Display device and array substrate

Abstract

To reduce reflection of external light in order to improve visibility in a display device.SOLUTION: An organic insulating film 100A is provided with a contact hole CH3. In the contact hole CH3, a pixel electrode PE being in contact with an inner wall of the contact hole CH3, a capacitance insulating film CI being in contact with the inner wall of the contact hole CH3 and the pixel electrode PE, a common electrode CE in contact with the capacitance insulating film CI, and an organic insulating film 100B being in contact with the common electrode CE and filling the contact hole CH3 are formed. Above the contact hole CH3, a conductive film TML being in contact with the organic insulating film 100B and an antireflection film AR being in contact with the conductive film TML are formed.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to a display device and an array substrate, and more particularly to a technique that is effective when applied to a display device and an array substrate that include a conductive film in contact with a common electrode, for example. [Background technology]

[0002] JP 2022-84146 A (Patent Document 1) describes a metal wiring having a first portion that entirely covers the surface of a common electrode inside a contact hole provided in an organic insulating film, and a second portion that covers the surface of the common electrode outside the contact hole. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-84146 Summary of the Invention [Problem to be solved by the invention]

[0004] In display devices, it is desirable to reduce reflection of external light in order to improve visibility. [Means for solving the problem]

[0005] A display device in one embodiment includes a first organic insulating film, a pixel electrode in contact with the first organic insulating film, a capacitive insulating film in contact with the pixel electrode, a common electrode in contact with the capacitive insulating film, a conductive film in contact with the common electrode, and an anti-reflection film in contact with the conductive film, in which a contact hole is provided in the first organic insulating film, in which a pixel electrode in contact with an inner wall of the contact hole, a capacitive insulating film in contact with the inner wall of the contact hole and the pixel electrode, a common electrode in contact with the capacitive insulating film, and a second organic insulating film in contact with the common electrode and filling the contact hole are formed, and above the contact hole, a conductive film in contact with the second organic insulating film, and the anti-reflection film in contact with the conductive film are formed.

[0006] An array substrate according to an embodiment has a switching element, the array substrate includes a first organic insulating film, a pixel electrode in contact with the first organic insulating film, a capacitance insulating film in contact with the pixel electrode, a common electrode in contact with the capacitance insulating film, a conductive film in contact with the common electrode, and an anti-reflection film in contact with the conductive film, the first organic insulating film has a contact hole, the pixel electrode in contact with an inner wall of the contact hole, the capacitance insulating film in contact with the inner wall of the contact hole and the pixel electrode, the common electrode in contact with the capacitance insulating film, and a second organic insulating film in contact with the common electrode and filling the contact hole, and the conductive film in contact with the second organic insulating film and the anti-reflection film in contact with the conductive film are formed above the contact hole. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is an exploded perspective view showing a schematic configuration example of a liquid crystal display device. [Diagram 2] FIG. 2 is a plan view showing a schematic configuration of a display panel. [Diagram 3] FIG. 2 is a plan view showing an example of a planar layout of sub-pixels. [Figure 4] FIG. 2 is a schematic plan view showing some of the elements that constitute a sub-pixel. [Diagram 5] FIG. 5 is a schematic cross-sectional view taken along line AA in FIG. 4. [Figure 6] 1 is a cross-sectional view showing the internal and external configurations of a contact portion in a related art; [Figure 7] 1A and 1B are schematic diagrams illustrating examples of the configuration of a conductive film. [Figure 8] 1 is a cross-sectional view showing the internal and external configurations of a contact portion in the investigated technology. [Figure 9] 4A to 4C are cross-sectional views showing the internal and external configurations of a contact portion in an embodiment. [Figure 10] 13 is a cross-sectional view showing the internal and external configurations of a contact portion in a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, embodiments will be described with reference to the drawings.

[0009] Note that the present disclosure is merely an example, and any modifications that a person skilled in the art can easily conceive of while maintaining the gist of the present disclosure are naturally included within the scope of the present disclosure.

[0010] In addition, in order to clarify the description, the drawings may show the width, thickness, shape, etc. of each part in a schematic manner compared to the actual embodiment, but these are merely examples and do not limit the interpretation of the present disclosure. In this specification and each drawing, elements similar to those shown in the previous drawings are given the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0011] In the present embodiment, as an example, a liquid crystal display device having a liquid crystal display element is disclosed. However, the embodiment does not prevent the application of the technical ideas disclosed in the embodiment to a display device having other types of display elements such as an organic electroluminescence display element, a micro LED, or a mini LED. In addition, the technical ideas disclosed in the embodiment can also be applied to an array substrate and an electronic device having a sensor element such as a capacitance sensor or an optical sensor.

[0012] <Overall configuration of liquid crystal display device> FIG. 1 is an exploded perspective view showing a schematic configuration example of a liquid crystal display device 1. As shown in FIG. As shown in Fig. 1, the X direction, Y direction, and Z direction are defined. The X direction, Y direction, and Z direction are mutually orthogonal, but may intersect at an angle other than a perpendicular angle. Viewing the liquid crystal display device 1 or its components parallel to the Z direction is called a "planar view." The direction indicated by the Z direction arrow is sometimes called "upward," and the opposite direction is sometimes called "downward."

[0013] 1, a liquid crystal display device 1 includes a display panel 2 and a backlight 3. For example, the backlight 3 can be configured as a side-edge type backlight including a light guide LG facing the display panel 2 and a plurality of light-emitting elements LS arranged at positions facing the side surfaces of the light guide LG. However, the backlight 3 is not limited to this, and backlights of various configurations that can supply light necessary for image display can be adopted.

[0014] The planar shapes of the display panel 2 and the light guide LG are, for example, rectangular shapes having long sides along the X direction and short sides along the Y direction, but are not limited to rectangular shapes and may be other shapes.

[0015] The display panel 2 is a liquid crystal panel having light transmissibility, and includes, for example, an array substrate SUB1, a counter substrate SUB2 facing the array substrate SUB1, and a liquid crystal layer LC sealed between the array substrate SUB1 and the counter substrate SUB2. The display panel 2 thus configured has, for example, a rectangular display area DA.

