Patent Publication Number: US-10775912-B2

Title: Display device having touch sensors and method of manufacturing the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of the Republic of Korea Patent Application No. 10-2017-0171289, filed on Dec. 13, 2017, which is hereby incorporated by reference in its entirety. 
     BACKGROUND 
     Technical Field 
     The present disclosure relates to a display device and a method of manufacturing the same, and more particularly, to a display device having touch sensors which may reduce parasitic capacitance and a method of manufacturing the same. 
     Discussion of the Related Art 
     A touch panel is one kind of input device which is provided in a display device, such as a liquid crystal display device, an organic light emitting display device or an electrophoretic display device, so that a user may input information by directly contacting a screen using a finger or a stylus pen. 
     Recently, in order to satisfy slimness of portable terminals, such as smartphones, tablet PCs, etc., demand for a display device, in which touch sensors constituting a touch panel are installed within a display panel of the display device, is increasing. 
     However, in such a display device having built-in touch sensors, a plurality of electrodes or signal lines of a display panel are arranged around the touch sensors. Unnecessary parasitic capacitances are formed due to these electrodes or signal lines of the display panel. The parasitic capacitances increase a touch driving load and lower accuracy in touch sensing, or, in severe cases, may cause impossibility of sensing touch. 
     SUMMARY 
     Accordingly, the present disclosure is directed to a display device having touch sensors and a method of manufacturing the same that substantially obviates one or more problems due to limitations and disadvantages of the related art. 
     An object of the present disclosure is to provide a display device having touch sensors which may reduce parasitic capacitance and a method of manufacturing the same. 
     Additional advantages, objects, and features of the disclosure will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the disclosure. The objectives and other advantages of the disclosure may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
     To achieve these objects and other advantages and in accordance with the purpose of the disclosure, as embodied and broadly described herein, a display device having touch sensors includes a plurality of touch sensing lines respectively arranged so as to traverse a plurality of common electrode blocks forming an electric field with pixel electrodes, a lower planarization layer having openings in regions overlapping drain electrodes of thin film transistors, and an upper planarization layer arranged between one of the pixel electrodes and the common electrode blocks, and the touch sensing lines so as to cover a side surface of the lower planarization layer. 
     Some embodiments relate to a display device having touch sensors comprising: a plurality of thin film transistors arranged on a substrate; a plurality of pixel electrodes, each of the plurality of pixel electrodes connected to a corresponding one of the plurality of thin film transistors; a plurality of common electrode blocks configured to form an electric field with the plurality of pixel electrodes, the plurality of common electrodes arranged on the substrate; a plurality of touch sensing lines, each of the plurality of touch sensing lines connected to a corresponding one of the plurality of common electrode blocks; a lower protective film arranged between the plurality of thin film transistors and the plurality of touch sensing lines, the lower protective film having a plurality of openings overlapping drain electrodes of the plurality of thin film transistors; a lower planarization layer arranged on the lower protective film, the lower planarization layer having a plurality of openings overlapping the plurality of openings of the lower protective film; an upper planarization layer arranged between one of the plurality of pixel electrodes and the plurality of common electrode blocks, and the plurality of touch sensing lines, wherein side surfaces of the upper planarization layer cover side surfaces of the lower planarization layer exposed by the plurality of openings of the lower planarization layer, and wherein the side surfaces of the upper planarization layer, the plurality of openings in the lower planarization layer, and the plurality of openings in the lower protective film form pixel contact holes that expose the drain electrodes of the plurality of thin film transistors; and an upper protective film arranged between the pixel electrodes and the common electrode blocks, wherein the plurality of pixel electrodes contact side surfaces of the upper planarization layer and the lower protective film exposed by the pixel contact holes. 
