Display device and manufacturing method for the same

Abstract

To provide a display device with less defects and deterioration suppressed, and a manufacturing method for the display device.SOLUTION: A display device includes a substrate, a display unit provided on the substrate and including a plurality of pixels each including a transistor with an oxide semiconductor layer, a first wire electrically connected to the pixels, a terminal electrically connected to the first wire, and a second wire formed of an oxide conductive layer with the same composition as the oxide semiconductor layer, having a cross-sectional surface along an outer edge of the substrate, and electrically connected to the terminal. The oxide semiconductor layer includes a channel region, and a source region and a drain region with the channel region therebetween. The oxide conductive layer can contain the same impurity element as the source region and the drain region.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] One embodiment of the present invention relates to a display device and a method for manufacturing the display device.

Background Art

[0002] A display device using an element utilizing organic electroluminescence (EL) or a liquid crystal element in a display area has, for example, a configuration in which a display unit and a plurality of terminals are provided on a substrate. The plurality of terminals are electrically connected to pixels in the display area, and various signals (for example, an image signal or a control signal) or a power supply potential are input thereto. During the manufacture of the display device, in order to prevent electrostatic breakdown of electronic components, a short-circuit wiring (short ring) for short-circuiting the plurality of terminals may be provided (for example, Patent Document 1). The short ring is removed from the display device before product shipment.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventional short-circuit wirings have used polysilicon or metal to which impurities are added. The short-circuit wiring using polysilicon has a problem that the wiring resistance becomes high and it is difficult to inspect the electrical characteristics in the manufacturing process of the display device. In addition, although the short ring using metal has a low wiring resistance, there is a problem that the cross-sectional area of the wiring is exposed due to cutting before product shipment, and the cross-sectional area of the wiring is likely to come into contact with moisture or the like and corrosion occurs.

[0005] One embodiment of the present invention has been made in view of the above problems, and one of the problems is to provide a display device with few defects and suppressed deterioration. Another embodiment of the present invention aims to provide a method for manufacturing the above display device.

Means for Solving the Problems

[0006] The display device according to one embodiment of the present invention includes a substrate, a display unit composed of a plurality of pixels each including a transistor having an oxide semiconductor layer provided on the substrate, a first wiring electrically connected to the plurality of pixels, a terminal electrically connected to the first wiring, an oxide conductive layer having the same composition as the oxide semiconductor layer, having a cross-sectional view along the outer edge of the substrate, and a second wiring electrically connected to the terminal.

[0007] The manufacturing method of the display device according to one embodiment of the present invention includes forming an oxide semiconductor layer of a transistor provided on each of a plurality of pixels constituting a display unit on a substrate, and a first wiring which is an oxide conductive layer having the same composition as the oxide semiconductor layer, forming a first insulating layer on the oxide semiconductor layer and the first wiring, forming a gate electrode of the transistor and a second wiring electrically connected to the first wiring on the first insulating layer, forming a second insulating layer on the gate electrode and the second wiring, forming a plurality of first openings reaching the first wiring and second openings reaching the second wiring in the second insulating layer, forming a third wiring electrically connected to the second wiring on the second insulating layer and in the plurality of first openings and the plurality of second openings, forming a third insulating layer on the third wiring, forming an inspection pad and a terminal electrically connected to the second wiring on the third insulating layer, and cutting the substrate so that the first wiring is divided.

[0008] A method for manufacturing a display device according to an embodiment of the present invention includes forming gate electrodes of transistors respectively provided for a first wiring and a plurality of pixels constituting a display unit on a substrate, forming a first insulating layer on the first wiring and the gate electrodes, forming an oxide semiconductor layer of the transistor and an oxide conductive layer having the same composition as the oxide semiconductor layer on the first insulating layer, forming a second wiring electrically connected to the first wiring, forming a plurality of openings reaching the first wiring in the first insulating layer, forming a third wiring on the second wiring and in the plurality of openings, forming a second insulating layer on the third wiring, forming inspection pads and terminals electrically connected to the first wiring on the second insulating layer, and cutting the substrate so that the second wiring is severed.

Brief Description of the Drawings

[0009]

Figure 1

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Figure 2B

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Figure 6E

Figure 6F

Figure 6G

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Figure 6I

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Figure 10A

Figure 10B

Figure 11A

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Figure 12A

Figure 12B

Embodiments for Carrying Out the Invention

[0010] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. The following disclosure is merely an example. Configurations that can be easily conceived by those skilled in the art by appropriately changing the configuration of the embodiment while maintaining the gist of the invention are naturally included in the scope of the present invention. For the sake of clearer explanation, the drawings may schematically represent the width, layer thickness, shape, etc. of each part compared to the actual aspect. However, the illustrated shape is merely an example and does not limit the interpretation of the present invention. In this specification and each figure, elements that are the same as those described above with respect to the previously shown figures may be given the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0011] The "semiconductor device" generally refers to all devices that can function by utilizing semiconductor characteristics. Transistors and semiconductor circuits are one form of semiconductor devices. The semiconductor device of the embodiment shown below may be, for example, a transistor used in a display device, an integrated circuit (IC) such as a microprocessor (Micro-Processing Unit: MPU), or a memory circuit.

[0012] The "display device" refers to a structure that displays an image using an electro-optical layer. For example, the term "display device" may refer to a display panel including an electro-optical layer, or may refer to a structure in which other optical members (for example, a polarizing member, a backlight, a touch panel, etc.) are attached to a display cell. The "electro-optical layer" may include a liquid crystal layer, an electroluminescence (EL) layer, an electrochromic (EC) layer, and an electrophoretic layer as long as there is no technical contradiction. Therefore, for the embodiments described below, a liquid crystal display device including a liquid crystal layer and an organic EL display device including an organic EL layer will be exemplified and described as display devices, but the structure in this embodiment can be applied to display devices including other electro-optical layers described above.

[0013] In each embodiment of the present invention, the direction from the substrate toward the oxide semiconductor layer is referred to as up or upward. Conversely, the direction from the oxide semiconductor layer toward the substrate is referred to as down or downward. Thus, for the sake of convenience in explanation, the terms upward or downward are used for explanation. However, for example, the substrate and the oxide semiconductor layer may be arranged such that their vertical relationship is reversed from that shown in the drawings. In the following description, for example, the expression "an oxide semiconductor layer on a substrate" merely explains the vertical relationship between the substrate and the oxide semiconductor layer as described above, and other members may be arranged between the substrate and the oxide semiconductor layer. Upward or downward means the stacking order in a structure in which a plurality of layers are stacked. When expressing a pixel electrode above a transistor, in a plan view, the transistor and the pixel electrode may have a positional relationship where they do not overlap. On the other hand, when expressing a pixel electrode directly above the transistor in a vertical direction, in a plan view, it means a positional relationship where the transistor and the pixel electrode overlap.