[0016] The liquid crystal display device 1 further includes an optical sheet group 4, and polarizing plates 5 and 6. The optical sheet group 4 is disposed between the light guide LG and the display panel 2. For example, the optical sheet group 4 includes a diffusion sheet DF that diffuses the light emitted from the light guide LG, and a prism sheet PR1 and a prism sheet PR2, each of which has a large number of prisms formed thereon.

[0017] The polarizing plate 5 is disposed between the optical sheet group 4 and the array substrate SUB1. On the other hand, the polarizing plate 6 is disposed above the counter substrate SUB2. Here, the polarization axis of the polarizing plate 5 and the polarization axis of the polarizing plate 6 are in a crossed Nicol relationship in which they are perpendicular to each other.

[0018] The liquid crystal display device 1 configured in this manner can be used in various types of devices, such as head mounted displays, in-vehicle devices, smartphones, tablet terminal devices, mobile phones, personal computers, television receivers, and game devices.

[0019] <Display panel configuration> Next, the configuration of the display panel 2 will be described. FIG. 2 is a plan view showing a schematic configuration of the display panel 2. As shown in FIG. 2, the display panel 2 has a display area DA and a peripheral area SA around the display area DA. For example, as shown in FIG. 2, the lower side of the array substrate SUB1 protrudes in the Y direction further than the counter substrate SUB2. As a result, the array substrate SUB1 has a mounting area MA that does not overlap with the counter substrate SUB2 in a plan view. This mounting area MA constitutes a part of the peripheral area SA.

[0020] In the display area DA, a plurality of pixels PX are arranged in a matrix. Each pixel PX includes a plurality of sub-pixels. For example, in FIG. 2, the pixel PX includes a red sub-pixel SPR, a green sub-pixel SPG, and a blue sub-pixel SPB. However, the pixel PX is not limited to this configuration, and may be configured to include sub-pixels of other colors, typically white.

[0021] As shown in Fig. 2, the display panel 2 includes a plurality of scanning lines G, a plurality of signal lines S (video lines), a scanning driver GD1, a scanning driver GD2, and a selector circuit ST. The plurality of scanning lines G extend in the X direction and are arranged in the Y direction. In contrast, the plurality of signal lines S extend in the Y direction and are arranged in the X direction. Each of the plurality of scanning lines G is connected to the scanning driver GD1 or the scanning driver GD2. Meanwhile, each of the plurality of signal lines S is connected to the selector circuit ST.

[0022] 2, a controller CT is mounted in the mounting area MA. A terminal portion T is provided in the mounting area MA, and a flexible substrate F is connected to the terminal portion T. The controller CT may be mounted on the flexible substrate F. The controller CT is formed of, for example, an IC chip or a circuit element.

[0023] Various types of signals transmitted from an electronic device in which the liquid crystal display device 1 is implemented are output to the controller CT via an integrated circuit mounted on the flexible substrate F. The controller CT inputs these signals and supplies a video signal to the selector circuit ST, while controlling the scan driver GD1, the scan driver GD2, and the selector circuit ST.

[0024] Each of the scan driver GD1 and the scan driver GD2 sequentially supplies scan signals to the plurality of scan lines G. On the other hand, the selector circuit ST sequentially supplies a video signal input from the controller CT to the signal lines S.

[0025] Each pixel PX includes a pixel electrode PE, a switching element SW (thin film transistor), and a common electrode CE to which a common potential is supplied. The switching element SW is connected to the pixel electrode PE, the scanning line G, and the signal line S.

[0026] For example, when the switching element SW is composed of a thin film transistor (field effect transistor), the gate electrode of the thin film transistor is electrically connected to the scanning line G. In addition, the source of the thin film transistor is electrically connected to the signal line S, while the drain of the thin film transistor is electrically connected to the pixel electrode PE.

[0027] When a scanning signal is supplied to the scanning line G, the thin film transistor is turned on and the video signal supplied to the signal line S is supplied to the pixel electrode PE. Meanwhile, the common electrode CE is formed across multiple sub-pixels, and when a video signal is supplied to the pixel electrode PE, a potential difference is generated between the pixel electrode PE and the common electrode CE. The electric field generated by this acts on the liquid crystal layer LC, thereby controlling the alignment direction of the multiple liquid crystal molecules that make up the liquid crystal layer LC.

[0028] For example, in the so-called "vertical electric field method," in which a pixel electrode PE is formed on an array substrate while a common electrode CE is formed on an opposing substrate, and a liquid crystal layer LC is sandwiched between the pixel electrode PE and the common electrode CE, the orientation direction of the multiple liquid crystal molecules that make up the liquid crystal layer LC is controlled by the vertical electric field generated between the pixel electrode PE and the common electrode CE.

[0029] On the other hand, in the so-called "horizontal electric field method," for example, a pixel electrode PE and a common electrode CE are formed on an array substrate, and a horizontal electric field (fringe electric field) leaking from a slit provided in the common electrode CE is utilized, the orientation direction of multiple liquid crystal molecules constituting the liquid crystal layer LC arranged above the array substrate is controlled by the horizontal electric field leaking from the slit.

[0030] As described above, there are two methods for controlling the alignment direction of liquid crystal molecules: the "vertical electric field method" and the "horizontal electric field method." For example, the "horizontal electric field method" has the advantage of being able to provide a wider viewing angle than the "vertical electric field method." In this embodiment, the "horizontal electric field method" is adopted, and the scanning lines G, signal lines S, scanning drivers GD1 and GD2, selector circuits ST, switching elements SW, pixel electrodes PE, and common electrodes CE are formed on the array substrate SUB1.

[0031] <Plane layout configuration of sub-pixels> Next, the planar layout configuration of the sub-pixels will be described. FIG. 3 is a plan view showing an example of a planar layout of sub-pixels. 3, the subpixels are subpixels SPR, SPG, and SPB. A red color filter CFR is disposed in the subpixel SPR, a green color filter CFG is disposed in the subpixel SPG, and a blue color filter CFB is disposed in the subpixel SPB.

