Display device and method of manufacturing display device

Abstract

The display device may include a first conductive line disposed on a substrate, a first insulating layer disposed on the substrate having a contact hole that covers the first conductive line and exposes the first conductive line, and a groove having a depth smaller than the depth of the contact hole, a second conductive line disposed in the groove on the first insulating layer and connected to the first conductive line through the contact hole, and a second insulating layer disposed on the first insulating layer and covering the second conductive line.

Description

Technology Field

[0001] The present invention relates to a display device. More specifically, the present invention relates to a display device comprising a conductive line and a method for manufacturing such a display device. Background Technology

[0002] An organic light-emitting display is a self-emissive display device that displays images using an organic light-emitting diode (OLED) that emits light. Such organic light-emitting displays are attracting attention as next-generation display devices because they possess high-quality characteristics such as low power consumption, high brightness, and high response speed. An organic light-emitting diode may include a pixel electrode, a light-emitting layer, and a counter electrode that are sequentially arranged on a substrate.

[0003] Conductive lines that transmit signals, voltage, etc. are arranged at the bottom of an organic light-emitting diode, and a protrusion may be formed on a part of the pixel electrode due to a step difference caused by the conductive lines. In such cases where the pixel electrode is not flat, the protrusion of the pixel electrode may be visible when the organic light-emitting display device is not displaying an image, and color deviation may occur depending on the viewing direction when the organic light-emitting display device displays an image. The problem to be solved

[0004] One objective of the present invention is to provide a display device with improved visibility.

[0005] Another objective of the present invention is to provide a method for manufacturing a display device to improve visibility.

[0006] However, the objectives of the present invention are not limited to such objectives, and may be expanded in various ways without departing from the spirit and scope of the invention. means of solving the problem

[0007] To achieve one objective of the present invention as described above, a display device according to embodiments may include a first conductive line disposed on a substrate, a contact hole disposed on the substrate that covers the first conductive line and exposes the first conductive line, a first insulating layer having a groove that is recessed toward the substrate and has a depth smaller than the depth of the contact hole, a second conductive line disposed in the groove on the first insulating layer and connected to the first conductive line through the contact hole, and a second insulating layer disposed on the first insulating layer that covers the second conductive line.

[0008] In one embodiment, the groove may have a round shape that is recessed in the direction of the substrate.

[0009] In one embodiment, the second conductive wire may have a 'U' shape.

[0010] In one embodiment, the groove may have a square shape that is recessed toward the substrate.

[0011] In one embodiment, the upper surface of the second conductive line may be flat.

[0012] In one embodiment, the maximum depth of the groove may be substantially equal to the thickness of the second conductive wire.

[0013] In one embodiment, the first conductive line extends in a first direction and can transmit a data signal.

[0014] In one embodiment, the second conductive line extends in the first direction and in a second direction intersecting the first direction, and can connect the pad and the first conductive line.

[0015] In one embodiment, the first insulating layer may include at least one of an organic insulating material and an inorganic insulating material.

[0016] In one embodiment, the second insulating layer may include an organic insulating material.

[0017] In one embodiment, the display device may further include a pixel electrode disposed on the second insulating layer and overlapping with the second conductive line, a light-emitting layer disposed on the pixel electrode, and a counter electrode disposed on the light-emitting layer.

[0018] In one embodiment, the pixel electrode may be a reflective electrode, and the counter electrode may be a transmissive electrode.

[0019] To achieve another objective of the present invention as described above, a method for manufacturing a display device according to embodiments may include the steps of: forming a first conductive line on a substrate; forming a first insulating layer covering the first conductive line on the substrate; using a halftone mask to substantially simultaneously form a contact hole exposing the first conductive line in the first insulating layer and a groove recessed toward the substrate and having a depth smaller than the depth of the contact hole; forming a second conductive line filling the contact hole in the groove on the first insulating layer; and forming a second insulating layer covering the second conductive line on the first insulating layer.

[0020] In one embodiment, the first insulating layer may include an organic insulating material.

[0021] In one embodiment, the groove may be formed by isotropically etching the first insulating layer.

[0022] In one embodiment, the groove may have a round shape that is recessed in the direction of the substrate.

[0023] To achieve another objective of the present invention as described above, a method for manufacturing a display device according to embodiments may include the steps of: forming a first conductive line on a substrate; forming a first insulating layer covering the first conductive line on the substrate; forming a contact hole in the first insulating layer that exposes the first conductive line using a first mask; forming a groove in the first insulating layer that is recessed toward the substrate and has a depth smaller than the depth of the contact hole using a second mask; forming a second conductive line that fills the contact hole in the groove on the first insulating layer; and forming a second insulating layer covering the second conductive line on the first insulating layer.

[0024] In one embodiment, the first insulating layer may include at least one of an organic insulating material and an inorganic insulating material.

[0025] In one embodiment, the groove may be formed by anisotropically etching the first insulating layer.