[0014] In this specification, expressions such as "α includes A, B, or C", "α includes any one of A, B, and C", "α includes one selected from the group consisting of A, B, and C" do not exclude the case where α includes a plurality of combinations of A to C unless otherwise specified. Furthermore, these expressions do not exclude the case where α includes other elements.

[0015] <First Embodiment> 1. Configuration of Display Device FIG. 1 shows the configuration of a display device 10 during the manufacturing process according to an embodiment of the present invention. FIG. 1 shows a top view of the display device during the manufacturing process of the display device 10. The display device 10 is a flexible display device formed in a thin shape as a whole. The display device 10 includes a substrate 110, a display unit 120, a driving circuit 130, a plurality of terminals 140, a flexible printed circuit 150, a plurality of wirings 135, and a plurality of wirings 400.

[0016] The substrate 110 is a plastic substrate. In this case, the substrate 110 may be referred to as a base material, a base film, or a sheet base material. Here, the substrate 110 is an organic resin substrate containing resin. The organic resin material constituting the substrate 110 is, for example, polyimide, acrylic, epoxy, or polyethylene terephthalate. The thickness of the substrate 110 is, for example, between 10 μm and several hundred μm.

[0017] The display unit 120, the drive circuit 130, the plurality of terminals 140, the plurality of wirings 142, and the plurality of terminals 140 are provided on the upper surface of the substrate 110, respectively. The display unit 120 displays a still image or a moving image in the display area 100. The drive circuit 130 and the plurality of terminals 140 are provided in a peripheral area along the same side of the display area 100 among the peripheral areas of the display area 100. The drive circuit 130 is provided between the display area 100 and the plurality of terminals 140. The plurality of wirings 142 are wirings electrically connected to the plurality of terminals 140 and are provided between the plurality of terminals 140 and the scan line drive circuit 126 or the drive circuit 130.

[0018] The display unit 120 includes a pair of scan line drive circuits 126 in addition to the display area 100. The display unit 120 includes, in the display area 100, a plurality of scan lines 122 extending in a first direction and a plurality of data signal lines 124 extending in a second direction intersecting the first direction. The pair of scan line drive circuits 126 are provided at positions facing each other with the display area 100 interposed therebetween. The pair of scan line drive circuits 126 are provided in a peripheral area different from the drive circuit 130 and the plurality of terminals 140 among the peripheral areas of the display area 100. The pair of scan line drive circuits 126 select the scan lines 122 electrically connected to themselves in a predetermined order and supply control signals.

[0019] The driving circuit 130 is electrically connected to a plurality of pixels 120A and drives the display unit 120 in order to control the plurality of pixels 120A that display an image. The driving circuit 130 supplies data voltages to a plurality of data signal lines 124 in a predetermined order. The driving circuit 130 may control the scan line driving circuit 126. The driving circuit 130 includes, for example, an integrated circuit such as an ASIC (Application Specific Integrated Circuit). Thus, when the driving circuit 130 includes an integrated circuit such as an ASIC, the driving circuit 130 may be adhered to the substrate 110 using an adhesive. The adhesive includes a resin and a material that cures by ultraviolet rays. The adhesive may include, for example, an ultraviolet (UV) curable film. The UV curable film includes, for example, a polymerizable resin such as an acrylic resin or an epoxy resin.

[0020] Alternatively, the scanning line driving circuit 126 and the driving circuit 130 may not be mounted on the display device 10, and an external driving circuit may be connected to a plurality of terminals 140 that are electrically connected to the plurality of scanning lines 122 and the plurality of data signal lines 124, and the plurality of pixels 120A may be driven by signals supplied from the external driving circuit. An IC (Integrated Circuit) for driving may be used for the external driving circuit.

[0021] The driving IC may be mounted on the substrate 110, for example, by a COF (Chip On Film) using an anisotropic conductive film (ACF: Anisotropic Conductive Film). In this case, for example, a FOG (Film On Glass) on which a wiring board is mounted using an anisotropic conductive film may be used for the terminal 140.

[0022] The pixel 120A is provided corresponding to each intersection of a plurality of scanning lines 122 and a plurality of data signal lines 124. The plurality of pixels 120A are arranged in an array here.

[0023] Here, the pixel circuit 300 for controlling each pixel 120A will be described with reference to FIGS. 2A and 2B. FIG. 2A shows an example of a pixel circuit using a light-emitting element (organic EL element) that utilizes organic electroluminescence in the pixel 120A. Further, FIG. 2B shows an example of a pixel circuit using a liquid crystal element in the pixel 120A.

[0024] FIG. 2A is a diagram showing the configuration of the pixel circuit 300 in the display device 10 according to an embodiment of the present invention. For convenience of explanation, a basic configuration using two semiconductor devices (thin-film transistors) will be exemplified and described. As shown in FIG. 2A, the pixel circuit 300 includes elements such as a driving transistor 301, a selection transistor 302, a holding capacitor 303, and a light-emitting element 304. The driving transistor 301 and the selection transistor 302 are composed of semiconductor devices such as thin-film transistors.

[0025] The source of the driving transistor 301 is connected to the anode power line 305, and the drain of the driving transistor 301 is connected to one end (anode) of the light-emitting element 304. The other end (cathode) of the light-emitting element 304 is connected to the cathode power line 306. In the present embodiment, a power supply voltage higher than that of the cathode power line 306 is applied to the anode power line 305. In FIG. 1, the illustration of the anode power line 305 is omitted.

[0026] The gate of the selection transistor 302 is connected to the scanning line 122, and the source of the selection transistor 302 is connected to the data signal line 124. The drain of the selection transistor 302 is connected to the gate of the driving transistor 301. Note that the source and drain of the selection transistor 302 may be interchanged depending on the relationship between the voltage applied to the data signal line 124 and the voltage stored in the holding capacitor 303.

[0027] The holding capacitor 303 is connected to the gate and drain of the driving transistor 301 and the drain of the selection transistor 302. A gradation signal for determining the emission intensity of the light-emitting element 304 is supplied to the data signal line 124. A scanning signal for selecting a pixel to which the gradation signal is written is supplied to the scanning line 122.

[0028] Next, with reference to FIG. 2B, an example of a pixel circuit using a liquid crystal element in the pixel 120A will be described.

[0029] FIG. 2B is a diagram showing the configuration of the pixel circuit 300 in the display device 10 according to an embodiment of the present invention. As shown in FIG. 2B, the pixel circuit 300 includes elements such as a transistor 307, a holding capacitor 308, and a liquid crystal element 309. The transistor 307 is composed of a semiconductor device such as a thin film transistor.