[0032] 3, the subpixels SPR, SPG, and SPB are arranged in the X direction in this order. Also, the subpixels SPR, SPB, and SPG are arranged in the Y direction in this order. As a result, the subpixels SPR are arranged in a diagonal direction intersecting the X and Y directions. Similarly, the subpixels SPG are arranged in a diagonal direction, and the subpixels SPB are arranged in a diagonal direction.

[0033] The color filters CFR, CFG, and CFB are arranged in a dot shape (island shape) with respect to the subpixels SPR, SPG, and SPB.

[0034] For example, gaps GP are formed between color filters CFR and CFG adjacent to each other in the Y direction, between color filters CFG and CFB, and between color filters CFB and CFR.

[0035] It should be noted that the planar layout of the subpixels SPR, SPG, and SPB and the color filters CFR, CFG, and CFB is not limited to the planar layout shown in FIG.

[0036] For example, the subpixels SPR may be arranged in the Y direction, the subpixels SPG may be arranged in the Y direction, and the subpixels SPB may be arranged in the Y direction, with the columns of the subpixels SPR, the columns of the subpixels SPG, and the columns of the subpixels SPB arranged in order in the X direction.

[0037] As described above, the liquid crystal display device 1 in the present embodiment has a so-called "COA (Color Filter on Array) structure" in which all of the color filters CFR, CFG, and CFB are disposed on the array substrate SUB1. According to the "COA structure," the color filters and the sub-pixels are provided on the same array substrate SUB1. Therefore, according to the "COA structure," a high-definition liquid crystal display device 1 can be realized without being affected by misalignment between the array substrate SUB1 and the counter substrate SUB2.

[0038] FIG. 4 is a schematic plan view showing some of the elements that constitute a sub-pixel. 4 shows two scanning lines G extending in the X direction and two signal lines S extending in the Y direction intersecting the scanning lines G. An aperture region OR of a sub-pixel is formed in a region surrounded by the two scanning lines G and the two signal lines S. A pixel electrode PE is provided in the aperture region OR so as to overlap the aperture region OR in a plan view.

[0039] A conductive film TML is disposed above the scanning lines G and the signal lines S. This conductive film TML has an X-direction extending portion extending in the X direction and a Y-direction extending portion extending in the Y direction. The X-direction extending portion is provided so as to overlap with the scanning lines G in a planar view. On the other hand, the Y-direction extending portion is provided so as to overlap with the signal lines S in a planar view. Due to these X-direction extending portion and Y-direction extending portion, the conductive film TML has an overall lattice-like planar shape as shown in FIG. 4. This conductive film TML functions as a "light-shielding film" that blocks light.

[0040] 4, the signal line S is connected to the semiconductor layer OS of the thin film transistor constituting the switching element at the contact portion PLG1. That is, the semiconductor layer OS is electrically connected to the signal line S via the contact portion PLG1. In this manner, the contact portion PLG1 has a function of electrically connecting the semiconductor layer OS and the signal line S.

[0041] The semiconductor layer OS also extends to intersect with the scanning line G and reach the opening region OR, and is connected to the relay electrode RE at the contact portion PLG2 located in the opening region OR. Therefore, the semiconductor layer OS is electrically connected to the relay electrode RE at the contact portion PLG2. That is, the contact portion PLG2 has a function of electrically connecting the semiconductor layer OS and the relay electrode RE.

[0042] Furthermore, a pixel electrode PE is provided so as to overlap the opening region OR in a plan view, and this pixel electrode PE and the relay electrode RE are connected at the bottom of the contact portion PLG3. That is, a part of the pixel electrode PE is formed inside the contact portion PLG3, and the part of the pixel electrode PE formed inside the contact portion PLG3 and the relay electrode RE are electrically connected at the bottom of the contact portion PLG3. From the above, the pixel electrode PE is electrically connected to the semiconductor layer OS via the relay electrode RE. That is, the contact portion PLG3 has the function of electrically connecting the pixel electrode PE and the relay electrode RE.

[0043] 4, a common electrode CE is provided so as to overlap in plan with all of the elements, such as the scanning lines G, the signal lines S, and the conductive film TML, etc. In the opening region OR, the common electrode CE is provided with a slit SL at a position facing the pixel electrode PE.

[0044] Here, for example, an electric field generated when a potential difference is generated between the common electrode CE and the pixel electrode PE leaks out from the slit SL provided in the common electrode CE. As a result, the lateral electric field leaking out from the slit SL controls the alignment direction of a plurality of liquid crystal molecules constituting the liquid crystal layer disposed above the array substrate. In other words, the slit SL provided in the common electrode CE has the function of applying a lateral electric field to the liquid crystal layer to control the alignment direction of a plurality of liquid crystal molecules. In this manner, the planar layout configuration of the sub-pixels is realized.

[0045] <Cross-sectional structure of sub-pixel> Next, the cross-sectional structure of the sub-pixel will be described. FIG. 5 is a schematic cross-sectional view taken along line AA in FIG. 4. Note that FIG. 5 is a schematic cross-sectional view and does not accurately reflect the cross-section taken along line AA in FIG. 4. For example, line AA in FIG. 4 intersects with scanning line G twice, but only one scanning line G (gate electrode GE1) is shown in FIG. 5. Also, although gate electrode GE2 is shown in FIG. 5, this gate electrode GE2 is not shown in FIG. 4. Furthermore, details of contact portion PLG3 relating to the connection portion between relay electrode RE and pixel electrode PE are omitted from FIG. 5 in order to explain the same in FIG. 6 to FIG. 10.

[0046] 5, an insulating layer IL1 is formed on a light-transmitting substrate 10. An insulating layer IL2 is formed on the insulating layer IL1. The substrate 10 is made of, for example, glass, but is not limited to this and may be made of a resin material such as polyimide resin. The insulating layers IL1 and IL2 are made of inorganic insulating films such as silicon nitride films and silicon oxide films.