[0026] In one embodiment, the groove may have a square shape that is recessed toward the substrate. Effects of the invention

[0027] In a display device according to embodiments of the present invention, since a second conductive line is disposed in a groove of a first insulating layer that is recessed toward the substrate, the thickness of a protrusion of the second insulating layer may be reduced or a protrusion may not be formed on the second insulating layer, and accordingly, the thickness of a protrusion of a pixel electrode may be reduced or a protrusion may not be formed on the pixel electrode. Accordingly, the visibility of the display device may be improved.

[0028] In a method for manufacturing a display device according to embodiments of the present invention, an additional process for forming a groove can be omitted by substantially simultaneously forming a contact hole and a groove in a first insulating layer using a halftone mask. Additionally, by anisotropically etching the first insulating layer using a second mask, a second conductive line and a second insulating layer having a flat upper surface are formed, and the visibility of the display device can be improved.

[0029] However, the effects of the present invention are not limited to the effects described above and may be extended in various ways without departing from the spirit and scope of the present invention. Brief explanation of the drawing

[0030] FIG. 1 is a plan view showing a display device according to one embodiment of the present invention. FIG. 2 is a plan view showing first conductive lines included in the display device of FIG. 1. FIG. 3 is a plan view showing second conductive lines included in the display device of FIG. 1. FIG. 4 is a plan view showing the second conductive lines of FIG. 3 in detail. FIG. 5 is a plan view showing pixel electrodes included in the display device of FIG. 1. FIG. 6 is a cross-sectional view showing a display device along line II' of FIG. 1. FIG. 7 is a cross-sectional view showing an example of a display device along the line II-II' of FIG. 1. FIGS. 8, FIGS. 9, FIGS. 10, and FIGS. 11 are cross-sectional views illustrating a method of manufacturing the display device of FIG. 7. FIG. 12 is a cross-sectional view showing another example of a display device along the line II-II' of FIG. 1. FIGS. 13, FIGS. 14, FIGS. 15, FIGS. 16, and FIGS. 17 are cross-sectional views illustrating a method of manufacturing the display device of FIG. 12. Specific details for implementing the invention

[0031] Hereinafter, a display device and a method for manufacturing a display device according to embodiments of the present invention will be described in more detail with reference to the attached drawings. Identical or similar reference numerals are used for identical components in the attached drawings.

[0032] FIG. 1 is a plan view showing a display device according to one embodiment of the present invention.

[0033] Referring to FIG. 1, a display device according to one embodiment of the present invention may include a display panel (DP) and a flexible printed circuit board (FPCB). The display panel (DP) may include a display area (DA) and a peripheral area (PA).

[0034] Multiple pixels (PX) may be arranged in the display area (DA). The pixels (PX) may be arranged in a substantial matrix form along a first direction (DR1) and a second direction (DR2) that intersects the first direction (DR1).

[0035] A peripheral area (PA) may be positioned on at least one side of a display area (DA). For example, the peripheral area (PA) may be located in a first direction (DR1) from the display area (DA). A pad portion (PP) may be positioned in the peripheral area (PA). The pad portion (PP) may be positioned in the center of the peripheral area (PA) in a second direction (DR2). In other words, the pad portion (PP) may not be positioned in the periphery of the peripheral area (PA) in a second direction (DR2). Multiple pads may be positioned in the pad portion (PP). A flexible printed circuit board (FPCB) is connected to the pad portion (PP), and signals may be provided to the pads from an external device through the flexible printed circuit board (FPCB).

[0036] FIG. 2 is a plan view showing first conductive lines included in the display device of FIG. 1.

[0037] Referring to FIGS. 1 and 2, a plurality of first conductive lines (110) may be disposed on a substrate (100). The first conductive lines (110) may transmit data signals to pixels (PX). The first conductive lines (110) may extend in a first direction (DR1) and be arranged along a second direction (DR2). The first conductive lines (110) may each be connected to a row of pixels arranged along the second direction (DR2).

[0038] Some of the first conductors (110a) located in the center of the display area (DA) in the second direction (DR2) among the first conductors (110) may be connected to the first pads (PD1). The first pads (PD1) are connected to a flexible printed circuit board (FPCB), and data signals may be applied from the flexible printed circuit board (FPCB) to the first pads (PD1). The first pads (PD1) may be placed on the same layer as the first conductors (110) or on a different layer.

[0039] FIG. 3 is a plan view showing second conductive lines included in the display device of FIG. 1.

[0040] Referring to FIGS. 1, 2, and 3, a first insulating layer (120) covering first conductive lines (110) is disposed on a substrate (100), and a plurality of second conductive lines (130) may be disposed on the first insulating layer (120). The second conductive lines (130) may connect some of the first conductive lines (110b) located in the periphery of the display area (DA) in the second direction (DR2) among the first conductive lines (110) with second pads (PD2). The second pads (PD2) are connected to a flexible printed circuit board (FPCB), and data signals may be applied from the flexible printed circuit board (FPCB) to the second pads (PD2). The second pads (PD2) may be disposed on the same layer as the second conductive lines (130) or on a different layer.

[0041] The second conductive lines (130) may extend in at least two directions to connect some of the first conductive lines (110b) located in the periphery of the display area (DA) in the second direction (DR2) of the first conductive lines (110) with the second pads (PD2). In one embodiment, the second conductive lines (130) may extend in the first direction (DR1) and the second direction (DR2).