[0030] The gate of the transistor 307 is connected to the scanning line 122, and the source of the transistor 307 is connected to the data signal line 124. The drain of the transistor 307 is connected to the holding capacitor 308 and the liquid crystal element 309. Although not shown in detail, one electrode of the holding capacitor 308 is connected to the drain of the transistor 307, and the other electrode is connected to the common electrode of the pixel 120A. Also, one electrode of the liquid crystal element 309 is connected to the drain of the transistor 307 via the pixel electrode, and the other electrode is connected to the common electrode. Note that the source and drain of the transistor 307 may be interchanged depending on the relationship between the voltage applied to the data signal line 124 and the voltage stored in the holding capacitor 308.

[0031] Returning to the description of FIG. 1. The plurality of terminals 140 are electrically connected to the flexible printed circuit 150. Each of the plurality of terminals 140 is electrically connected to the display unit 120 or the drive circuit 130. A signal or a power supply potential supplied from the flexible printed circuit 150 is input to the plurality of terminals 140. The signal is a signal for operating the display unit 120, for example, an image signal indicating an image to be displayed in the display area 100, or a control signal for controlling the scan line drive circuit 126 or the drive circuit 130. Note that the number of terminals 140 included in the display device 10 may be any plurality.

[0032] The flexible printed circuit 150 outputs a signal input from an external circuit (not shown) to the plurality of terminals 140. The flexible printed circuit 150 has a configuration in which a plurality of wirings are arranged on a flexible substrate. Each of the plurality of wirings is electrically connected to any one of the terminals 140.

[0033] One end of each of the plurality of wirings 400 is electrically connected to the terminal 140, and the other end is located at the outer edge 102. That is, when the display device 10 is viewed from above, the outer edge 102 and the other ends of the plurality of wirings 400 are at the same position. The manufacturing process of the display device 10 includes a cutting process of cutting the substrate 110 in order to shape the display device 10. The outer edge 102 is the outer edge of the substrate 110 formed by the cutting process.

[0034] Here, referring to FIG. 3, the substrate 110 before performing the cutting process of cutting the substrate 110 will be described.

[0035] 2. Configuration of the display device during manufacturing FIG. 3 is a top view showing the configuration of the display device 10 during manufacturing. The manufacturing method of the display device 10 includes a forming process of forming a plurality of terminals 140 and a plurality of wirings 400 on a substrate 110 disposed on a glass substrate (not shown). The forming process may further form transistors and light-emitting elements included in the display unit 120 on the substrate 110.

[0036] In addition to the display unit 120, as shown in FIG. 3, inspection pads 500, shorting rings 510, etc. can be formed between the display unit 120 and the end of the substrate 110.

[0037] The shorting ring 510 is electrically connected to a drive circuit 130 composed of transistors provided in the display unit 120, a scanning line drive circuit 126, a pixel circuit 300, a scanning line 122, a data signal line 124, etc., and is provided to discharge static electricity generated in the manufacturing process of the display device 10 and suppress the display device 10 from being electrostatically damaged.

[0038] The inspection pad 500 is electrically connected to a drive circuit 130 composed of transistors provided in the display unit 120, a scanning line drive circuit 126, a pixel circuit 300, etc., and can be used for inspection before the display device 10 is shipped.

[0039] Referring to FIG. 4, the wiring 400 constituting the shorting ring 510 and the wiring 400 connecting the inspection pad 500 and the terminal 140 will be described.

[0040] FIG. 4 shows the terminal 140 of the display device and the surrounding configuration during the manufacturing process of the display device 10. The wiring 400 includes the wiring 400 constituting the shorting ring 510, the inspection pad 500, and the wiring 400 connecting the terminal 140. The wiring 400 constituting the shorting ring 510 is configured such that the ends of the wiring 400-1, wiring 400-2, and wiring 400-3 extending from a plurality of terminals 140 are electrically or directly connected to each other and these wirings are short-circuited. In FIG. 4, an example of forming the shorting ring 510 with the wiring 400 extending from three terminals 140 is shown, but the number of the wiring 400 may be plural, and it may be composed of the wiring 400 extending from two terminals 140 or may be composed of the wiring 400 extending from four or more terminals 140.

[0041] The wiring 400 that constitutes the short ring 510, the inspection pad 500, and the wiring 400 that connects the terminal 140 can use the active layer of the transistor provided in the display unit 120, for example, an oxide semiconductor layer, although details will be described later.

[0042] Also, as described above, the wiring 400 that constitutes the short ring 510 forms the short-circuited portion of the wiring using a material such as polysilicon in the process of forming a configuration where electrostatic breakdown is likely to occur in the manufacturing process of the display device 10, and then forms the wiring for connecting the terminal 140 and the short ring 510 in the process of forming the oxide semiconductor layer of the transistor later, thereby forming the short ring 510.

[0043] Furthermore, as shown in FIG. 4, the wiring 400 can be constituted by wiring formed in the same process as the electrodes and the like used in the transistors and elements of the display unit 120. For example, the wirings 400-1 to 3 used for the short ring 510 are each constituted by the wiring 160, the wiring 170, the wiring 180, and the wiring 135, and are short-circuited with each other by the wiring 160. Also, the wiring 400-6 that connects the inspection pad 500-3 and the terminal 140-6 is also constituted by the wiring 160, the wiring 170, the wiring 180, and the wiring 135. At this time, the cut line 110C is provided so as to cut the wiring 400 and is arranged so as to cut the wiring 160 that constitutes the wiring 400.

[0044] The cut line 110C passes between the inspection pad 500 and the short ring 510 and the position where the plurality of wirings 400 are short-circuited. The cutting process of the substrate 110 in the cut line 110C is performed using a laser after the structure provided on the substrate 110 is formed. Therefore, the plurality of wirings 400 are separated from each other, and the inspection pad 500 and the short ring 510 are removed from the display device 10, resulting in the display device 10 shown in FIG. 1.

[0045] Referring to FIG. 5, the details of the wiring 400 that connects the terminal 140 to the inspection pad 500 will be described.

[0046] FIG. 5 is an end view of the terminals of the display device and the surrounding areas thereof during the manufacturing process of the display device 10 according to an embodiment of the present invention. Specifically, FIG. 5 corresponds to an end view showing a cross-section cut along A1 - A2 in FIG. 4.

[0047] The display device during the manufacturing process of the display device 10 has a substrate 110. A base film 112 can be provided on the substrate 110. The base film 112 can prevent contamination from the substrate 110. For example, an inorganic insulating material can be used. As the inorganic insulating material, for example, silicon nitride, silicon oxide, a composite thereof, and a structure in which these are laminated can be used.