[0047] 5, a gate electrode GE1 of a thin film transistor (field effect transistor) serving as a switching element is formed on the insulating layer IL2. This gate electrode GE1 functions as a scanning line G. The gate electrode GE1 is made of, for example, a metal material. The gate electrode GE1 may have a single-layer structure made of a single metal material, or may have a multi-layer structure in which different types of metal materials are laminated.

[0048] Next, an insulating layer IL3 is formed on the insulating layer IL2 so as to cover the gate electrode GE1. A semiconductor layer OS is formed on the insulating layer IL3. The insulating layer IL3 is made of an inorganic insulating film such as a silicon nitride film or a silicon oxide film. On the other hand, the semiconductor layer OS is made of an amorphous silicon film or an oxide semiconductor film.

[0049] The semiconductor layer OS functions as a channel of the thin film transistor. That is, a channel is formed in the semiconductor layer OS based on a gate voltage applied to the gate electrode GE1. For example, when a gate voltage equal to or greater than a threshold voltage is applied to the gate electrode GE1, a channel is formed in the semiconductor layer OS. On the other hand, when a gate voltage less than the threshold voltage is applied to the gate electrode GE1, the channel formed in the semiconductor layer OS disappears.

[0050] This makes it possible to control the on / off operation of the thin film transistor based on the gate voltage applied to the gate electrode GE1.

[0051] For example, the semiconductor layer OS is desirably formed of an oxide semiconductor film, because a thin film transistor using an oxide semiconductor film as a channel has an advantage of having higher electron mobility and a very low off-leakage current than a thin film transistor using an amorphous silicon film as a channel.

[0052] 5, an insulating layer IL4 is formed on the insulating layer IL3 so as to cover the semiconductor layer OS. Then, a gate electrode GE2 is formed on the insulating layer IL4. The insulating layer IL4 is made of an inorganic insulating film such as a silicon nitride film or a silicon oxide film. On the other hand, the gate electrode GE2 is made of a metal material, for example. In this manner, the thin-film transistor has the gate electrodes GE1 and GE2 arranged to sandwich the semiconductor layer OS from above and below. In this configuration, for example, a channel can be formed on the lower surface of the semiconductor layer OS by applying a gate voltage equal to or higher than the threshold voltage to the gate electrode GE1 arranged below the semiconductor layer OS, and a channel can also be formed on the upper surface of the semiconductor layer OS by applying a gate voltage equal to or higher than the threshold voltage to the gate electrode GE2 arranged above the semiconductor layer OS.

[0053] That is, in the thin film transistor of the present embodiment, since channels can be formed on both the upper and lower surfaces of the semiconductor layer OS, the current driving force of the thin film transistor can be improved. However, the configuration of the thin film transistor is not limited to this, and the gate electrode GE2 may be omitted. For this reason, for example, the gate electrode GE2 is not illustrated in FIG. 4.

[0054] Next, an insulating layer IL5 is formed on the insulating layer IL4 so as to cover the gate electrode GE2. Then, a source electrode SE is formed on the insulating layer IL5. This source electrode SE functions as a signal line S. The insulating layer IL5 is made of an inorganic insulating film such as a silicon nitride film or a silicon oxide film. On the other hand, the source electrode SE is made of a metal material, for example.

[0055] 5, a contact hole CH1 is formed in the insulating layer IL4 and the insulating layer IL5, penetrating these insulating layers to reach the semiconductor layer OS, and the source electrode SE contacts the semiconductor layer OS at the contact hole CH1. This forms a contact portion PLG1 in which a conductive material (a part of the source electrode SE) and the semiconductor layer OS contact each other in the contact hole CH1. As a result, the source electrode SE is electrically connected to the semiconductor layer OS at the contact portion PLG1.

[0056] Next, an insulating layer IL6 is formed on the insulating layer IL5 so as to cover the source electrode SE. This insulating layer IL6 is also made of an inorganic insulating film such as a silicon nitride film or a silicon oxide film. Then, as shown in FIG. 5, a contact hole CH2 is formed penetrating the insulating layer IL6, the insulating layer IL5, and the insulating layer IL4 to reach the semiconductor layer OS. At this time, a relay electrode RE is formed from inside the contact hole CH2 over the insulating layer IL6. The relay electrode RE is made of, for example, a light-transmitting conductive material.

[0057] Subsequently, an insulating layer IL7 is formed so as to fill the inside of the contact hole CH2 and extend over the insulating layer IL6. The insulating layer IL7 is also made of an inorganic insulating film such as a silicon nitride film or a silicon oxide film.

[0058] Here, the relay electrode RE and the semiconductor layer OS are connected via the contact hole CH2. As a result, the relay electrode RE and the semiconductor layer OS come into contact with each other at the contact hole CH2, forming a contact portion PLG2. As a result, the relay electrode RE is electrically connected to the semiconductor layer OS via the contact portion PLG2. In other words, the relay electrode RE is electrically connected to the drain of the thin film transistor.

[0059] Then, as shown in FIG. 5, the color filter CFB and the color filter CFG are formed on the insulating layer IL7. This realizes a "COA structure" in this embodiment. Next, an organic insulating film 100A is formed so as to cover the color filter CFB and the color filter CFG. The organic insulating film 100A is made of an organic material such as an acrylic resin. A contact hole CH3 is formed in the organic insulating film 100A and the insulating layer IL7, penetrating the organic insulating film 100A and the insulating layer IL7 and reaching the relay electrode RE. A plurality of types of components are embedded in the contact hole CH3 to form a contact portion PLG3. In this manner, the contact portion PLG3 is electrically connected to the semiconductor layer OS (drain side) via the relay electrode RE.

[0060] Note that Figure 5 does not describe the detailed configuration of the contact portion PLG3 and the detailed structure formed between the organic insulating film 100A and the alignment film 200A, but the detailed configuration of the contact portion PLG3 and the detailed structure formed between the organic insulating film 100A and the alignment film 200A will be described using other drawings described later.