[0042] Contact holes (CH1) may be formed in the first insulating layer (120). Some of the first conductive wires (110b) located in the periphery of the marked area (DA) in the second direction (DR2) among the second conductive wires (130) and the first conductive wires (110) may be connected through the contact holes (CH1).

[0043] FIG. 4 is a plan view showing the second conductive lines (130) of FIG. 3 in detail. For example, FIG. 4 may show area A of FIG. 3.

[0044] Referring to FIG. 4, the second conductive lines (130) may include first extensions (EX1) and second extensions (EX2). Each of the first extensions (EX1) extends in a first direction (DR1), and the first extensions (EX1) may be arranged along a second direction (DR2). Each of the second extensions (EX2) extends in a second direction (DR2), and the second extensions (EX2) may be arranged along a first direction (DR1). The first extensions (EX1) and second extensions (EX2) intersecting each other may form a cross shape.

[0045] First extensions (EX1) adjacent to the first direction (DR1) are connected to form a vertical wiring extending in the first direction (DR1), and second extensions (EX2) adjacent to the second direction (DR2) are connected to form a horizontal wiring extending in the second direction (DR2). The vertical wiring and the horizontal wiring can be connected to form a single second conductive line (130).

[0046] As the first extension (EX1) and the second extension (EX2) intersect each other to form a cross shape, and are uniformly arranged along the first direction (DR1) and the second direction (DR2), the visibility of the display device can be prevented or minimized even if the second conductive line (130) is visible when the display device is not displaying an image.

[0047] FIG. 5 is a plan view showing pixel electrodes included in the display device of FIG. 1.

[0048] Referring to FIGS. 1, 3, and 5, a second insulating layer (140) covering second conductive lines (130) is disposed on a first insulating layer (120), and a plurality of pixel electrodes (150) may be disposed in a display area (DA) on the second insulating layer (140). The pixel electrodes (150) may be arranged in a substantial matrix form along a first direction (DR1) and a second direction (DR2). Pixels (PX) may be defined in the area where the pixel electrodes (150) are disposed within the display area (DA).

[0049] FIG. 6 is a cross-sectional view showing a display device along line II' of FIG. 1. Line II' of FIG. 1 may not intersect the first conductive line (110) and the second conductive line (130).

[0050] A buffer layer (101) may be disposed on the substrate (100). The substrate (100) may be an insulating substrate including glass, quartz, plastic, etc.

[0051] The buffer layer (101) can block impurities, such as oxygen and moisture, from diffusing to the upper surface of the substrate (100) through the substrate (100). Additionally, the buffer layer (101) can provide a flat upper surface on the upper surface of the substrate (100). The buffer layer (101) may include an inorganic insulating material such as silicon oxide, silicon nitride, silicon oxynitride, etc. Optionally, the buffer layer (101) may be omitted.

[0052] An active layer (102) may be disposed on the buffer layer (101). The active layer (102) may be formed of amorphous silicon, polycrystalline silicon, oxide semiconductor, etc. The active layer (102) may include a source region, a drain region, and a channel region disposed between the source region and the drain region. The source region and the drain region may be doped with P-type or N-type impurities.

[0053] A gate insulating layer (103) covering an active layer (102) may be disposed on the buffer layer (101). The gate insulating layer (103) may insulate a gate electrode (104b) disposed on the active layer (102) from the active layer (102). The gate insulating layer (103) may include an inorganic insulating material such as silicon oxide, silicon nitride, silicon oxynitride, etc.

[0054] A gate line (104a) and a gate electrode (104b) may be disposed on the gate insulating layer (103). The gate line (104a) may extend in a second direction that intersects the first conductive line. The gate line (104a) may transmit a gate signal to a pixel. The gate electrode (104b) may overlap the channel region of the active layer (102). The gate line (104a) and the gate electrode (104b) may include a conductive material such as molybdenum (Mo), copper (Cu), etc. The active layer (102) and the gate electrode (104b), which include a source region, a drain region, and a channel region, may form a transistor (TR).

[0055] A first interlayer insulating layer (105) covering a gate line (104a) and a gate electrode (104b) may be disposed on the gate insulating layer (103). The first interlayer insulating layer (105) may insulate a capacitor electrode (106) disposed on the gate electrode (104b) from the gate electrode (104b). In one embodiment, the first interlayer insulating layer (105) may include an inorganic insulating material such as silicon oxide, silicon nitride, silicon oxynitride, etc.

[0056] A capacitor electrode (106) may be disposed on the first interlayer insulating layer (105). The capacitor electrode (106) may be superimposed on the gate electrode (104b). The capacitor electrode (106) may include a conductive material such as molybdenum (Mo), copper (Cu), etc. The gate electrode (104b) and the capacitor electrode (106) may form a capacitor (CAP).

[0057] A second interlayer insulating layer (107) covering a capacitor electrode (106) may be disposed on the first interlayer insulating layer (105). The second interlayer insulating layer (107) may insulate a source electrode (108a) and a drain electrode (108b) disposed on the capacitor electrode (106) from the capacitor electrode (106). In one embodiment, the second interlayer insulating layer (107) may include an inorganic insulating material such as silicon oxide, silicon nitride, silicon oxynitride, etc.

