness of the organic insulating film 32. Acrylic resin is particularly preferable.

The second inorganic insulating film 33 is formed by the same manner as the first inorganic insulating film 31 is deposited a film made of SiN _X or SiO ₂ for example by using a plasma CVD. By forming the second inorganic insulating film 33, it is possible to prevent the permeation of various solvents such as a cleaning agent that can be used in the subsequent process into the organic insulating film 32 and the resulting deterioration of the TFT 20.

The second inorganic insulating film 33 is preferably formed to a thickness selected based on the maximum height difference DT of the unevenness on the surface of the organic insulating film 32. For example, the second inorganic insulating film 33 is formed to have a thickness more than twice the maximum height difference DT in the unevenness of the surface of the organic insulating film 32 facing the second inorganic insulating film 33. By doing so, the dent on the surface of the organic insulating film 32 can be reliably embedded in a part of the second inorganic insulating film 33. Further, it is more preferable that the second inorganic insulating layer 33 is formed to have a thickness of 2 times or more and 3 times or less the maximum height difference DT of the unevenness on the surface of the organic insulating film 32. By doing so, the dent of the organic insulating film 32 can be surely filled as described above. Further, without making the second inorganic insulating film 33 thicker than necessary, the unevenness based on the unevenness of the surface of the organic insulating film 32 that may appear on the surface of the second inorganic insulating film 33 after the film is formed is ensured in the polishing step described later. Moreover, it is possible to substantially reliably prevent the organic insulating film 32 from being exposed after polishing.

Next, as shown in FIG. 6C, the surface of the second inorganic insulating film 33 is polished (S3 in FIG. 5A). As described above, the present inventors have found that if the surface of the flattening film 30 that is the base of the organic light emitting element 40 (see FIG. 2A) is not sufficiently flat, display unevenness may occur in the organic EL display device. Was done. Therefore, the surface of the second inorganic insulating film 33, which is the surface of the flattening film 30, is polished. The surface of the second inorganic insulating film 33 is preferably polished so as to have an arithmetic mean roughness of 50 nm or less. By polishing to such a surface roughness, and further, by forming the organic light emitting layer 43 so as to avoid directly above the contact hole 30a as described later, display unevenness as described above is perceived by humans. Can be prevented from occurring. Further, in flattening the surface of the flattening film 30, the arithmetic mean roughness as targeted in the semiconductor process is not always required. Rather, in order to avoid complicated and time-consuming polishing steps including surface roughness inspection, the surface of the second inorganic insulating film 33 may be polished to an arithmetic mean roughness of 20 nm or more and 50 nm or less. preferable.

In the polishing of the surface of the second inorganic insulating film 33, for example, the polishing amount (the amount of decrease in the thickness of the second inorganic insulating film 33 due to polishing) is at least partially the surface of the organic insulating film 32. Polishing is performed so that the maximum height difference DT of the unevenness in the above is 1 times or more and less than 2 times. By doing so, when the second inorganic insulating layer 33 is formed to have a thickness of twice or more the maximum height difference DT of the unevenness of the organic insulating film 32 as described above, it is based on the unevenness of the organic insulating film 32. The unevenness that may appear on the surface of the second inorganic insulating film 33 after the film formation can be reliably leveled, and the exposure of the organic insulating film 32 due to polishing can be substantially prevented. For example, in the example of FIG. 6C, the polishing amount P1 in the region that was a convex portion on the surface of the second inorganic insulating film 33 after film formation (for example, the region where the TFT 20 is formed) is uneven on the surface of the organic insulating film 32. The maximum height difference of DT is approximately twice. Further, in the example of FIG. 6C, the polishing amount P2 in the region that was a concave portion on the surface of the second inorganic insulating film 33 after the film formation (for example, the region where the TFT 20 is not formed) is the maximum of the unevenness of the organic insulating film 32. Although it is substantially the same as the height difference DT, it is slightly less than the amount.

The method of polishing the second inorganic insulating film 33 is not particularly limited. However, in order to achieve an arithmetic mean roughness of 50 nm or less, it is preferable to polish by CMP polishing using a neutral slurry containing cerium, colloidal silica, or fumed silica as an abrasive. In the case of CMP polishing, for example, the effect of mechanical polishing can be increased by the surface chemical action of the abrasive, and a smooth polished surface can be quickly obtained. Cerium has a high hardness, and its oxide, ceria (CeO ₂ ), chemically reacts with glass, so that it can be an effective abrasive for the second inorganic insulating film 33 formed of _{SiO 2 or the like. Colloidal silica is a colloid of SiO 2} or its hydrate, which usually has a particle size of 10 nm to 300 nm, and fumed silica (also called dry silica or highly dispersed silica) is a spherical shape having a particle size of 10 nm to 30 nm. The SiO ₂ particles of the above are aggregated (particle size 100 nm to 400 nm), and all of them function effectively as a polishing agent.