[0061] 5, a liquid crystal layer LC is disposed above the organic insulating film 100A on which the contact portion PLG3 is formed, with an alignment film 200A therebetween, and a spacer SP is provided above the contact portion PLG3. A substrate 20 is disposed above the liquid crystal layer LC, with an alignment film 200B and an overcoat film OC therebetween. In this manner, the cross-sectional structure of the sub-pixel is realized.

[0062] <Sub-pixel operation> Next, the operation of the sub-pixel will be briefly described. For example, when a scanning signal is supplied to the gate electrodes GE1 and GE2 of a thin-film transistor, which is one of the components of a subpixel, a gate voltage equal to or higher than the threshold voltage is applied to each of the gate electrodes GE1 and GE2. Then, a channel is formed on both the lower and upper surfaces of the semiconductor layer OS sandwiched between the gate electrodes GE1 and GE2. This electrically connects the source and drain of the thin-film transistor to turn it on. At this time, for example, when a video signal is supplied to the source electrode SE of the thin-film transistor, the video signal is transmitted to the relay electrode RE, which is electrically connected to the drain of the semiconductor layer OS, via the thin-film transistor that is turned on. The video signal is then transmitted from the relay electrode RE to the pixel electrode at the contact portion PLG3.

[0063] Although the detailed structure will be described later, inside and outside the contact portion PLG3, a capacitance composed of a pixel electrode, a common electrode, and a capacitance insulating film is formed, and a video signal is supplied to the pixel electrode constituting the capacitance. As a result, a potential difference is generated between the pixel electrode and the common electrode, and an electric field generated based on this potential difference leaks out from a slit provided in the common electrode. Then, the lateral electric field leaking out from the slit controls the orientation direction of multiple liquid crystal molecules constituting the liquid crystal layer LC arranged above the array substrate. As a result, the transmission and blocking of light from the liquid crystal layer LC is controlled in the sub-pixels. Such control is performed for all sub-pixels arranged in the display area, and an image is displayed in the display area.

[0064] <Description of Related Art> Next, the related art will be described. The term "related art" as used herein refers to art that is not publicly known, but has problems that the inventors have found, and is a technology that serves as a premise for the present invention. FIG. 6 is a cross-sectional view showing the internal and external configuration of a contact portion PLG3 in the related art.

[0065] 6, a relay electrode RE is provided on an insulating layer IL6, and an insulating layer IL7 is disposed so as to cover the relay electrode RE. A color filter CFB and a color filter CFG are provided on the insulating layer IL7. In order to flatten the unevenness caused by the color filter CFB and the color filter CFG, an organic insulating film 100A is provided so as to cover the color filter CFB and the color filter CFG.

[0066] As shown in FIG. 6, the organic insulating film 100A is provided with a contact hole CH3 that penetrates the organic insulating film 100A and the insulating layer IL7 to reach the relay electrode RE. A pixel electrode PE made of a light-transmitting conductive material such as ITO is formed on the inner wall of the contact hole CH3. As shown in FIG. 6, the pixel electrode PE is electrically connected to the relay electrode RE at the bottom of the contact hole CH3. Furthermore, a capacitive insulating film CI is formed in the contact hole CH3 and is in contact with the pixel electrode PE and the inner wall of the contact hole CH3. The capacitive insulating film CI is made of, for example, a silicon nitride film. Next, a conductive film TML in contact with the capacitive insulating film CI, a common electrode CE in contact with the conductive film TML, and an organic insulating film 100B in contact with the common electrode CE and filling the contact hole CH3 are formed in the contact hole CH3. In this manner, the contact portion PLG3 in the related art is configured.

[0067] Here, a capacitance is formed by the pixel electrode PE, the capacitance insulating film CI, and the common electrode CE, and when a potential difference is generated between the pixel electrode PE and the common electrode CE, an electric field is induced between the pixel electrode PE and the common electrode CE. Although not shown in Fig. 6, a slit is provided in the common electrode CE, and the electric field leaks out from this slit to the outside of the capacitance. The alignment direction of the liquid crystal molecules is controlled based on the electric field leaking out from the slit.

[0068] The common electrode CE is made of a transparent conductive material such as ITO. In order to reduce the resistance of the common electrode CE, a conductive film TML is provided in contact with the common electrode CE. In other words, the conductive film TML has the function of reducing the resistance of the common electrode CE.

[0069] An example of the configuration of the conductive film TML will be described below. FIG. 7 is a schematic diagram showing a configuration example of the conductive film TML.

[0070] In FIG. 7, the conductive film TML is composed of a laminated film of a titanium film 310, an aluminum film 320, a titanium film 330, an ITO film 340, and a molybdenum film 350. That is, the conductive film TML is composed to include a metal film and a light-transmitting conductive film (metal oxide film). For example, the titanium film 310, the aluminum film 320, the titanium film 330, and the molybdenum film 350 constituting a part of the conductive film TML are metal films with low resistance, and these metal films have a function of reducing the resistance of the common electrode CE. On the other hand, the ITO film 340 is a light-transmitting conductive film, and is composed so that the phase difference between the light transmitted through the ITO film 340 and reflected by the titanium film 330 and the light reflected on the surface of the ITO film 340 is 180 degrees. As a result, the light transmitted through the ITO film 340 and reflected by the titanium film 330 and the light reflected on the surface of the ITO film 340 are offset by interference, and the reflection of external light is suppressed. In this way, the conductive film TML also functions as an anti-reflection film that suppresses reflection of external light.

[0071] <Room for improvement> Next, room for improvement in the related art will be described. As shown in FIG. 6, in the related art, the conductive film TML is provided inside the contact hole CH3. The conductive film TML is formed, for example, by a sputtering method. In this case, the thickness of the conductive film TML formed inside the contact hole CH3 tends to be thinner than the design value. For example, in the conductive film TML shown in FIG. 7, when the thickness of the molybdenum film 350 becomes thinner than the design value, the reflection of external light from the conductive film TML becomes large. In addition, when the thickness of the ITO film 340 functioning as an anti-reflection film becomes thinner than the design value, the phase difference between the light transmitted through the ITO film 340 and reflected by the titanium film 330 and the light reflected by the surface of the ITO film 340 deviates from 180 degrees. This means that the effect of reducing reflected light due to thin film interference becomes smaller. That is, in the related art, the conductive film TML is formed inside the contact hole CH3, and as a result, the thickness of the conductive film TML becomes thinner than the design value, and the reflection of external light by the conductive film TML becomes apparent.