[0058] A source electrode (108a) and a drain electrode (108b) may be disposed on the second interlayer insulating layer (107). The source electrode (108a) and the drain electrode (108b) may be connected to the source region and the drain region of the active layer (102), respectively. For example, the source electrode (108a) and the drain electrode (108b) may contact the source region and the drain region of the active layer (102), respectively, through contact holes formed in the gate insulating layer (103), the first interlayer insulating layer (105), and the second interlayer insulating layer (107). The source electrode (108a) and the drain electrode (108b) may include a conductive material such as aluminum (Al), titanium (Ti), copper (Cu), etc.

[0059] A first insulating layer (120) covering a source electrode (108a) and a drain electrode (108b) may be disposed on the second interlayer insulating layer (107).

[0060] A connecting electrode (109) may be disposed on the first insulating layer (120). The connecting electrode (109) may be connected to a drain electrode (108b). For example, the connecting electrode (109) may contact the drain electrode (108b) through a contact hole formed in the first insulating layer (120). The connecting electrode (109) may include a conductive material such as aluminum (Al), titanium (Ti), copper (Cu), etc.

[0061] A second insulating layer (140) covering a connecting electrode (109) may be disposed on the first insulating layer (120).

[0062] A pixel electrode (150) may be disposed on the second insulating layer (140). The pixel electrode (150) may be connected to a connecting electrode (109). For example, the pixel electrode (150) may contact the connecting electrode (109) through a contact hole formed in the second insulating layer (140).

[0063] A pixel defining film (PDL) covering a pixel electrode (150) may be disposed on the second insulating layer (140). The pixel defining film (PDL) may have a pixel opening that exposes at least a portion of the pixel electrode (150). In one embodiment, the pixel opening exposes the central portion of the pixel electrode (150), and the pixel defining film (PDL) may cover the peripheral portion of the pixel electrode (150). The pixel defining film (PDL) may include an organic insulating material such as polyimide (PI).

[0064] A light-emitting layer (160) may be disposed on the pixel electrode (150). The light-emitting layer (160) may be disposed on the pixel electrode (150) exposed by the pixel opening. The light-emitting layer (160) may include at least one of an organic light-emitting material and quantum dots.

[0065] In one embodiment, the organic light-emitting material may include a low molecular weight organic compound or a high molecular weight organic compound. For example, the low molecular weight organic compound may include copper phthalocyanine, N,N'-diphenylbenzidine, tris-(8-hydroxyquinoline)aluminum, etc., and the high molecular weight organic compound may include poly(3,4-ethylenedioxythiophene), polyaniline, polyphenylenevinylene, polyfluorene, etc.

[0066] In one embodiment, the quantum dot may include a core comprising a group II-VI compound, a group III-V compound, a group IV-VI compound, a group IV element, a group IV compound, and combinations thereof. In one embodiment, the quantum dot may have a core-shell structure comprising a core and a shell surrounding the core. The shell may serve as a protective layer to maintain semiconductor properties by preventing chemical degradation of the core, and as a charging layer to impart electrophoretic properties to the quantum dot.

[0067] A counter electrode (170) may be disposed on the light-emitting layer (160). In one embodiment, the counter electrode (170) may also be disposed on the pixel defining film (PDL). The pixel electrode (150), the light-emitting layer (160), and the counter electrode (170) may form a light-emitting element (EL).

[0068] FIG. 7 is a cross-sectional view showing an example of a display device along the line II-II' of FIG. 1. The line II-II' of FIG. 1 may intersect the first conductive line (110) and the second conductive line (130).

[0069] Referring to FIGS. 6 and 7, a first conductive line (110) may be disposed on the second interlayer insulating layer (107). The first conductive line (110) may be disposed on substantially the same layer as the source electrode (108a) and the drain electrode (108b) and may include substantially the same material.

[0070] A first insulating layer (120) covering a first conductive line (110) may be disposed on the second interlayer insulating layer (107). In one embodiment, the first insulating layer (120) may include an organic insulating material. For example, the first insulating layer (120) may include a photosensitive material such as photoresist.

[0071] The first insulating layer (120) may have a contact hole (CH1) and a groove (GR1). The contact hole (CH1) may expose the first conductive wire (110). For example, the contact hole (CH1) may expose a portion of the upper surface of the first conductive wire (110). In this case, the contact hole (CH1) may have a depth (D11) corresponding to the distance from the upper surface of the first conductive wire (110) to the upper surface of the first insulating layer (120).

[0072] The groove (GR1) is recessed toward the substrate (100) and may have a depth smaller than the depth (D11) of the contact hole (CH1). Due to the groove (GR1), the upper surface of the first insulating layer (120) may have a cross-sectional shape that is recessed toward the substrate (100).

[0073] In one embodiment, the groove (GR1) may have a round shape that is recessed toward the substrate (100). The depth of the groove (GR1) may increase from the periphery toward the center of the groove (GR1). In this case, the groove (GR1) may have a maximum depth (D12) at the center.