[0048] The insulating layer 114 can be provided on the base film 112. In the display area 100, the insulating layer 114 can have the function of the gate insulating layer of the transistors provided in the pixel 120A, the scanning line driving circuit 126, and the driving circuit 130. The same material as the base film 112 can be used for the insulating layer 114. Preferably, a CVD (Chemical Vapor Deposition) film using TEOS (Tetraethoxysilane), which is a deposited film of silicon oxide in particular, is used for the insulating layer 114.

[0049] The wiring 135 can be provided on the insulating layer 114. The wiring 135 is connected to the terminal 140 and is electrically connected to the transistors provided in the display unit 120. For the wiring 135, for example, a material mainly composed of titanium, aluminum, copper, molybdenum, etc. can be used, and these can be used alone or in a laminated manner. When the transistors provided in the display unit 120 have a bottom gate structure or a dual gate structure, the wiring 135 can be formed in the same process as the bottom gate electrode of the transistors.

[0050] An insulating layer 116 can be provided over the wiring 135 and the insulating layer 114 so as to cover the wiring 135 and the insulating layer 114. The insulating layer 116 can also function as a planarization layer for the wiring 172 and the wiring 138. When the transistor provided in the display unit 120 has a bottom gate structure or a dual gate structure, the insulating layer 116 can be formed in the same process as the insulating layer provided between the bottom gate electrode of the transistor and the active layer. The same material and structure as those of the underlayer film 112 can be used for the insulating layer 116.

[0051] The wiring 160 can be provided over the insulating layer 116. The same material as that of the active layer of the transistor provided in the display unit 120 can be used for the wiring 160. Further, the wiring 160 can be formed in the same process as the process in which the active layer of the transistor provided in the display unit 120 is formed. Although details will be described later, an oxide semiconductor layer can be used as the active layer of the transistor, and by reducing the resistance of the oxide semiconductor layer, it can be used for the wiring 160. Therefore, the wiring 160 is an oxide conductive layer having the same composition as the active layer of the transistor provided in the display unit 120.

[0052] As shown in FIG. 4, the wiring 160 is connected to the inspection pad 500-3. For example, it can be connected to a wiring formed in the same layer as the wiring 170 shown in FIG. 5, and the wiring formed in the same layer as the wiring 170 can be connected to the inspection pad 500-3 to be connected to the inspection pad 500-3.

[0053] An insulating layer 118 can be provided over the wiring 160 and the insulating layer 116. When the transistor provided in the display unit 120 has a top gate structure or a dual structure, the insulating layer 118 can be formed in the same process as the process of forming the insulating layer 118 provided between the active layer and the gate electrode of the transistor. The same material and structure as those of the underlayer film 112 can be used for the insulating layer 118.

[0054] The wiring 180 can be provided on the insulating layer 118. The wiring 180 is formed in the insulating layer 118 and the opening 200 reaching the wiring 135 in the insulating layer 118, and can be connected to the wiring 135. For the wiring 180, for example, aluminum (Al), titanium (Ti), chromium (Cr), cobalt (Co), nickel (Ni), molybdenum (Mo), hafnium (Hf), tantalum (Ta), tungsten (W), bismuth (Bi), silver (Ag), copper (Cu), and alloys or compounds thereof can be used. The wiring 180 may be used in a single-layer structure or a laminated structure with the above materials.

[0055] The insulating layer 132 can be provided on the wiring 180 and the insulating layer 118. The insulating layer 132 can use a single-layer or laminated structure. For the insulating layer 132, for example, silicon nitride, silicon oxide, etc. can be used. When a laminated structure is used for the insulating layer 132, it is preferable to use silicon nitride for the film in contact with the wiring 180 and silicon oxide thereon for the insulating layer 132.

[0056] The wiring 170 can be provided on the insulating layer 132. The wiring 170 is formed in the insulating layer 132 and the opening 210 reaching the wiring 160 in the insulating layer 118, and can be connected to the wiring 160. Also, the wiring 170 is formed in the opening 220 reaching the wiring 180 in the insulating layer 132, and can be connected to the wiring 180. Therefore, the wiring 170 can have the function of electrically connecting the wiring 160 and the wiring 180. The wiring 170 can be formed in the same process as the process of forming the source electrode or drain electrode of the transistor provided in the display unit 120. The wiring 170 can be formed using a general metal material. As the metal material, for example, aluminum (Al), titanium (Ti), chromium (Cr), cobalt (Co), nickel (Ni), molybdenum (Mo), hafnium (Hf), tantalum (Ta), tungsten (W), bismuth (Bi), silver (Ag), copper (Cu), and alloys or compounds thereof can be used. The wiring 170 may be a single-layer structure or a laminated structure.

[0057] The insulating layer 134 can be provided on the wiring 170 and the insulating layer 132. For the insulating layer 134, the same material and structure as those of the base film 112 can be used. Also, it is preferable to use silicon nitride for the insulating layer 134.

[0058] The terminal 140 can be provided on the insulating layer 132. As shown in FIG. 5, the terminal 140-6 has a portion exposed from the insulating layer 152, and the exposed portion can be connected to a driving IC such as a COF. Also, although not shown, the terminal 140 is electrically or directly connected to the wiring 135 either at the display unit 120 or between the display unit 120 and the terminal 140. For example, the terminal 140 is connected to a wiring formed in the same layer as the wiring 170, the wiring formed in the same layer as the wiring 170 is connected to a wiring formed in the same layer as the wiring 180, and the wiring formed in the same layer as the wiring 180 is connected to the wiring 135, so that the terminal 140 and the wiring 135 can be electrically connected. For the terminal 140, the material used for the wiring 170 may be used.

[0059] The insulating layer 152 can be provided on the insulating layer 134. The insulating layer 152 can be partially provided on the terminal 140 so that the terminal 140 is partially exposed as described above. The light-emitting element or liquid crystal element provided in the pixel 120A is formed on the insulating layer 152. For the insulating layer 152, a photosensitive organic resin material containing an acrylic resin, polysiloxane, polyimide, polyester, etc. can be used, and it can function as an organic insulating layer.

[0060] The insulating layer 152 is not provided on the cut line 110C, and even when the substrate 110 is cut along the cut line 110C, a cross-sectional surface of the insulating layer 152 is not formed. However, the layers provided below the insulating layer 152 and the substrate 110 are divided along the cut line 110C, and each layer, each film, and the substrate 110 have cross-sectional surfaces respectively. Also, those cross-sectional surfaces are generally flat and aligned without steps in a cross-sectional view.