[0072] As described above, there is room for improvement in the related art in terms of suppressing reflection of external light, and this room for improvement is a new finding made by the present inventor. Therefore, hereinafter, first, a technology under consideration for overcoming the room for improvement that exists in the related art will be described.

[0073] <Explanation of the technology under consideration> In this specification, the "consideration technology" refers to a technology that overcomes the room for improvement that exists in the related technology, and is a technology that takes an approach different from the technical idea of ​​the present embodiment. FIG. 8 is a cross-sectional view showing the internal and external configurations of the contact portion PLG3 in the examined technique.

[0074] 8, in the examined technique, a light-shielding film BM that is in contact with the organic insulating film 100B and the common electrode CE is formed in a region that overlaps with the contact hole CH3 in a cross-sectional view. This light-shielding film BM is, for example, a light-absorbing layer (light-absorbing film) that absorbs light.

[0075] As a result, the external light is absorbed by the light-shielding film BM before it reaches the conductive film TML formed inside the contact portion PLG3. As a result, according to the studied technology, the presence of the light-shielding film BM prevents reflection of external light by the conductive film TML from becoming apparent as a problem. That is, in the studied technology, reflection of external light by the conductive film TML is suppressed by an approach of forming the light-shielding film BM above the contact portion PLG3. As a result, according to the studied technology, it is possible to overcome the room for improvement that exists in the related technology.

[0076] For example, the light-shielding film BM can be composed of a black matrix. In this case, a "COA structure" including a black matrix is ​​realized. The configuration of the studied technology shown in FIG. 8 can be realized by adding only the light-shielding film BM to the structure of the related technology shown in FIG. 6. For this reason, the studied technology has the advantage that it can be realized by easily modifying the related technology.

[0077] <Room for further improvement> As described above, the studied technique is useful in that it can overcome the room for improvement that exists in the related technique. However, in the studied technique, the conductive film TML is formed inside the contact hole CH3, as in the related technique, and based on this, there is still room for further improvement in the studied technique, as described below.

[0078] For example, when the conductive film TML is formed both inside and outside the contact hole CH3, the thickness of the conductive film TML differs between the inside and outside of the contact hole CH3. Specifically, the thickness of the conductive film TML formed inside the contact hole CH3 is thinner than the thickness of the conductive film TML formed outside the contact hole CH3. In other words, the thickness of the conductive film TML formed outside the contact hole CH3 is thicker than the thickness of the conductive film TML formed inside the contact hole CH3. As a result, stress is applied to the common electrode CE formed on the conductive film TML based on the difference in thickness of the conductive film TML, which is the base film, and there is a risk of "disconnection of the common electrode CE".

[0079] In other words, in the investigated technology, a phenomenon called “disconnection” is likely to occur in the common electrode CE due to the following factors: (1) the conductive film TML is formed both inside and outside the contact hole CH3, and (2) the common electrode CE is formed on the conductive film TML.

[0080] While the investigated technology can suppress the reflection of external light by the conductive film TML by using the light-shielding film BM, the above-mentioned factors (1) and (2) may result in another room for improvement, that is, the "step discontinuity" of the common electrode CE. It is desirable to overcome this other room for improvement, that is, the "step discontinuity" of the common electrode CE.

[0081] Therefore, in this embodiment, a technique is implemented to overcome both the problem of suppressing reflection of external light by the conductive film TML and the problem of "disconnection" of the common electrode CE. The technical idea of ​​this embodiment that implements this technique will be described below.

[0082] <Basic Concept of the Embodiment> Next, the basic concept of this embodiment will be described. The basic idea of ​​this embodiment is to form a conductive film on the common electrode without forming a conductive film inside the contact hole, i.e., to provide a conductive film above the common electrode without forming a conductive film below the common electrode.

[0083] According to this basic concept, first, since no conductive film is formed inside the contact hole, it is possible to prevent the formation of a conductive film with a thickness thinner than the design value inside the contact hole. This means that, according to the basic concept, the increase in reflection of external light caused by the conductive film provided inside the contact hole is suppressed, and thus the reflection of external light by the conductive film can be reduced. Then, according to the basic concept, on the premise that no conductive film is formed inside the contact hole, the conductive film is provided above the common electrode, not below the common electrode, which avoids the difference in thickness of the conductive film inside and outside the contact hole and the conductive film becoming the base film of the common electrode. This makes it possible to prevent the "step discontinuity" of the common electrode from occurring, according to the basic concept.

[0084] In this way, according to the basic idea, it is possible to overcome both the room for improvement that exists in the related art (increased reflection of external light by the conductive film) and the room for further improvement that exists in the studied art (the "disconnection" of the common electrode). Therefore, the basic idea of ​​the present embodiment is a useful technical idea in that it solves the problems that exist in the related art with an approach different from that of the studied art, while not causing further problems as a side effect, as in the studied art. The following describes an embodiment that embodies this basic concept.

[0085] <Embodiment> FIG. 9 is a cross-sectional view showing the internal and external configuration of the contact portion PLG3 in the embodied embodiment. 9, a relay electrode RE is provided on an insulating layer IL6. An insulating layer IL7 is disposed so as to cover the relay electrode RE. A color filter CFB and a color filter CFG are provided on the insulating layer IL7. In order to flatten the unevenness caused by the color filters CFB and CFG, an organic insulating film 100A is provided so as to cover the color filters CFB and CFG.