[0074] A second conductive wire (130) may be disposed in a groove (GR1) on the first insulating layer (120). The second conductive wire (130) may be connected to the first conductive wire (110) through a contact hole (CH1). Accordingly, a data signal may be transmitted from the second conductive wire (130) to the first conductive wire (110).

[0075] The second conductive line (130) may have a 'U' shape in cross-section. The second conductive line (130) is placed in a groove (GR1) on the first insulating layer (120), and the second conductive line (130) may be formed along the profile of the groove (GR1). Accordingly, the second conductive line (130) may have a 'U' shape that is bent in cross-section toward the substrate (100) along the profile of the groove (GR1), which has a rounded shape that is recessed toward the substrate (100).

[0076] In one embodiment, the maximum depth (D12) of the groove (GR) may be substantially equal to the thickness of the second conductive wire (130). In this case, the height of the center of the upper surface of the second conductive wire (130) and the height of the upper surface of the first insulating layer (120) may be substantially equal.

[0077] A second insulating layer (140) covering a second conductive wire (130) may be disposed on the first insulating layer (120). The second insulating layer (140) may include an organic insulating material. For example, the second insulating layer (140) may include polyimide (PI), etc.

[0078] The upper surface of the second insulating layer (140) may be formed along the profile of the upper surface of the first insulating layer (120) positioned below and the profile of the upper surface of the second conductive line (130). Since the second conductive line (130) is positioned in the groove (GR1) of the first insulating layer (120) that is recessed toward the substrate (100), the thickness (D13) of the protrusion on the upper surface of the second insulating layer (140) may be smaller than the thickness of the second conductive line (130).

[0079] A pixel electrode (150) may be disposed on the second insulating layer (140). The pixel electrode (150) may be superimposed on the second conductive line (130).

[0080] The upper surface of the pixel electrode (150) may be formed along the profile of the upper surface of the second insulating layer (140) disposed below. A protrusion corresponding to the protrusion formed on the upper surface of the second insulating layer (140) may be formed on the upper surface of the pixel electrode (150).

[0081] A light-emitting layer (160) may be disposed on the pixel electrode (150), and a counter electrode (170) may be disposed on the light-emitting layer (160).

[0082] In one embodiment, the pixel electrode (150) may be a reflective electrode and the counter electrode (170) may be a transparent electrode. For example, the pixel electrode (150) may include at least one reflective film formed of a metal such as magnesium (Mg), silver (Ag), gold (Au), calcium (Ca), lithium (Li), chromium (Cr), aluminum (Al) and having a relatively large thickness, and at least one transparent film including a transparent conductive oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), or indium oxide (In2O3). Additionally, the counter electrode (170) may include a semipermeable film having a relatively small thickness formed of a metal such as magnesium (Mg), silver (Ag), gold (Au), calcium (Ca), lithium (Li), chromium (Cr), aluminum (Al), or a transparent conductive oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), or indium oxide (In2O3).

[0083] When the display device does not display an image, a user looking at the display device from the top of a light-emitting element (EL), in which the pixel electrode (150) is a reflective electrode and the opposing electrode (170) is a transmissive electrode, can see the protrusion of the pixel electrode (150). However, in the embodiments of the present invention, since the second conductive line (130) is placed in the groove (GR1) of the first insulating layer (120) which is recessed toward the substrate (100), the thickness of the protrusion of the pixel electrode (150) can be reduced, and accordingly, the visibility of the display device can be improved.

[0084] FIGS. 8, FIGS. 9, FIGS. 10, and FIGS. 11 are cross-sectional views illustrating a method of manufacturing the display device of FIG. 7.

[0085] Referring to FIG. 8, a first conductive line (110) can be formed on a substrate (100), and a first insulating layer (120) covering the first conductive line (110) can be formed on the substrate (100).

[0086] First, a first conductive line (110) can be formed on the second interlayer insulating layer (107). For example, a first conductive layer can be formed by depositing a conductive material such as aluminum (Al), titanium (Ti), copper (Cu), etc., on the second interlayer insulating layer (107) using physical vapor deposition such as sputtering, and the first conductive line (110) can be formed by etching the first conductive layer.

[0087] Next, a first insulating layer (120) covering the first conductive wire (110) can be formed on the second interlayer insulating layer (107). For example, the first insulating layer (120) can be formed by applying an organic insulating material, such as photoresist, onto the second interlayer insulating layer (107) on which the first conductive wire (110) is formed, using spin coating or the like.

[0088] Referring to FIG. 9, a contact hole (CH1) and a groove (GR1) can be formed in the first insulating layer (120).

[0089] In one embodiment, the contact hole (CH1) and the groove (GR1) may be formed using a halftone mask (HM). The halftone mask (HM) may include a light-blocking portion (P1), a light-transmitting portion (P2), and a semi-transmitting portion (P3). The light-blocking portion (P1) blocks light, and the light-transmitting portion (P2) transmits light. The semi-transmitting portion (P3) blocks a portion of light and transmits another portion of light. In other words, the transmittance of the semi-transmitting portion (P3) may be greater than the transmittance of the light-blocking portion (P1) and less than the transmittance of the light-transmitting portion (P2).