[0061] Specifically, as shown in FIG. 5, the cross-sections of the base film 112, the insulating layer 114, the insulating layer 116, the insulating layer 118, the wiring 160, the insulating layer 132, and the insulating layer 134 are formed along the cut line 110C. The cross-section along the cut line 110C corresponds to the outer edge 102 of the substrate 110 in plan view. Therefore, the cross-sections of the base film 112, the insulating layer 114, the insulating layer 116, the insulating layer 118, the wiring 160, the insulating layer 132, and the insulating layer 134 have cross-sections along the outer edge 102 of the substrate 110.

[0062] So far, with reference to the end face views of the terminals of the display device and the periphery thereof during the manufacturing process of the display device 10, it has been explained that the manufacturing process is formed together with the manufacturing process of the transistor provided in the display unit 120. Here, referring to FIGS. 6B to 6J, an example of the manufacturing method of the transistor provided in the display unit 120 will be described. FIGS. 6B to 6J are diagrams for explaining the manufacturing method of the display device according to an embodiment of the present invention. The manufacturing method of the transistor shown in FIGS. 6B to 6J relates to, for example, the transistor having a top gate structure shown in FIG. 6A.

[0063] 3. Manufacturing Method of Display Device FIG. 6A is an end face view showing the configuration of a display device according to an embodiment of the present invention. The top gate structure is often adopted for the transistor when an organic EL element is provided in the display device. Therefore, the transistor shown in FIG. 6A is, for example, the driving transistor 301 shown in FIG. 2A.

[0064] As shown in FIG. 6A, the driving transistor 301 includes a base film 112, an insulating layer 114, an oxide semiconductor layer 164, an insulating layer 118, a gate electrode 182, insulating layers 132-1, 132-2, a source electrode 172S, and a drain electrode 172D on the substrate 110.

[0065] Next, the manufacturing method of the driving transistor 301 will be described.

[0066] As shown in FIG. 6B, the base film 112 and the insulating layer 114 are formed on the substrate 110.

[0067] Next, as shown in FIG. 6C, an oxide semiconductor layer 162 is formed over the insulating layer 114. A metal oxide having semiconductor characteristics can be used for the oxide semiconductor layer 162. 。

[0068] S When the oxide semiconductor layer 162 is formed by a patterning method, the oxide semiconductor layer 162 is formed while controlling the temperature of an object to be coated, for example, a substrate 110. In order to control the temperature of the object to be coated, for example, film formation is performed while cooling the object to be coated. For example, the object to be coated may be cooled from the surface opposite to the surface to be coated so that the temperature of the surface to be coated of the object to be coated (hereinafter referred to as "film formation temperature") becomes 100°C or lower, 70°C or lower, 50°C or lower, or 30°C or lower. 。

[0069] Next, as shown in FIG. 6D, a pattern of the oxide semiconductor layer 162 is formed. It is preferable to form a pattern of the oxide semiconductor layer 162 before firing the oxide semiconductor layer 162. 。E Even if the oxide semiconductor layer 162 is damaged by etching, the damage can be repaired by firing the oxide semiconductor layer 162.

[0070] After the pattern of the oxide semiconductor layer 162 is formed, the oxide semiconductor layer 162 is fired. In the firing of the oxide semiconductor layer 162, the oxide semiconductor layer 162 is held at a predetermined reach temperature for a predetermined time. The predetermined reach temperature is 300°C or higher and 500°C or lower, preferably 350°C or higher and 450°C or lower. Further, the holding time at the reach temperature is 15 minutes or longer and 120 minutes or shorter, preferably 30 minutes or longer and 60 minutes or shorter. 。

[0071] Next, as shown in FIG. 6E, an insulating layer 118 is formed over the oxide semiconductor layer 162. It is preferable to use an insulating layer with few defects for the insulating layer 118. In order to form an insulating layer with few defects as the insulating layer 118, the insulating layer 118 may be formed at a film formation temperature of 350° C. or higher. Further, after forming the insulating layer 118, a process of implanting oxygen into a part of the insulating layer 118 may be performed. The insulating layer 118 can function as a gate insulating layer.

[0072] Next, as shown in FIG. 6F, a metal oxide layer 166 mainly composed of aluminum is formed over the insulating layer 118, and after firing, the metal oxide layer 166 is removed.

[0073] Inorganic insulating layers such as aluminum oxide (AlO x ), aluminum oxynitride (AlO x N y ), aluminum nitride oxide (AlN x O y ), and aluminum nitride (AlN x ) are used for the metal oxide layer 166. Here, the ratio of aluminum contained in the metal oxide layer 166 is preferably 1% or more of the entire metal oxide layer 166. Further, the ratio of aluminum contained in the metal oxide layer 166 may be 5% or more and 70% or less, 10% or more and 60% or less, or 30% or more and 50% or less of the entire metal oxide layer 166.

[0074] The film thickness of the metal oxide layer 166 is, for example, preferably 5 nm or more and 100 nm or less, 5 nm or more and 50 nm or less, 5 nm or more and 30 nm or less, or 7 nm or more and 15 nm or less.

[0075] After the metal oxide layer 166 is formed, the metal oxide layer 166 is fired. After firing the metal oxide layer 166, the metal oxide layer 166 is removed. At least the portion of the metal oxide layer 166 that overlaps with the oxide semiconductor layer 164 may be entirely removed.

[0076] Next, as shown in FIG. 6G, a gate electrode 182 is formed over the insulating layer 118. The gate electrode 182 is formed to be in contact with the insulating layer 118 exposed by the removal of the metal oxide layer 166.

[0077] A source region 164S and a drain region 164D of the oxide semiconductor layer 164 are formed. Specifically, impurity elements are implanted into the oxide semiconductor layer 164 through the insulating layer 118 using the gate electrode 182 as a mask by an ion implantation or ion doping method. Impurity elements such as argon (Ar), phosphorus (P), and boron (B) are implanted into a part of the oxide semiconductor layer 164 not covered by the gate electrode 182. By implanting such impurities into a part of the oxide semiconductor layer 164, the resistance of that part is reduced. Specifically, the source region 164S and the drain region 164D sandwiching the channel region 164C of the oxide semiconductor layer 164 shown in FIG. 6H correspond to a part of the oxide semiconductor layer 164 not covered by the gate electrode 182, and impurity elements are implanted. Since the channel region 164C of the oxide semiconductor layer 164 is covered by the gate electrode 182, no impurity elements are implanted.