Further, for polishing the second inorganic insulating film 33, an aqueous solution of a neutral water-soluble alcohol or potassium hydroxide is used together with the above-mentioned abrasive. In particular, when the substrate 10 is made of a polyimide resin, it is preferable to polish the surface of the second inorganic insulating film 33 with a neutral alcohol solution together with the above-mentioned abrasive from the viewpoint of preventing corrosion of the substrate 10.

As shown in FIG. 6D, a contact hole 30a reaching the drive circuit 2 (see FIG. 6A) is formed in the second inorganic insulating film 33, the organic insulating film 32, and the first inorganic insulating film 31 (S4 in FIG. 5A). ). Preferably, a contact hole 30a that penetrates these three insulating films at once is formed. The contact holes 30a are preferably formed in a region where the organic light emitting layer 43 should be formed in the formation of the organic light emitting layer 43 (see FIG. 6F) described later and a region where the organic light emitting layer 43 does not overlap in the thickness direction of the substrate 10. By doing so, the occurrence of display unevenness can be prevented as described above. The contact holes 30a are formed, for example, by forming a resist mask and then dry etching. When the contact hole 30a is formed, the contact hole 30b for the cathode contact 44a (see FIG. 2A) is also formed in the portion of the flattening film 30 above the cathode wiring 27.

As shown in FIG. 6E, the metal is embedded in the contact hole 30a, and the first electrode 41 of the organic light emitting element 40 (see FIG. 2A) is formed in a predetermined region (S5 in FIG. 5A). Specifically, for example, by using sputtering or the like, an ITO film having a thickness of about 10 nm, an lower layer in which an Ag film or an APC film having a thickness of about 100 nm are laminated, and an upper layer mainly composed of an ITO film having a thickness of about 10 nm are formed. To. As a result, the metal is embedded in the contact hole 30a, and the ITO film, the Ag film or the APC film, and the laminated film of the ITO film are formed on the surface of the flattening film 30. After that, the first electrode 41 is formed by patterning the laminated film. This laminated film is preferably patterned so that the first electrode 41 has a region that does not overlap the contact hole 30a in a plan view and is sufficiently large for the formation of the organic light emitting layer 43, as shown in FIG. 6E. To. When the metal is embedded in the contact hole 30a, the contact hole 30b is embedded with at least an ITO film and an Ag film or an APC film to form a cathode contact 44a.

As shown in FIG. 6F, the organic light emitting layer 43 is formed on the first electrode 41 (S6 in FIG. 5A). Specifically, the insulating bank 42 is formed on the peripheral edge of the first electrode 41. The insulating bank 42 _{may be an inorganic insulating film such as SiO 2} or an organic insulating film such as polyimide or acrylic resin. For example, these insulating films are formed on the entire surfaces of the flattening film 30 and the first electrode 41, and the patterning thereof exposes a predetermined region of the first electrode 41. Preferably, the region of the first electrode 41 that does not overlap with the contact hole 30a in the thickness direction of the substrate 10 is exposed. The insulation bank 42 is formed at a height of about 1 μm. As described above, various organic materials are laminated in the formation of the organic light emitting layer 43. Lamination of the organic material is performed, for example, by vacuum deposition, in which case the organic material is deposited via a vapor deposition mask having openings corresponding to the desired pixels such as R, G, B. A layer such as LiF may be formed on the surface of the organic light emitting layer 43 to improve the electron injection property. The organic light emitting layer 43 may be formed by printing using an inkjet method or the like instead of vapor deposition.

As shown in FIG. 6G, the second electrode 44 is formed on the organic light emitting layer 43 (S7 in FIG. 5A). The second electrode 44 is formed by forming a thin Mg-Ag eutectic film, for example, by co-depositing. The second electrode 44 is also formed on the cathode contact 44a and is connected to the cathode wiring 27 via the cathode contact 44a. The Mg-Ag eutectic film contains, for example, Mg in an amount of about 90% by mass and Ag in an amount of about 10% by mass. The second electrode 44 is formed to have a thickness of, for example, about 10 to 20 nm.

A coating layer 46 (see FIG. 2A) that protects the second electrode 44 and the organic light emitting layer 43 from moisture, oxygen, or the like is formed on the second electrode 44. Coating layer 46 is formed by depositing an inorganic insulating film such as SiO ₂ or SiN _X using a plasma CVD method. The coating layer 46 is preferably formed so that its end is in close contact with an inorganic film such as the second inorganic insulating film 33. This is because the inorganic films are bonded to each other with good adhesion. By doing so, it is possible to more reliably prevent the ingress of moisture and the like. By going through the above steps, the organic EL display device 1 shown in FIG. 2A can be manufactured.

[Summary]
(1) The organic EL display device according to the first embodiment of the present invention flattens a substrate having a surface on which a drive circuit including a thin film transistor is formed, and flattens the surface of the substrate by covering the drive circuit. The surface of the flattening film comprises an organic light emitting element formed on a surface of the flattening film facing in the direction opposite to the drive circuit and electrically connected to the drive circuit. It has an arithmetic average roughness of 50 nm or less, and the thin film transistor includes a gate electrode, a drain electrode, a source electrode, and a region serving as a channel of the thin film transistor, and partially overlaps the source electrode and the drain electrode. A part of the first conductor film forming the drain electrode and the second conductor film forming the source electrode are alternately arranged along a predetermined direction, and the channel and the channel have the same semiconductor layer. The region is sandwiched between the part of the first conductor film and the part of the second conductor film.

According to the configuration of (1), in the organic EL display device, the capacity of the drive circuit can be enhanced by a structure capable of realizing cost reduction, and display unevenness can be reduced.

(2) In the organic EL display device of the above (1), there are a plurality of regions serving as the channel sandwiched between a part of the first conductor film and a part of the second conductor film, and the semiconductor layer is formed. The sum of the plurality of lengths of the part of the first conductor film and the part of the second conductor film facing each other in the region formed of amorphous silicon is W, and the opposite parts are opposed to each other. When the distance between the first conductor film and the second conductor film in the portion is L, the W / L may be 50 or more and 500 or less. In that case, a drive circuit having a high current drive capability can be formed.

(3) In the organic EL display device according to (1) or (2), the first conductor film and the second conductor film are formed in a planar shape and a comb shape, respectively, and the first conductor film and the second conductor film are formed. The comb-tooth portions of each of the second conductor films may be formed so as to mesh with each other. In that case, many facing portions of a part of the first conductor film and a part of the second conductor film can be efficiently formed.

(4) In the organic EL display device according to any one of (1) to (3) above, the light emitting region of the organic light emitting element is formed in a rectangular shape, and the thin film transistor is formed in the lower layer of the light emitting region. , The part of the first conductor film and the part of the second conductor film facing each other may be formed along the long side of the rectangular shape. In that case, it is possible to obtain a TFT having a long channel width and having characteristics close to a design value that fits in a rectangular light emitting region or a pixel.

(5) In the organic EL display device according to any one of (1) to (4), the gate electrode is a portion of the first conductor film and the part of the second conductor film facing each other. It may be formed over the entire length range of. In that case, it is possible to obtain a TFT having a long channel width including the total length of the opposite portions of the first conductor film and the second conductor film.

(6) In the organic EL display device according to any one of (1) to (5), the flattening film is formed on the first inorganic insulating film and the first inorganic insulating film laminated on the drive circuit. The surface of the second inorganic insulating film, which includes the organic insulating film laminated in the above and the second inorganic insulating film laminated on the organic insulating film and faces in the opposite direction to the organic insulating film, is 20 nm or more. It may have a surface roughness of 50 nm or less. In that case, it is easy to achieve both effective suppression of display unevenness that may affect display quality and simple manufacturing.

(7) In the organic EL display device of the above (6), the thickness of the second inorganic insulating film varies based on the unevenness of the surface of the organic insulating film facing the second inorganic insulating film, and is described above. It may be 1 times or more and 3 times or less of the maximum height difference of the unevenness on the entire surface of the organic insulating film. In that case, the unevenness of the surface of the organic insulating film can be leveled on the surface of the flattening film without exposing the organic insulating film.

(8) The method for manufacturing the organic EL display device according to the second embodiment of the present invention includes a step of forming a drive circuit including a thin film transistor on a substrate, and a first inorganic insulating film and organic insulation on the surface of the drive circuit. The step of forming the film and the second inorganic insulating film, the step of polishing the surface of the second inorganic insulating film, the second inorganic insulating film, the organic insulating film, the first inorganic insulating film, and the thin film transistor. A step of forming a contact hole to reach, a step of embedding a metal in the contact hole and forming a first electrode in a predetermined region, a step of forming an organic light emitting layer on the first electrode, and the above-mentioned The thin film transistor includes a step of forming a second electrode on the organic light emitting layer, the thin film transistor includes a gate electrode, a gate insulating film, a semiconductor layer including a region to be a channel, and a first conductor film constituting a drain electrode. The first conductor film and the second conductor film are formed in a laminated structure with the second conductor film constituting the source electrode, and a part of each of the first conductor film and the second conductor film is formed so as to be alternately arranged along a predetermined direction. The region serving as the channel is sandwiched between the part of the first conductor film and the part of the second conductor film.

According to the configuration of (8), it is possible to appropriately manufacture an organic EL display device having a drive circuit having excellent drive capability and having less display unevenness.

(9) In the method for manufacturing an organic EL display device according to (8), the thin film transistor is formed by forming a gate electrode extending along a predetermined direction on a substrate and gate insulating on the gate electrode. A step of forming a film, a step of forming an amorphous silicon semiconductor layer extending along the predetermined direction on the gate insulating film so as to cover the gate electrode, and a direction intersecting the predetermined direction. The first portion of the first conductor film having a plurality of first portions extending along the above and the second conductor film having a plurality of second portions extending along a direction intersecting the predetermined direction. And the step of forming the second portion so as to be alternately arranged along the predetermined direction may be included. By doing so, a TFT having a bottom gate structure (inverted stagger structure) can be formed.

(10) In the method for manufacturing an organic EL display device according to (8), the first conductor having a plurality of first portions in which the formation of the thin film transistor extends along a direction intersecting the predetermined direction on the substrate. The first portion and the second portion of the second conductor film having a film and a plurality of second portions extending along a direction intersecting the predetermined direction are alternately arranged along the predetermined direction. A step of forming the semiconductor layer so as to be arranged, a step of forming an amorphous silicon semiconductor layer extending along the predetermined direction on the first conductor film and the second conductor film, and a gate on the semiconductor layer. A step of forming an insulating film and a step of forming a gate electrode extending along a predetermined direction on the gate insulating film so as to cover a portion where the first portion and the second portion face each other. And may be included. By doing so, a TFT having a top gate structure (stagger structure) can be formed.

(11) In the method for manufacturing an organic EL display device according to any one of (8) to (10), the first conductor film and the second conductor film are formed in a comb shape, respectively, and the first conductor film is formed. And the comb-tooth portions of each of the second conductor films may be formed so as to mesh with each other. By doing so, it is possible to efficiently form many facing portions of a part of the first conductor film and a part of the second conductor film.

(12) In the method for manufacturing an organic EL display device according to any one of (8) to (11) above, a second having a high impurity concentration between the semiconductor layer and the first conductor film and the second conductor film. A semiconductor layer may be interposed. By doing so, the contact resistance between the semiconductor layer and the drain electrode and the source electrode can be lowered.

(13) In the method for manufacturing the organic EL display device according to any one of (8) to (12) above, in the formation of the second inorganic insulating film, the maximum height difference in the unevenness of the surface of the organic insulating film is twice or more. The second inorganic insulating film is formed to the thickness of the above, and in polishing the surface of the second inorganic insulating film, the amount of decrease in the thickness of the second inorganic insulating film due to the polishing is at least partially the maximum height. The second inorganic insulating film may be polished so as to be 1 times or more and less than 2 times the difference. By doing so, it is possible to reliably even out the irregularities that may appear on the surface of the second inorganic insulating film after film formation based on the irregularities of the organic insulating film, and moreover, the exposure of the organic insulating film by polishing is almost certain. It can be prevented.

1 Organic EL display device 2 Drive circuit 3 Organic EL display panel 10 Substrate 20 Thin film transistor (drive TFT, TFT)
21 Semiconductor layer 21c Region to be channel 22 Gate insulating film 23 Gate electrode 25 Source electrode 25a Second conductor film 25a 1 to 25a 6 Second part (comb tooth part)
26 Drain electrode 26a First conductor film 26a1 to 26a6 First part (comb tooth part)
30 Flattening film 30a, 30b Contact hole 31 First inorganic insulating film 32 Organic insulating film 33 Second inorganic insulating film 40 Organic light emitting element (OLED)
41 First electrode 43 Organic light emitting layer 44 Second electrode

Claims (6)