[0090] First, a halftone mask (HM) can be placed on top of the first insulating layer (120). The light-transmitting portion (P2) can be superimposed on the area where the contact hole (CH1) is formed, and the semi-transparent portion (P3) can be superimposed on the area where the groove (GR1) is formed. Next, the first insulating layer (120) can be exposed using the halftone mask (HM), and the exposed first insulating layer (120) can be developed to substantially simultaneously form the contact hole (CH1) and the groove (GR1).

[0091] In one embodiment, the groove (GR1) may be formed by isotropically etching the first insulating layer (120). The portion of the first insulating layer (120) exposed by the semi-transparent portion (P3) of the halftone mask (HM) may be isotropically etched during the development process. In this case, the groove (GR1) may have a round shape that is indented toward the substrate (100).

[0092] Referring to FIG. 10, a second conductive line (130) can be formed to fill a contact hole (CH1) in a groove (GR1) on a first insulating layer (120). For example, a second conductive layer can be formed by depositing a conductive material such as aluminum (Al), titanium (Ti), copper (Cu), etc., on the first insulating layer (120) using physical vapor deposition such as sputtering, and the second conductive line (130) can be formed by etching the second conductive layer.

[0093] The second conductive line (130) can be formed in a groove (GR1) having a round shape that is recessed toward the substrate (100), and accordingly, the second conductive line (130) can have a 'U' shape in cross-section.

[0094] Referring to FIG. 11, a second insulating layer (140) covering a second conductive wire (130) can be formed on a first insulating layer (120). For example, the second insulating layer (140) can be formed by applying an organic insulating material, such as polyimide (PI), on the first insulating layer (120) on which the second conductive wire (130) is formed, using spin coating or the like.

[0095] In this embodiment, by using a halftone mask (HM) to substantially simultaneously form a contact hole (CH1) and a groove (GR1) in the first insulating layer (120), an additional process for forming the groove (GR1) can be omitted. Accordingly, the manufacturing cost and manufacturing time of the display device can be reduced.

[0096] FIG. 12 is a cross-sectional view showing another example of a display device along the line II-II' of FIG. 1. In the other example of a display device described with reference to FIG. 12, descriptions of configurations that are substantially identical or similar to the example of a display device described with reference to FIG. 7 are omitted.

[0097] Referring to FIG. 12, a first conductive wire (110) may be disposed on the second interlayer insulating layer (107). A first insulating layer (1120) covering the first conductive wire (110) may be disposed on the second interlayer insulating layer (107).

[0098] In one embodiment, the first insulating layer (1120) may include at least one of an organic insulating material and an inorganic insulating material. For example, the first insulating layer (1120) may include a photosensitive material such as a photoresist and / or silicon oxide, silicon nitride, silicon oxynitride, etc.

[0099] The first insulating layer (1120) may have a contact hole (CH2) and a groove (GR2). The contact hole (CH2) may have a depth (D21) corresponding to the distance from the upper surface of the first conductive wire (110) to the upper surface of the first insulating layer (1120).

[0100] The groove (GR2) is recessed toward the substrate (100) and may have a depth (D22) smaller than the depth (D21) of the contact hole (CH2). Due to the groove (GR2), the upper surface of the first insulating layer (1120) may have a cross-sectional shape that is recessed toward the substrate (100).

[0101] In one embodiment, the groove (GR2) may have a square shape that is recessed toward the substrate (100). The depth (D22) of the groove (GR2) may be substantially the same from the periphery of the groove (GR2) to the center. In this case, the depth (D22) of the groove (GR2) may be uniform.

[0102] A second conductive wire (1130) may be disposed in a groove (GR2) on the first insulating layer (1120). The second conductive wire (1130) may be connected to the first conductive wire (110) through a contact hole (CH2).

[0103] The upper surface of the second conductive line (1130) may be flat. The second conductive line (1130) is placed in a groove (GR2) on the first insulating layer (1120), and the upper surface of the second conductive line (1130) may be formed along the profile of the groove (GR2). Accordingly, the second conductive line (1130) may have a flat upper surface along the profile of the groove (GR2), which has a square shape that is recessed toward the substrate (100).

[0104] In one embodiment, the depth (D22) of the groove (GR) may be substantially equal to the thickness of the second conductive wire (1130). In this case, the height of the upper surface of the second conductive wire (1130) and the height of the upper surface of the first insulating layer (1120) may be substantially equal.

[0105] A second insulating layer (1140) covering a second conductive wire (1130) may be disposed on the first insulating layer (1120). The second insulating layer (1140) may include an organic insulating material.

[0106] The upper surface of the second insulating layer (1140) may be formed along the profile of the upper surface of the first insulating layer (1120) positioned below and the profile of the upper surface of the second conductive line (1130). Since the second conductive line (1130) is positioned in the groove (GR2) of the first insulating layer (1120) which is recessed toward the substrate (100), and the thickness of the second conductive line (1130) is substantially equal to the depth (D22) of the groove (GR2), no protrusion may be formed on the upper surface of the second insulating layer (1140). In other words, the upper surface of the second insulating layer (1140) may be flat.

[0107] A pixel electrode (1150) may be disposed on the second insulating layer (1140). The pixel electrode (1150) may be superimposed on the second conductive line (1130).