     Some embodiments relate to a method of manufacturing a display device having touch sensors, comprising: forming a plurality of thin film transistors on a substrate; forming a lower protective film so as to cover the plurality of thin film transistors, the lower protective film having a plurality of openings overlapping drain electrodes of the plurality of thin film transistors; forming a lower planarization layer on the lower protective film, the lower planarization layer having a plurality of openings overlapping the openings of the lower protective film; forming a plurality of touch sensing lines on the lower planarization layer; forming an upper planarization layer on the plurality of touch sensing lines and the lower planarization layer, wherein side surfaces of the upper planarization layer cover side surfaces of the lower planarization layer exposed by the plurality of openings of the lower planarization layer, and wherein the side surfaces of the upper planarization, the plurality of openings in the lower planarization layer, and the plurality of openings in the lower protective film form pixel contact holes that expose the drain electrodes of the plurality of thin film transistors; forming a plurality of pixel electrodes, each of the plurality of pixel electrodes connected to a corresponding one of the plurality of thin film transistors through side surfaces of the pixel contact holes; forming an upper protective film on the upper planarization layer and the plurality of pixel electrodes; and forming a plurality of common electrode blocks configured to form an electric field with the plurality of pixel electrodes, each of the plurality of common electrode blocks arranged on the upper protective film to be connected to a corresponding one of the plurality of touch sensing lines. 
     Some embodiments relate to a display device having touch sensors comprising: a substrate; a thin film transistor (TFT) arranged on the substrate, wherein the TFT includes an electrode; a first protective film on the TFT, the first protective film including a hole that exposes a portion of an electrode of the TFT; a first planarization layer over the first protective film and the TFT, the first planarization layer including a hole overlapping the portion of the electrode exposed through the hole in the first protective film; a touch sensing line (TSL) on the lower planarization layer; a second planarization layer over the TSL and the first planarization layer, the second planarization layer covering a side surface of the first planarization layer exposed by the hole in the first planarization layer such that a hole is formed in the second planarization layer; a pixel electrode on the second planarization layer, the pixel electrode electrically connected to the electrode of the TFT through the hole in the second planarization layer, the hole in the first planarization layer, and the hole in the first protective film; and a common electrode block over the pixel electrode the common electrode block electrically connected to the TSL. 
     It is to be understood that both the foregoing general description and the following detailed description of the present disclosure are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the disclosure and together with the description serve to explain the principle of the disclosure. In the drawings: 
         FIG. 1  is a block diagram illustrating a display device having touch sensors in accordance with an embodiment; 
         FIG. 2  is a plane view illustrating a display panel having the touch sensors shown in  FIG. 1  in more detail, according to an embodiment; 
         FIG. 3  is an enlarged plan view of a portion “A” of  FIG. 2 , according to an embodiment; 
         FIG. 4  is a cross-sectional view of the display panel, taken along lines “I-I′” and “II-II′” of  FIG. 3 ; and 
         FIGS. 5A to 5G  are cross-sectional views illustrating a method of manufacturing the display device shown in  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the preferred embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. 
       FIG. 1  is a block diagram illustrating a display device having touch sensors in accordance with one embodiment of the present disclosure. 
     The display device shown in  FIG. 1  includes a data driver  204 , a gate driver  202 , a touch driver  206 , and a display panel  200 . 
     The data driver  204  converts data from a timing controller (not shown) into analog data voltage and supplies the analog data voltage to data lines DL in response to a data control signal from the timing controller. 
     The gate driver  202  sequentially drives gate lines GL of the display panel  200  in response to a gate control signal from the timing controller. The gate driver  202  supplies a scan pulse of a gate-on voltage to each gate line GL during a scan period of the corresponding gate line GL, and supplies a gate-off voltage to the corresponding gate line GL during remaining periods when other gate lines GL are driven. The gate driver  202  is formed together with thin films transistors of respective pixels during a process of manufacturing the thin film transistors and is located at a non-display area formed at one side or both sides of a substrate of the display panel  200 . 
     The touch driver  206  is connected to touch sensing lines TSL of the display panel  200  and thus receives a user touch signal from the touch sensing lines TSL. The touch driver  206  detects whether or not user touch occurs and a touch position by sensing change in capacitance due to the user touch. 
     In the display panel  200 , a plurality of pixels are arranged in a matrix and thus displays an image. If a liquid crystal panel is used as the display panel  200 , the display panel  200  may include a color filter substrate on which a color filter array is formed, a thin film transistor substrate on which a thin film transistor array is formed, and a liquid crystal layer provided between the color filter substrate and the thin film transistor substrate. 
     The display panel  200  includes an active area AA and a bezel area BA arranged at at least one side of the active area AA, as exemplarily shown in  FIG. 2 . 