[0078] Here, the wiring 160 shown in FIG. 5 is also formed in the same process as the active layer of the driving transistor 301. Since there is no portion of the wiring 160 covered by a gate electrode like the driving transistor 301, impurity elements are implanted throughout the wiring 160. Therefore, the wiring 160 has the same composition as the oxide semiconductor layer 164 and has a reduced resistance due to the implantation of impurity elements, and thus becomes an oxide conductive layer. The wiring 160, which is an oxide conductive layer, contains the same impurity elements as the source region 164S and the drain region 164D because impurity elements are implanted in the same manner as the source region 164S and the drain region 164D of the oxide semiconductor layer 164 as described above.

[0079] Next, as shown in FIG. 6I, an insulating layer 132-1 and an insulating layer 132-2 are formed over the gate electrode 182 and the insulating layer 118.

[0080] Next, as shown in FIG. 6J, openings 240 and 250 are formed in the insulating layer 118, the insulating layer 132-1, and the insulating layer 132-2. The source region 164S is exposed by the opening 240, and the drain region 164D is exposed by the opening 250. After the source region 164S and the drain region 164D are exposed by the openings 240 and 250, the source electrode 172S and the drain electrode 172D shown in FIG. 6K are formed.

[0081] Through the above manufacturing process, the driving transistor 301 can be formed.

[0082] Also, when an organic EL element or a liquid crystal element is mounted on the display device 10, the insulating layer 152 shown in FIG. 5 is formed on the insulating layer 134, and the organic EL element or the liquid crystal element is formed. As shown in FIG. 6L, the insulating layer 134 is formed on the insulating layer 132, the source electrode 172S, and the drain electrode 172D. The terminal 140 shown in FIG. 5 is formed on the insulating layer 134.

[0083] Together with each manufacturing process of the above transistor, the wiring 400 and the terminal 140 can be formed.

[0084] 4. Modification Example of Display Device during Manufacturing Referring to FIGS. 7A and 7B, a modification example of the display device during the manufacturing of the display device 10 will be described. FIG. 7A is a top view showing the terminal of the display device and its periphery during the manufacturing of the display device according to an embodiment of the present invention. FIG. 7B is an end view showing the terminal of the display device and its periphery during the manufacturing of the display device according to an embodiment of the present invention. Specifically, FIG. 7B corresponds to an end view showing a cross-section cut along B1 - B2 in FIG. 7A.

[0085] The difference between the display device during the manufacturing process of the display device 10 shown in FIGS. 4 and 5 and the display device is that only the wiring that straddles the cut line 110C uses the wiring 160 which is an oxide conductive layer, and a metal wiring is used for the wiring connecting the wiring 160 and the inspection pad 500. For the components that are the same as or similar to those of the display device 10 shown in FIGS. 1 to 6 or the display device during the manufacturing process, the description may be omitted.

[0086] FIGS. 7A and 7B show the partial structure 600 shown in FIG. 4. As shown in FIGS. 7A and 7B, a wiring 172 and a wiring 137 are provided between the cut line 110C and the inspection pad 500-3. The wiring 172 is connected to the wiring 160 that straddles the cut line 110C through an opening 240. The wiring 184 is connected to the wiring 172 through an opening 250 and is connected to the wiring 137 through an opening 260. The wiring 137 is connected to the inspection pad 500-3.

[0087] The wiring 172 is formed in the same layer as the wiring 170 and is formed in the same manner as the wiring 170. The wiring 184 is formed in the same layer as the wiring 180 and is formed in the same manner as the wiring 180. The wiring 137 is formed in the same layer as the wiring 135 and is formed in the same manner as the wiring 135.

[0088] As shown in FIGS. 7A and 7B, by using a metal wiring on the inspection pad 500 side from the cut line 110C, the wiring resistance of the wiring 400 composed of the above-described wirings can be reduced.

[0089] The display device 10 of the present embodiment can use an oxide conductive layer formed in the same manner as the formation of the source region 164S and the drain region 164D of the oxide semiconductor layer of the transistor for the wiring 160 that connects the short ring 510 and the inspection pad 500 to the terminal 140. The short ring 510 and the inspection pad 500 are removed before the product shipment of the display device 10. Therefore, although the wiring 160 connecting them to the terminal 140 is disconnected, since the oxide conductive layer is used for the wiring 160, corrosion of the cross-section thereof is less likely to occur. Further, by using a metal wiring for the wiring 400 on the inspection pad 500 side from the cut line 110C, the wiring resistance of the wiring 400 becomes lower, and variations in electrical characteristics in the manufacturing process of the display device 10 are further suppressed. Therefore, the present embodiment can provide a display device 10 with few defects and suppressed deterioration.

[0090] <Second Embodiment> Next, with reference to FIGS. 8 to 10, a second embodiment of the present invention will be described.

[0091] 1. Configuration of the display device during manufacturing FIG. 8A is a top view showing the terminal of the display device and its periphery during the manufacturing of the display device according to an embodiment of the present invention. FIG. 8B is an end view showing the terminal of the display device and its periphery during the manufacturing of the display device according to an embodiment of the present invention. Specifically, FIG. 8B corresponds to an end view showing a cross-section cut along C1 - C2 in FIG. 8A.

[0092] The difference from the display device during the manufacturing of the display device 10 shown in FIGS. 4 to 7 is that the transistor provided in the display unit 120 has a bottom gate structure. Note that the description of the same or similar configurations as those of the display device 10 shown in FIGS. 1 to 7 or the display device during the manufacturing of the display device 10 may be omitted.

[0093] FIGS. 8A and 8B show a partial structure 600 of the display device during the manufacturing of the display device 10 on which the liquid crystal element 309 is mounted.

[0094] As shown in FIGS. 8A and 8B, an insulating layer 136 is formed over the insulating layer 114 and over the wiring 135. As shown in FIG. 8B, the insulating layer 116 may partially expose the wiring 135 so as to be directly connected to the terminal 140-6. The insulating layer 116 can be formed in the same process as the insulating layer 116 of the transistor having a bottom gate structure. The same material as that of the insulating layer 118 can be used for the insulating layer 116. Also, the wiring 135 can be formed in the same process as the gate electrode of the transistor provided in the display portion 120.

[0095] The wiring 160 is provided over the insulating layer 116.

[0096] The wiring 170 is formed so as to be in direct contact with the wiring 160. Also, the wiring 170 is formed over the insulating layer 136. An opening 270 reaching the wiring 135 is formed in the insulating layer 116, and the wiring 170 is connected to the wiring 135 through the opening 270. The wiring 174 formed simultaneously with the wiring 170 is formed over the wiring 135 exposed from the insulating layer 116.

[0097] Next, an insulating layer 119 is formed over the wiring 160, the wiring 170, the wiring 174, and the insulating layer 116. The same material as that used for the insulating layer 118 and the insulating layer 132 can be used for the insulating layer 119. The insulating layer 119 may have a single-layer structure or a laminated structure. However, when the insulating layer 119 has a single-layer structure, the insulating layer 119 is preferably made of an inorganic insulating material such as silicon nitride (SiN x ) formed by CVD (Chemical Vapor Deposition). Also, when the insulating layer 119 has a laminated structure, the layer in contact with the wiring 160 is preferably made of an inorganic insulating material such as the above-described silicon nitride (SiN x ). By forming such an insulating layer 119 in direct contact with the wiring 160, the wiring 160 formed with the same composition as the oxide semiconductor layer of the transistor can be made to have a lower resistance and become an oxide conductive layer.

[0098] Next, wiring 178 is formed over wiring 174 and insulating layer 119. Wiring 178 can be formed in the same process as the process for forming the common electrode of liquid crystal element 309. Further, for wiring 178, since a transparent conductive film of a light-transmissive oxide such as indium-tin oxide (ITO), indium-zinc oxide (IZO), zinc oxide (ZnO), or indium tin zinc oxide (ITZO) having conductivity is used, it is possible to suppress corrosion of terminal 140-6 even when wiring 178 is exposed.

[0099] Here, referring to FIGS. 9B to 9H, an example of a method for manufacturing a transistor provided in display section 120 will be described. FIGS. 9B to 9H are diagrams for explaining a method for manufacturing a display device according to an embodiment of the present invention. The method for manufacturing the transistor shown in FIGS. 9B to 9H relates to, for example, transistor 307 having a bottom gate structure shown in FIG. 9A.

[0100] 2. Method for manufacturing a display device FIG. 9A is an end view showing the configuration of a display device according to an embodiment of the present invention. The bottom gate structure is often adopted for a transistor in the case where a liquid crystal element is provided in the display device. Therefore, the transistor shown in FIG. 9A is taken as transistor 307 shown in FIG. 2B as an example.

[0101] As shown in FIG. 9A, transistor 307 includes gate electrode 182, gate insulating layer 136, oxide semiconductor layer 162, source electrode 172S, and drain electrode 172D over insulating layer 114.

[0102] Next, a method for manufacturing transistor 307 will be described.

[0103] As shown in FIG. 9B, gate electrode 182 is formed over insulating layer 114. Gate electrode 182 is patterned as shown in FIG. 9C.

[0104] Next, insulating layer 136 is formed over gate electrode 182 and insulating layer 114.

[0105] Next, as shown in FIGS. 9E and 9F, an oxide semiconductor layer 162 is formed over the insulating layer 136 so as to overlap with the gate electrode 182.

[0106] The source electrode 172S and the drain electrode 172D are formed in contact with the oxide semiconductor layer 162, as shown in FIG. 9G.

[0107] Next, an insulating layer 152 is formed over the oxide semiconductor layer 162, the source electrode 172S, and the drain electrode 172D, and an insulating layer 154 made of a material different from that of the insulating layer 152 formed over the wiring 160 is formed. The insulating layer 154 may have a single-layer structure or a stacked structure. However, the same material as that of the insulating layer 136 may be used for the layer in contact with the oxide semiconductor layer 162.

[0108] 3. Modification Example of Display Device During Manufacturing With reference to FIGS. 10A and 10B, a modification example of the display device during the manufacturing of the display device 10 will be described. FIG. 10A is a top view showing terminals of the display device and the periphery thereof during the manufacturing of the display device according to an embodiment of the present invention. FIG. 10B is an end view showing terminals of the display device and the periphery thereof during the manufacturing of the display device according to an embodiment of the present invention. Specifically, FIG. 10B corresponds to an end view showing a cross section cut along D1 - D2 in FIG. 10A.

[0109] The difference from the display device during the manufacturing of the display device 10 shown in FIGS. 8A and 8B is that the wiring 160, which is an oxide conductive layer, is used only for the wiring straddling the cut line 110C, and a wiring connecting the wiring 160 and the inspection pad 500 uses a metal Line for use. Note that descriptions of configurations the same as or similar to those of the display device 10 shown in FIGS. 1 to 9 or the display device during manufacturing may be omitted.

[0110] Figures 10A and 10B show the partial structure 600 shown in FIG. 4. As shown in FIGS. 10A and 10B, the wiring 172 contacts and connects to the wiring 160 that crosses the cut line 110C. The wiring 137 connects to the wiring 172 and connects to the wiring 137 via the opening 280. Also, the wiring 137 connects to the inspection pad 500-3.

[0111] 4. Modification Example 2 of the Display Device during Manufacturing Referring to FIGS. 11A and 11B, a modification example of the display device during the manufacturing of the display device 10 will be described. FIG. 11A is a top view showing the terminals of the display device and its surroundings during the manufacturing of the display device according to an embodiment of the present invention. FIG. 11B is an end view showing the terminals of the display device and its surroundings during the manufacturing of the display device according to an embodiment of the present invention. Specifically, FIG. 11B corresponds to an end view showing a cross-section cut along E1-E2 in FIG. 11A.

[0112] The difference from the display device during the manufacturing of the display device 10 shown in FIGS. 8A and 8B is that the scanning line driving circuit 126 is not provided, the same material is used for the insulating layer 136 and the insulating layer 152, and the wiring 178 and the wiring 135 are formed in contact with each other. Note that the description of the same or similar configurations as those of the display device 10 shown in FIGS. 1 to 10 or the display device during manufacturing may be omitted.

[0113] Figures 11A and 11B show the partial structure 600 shown in FIG. 4. As shown in FIGS. 11A and 11B, the wiring 178 is formed in contact with the insulating layer 152 and the wiring 135 exposed from the insulating layer 152. Also, the wiring 178 is formed to connect to the wiring 170 via the opening 290 that reaches the wiring 170.

[0114] 5. Modification Example 3 of the Display Device during Manufacturing Referring to FIGS. 12A and 12B, a modified example of the display device during the manufacturing process of the display device 10 will be described. FIG. 12A is a top view showing the terminals of the display device and its surroundings during the manufacturing process of the display device according to an embodiment of the present invention. FIG. 12B is an end view showing the terminals of the display device and its surroundings during the manufacturing process of the display device according to an embodiment of the present invention. Specifically, FIG. 12B corresponds to an end view showing a cross-section cut along F1 - F2 in FIG. 12A.

[0115] The difference between the display device during the manufacturing process of the display device 10 shown in FIGS. 12A and 12B and the previous ones is that only the wiring straddling the cut line 110C uses the wiring 160 which is an oxide conductive layer, and for the wiring connecting the wiring 160 and the inspection pad 500, a wiring made of metal is used. Regarding the configurations that are the same as or similar to the display device 10 shown in FIGS. 1 to 11 or the display device during the manufacturing process, the description may be omitted.