[0108] The upper surface of the pixel electrode (1150) can be formed along the profile of the upper surface of the second insulating layer (1140) disposed below. Since the upper surface of the second insulating layer (1140) is flat, no protrusions may be formed on the upper surface of the pixel electrode (1150).

[0109] FIGS. 13, 14, 15, 16, and 17 are cross-sectional views illustrating a method for manufacturing a display device of FIG. 12. In the method for manufacturing a display device described with reference to FIGS. 13 to 17, descriptions of configurations that are substantially identical or similar to the method for manufacturing a display device described with reference to FIGS. 8 to 11 are omitted.

[0110] Referring to FIG. 13, a first conductive line (110) can be formed on a substrate (100), and a first insulating layer (1120) covering the first conductive line (110) can be formed on the substrate (100).

[0111] First, a first conductive line (110) can be formed on the second interlayer insulating layer (107).

[0112] Next, a first insulating layer (1120) covering the first conductive line (110) can be formed on the second interlayer insulating layer (107). In one embodiment in which the first insulating layer (1120) comprises an organic insulating material, for example, the first insulating layer (1120) can be formed by applying an organic insulating material, such as photoresist, onto the second interlayer insulating layer (107) on which the first conductive line (110) is formed, using spin coating or the like. In another embodiment in which the first insulating layer (1120) comprises an inorganic insulating material, for example, the first insulating layer (1120) can be formed by depositing an inorganic insulating material, such as silicon oxide, silicon nitride, silicon oxynitride, etc., onto the second interlayer insulating layer (107) on which the first conductive line (110) is formed, using chemical vapor deposition such as PECVD.

[0113] Referring to FIG. 14, a contact hole (CH2) can be formed in the first insulating layer (1120). The contact hole (CH2) can expose the first conductive wire (110).

[0114] In one embodiment, the contact hole (CH2) may be formed using a first mask (M1). The first mask (M1) may include a light-blocking portion (P1) and a light-transmitting portion (P2). The light-blocking portion (P1) blocks light, and the light-transmitting portion (P2) transmits light.

[0115] In one embodiment in which the first insulating layer (1120) comprises an organic insulating material, first, a first mask (M1) may be placed on top of the first insulating layer (1120). A light-transmitting portion (P2) may overlap with the area where the contact hole (CH2) is formed. Next, the first insulating layer (1120) may be exposed using the first mask (M1), and the exposed first insulating layer (1120) may be developed to form the contact hole (CH2).

[0116] In another embodiment in which the first insulating layer (1120) comprises an inorganic insulating material, first, a first photoresist layer can be formed on the first insulating layer (1120). Next, a first mask (M1) can be placed on the first photoresist layer. The light-transmitting portion (P2) can overlap the area where the contact hole (CH2) is formed. Next, the first photoresist layer can be exposed using the first mask (M1), and the exposed first photoresist layer can be developed to form a first photoresist pattern. Next, the first insulating layer (1120) can be etched using the first photoresist pattern as an etching mask to form the contact hole (CH2). Next, the first photoresist pattern can be stripped.

[0117] Referring to FIG. 15, a groove (GR2) can be formed in the first insulating layer (1120). The groove (GR2) is recessed toward the substrate (100) and may have a depth (D22) smaller than the depth (D21) of the contact hole (CH2).

[0118] In one embodiment, the groove (GR2) may be formed using a second mask (M2). The second mask (M2) may include a light-blocking portion (P1) and a light-transmitting portion (P2). The light-blocking portion (P1) blocks light, and the light-transmitting portion (P2) transmits light.

[0119] First, a second photoresist layer can be formed on the first insulating layer (1120). Next, a second mask (M2) can be placed on the second photoresist layer. The light-transmitting portion (P2) can be superimposed on the area where the groove (GR2) is formed. Next, the second photoresist layer can be exposed using the second mask (M2), and the exposed second photoresist layer can be developed to form a second photoresist pattern. Next, the first insulating layer (1120) can be etched using the second photoresist pattern as an etching mask to form the groove (GR2). Next, the second photoresist pattern can be stripped.

[0120] In one embodiment, the groove (GR2) may be formed by anisotropically etching the first insulating layer (1120). For example, the insulating layer (1120) may be anisotropically etched during the process of etching the first insulating layer (1120) exposed by the second photoresist pattern using a dry etching method. In this case, the groove (GR2) may have a square shape that is recessed toward the substrate (100).

[0121] Referring to FIG. 16, a second conductive wire (1130) can be formed to fill a contact hole (CH2) in a groove (GR2) on the first insulating layer (1120).

[0122] The second conductive line (1130) can be formed in a groove (GR2) having a square shape that is recessed toward the substrate (100), and accordingly, the upper surface of the second conductive line (1130) can be flat.

[0123] Referring to FIG. 17, a second insulating layer (1140) covering a second conductive wire (1130) can be formed on a first insulating layer (1120).

[0124] In this embodiment, a second conductive line (1130) having a flat upper surface can be formed by anisotropically etching the first insulating layer (1120) using a second mask (M2) to form a groove (GR2) having a square shape that is recessed toward the substrate (100). Accordingly, a second insulating layer (1140) having a flat upper surface is formed, and the visibility of the display device can be improved. Industrial applicability

[0125] A display device according to exemplary embodiments of the present invention can be applied to a display device including a computer, laptop, mobile phone, smartphone, smartpad, PMP, PDA, MP3 player, etc.

[0126] Although a display device and a method for manufacturing a display device according to exemplary embodiments of the present invention have been described above with reference to the drawings, the described embodiments are exemplary and may be modified and changed by those skilled in the art without departing from the technical spirit of the present invention as described in the following claims. Explanation of the symbols

[0127] 100: Substrate 110: First conductive line 120, 1120: First insulating layer 130, 1130: Second conductive wire 140, 1140: Second insulating layer 150, 1150: Pixel electrode 160: Emitting layer 170: Counter electrode

Claims

Claim 1 A display device comprising: a substrate including a display area and a peripheral area located on one side of the display area and on which a pad is placed; a first conductive line disposed on the substrate and extending in a first direction and transmitting a data signal; a first insulating layer disposed on the substrate and covering the first conductive line and having a contact hole that exposes the first conductive line and a groove that is recessed from the upper surface toward the substrate and has a depth smaller than the depth of the contact hole; a second conductive line disposed in the groove on the first insulating layer, having a first end connected to the pad and a second end connected to the first conductive line through the contact hole; and a second insulating layer disposed on the first insulating layer and covering the second conductive line, wherein the second conductive line is disposed only in the groove of the first insulating layer and is not disposed on the upper surface of the first insulating layer. Claim 2 A display device according to claim 1, wherein the groove has a round shape that is recessed in the direction of the substrate. Claim 3 In claim 2, the second conductive line is a display device having a 'U' shape. Claim 4 A display device according to claim 1, wherein the groove has a square shape that is recessed in the direction of the substrate. Claim 5 In claim 4, the upper surface of the second conductive line is flat, a display device. Claim 6 A display device according to claim 1, wherein the maximum depth of the groove is equal to the thickness of the second conductive wire. Claim 7 delete Claim 8 A display device according to claim 1, wherein the second conductive line extends in the first direction and in a second direction intersecting the first direction. Claim 9 A display device according to claim 1, wherein the first insulating layer comprises at least one of an organic insulating material and an inorganic insulating material. Claim 10 A display device according to claim 1, wherein the second insulating layer comprises an organic insulating material. Claim 11 A display device according to claim 1, further comprising: a pixel electrode disposed on the second insulating layer and overlapping with the second conductive line; a light-emitting layer disposed on the pixel electrode; and a counter electrode disposed on the light-emitting layer. Claim 12 A display device according to claim 11, wherein the pixel electrode is a reflective electrode and the counter electrode is a transmissive electrode. Claim 13 A method for manufacturing a display device comprising: forming a first conductive line extending in a first direction and transmitting a data signal on a substrate including a display area and a peripheral area located on one side of the display area and on which a pad is disposed; forming a first insulating layer covering the first conductive line on the substrate; simultaneously forming a contact hole that exposes the first conductive line in the first insulating layer and a groove that is recessed from the upper surface of the first insulating layer toward the substrate and has a depth smaller than the depth of the contact hole using a halftone mask; forming a second conductive line that fills the contact hole in the groove on the first insulating layer; and forming a second insulating layer covering the second conductive line on the first insulating layer, wherein the second conductive line is disposed only in the groove of the first insulating layer and is not disposed on the upper surface of the first insulating layer, the first end of the second conductive line is connected to the pad, and the second end of the second conductive line is connected to the first conductive line through the contact hole. Claim 14 A method for manufacturing a display device according to claim 13, wherein the first insulating layer comprises an organic insulating material. Claim 15 A method for manufacturing a display device according to claim 13, wherein the groove is formed by isotropically etching the first insulating layer. Claim 16 A method for manufacturing a display device according to claim 13, wherein the groove has a round shape that is recessed in the direction of the substrate. Claim 17 A method for manufacturing a display device comprising: forming a first conductive line extending in a first direction and transmitting a data signal on a substrate including a display area and a peripheral area located on one side of the display area and on which a pad is disposed; forming a first insulating layer covering the first conductive line on the substrate; forming a contact hole in the first insulating layer that exposes the first conductive line using a first mask; forming a groove in the first insulating layer that is recessed from the upper surface of the first insulating layer toward the substrate and has a depth smaller than the depth of the contact hole using a second mask; forming a second conductive line that fills the contact hole in the groove on the first insulating layer; and forming a second insulating layer covering the second conductive line on the first insulating layer, wherein the second conductive line is disposed only in the groove of the first insulating layer and is not disposed on the upper surface of the first insulating layer, and the first end of the second conductive line is connected to the pad, and the second end of the second conductive line is connected to the first conductive line through the contact hole. Claim 18 A method for manufacturing a display device according to claim 17, wherein the first insulating layer comprises at least one of an organic insulating material and an inorganic insulating material. Claim 19 A method for manufacturing a display device according to claim 17, wherein the groove is formed by anisotropically etching the first insulating layer. Claim 20 A method for manufacturing a display device according to claim 17, wherein the groove has a square shape that is recessed in the direction of the substrate.

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