[0086] As shown in FIG. 9, the organic insulating film 100A has a contact hole CH3 penetrating the organic insulating film 100A and the insulating layer IL7 to reach the relay electrode RE. A pixel electrode PE made of a light-transmitting conductive material such as ITO is formed on the inner wall of the contact hole CH3. As shown in FIG. 9, the pixel electrode PE is electrically connected to the relay electrode RE at the bottom of the contact hole CH3. Furthermore, a capacitive insulating film CI is formed in the contact hole CH3 and in contact with the pixel electrode PE and the inner wall of the contact hole CH3. The capacitive insulating film CI is made of, for example, a silicon nitride film. Next, a common electrode CE in contact with the capacitive insulating film CI is formed in the contact hole CH3. An organic insulating film 100B is formed in contact with the common electrode CE and filling the contact hole CH3.

[0087] In this manner, the contact portion PLG3 filling the contact hole CH3 is formed. Next, as shown in Fig. 9, a conductive film TML in contact with the organic insulating film 100B and an antireflection film AR in contact with the conductive film TML are provided above the contact portion PLG3.

[0088] Here, the conductive film TML has a lower resistance value than the common electrode CE. In Fig. 9, the conductive film TML does not seem to be in contact with the common electrode CE, but in a plan view taking into account the planar spread, the conductive film TML has a portion in contact with the common electrode CE. As a result, the conductive film TML functions as a common auxiliary electrode that reduces the resistance of the common electrode CE.

[0089] For example, the conductive film TML is configured to include a metal film having a light-shielding property and a metal oxide film in contact with the metal film. As an example, the conductive film TML is configured from a laminated film as shown in FIG. 7. Specifically, the conductive film TML is configured from a laminated film of a titanium film 310, an aluminum film 320, a titanium film 330, an ITO film 340, and a molybdenum film 350.

[0090] Each of the pixel electrode PE, the common electrode CE, and the anti-reflection film AR is made of a metal oxide film (for example, an ITO film) having light-transmitting properties. In this manner, the internal and external configuration of the contact portion PLG3 in the embodied embodiment is realized.

[0091] <<Features of the Realization>> Next, features of the embodiment will be described. A first feature of the embodiment is that, for example, as shown in Fig. 9, in a cross-sectional view, the conductive film TML is not formed inside the contact hole CH3 and is provided above the common electrode CE. That is, in the first feature, the conductive film TML is not a component of the contact portion PLG3, but is provided above the contact portion PLG3.

[0092] As a result, first, the conductive film TML is not formed inside the contact hole CH3. Therefore, it is possible to suppress an increase in reflection of external light caused by the conductive film TML due to the thickness of the conductive film TML formed inside the contact hole CH3 being thinner than the design value. That is, according to the first characteristic point, since the conductive film TML is not formed inside the contact hole CH3, it is possible to suppress an increase in reflection of external light caused by the conductive film TML formed inside the contact hole CH3.

[0093] Furthermore, according to the first characteristic point, the conductive film TML is provided above the common electrode CE, not below the common electrode CE. Therefore, a "step discontinuity" of the common electrode CE caused by a difference in film thickness of the conductive film TML does not occur. This is because a "step discontinuity" of the common electrode CE is a phenomenon that occurs when the conductive film TML is formed below the common electrode CE, and does not occur when the conductive film TML is provided above the common electrode CE as in the first characteristic point. Therefore, when the first characteristic point is adopted, it becomes unnecessary to consider a "step discontinuity" caused by the conductive film TML, and there is no room for further improvement that exists in the examined technology.

[0094] In this way, the first characteristic overcomes the room for improvement in the related art or the considered art. Therefore, the first characteristic in the embodied embodiment is excellent in that it can suppress an increase in the reflection of external light without causing side effects.

[0095] Next, a second feature of the embodiment is that, for example, an anti-reflection film AR is provided on the conductive film TML as shown in Fig. 9. This makes it possible to suppress reflection of external light on the surface of the conductive film TML, thereby improving the visibility of the display device.

[0096] 7, the conductive film TML is composed of a laminated film of a titanium film 310, an aluminum film 320, a titanium film 330, an ITO film 340, and a molybdenum film 350. In this case, since the molybdenum film 350 is disposed as the uppermost layer of the conductive film TML, it is considered that external light is reflected on the surface of the molybdenum film 350.

[0097] Regarding this point, in the second characteristic, an anti-reflection film AR is disposed on the molybdenum film 350. The anti-reflection film AR is made of a light-transmitting conductive material typified by an ITO film, and its thickness is designed so that the phase difference between the light reflected on the surface of the anti-reflection film AR and the light transmitted through the anti-reflection film AR and reflected on the surface of the molybdenum film 350 is 180 degrees.

[0098] As a result, according to the second feature, reflection of external light can be effectively suppressed, and as a result, visibility of the display device can be improved. As described above, according to the embodiment, by combining the above-mentioned first feature and second feature, reflection of external light can be effectively suppressed without causing a "discontinuity" in the common electrode CE. As a result, according to the embodiment, visibility can be improved while improving the reliability of the display device.

[0099] <Modification> Next, this modified example will be described. FIG. 10 is a cross-sectional view showing the internal and external configuration of a contact portion PLG3 in this modified example. As shown in FIG. 10, in this modification, an antireflection film AR is provided so as to cover the conductive film TML, and this antireflection film AR is also in contact with the common electrode CE.

[0100] The anti-reflection film AR configured in this manner can maintain a state of covering the conductive film TML even if misalignment occurs between the anti-reflection film AR and the conductive film TML during patterning. Therefore, according to this modification, even if misalignment occurs due to patterning, the conductive film TML will not be exposed from the anti-reflection film AR, and thus reflection of external light can be reliably suppressed.

[0101] Within the scope of the concept of the present invention, a person skilled in the art may conceive of various modifications and alterations, and it is understood that such modifications and alterations also fall within the scope of the present invention. For example, those in which a person skilled in the art appropriately adds, deletes, or modifies the design of the above-mentioned embodiment, or adds, omits, or modifies the conditions of a process, are also included in the scope of the present invention as long as they include the gist of the present invention.