[0116] FIGS. 12A and 12B show the partial structure 600 shown in FIG. 4. As shown in FIGS. 12A and 12B, the wiring 172 is connected to the wiring 160 straddling the cut line 110C. The wiring 179 is connected to the wiring 172 via the opening 292 and is connected to the wiring 137 via the opening 294. The wiring 137 is connected to the inspection pad 500 - 3.

[0117] As long as the embodiments described above as embodiments of the present invention do not conflict with each other, they can be implemented in appropriate combinations. Also, based on each embodiment, those in which those skilled in the art have appropriately added, deleted, or changed the design of components, or added, omitted, or changed the conditions of the process, as long as they have the gist of the present invention, they are included in the scope of the present invention.

[0118] Even if there are other effects different from the effects brought about by the aspects of the above-described embodiments, as long as they are obvious from the description in this specification or can be easily predicted by those skilled in the art, they are naturally considered to be brought about by the present invention.

Explanation of Reference Numerals

[0119] 10: indicating device, 100: indicating area, 102: outer edge, 110: substrate, 110C: cut line, 112: underlayer film, 114: insulating layer, 116: insulating layer, 118: insulating layer, 119: insulating layer, 120: indicating portion, 120A: pixel, 122: scanning line, 124: data signal line, 126: scanning line driving circuit, 130: driving circuit, 132: insulating layer, 132-1: insulating layer, 132-2: insulating layer, 134: insulating layer, 135: wiring, 136: insulating layer, 137: wiring, 138: wiring, 140: terminal, 140-6: terminal, 142: wiring, 150: flexible printed circuit, 152: insulating layer, 154: insulating layer, 160: wiring, 162: oxide semiconductor layer, 164: oxide semiconductor layer, 164C: channel region, 164D: drain region, 164S: source region, 166: metal oxide layer, 170: wiring, 172: wiring, 172D: drain electrode, 172S: source electrode, 174: wiring, 178: wiring, 179: wiring, 180: wiring, 182: gate electrode, 184: wiring, 200: opening, 210: opening, 220: opening, 240: opening, 250: opening, 260: opening, 270: opening, 280: opening, 290: opening, 292: opening, 294: opening, 300: pixel circuit, 301: driving transistor, 302: selection transistor, 303: holding capacitor, 304: light-emitting element, 305: anode power line, 306: cathode power line, 307: transistor, 308: holding capacitor, 309: liquid crystal element, 400: wiring, 400-1: wiring, 400-2: wiring, 400-3: wiring, 400-6: wiring, 500: inspection pad, 500-3: inspection pad, 510: shorting ring, 600: partial structure

Claims

1. A substrate; a display unit including a plurality of pixels each including a transistor having an oxide semiconductor layer, the display unit being provided over the substrate; A first wiring electrically connected to the plurality of pixels; A terminal electrically connected to the first wiring; a second wiring that is an oxide conductive layer having the same composition as the oxide semiconductor layer, has a cut surface along an outer edge of the substrate, and is electrically connected to the terminal; Display device.

2. the oxide semiconductor layer has a channel region and a source region and a drain region sandwiching the channel region; the oxide conductive layer contains the same impurity element as the source region and the drain region; The display device according to claim 1 .

3. a third wiring that electrically connects the second wiring and the first wiring; An insulating layer provided between the second wiring and the third wiring. The display device according to claim 1 .

4. a fourth wiring provided in the same layer as the first wiring; a fifth wiring provided in the same layer as the third wiring and electrically connecting the second wiring and the fourth wiring; The display device according to claim 3 .

5. a sixth wiring electrically connecting the second wiring and the first wiring and directly connecting the second wiring; The display device according to claim 1 .

6. a seventh wiring provided in the same layer as the first wiring; an eighth wiring provided in the same layer as the sixth wiring and electrically connected to the second wiring via the seventh wiring; The display device according to claim 5 .

7. forming an oxide semiconductor layer of a transistor provided in each of a plurality of pixels constituting a display unit on a substrate, and a first wiring which is an oxide conductive layer having the same composition as the oxide semiconductor layer; forming a first insulating layer on the oxide semiconductor layer and the first wiring; forming a gate electrode of the transistor on the first insulating layer and a second wiring electrically connected to the first wiring; forming a second insulating layer on the gate electrode and the second wiring; forming a plurality of first openings in the second insulating layer, the first openings reaching the first wiring and a second opening reaching the second wiring; forming a third wiring electrically connected to the second wiring on the second insulating layer and in the first openings and the second openings; forming a third insulating layer on the third wiring; forming a test pad and a terminal electrically connected to the second wiring on the third insulating layer; cutting the substrate so that the first wiring is disconnected; A method for manufacturing a display device.

8. After the gate electrode is formed, impurities are added to a source region and a drain region sandwiching a channel region of the oxide semiconductor layer and to the first wiring. The method for manufacturing the display device according to claim 7 .

9. the oxide semiconductor layer has a channel region and a source region and a drain region sandwiching the channel region; the oxide conductive layer contains the same impurity element as the impurity contained in the source region and the drain region; The method for manufacturing a display device according to claim 8 .

10. Before forming the oxide semiconductor layer and the first wiring, A fourth wiring is further formed on the substrate; further forming a fourth insulating layer on the fourth wiring; The method for manufacturing the display device according to claim 7 .

11. forming a first wiring and a gate electrode of a transistor provided in each of a plurality of pixels constituting a display unit on a substrate; forming a first insulating layer on the first wiring and the gate electrode; forming an oxide semiconductor layer of the transistor on the first insulating layer, and a second wiring which is an oxide conductive layer having the same composition as the oxide semiconductor layer and is electrically connected to the first wiring; forming a plurality of openings in the first insulating layer reaching the first wiring; forming a third wiring on the second wiring and in the plurality of openings; forming a second insulating layer on the third wiring; forming a test pad and a terminal electrically connected to the first wiring on the second insulating layer; cutting the substrate so that the second wiring is disconnected; A method for manufacturing a display device.

12. forming a fourth wiring in the same layer as the first wiring; forming a fifth wiring electrically connected to the second wiring via the fourth wiring in the same layer as the third wiring; The method for manufacturing the display device according to claim 11 .

13. the second wiring is an oxide conductive layer having the same composition as the oxide semiconductor layer; The method for manufacturing the display device according to claim 11 .

14. The second insulating layer includes silicon nitride and is formed in contact with the second wiring. The method for manufacturing the display device according to claim 13 .

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