     A plurality of pads connected to the signal lines GL, DL and TSL of the active are AA are arranged in the bezel area BA. That is, gate pads (not shown) connected to the gate lines GL, data pads (not shown) connected to the data lines DL and common pads (not shown) connected to the touch sensing lines TSL are arranged in the bezel area BA. Further, at least one of the gate driver  202 , the data driver  204 , or the touch driver  206  may be arranged in the bezel area BA. 
     A plurality of common electrode blocks  132  and a plurality of touch sensing lines TSL respectively connecting the common electrode blocks  132  to the touch driver  206  are arranged in the active area AA. Here, each touch sensing line TSL is arranged so as to extend in a vertical or horizontal direction and thus to traverse the common electrode blocks  132 . For example, the touch sensing lines TSL may be arranged so as to extend in a direction parallel to the data lines DL and thus to traverse the common electrode blocks  132 , which are arranged in the direction of the data lines DL. 
     In the example of  FIG. 2 , a plurality of the common electrode blocks  132  are arranged in a first direction parallel to the gate lines GL and in a second direction parallel to the data lines DL. The common electrode blocks  132  may also be arranged so as to be spaced apart from each other. 
     The common electrode blocks  132  are formed by dividing a common electrode of the display device into a plurality of pieces. The common electrode blocks  132  can operate as common electrodes during an image display period, and can operate as touch electrodes during a touch sensing period. That is, during the image display period, the common electrode blocks  132  receive a common voltage supplied through the touch sensing lines TSL. Further, during the touch sensing period (e.g., an image non-display period) the common electrode blocks  132  supply sensed touch sensing voltages to the touch driver  206  through the touch sensing lines TSL. 
     Each of the common electrode blocks  132  can have a size corresponding to at least two pixel areas in consideration of a user touch area. Therefore, one common electrode block  132  may be arranged so as to overlap a plurality of pixel electrodes  122 , as exemplarily shown in  FIG. 3 . 
     The pixel electrode  122  is connected to a thin film transistor  100  in each pixel area, prepared by intersection of the gate line GL and the data line DL, as exemplarily shown in  FIG. 4 . 
     The thin film transistor  100  charges the pixel electrode  122  with a data signal of the data line DL in response to a scan signal of the gate line GL (not shown in  FIG. 4 ) and maintains the charged state of the pixel electrode  122 . For this purpose, the thin film transistor  100  includes a gate electrode  106  connected to the gate line GL, a source electrode  108  connected to the data line DL, a drain electrode  110  connected to the pixel electrode  122 , and a semiconductor layer formed on a gate insulating film  112  so as to form a channel between the source electrode  108  and the drain electrode  110 . Here, the semiconductor layer includes an active layer  102  and an ohmic contact layer  104 . The active layer  102  is formed on the gate insulating film  112  so as to overlap the gate electrode  106 , thus forming the channel between the source and drain electrodes  108  and  110 . The ohmic contact layer  104  is formed on the active layer  102  except for the channel so as to form ohmic contact between each of the source and drain electrodes  108  and  110  and the active layer  102 . The active layer  102  and the ohmic contact layer  104  are formed to overlap the data line DL as well as the source and drain electrodes  108  and  110 . 
     A lower protective film  118 , a lower planarization layer  116 , an interlayer protective film  124 , an upper planarization layer  126 , and an upper protective film  128  are sequentially stacked on the thin film transistor  100 . 
     Each of the lower protective film  118 , the interlayer protective film  124  and the upper protective film  128  is formed to have a monolayer or multilayer structure using an inorganic insulating material, such as SiN x , SiON, or SiO 2 . Particularly, if the active layer  102  is formed of an oxide semiconductor, the lower protective film  118  contacting the active layer  102  may be formed of silicon oxide (SiO x ) having a lower hydrogen content than silicon nitride (SiN x ) grown as a film using hydrogen gas. Therefore, diffusion of hydrogen into the active layer  102  during formation of the lower protective film  118  may be prevented and thus a change in a threshold voltage of the thin film transistor  100  may be prevented. Further, the interlayer protective film  124  can be formed of silicon nitride (SiN x ) and may thus prevent oxidation of the touch sensing lines TSL. 