[0102] Furthermore, other effects and advantages brought about by the aspects described in the embodiments that are obvious from the description in this specification or that can be appropriately thought of by a person skilled in the art are naturally understood to be brought about by the present invention. The above embodiment includes the following aspects. (Appendix 1) A first organic insulating film; a pixel electrode in contact with the first organic insulating film; a capacitance insulating film in contact with the pixel electrode; a conductive film in contact with the capacitive insulating film; a common electrode in contact with the conductive film; Equipped with The first organic insulating film is provided with a contact hole, The contact hole has the pixel electrode in contact with an inner wall of the contact hole; the capacitive insulating film in contact with an inner wall of the contact hole and the pixel electrode; the conductive film in contact with the capacitive insulating film; the common electrode in contact with the conductive film; a second organic insulating film in contact with the common electrode and filling the contact hole; is formed, Above the contact hole, a light-shielding film in contact with the second organic insulating film and the common electrode is formed on the display device. (Appendix 2) In the display device according to claim 1, The display device, wherein the light-shielding film is a black matrix. (Appendix 3) In the display device according to claim 1, the conductive film has a lower resistance than the common electrode, The conductive film is A metal film; a metal oxide film in contact with the metal film; A display device comprising: (Appendix 4) An array substrate having switching elements, The array substrate includes: A first organic insulating film; a pixel electrode in contact with the first organic insulating film; a capacitive insulating film in contact with the pixel electrode; a conductive film in contact with the capacitive insulating film; a common electrode in contact with the conductive film; Equipped with The first organic insulating film is provided with a contact hole, The contact hole has the pixel electrode in contact with an inner wall of the contact hole; the capacitive insulating film in contact with an inner wall of the contact hole and the pixel electrode; the conductive film in contact with the capacitive insulating film; the common electrode in contact with the conductive film; a second organic insulating film in contact with the common electrode and filling the contact hole; is formed, Above the contact hole, an array substrate on which a light-shielding film is formed in contact with the second organic insulating film and the common electrode; [Explanation of symbols]

[0103] 1 LCD display device 2 Display Panel 3. Backlight 4 Optical sheets 5. Polarizing Plate 6 Polarizing Plate 10 Substrate 20 Substrate 100A Organic Insulating Film 100B Organic insulating film 200A alignment film 200B alignment film 310 Titanium film 320 Aluminum Film 330 Titanium Film 340 ITO film 350 Molybdenum film AR anti-reflection coating BM light shielding film CE Common electrode CFR Color Filter CFG Color Filter CFB Color Filter CH1 Contact hole CH2 Contact Hole CH3 Contact Hole CI Capacitive insulating film CT Controller DA display area DF Diffusion Sheet F Flexible board G scan line GD1 Scan Driver GD2 Scan Driver GE1 Gate electrode GE2 Gate electrode GP Gap IL1 Insulation layer IL2 Insulation layer IL3 Insulation layer IL4 Insulation Layer IL5 Insulation Layer IL6 Insulation Layer IL7 Insulation Layer LC liquid crystal layer LG light guide LS Light Emitting Element MA implementation area OC overcoat film OR opening area OS semiconductor layer PE pixel electrode PLG1 Contact part PLG2 Contact part PLG3 Contact part PR1 Prism sheet PR2 Prism sheet PX pixels RE relay electrode S signal line SA Surrounding Areas SE source electrode SL Slit SP Spacer SPR subpixel SPG Subpixel SPB subpixel ST selector circuit SUB1 Array board SUB2 Opposing board SW Switching element T terminal section TML Conductive Film

Claims

1. A first organic insulating film; a pixel electrode in contact with the first organic insulating film; a capacitive insulating film in contact with the pixel electrode; a common electrode in contact with the capacitive insulating film; a conductive film in contact with the common electrode; an anti-reflection film in contact with the conductive film; Equipped with The first organic insulating film is provided with a contact hole; The contact hole has the pixel electrode in contact with an inner wall of the contact hole; the capacitive insulating film in contact with an inner wall of the contact hole and the pixel electrode; the common electrode in contact with the capacitive insulating film; a second organic insulating film in contact with the common electrode and filling the contact hole; is formed, Above the contact hole, the conductive film in contact with the second organic insulating film; the anti-reflection film in contact with the conductive film; A display device is formed.

2. 2. The display device according to claim 1, the anti-reflection film is provided to cover the conductive film, The display device, wherein the anti-reflection film is also in contact with the common electrode.

3. 2. The display device according to claim 1, The conductive film has a lower resistance than the common electrode.

4. 2. The display device according to claim 1, The conductive film is A metal film; a metal oxide film in contact with the metal film; A display device comprising:

5. 2. The display device according to claim 1, The display device, wherein the pixel electrode, the common electrode and the anti-reflection film are each made of a light-transmitting metal oxide film.

6. An array substrate having switching elements, The array substrate includes: A first organic insulating film; a pixel electrode in contact with the first organic insulating film; a capacitive insulating film in contact with the pixel electrode; a common electrode in contact with the capacitive insulating film; a conductive film in contact with the common electrode; an anti-reflection film in contact with the conductive film; Equipped with The first organic insulating film is provided with a contact hole; The contact hole has the pixel electrode in contact with an inner wall of the contact hole; the capacitive insulating film in contact with an inner wall of the contact hole and the pixel electrode; the common electrode in contact with the capacitive insulating film; a second organic insulating film in contact with the common electrode and filling the contact hole; is formed, Above the contact hole, the conductive film in contact with the second organic insulating film; the anti-reflection film in contact with the conductive film; An array substrate on which is formed.

7. 7. The array substrate according to claim 6, the anti-reflection film is provided to cover the conductive film, The anti-reflection film is also in contact with the common electrode.

8. 7. The array substrate according to claim 6, the conductive film has a lower resistance than the common electrode, The conductive film is A metal film; a metal oxide film in contact with the metal film; 1. An array substrate comprising:

9. 7. The array substrate according to claim 6, the switching element is composed of a thin film transistor, The array substrate includes: a relay electrode connected to the drain of the thin film transistor; the pixel electrode connected to the relay electrode at the bottom of the contact hole; An array substrate comprising:

10. 7. The array substrate according to claim 6, an array substrate having a color filter covered with the first organic insulating film;

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