A substrate having a surface on which a drive circuit including a thin film transistor is formed for each pixel,
A flattening film that flattens the surface of the substrate by covering the drive circuit,
A top emission type organic light emitting element formed for each pixel on the surface of the flattening film facing in the direction opposite to the drive circuit and electrically connected to the drive circuit.
With
The surface of the flattening film has an arithmetic mean roughness of 50 nm or less.
The thin film transistor has a gate electrode, a drain electrode, a source electrode, and a semiconductor layer that includes a region to be a channel of the thin film transistor and is partially overlapped with the source electrode and the drain electrode.
A part of each of the first conductor film constituting the drain electrode and the second conductor film constituting the source electrode are alternately arranged along a predetermined direction.
A plurality of regions serving as the channels are provided, and each of them is sandwiched between the part of the first conductor film and the part of the second conductor film.
Each of the thin film transistors is formed below the light emitting region of each of the organic light emitting elements so as to cover the entire surface of the light emitting region.
The semiconductor layer is made of amorphous silicon.
The sum of the plurality of lengths of the part of the first conductor film and the part of the second conductor film facing each other in the region to be the channel is W, and the first in the facing part. An organic EL display device having a W / L of 50 or more and 500 or less, where L is the distance between the conductor film and the second conductor film. The light emitting region of the organic light emitting element is formed in a rectangular shape, and the thin film transistor is formed in the lower layer of the light emitting region.
The part of the first conductor film and the part of the second conductor film facing each other are formed along the long side of the rectangular shape.
The length of the part of the first conductor film along the long side is longer than the length of the connecting portion connecting the plurality of parts of the first conductor film, and the length of the second part along the long side is longer. The organic EL display device according to claim 1, wherein the length of the part of the conductor film is longer than the length of the connecting part connecting the plurality of parts of the second conductor film. One of the first conductor film and the second conductor film has a zigzag planar shape by connecting a plurality of the portions of the first conductor film to each other at their respective ends.
The other of the first conductor film and the second conductor film is formed around the one.
The organic EL display device according to claim 1, wherein the other part is inserted into the zigzag planar recess. The flattening film is a first inorganic insulating film laminated on the drive circuit, an organic insulating film laminated on the first inorganic insulating film, and a first laminated on the organic insulating film. 2 Contains an inorganic insulating film
The claim that the organic insulating film contains an additive for improving the flatness of the surface of the organic insulating film facing the second inorganic insulating film at a content of 0.5% by mass or more and 5% by mass or less. The organic EL display device according to any one of 1 to 3. The flattening film is a first inorganic insulating film laminated on the drive circuit, an organic insulating film laminated on the first inorganic insulating film, and a first laminated on the organic insulating film. 2 Contains an inorganic insulating film
The thickness of the second inorganic insulating film varies based on the unevenness of the surface of the organic insulating film facing the second inorganic insulating film.
The maximum thickness of the second inorganic insulating film is two times or more and three times or less the maximum height difference of the unevenness of the organic insulating film, and the minimum thickness of the second inorganic insulating film is the organic insulation. The organic EL display device according to any one of claims 1 to 4, wherein the maximum height difference of the unevenness of the film is 1 times or more and 2 times or less. A process of forming a drive circuit including a thin film transistor on a substrate for each pixel,
A step of forming a first inorganic insulating film, an organic insulating film and a second inorganic insulating film on the surface of the drive circuit, and
The step of polishing the surface of the second inorganic insulating film and
A step of forming contact holes reaching the thin film transistor in the second inorganic insulating film, the organic insulating film, and the first inorganic insulating film.
With a metal is buried in the interior of the contact hole, and forming a first electrode for each of the pixels in a predetermined area, and forming an organic light-emitting layer on the first electrode, on the organic light-emitting layer The process of forming a top-emission type organic light-emitting element by forming a second electrode on the surface, and
Including
The thin film transistor has a laminated structure of a gate electrode, a gate insulating film, a semiconductor layer including a region formed of amorphous silicon and a channel, a first conductor film constituting a drain electrode, and a second conductor film constituting a source electrode. Formed in
Each of the thin film transistors is formed so as to cover the entire surface of the light emitting region below the light emitting region in which each of the organic light emitting layers is formed.
The first conductor film and the second conductor film are formed so that a part thereof is alternately arranged along a predetermined direction.
A plurality of regions serving as the channels are provided, and each of them is sandwiched between the part of the first conductor film and the part of the second conductor film.
The sum of the plurality of lengths of the part of the first conductor film and the part of the second conductor film facing each other in the region to be the channel is W, and the first in the facing part. A method for manufacturing an organic EL display device, wherein the W / L is 50 or more and 500 or less, where L is the distance between the conductor film and the second conductor film.

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