     Each of the lower planarization layer  116  and the upper planarization layer  126  can be formed of a photosensitive organic insulating material so as not to require an etching process. For example, the lower planarization layer  116  and the upper planarization layer  126  is formed of a photoacryl, parylene, or siloxane-based organic insulating materials. Here, the lower planarization layer  116  has an opening  116 A in a region overlapping the drain electrode  110  of the thin film transistor  100 . The upper planarization layer  126  and the interlayer protective film  124  are arranged to cover the side surface of the lower planarization layer  116  exposed through the opening  116 A. Thereby, a pixel contact hole  120  formed through the upper planarization layer  126 , the interlayer protective film  124  and the lower protective film  118  is arranged within the opening  116 A so as to have a smaller line width than that of the opening  116 A. Since the interlayer protective film  124  and the lower protective film  118  are self-aligned under the upper planarization layer  126  between the upper planarization layer  126  and the drain electrode  110  around the pixel contact hole  120 , only the interlayer protective film  124  and the lower protective film  118  are arranged between the upper planarization layer  126  and the drain electrode  110  around the pixel contact hole  120 . 
     As such, in the present disclosure, the lower protective film  118  formed of an inorganic insulating material is arranged between the thin film transistor  100  and the lower planarization layer  116  formed of an organic insulating material, and the interlayer protective film  124  formed of an inorganic insulating material is arranged between the touch sensing line TSL and the upper planarization layer  126  formed of an organic insulating material. The lower protective film  118  and the interlayer protective film  124  formed of inorganic insulating materials can have excellent adhesive strength with the thin film transistor  100  and the touch sensing line TSL, as compared to the lower and upper planarization layers  116  and  126  formed of organic insulating materials. Therefore, separation of the lower protective film  118  and the interlayer protective film  124  from the upper surfaces of the thin film transistor  100  and the touch sensing line TSL may be prevented and, thus, oxidation of the thin film transistor  100  and the touch sensing line TSL may be prevented. 
     The pixel electrode  122  is conductively connected to the drain electrode  110  exposed through the pixel contact hole  120  formed through the lower protective film  118 , the interlayer protective film  124  and the upper planarization layer  126 . The pixel electrode  122  directly contacts the side surface of each of the lower protective film  118 , the interlayer protective film  124  and the upper planarization layer  126 , exposed through the pixel contact hole  120 . 
     Here, the side surface of the upper planarization layer  126  formed of an organic insulating material and the side surfaces of the lower protective film  118  and the interlayer protective film  128  formed of inorganic insulating materials are exposed through the same pixel contact hole  120 . Therefore, the present disclosure may minimize the number of necessary pixel contact holes  120  and, thus, reduce an area occupied by the pixel contact holes  120  and improve an aperture ratio. 
     The common electrode block  132  is formed on the upper protective film  128  of each pixel area so as to have a plurality of slits  130 . The common electrode block  132  overlaps the pixel electrode  122  with the upper protective film  128  disposed between each pixel area and thus forms a fringe field. Thereby, during the image display period, a common voltage is supplied to the common electrode block  132 , the common electrode block  132  to which the common voltage is supplied, forms the fringe field with the pixel electrode  122  to which a pixel voltage signal is supplied, and, thus, liquid crystal molecules arranged between the thin film transistor substrate and the color filter substrate are rotated by dielectric anisotropy. Further, light transmissivity of the pixel area is varied according to a degree of rotation of the liquid crystal molecules and, thus, gradation is implemented. 
     Further, the common electrode blocks  132  serve as touch electrodes which sense a user&#39;s touch position during the touch sensing period, e.g., the image non-display period. 
     For this purpose, each common electrode block  132  is connected to one of the touch sensing lines TSL traversing the common electrode block  132 . For example, the common electrode block  132  shown in  FIG. 3  is connected to a first touch sensing line TSL 1  out of first to third touch sensing lines TSL 1 , TSL 2 , and TSL 3  (not shown in  FIG. 3 ). In more detail, the touch sensing line TSL is arranged on the lower planarization layer  116 , exposed through a first touch contact hole  166  formed through the interlayer protective film  124  and the upper planarization layer  126  and a second touch contact hole  168  formed through the upper protective film  128 , and connected to the common connection electrode  162  arranged on the upper protective film  128 . 
     Each common electrode block  132  is not connected to the remaining touch sensing lines TSL except for one of the touch sensing lines TSL traversing the common electrode block  132 . For example, the common electrode block  132  shown in  FIG. 3  is not connected to the second and third touch sensing lines TSL 2  and TSL 3  except for the first touch sensing line TSL 1  out of the first to third touch sensing lines TSL 1 , TSL 2  and TSL 3 . In more detail, out of the touch sensing lines TSL traversing each common electrode block  132 , the remaining touch sensing lines TSL which are not connected to the common electrode block  132  overlap the common electrode block  132  with the interlayer protective film  124  formed of an inorganic insulating material, the upper planarization layer  126  formed of an organic insulating material, and the upper protective film  128  formed of an inorganic insulating material, disposed between. Therefore, a distance between the touch sensing lines TSL and the common electrode blocks  132  is increased by the thickness of the upper planarization layer  126  formed of an organic insulating material and, thus, parasitic capacitance Cc generated between the touch sensing lines TSL and the common electrode blocks  132  may be reduced. A touch driving load may be reduced as much as such a reduction in the parasitic capacitance Cc and thus accuracy in touch sensing may be improved. 
     As such, in the present disclosure, the common electrode block  132  and the pixel electrodes  122  are spaced apart from each other with the upper protective film  128 , formed of an inorganic insulating material, disposed between, and the touch sensing lines TSL and the common electrode block  132  are spaced apart from each other with the interlayer protective film  124  and the upper protective film  128 , formed of inorganic insulating materials, and the upper planarization layer  126 , formed of an organic insulating material, disposed between. Therefore, in the present disclosure, parasitic capacitance generated between the touch sensing lines TSL and the common electrode blocks  132  may be reduced without reduction in liquid crystal capacitance and storage capacitance generated between the common electrode blocks  132  and the pixel electrodes  122 . 
       FIGS. 5A to 5G  are cross-sectional views illustrating a method of manufacturing the display device shown in  FIG. 4 , according to an embodiment. 
     With reference to  FIG. 5A , the data lines DL and the thin film transistors  100  are formed on a substrate  101  through at least two mask processes. 
     In more detail, a gate metal layer is deposited on the entire upper surface of the substrate  101  and then patterned, thus forming the gate electrodes  106 . Thereafter, the gate insulating film  112  is formed by coating the entire surface of the substrate  101  provided with the gate electrodes  106  formed thereon with an inorganic insulating material. A semiconductor material and a data metal layer are sequentially stacked on the gate insulating film  112  and then patterned, thus forming the active layer  102 , the ohmic contact layer  104 , the source and drain electrodes  108  and  110  and the data lines DL. 
     With reference to  FIG. 5B , the lower protective film  118  and the lower planarization layer  116  are sequentially formed on the substrate  101  provided with the data lines DL and the thin film transistors  100  formed thereon. 
     In more detail, the lower protective film  118  is formed by stacking an inorganic insulating material on the entire upper surface of the substrate  101  provided with the data lines DL and the thin film transistors  100  formed thereon. Here, the lower protective film  118  uses an inorganic insulating material, such as SiN x , SiON, or SiO 2 . Thereafter, an organic insulating material is coated on the entire upper surface of the lower protective film  118  and then patterned through a photolithographic process, thus forming the lower planarization layer  116  having the openings  116 A. The lower planarization layer  116  uses a photoacryl, parylene, or siloxane-based organic insulating material. The openings  116 A overlap the drain electrodes  110  of the thin film transistors  100 . 
     With reference to  FIG. 5C , the touch sensing lines TSL are formed on the substrate  101  provided with the lower planarization layer  116  formed thereon. 
     An opaque conductive layer is deposited on the entire upper surface of the substrate  101  provided with the lower planarization layer  116  formed thereon and is then patterned through a photolithographic process and an etching process. Thereby, the touch sensing lines TSL are formed on the lower planarization layer  116 . Here, the touch sensing lines TSL are formed of an opaque conductive layer so as to have a monolayer or multilayer structure using at least one metal selected from the group consisting of Al, Ti, Cu, Mo, Ta and MoTi. 
     With reference to  FIG. 5D , the interlayer protective film  124  and the upper planarization layer  126  are formed on the substrate  101  provided with the touch sensing lines TSL formed thereon. 
     In more detail, the interlayer protective film  124  is formed by depositing an inorganic insulating material on the entire upper surface of the substrate  101  provided with the touch sensing lines TSL formed thereon. Here, the interlayer protective film  124  uses an inorganic insulating material, such as SiN x , SiON, or SiO 2 . Thereafter, the upper planarization layer  126  is formed by depositing an organic insulating material on the entire upper surface of the interlayer protective film  124 . The upper planarization layer  126  uses a photoacryl, parylene, or siloxane-based organic insulating material. The upper planarization layer  126  is patterned through a photolithographic process, thus forming the pixel contact holes  120  and the first touch contact holes  166 . Thereafter, the interlayer protective film  124  and the lower protective film  118  are etched through an etching process using the upper planarization layer  126  as a mask. Thereby, the pixel contact holes  120  are formed through the upper planarization layer, the interlayer protective film  124 , and the lower protective film  118  and thus expose the drain electrodes  110 . Furthermore, the first touch contact holes  166  are formed through the upper planarization layer  126  and the interlayer protective film  124  and thus expose the touch sensing lines TSL. 
     With reference to  FIG. 5E , the pixel electrodes  122  are formed on the substrate  101  provided with the interlayer protective film  124  and the upper planarization layer  126  formed thereon. 
     In more detail, a transparent conductive layer is deposited on the entire upper surface of the substrate  101  provided with the upper planarization layer  126  formed thereon. Thereafter, the transparent conductive layer is patterned through a photolithographic process and an etching process, thus forming the pixel electrodes  122 . 
     With reference to  FIG. 5F , the upper protective film  128  having the second touch contact holes  168  is formed on the substrate  101  provided with the pixel electrodes  122  formed thereon. 
     In more detail, the upper protective film  128  using an inorganic insulating material, such as SiN x , SiON, or SiO 2 , is formed on the entire surface of the substrate  101  provided with the pixel electrodes  122  formed thereon. Thereafter, the upper protective film  128  is patterned through a photolithographic process and an etching process, thus forming the second touch contact holes  168  exposing the touch sensing lines TSL. 
     With reference to  FIG. 5G , the common electrode blocks  132  are formed on the substrate  101  having the second touch contact holes  168 . 
     In more detail, a transparent conductive film is deposited on the entire upper surface of the substrate  101  having the second touch contact holes  168 . Thereafter, the transparent conductive layer is patterned through a photolithographic process and an etching process, thus forming the common electrode blocks  132 . 
     Although the present disclosure exemplarily describes a structure in which the pixel electrodes  122  are arranged below the common electrode blocks  132 , the common electrode blocks  132  may be arranged below the pixel electrodes  122 . 
     As apparent from the above description, in a display device having touch sensors in accordance with the present disclosure, common electrode blocks and pixel electrodes are spaced apart from each other with an upper protective film formed of an inorganic insulating material, disposed between, and touch sensing lines and the common electrode blocks are spaced apart from each other with an interlayer protective film and the upper protective film formed of inorganic insulating materials and an upper planarization layer formed of an organic insulating material, disposed between. Therefore, in the present disclosure, parasitic capacitance generated between the touch sensing lines and the common electrode blocks may be reduced without reduction in liquid crystal capacitance and storage capacitance generated between the common electrode blocks and the pixel electrodes. Further, in the present disclosure, the side surface of the upper planarization layer formed of an organic insulating material and the side surfaces of a lower protective film and the interlayer protective film formed of inorganic insulating materials are exposed through the same pixel contact hole and, thus, the pixel electrode is conductively connected to a drain electrode exposed through one pixel contact hole. Therefore, the display device in accordance with the present disclosure may minimize the number of necessary pixel contact holes and, thus, reduce an area occupied by the pixel contact holes and improve an aperture ratio. Moreover, in the present disclosure, the pixel contact holes formed through the lower protective film and the interlayer protective film are formed using the upper planarization layer as a mask and, thus, a manufacturing process of the display device may be simplified and manufacturing costs of the display device may be reduced. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the spirit or scope of the disclosure. Thus, it is intended that the present disclosure cover the modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents.