Abstract:
The optical patterning mask had a protection layer on a light absorption layer. It prevents the light absorption layer from damaged by the cleaning gas when processing the used optical patterning mask for reuse. The protection layer may be made of the same material as bank layer or of material different from the bank layer. The bank layer defines the boundary of the area to be transferred in the transfer layer. The protection layer of the present invention can maintain longer the transfer efficiency of the optical patterning mask, even when the same mask is used repeatedly after cleaning, since the light absorption layer protected from cleaning process can maintain longer its heat conversion property.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority from Korean Patent Application No. 10-2014-0146240, filed on Oct. 27, 2014 with the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    The present invention relates to an optical patterning mask and a method for fabricating a display device using the same. 
         [0004]    2. Description of Background 
         [0005]    Among display devices, an organic light emitting display device is a self-luminous display device that has the advantages of wide viewing angle, superior contrast, and high response speed, and thus has been noticed as the next-generation display device. 
         [0006]    An organic light emitting display device has an organic light emitting layer that is made of an organic light emitting material disposed between an anode electrode and a cathode electrode. If an anode voltage and a cathode voltage are applied to these electrodes, respectively, holes injected from the anode electrode move to the organic light emitting layer through a hole injection layer and a hole transport layer, and electrons move from the cathode electrode to the organic light emitting layer through an electron injection layer and an electron transport layer. In the organic light emitting layer, the electrons and the holes are recombined. Through this recombination, excitons are generated. As the excitons change from an excited state to a ground state, the organic light emitting layer emits light to display an image. 
         [0007]    Typically, in fabricating an organic light emitting display device, the hole injection layer, the hole transport layer, the organic light emitting layer, the electron transport layer, and the electron injection layer are formed using an ink jet printing method, a nozzle print method, a deposition method using a metal mask, or a transfer method using heat or laser. 
       SUMMARY 
       [0008]    On the other hand, the transfer method using heat or laser is a method for forming a pattern layer by transferring a transfer material of a transfer layer to a specific device substrate through irradiation of heat or laser onto an optical patterning mask that includes a base substrate, a reflective layer, a thermal insulation layer, a light absorption layer, a bank layer, and a transfer layer. Through the method, for example, an organic light emitting material of an organic light emitting material layer that is provided to the transfer layer of the optical patterning mask is transferred onto the substrate of the organic light emitting display device to form the organic light emitting layer. 
         [0009]    After forming the pattern layer, the optical patterning mask is cleaned to remove the transfer material remaining on the optical patterning mask by injecting thermal energy or O 2  gas energy. Then, the optical patterning mask cleaned from the remaining transfer material can be reused. 
         [0010]    However, when cleaning the transfer material remaining on the optical patterning mask by injecting O 2  gas energy, the light absorption layer may react on O 2  gas and be damaged because it is exposed bare after the transfer material is transferred from the optical patterning mask. Damaged light absorption layer may deteriorate the function of the light absorption layer that converts light into heat. This may deteriorate the transfer efficiency of the transfer material. 
         [0011]    Accordingly, the present invention is to provide an optical patterning mask that may prevent the damage on the light absorption layer and reduce the chance of deteriorating transfer efficiency of a transfer material. 
         [0012]    The present invention is also to provide a method for fabricating a display device using an optical patterning mask, which can reduce deterioration of the transfer efficiency of a transfer material through preventing a light absorption layer from being damaged and preventing the function of the light absorption layer from deteriorating. 
         [0013]    Additional advantages, subjects, and features of the invention 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 invention. 
         [0014]    In one aspect of the present invention, there is provided an optical patterning mask comprising: a base substrate; a reflective layer formed on the base substrate and including an opening; a thermal insulation layer formed on the reflective layer to cover the opening; a light absorption layer formed on the thermal insulation layer; a protection layer formed in a position that overlaps the opening on the light absorption layer; a bank layer formed on the light absorption layer to expose the protection layer; and a transfer layer formed on the protection layer and the bank layer, wherein a thickness of the protection layer is thinner than a thickness of the bank layer. 
         [0015]    The protection layer and the bank layer may be integrally formed. 
         [0016]    The bank layer and the protection layer may be formed of an inorganic material. 
         [0017]    A portion of the transfer layer that overlaps the opening may be flat. 
         [0018]    The transfer layer may comprise a transfer inclination portion having an inclination shape in a portion that overlaps an edge portion of the opening. 
         [0019]    The thermal insulation layer may comprise a groove that is formed in a region that overlaps the opening of an upper surface that comes in contact with the light absorption layer. 
         [0020]    The optical patterning mask may further comprise a tapered layer arranged between the thermal insulation layer and the light absorption layer, wherein the tapered layer may include a tapered inclination portion formed to expose a portion of the thermal insulation layer that overlaps the opening and having an inclination shape in the portion that overlaps an edge portion of the opening. 
         [0021]    In another aspect of the present invention, there is provided an optical patterning mask comprising: a base substrate; a reflective layer formed on the base substrate and including an opening; a thermal insulation layer formed on the reflective layer to cover the opening; a light absorption layer formed on the thermal insulation layer; a protection layer formed on the light absorption layer; a bank layer formed on the protection layer so that a portion of the protection layer that overlaps the opening is exposed; and a transfer layer formed on a region of the protection layer that overlaps the opening and the bank layer, wherein a thickness of the protection layer is thinner than a thickness of the bank layer. 
         [0022]    The protection layer and the bank layer may be formed of different materials. 
         [0023]    An etching rate of the protection layer and an etching rate of the bank layer may be different from each other. 
         [0024]    The bank layer and the protection layer may be formed of an inorganic material. 
         [0025]    A region of the transfer layer that overlaps the opening may be flat. 
         [0026]    The transfer layer may comprise a transfer inclination portion having an inclination shape in a portion that overlaps an edge portion of the opening. 
         [0027]    The thermal insulation layer may comprise a groove that is formed in a region that overlaps the opening of an upper surface that comes in contact with the light absorption layer. 
         [0028]    The optical patterning mask may further comprise a tapered layer arranged between the thermal insulation layer and the light absorption layer, wherein the tapered layer may include a tapered inclination portion formed to expose a portion of the thermal insulation layer that overlaps the opening and having an inclination shape in the portion that overlaps an edge portion of the opening. 
         [0029]    In still another aspect of the present invention, there is provided a method for fabricating a display device, comprising: a preparing an optical patterning mask including a base substrate, a reflective layer formed on the base substrate and including an opening, a thermal insulation layer formed on the reflective layer to cover the opening, a light absorption layer formed on the thermal insulation layer, a protection layer formed in a position that overlaps the opening on the light absorption layer, a bank layer formed on the light absorption layer to expose the protection layer, and a transfer layer formed on the protection layer and the bank layer, wherein a thickness of the protection layer is thinner than a thickness of the bank layer; arranging the substrate on an upper portion of the optical patterning mask so that the transfer layer faces a first electrode of a substrate of the display device; forming an organic material layer by transferring a transfer material of the transfer layer, which is positioned on the light absorption layer and the protection layer that overlaps the opening of the reflective layer, to the first electrode of the substrate through irradiating a lower portion of the base substrate with light; and removing the residual transfer material of the transfer layer that remains on the bank layer. 
         [0030]    The transfer layer may comprise at least one organic material selected from the group including an organic light emitting layer (EML), an organic hole injection layer (HIL), an organic hole transport layer (HTL), an organic electron injection layer (EIL), and an organic electron transport layer (ETL) of an organic light emitting display device. 
         [0031]    The removing the residual transfer material may be performed by injecting O 2  gas energy into an upper portion of the bank layer. 
         [0032]    The bank layer and the protection layer may be formed of an inorganic material. 
         [0033]    According to embodiments of the present invention, at least the following effects can be achieved. 
         [0034]    Since the optical patterning mask according to an embodiment of the present invention includes the protection layer that is formed on the light absorption layer that overlaps the opening of the reflective layer, an asher, for example, O 2  gas, which is used to remove the residual transfer material of the transfer layer that remains on the bank layer after the transfer process using the optical patterning mask, can be prevented from coming in contact with and reacting on a part of the light absorption layer that is exposed from the optical patterning mask. 
         [0035]    Through this, the light absorption layer can be prevented from reacting on the asher that is used to remove the residual transfer material of the transfer layer that remains on the bank layer. Accordingly, the light absorption layer can be prevented from being damaged, and the function of the light absorption layer can be prevented from deteriorating. 
         [0036]    Further, in the case of reusing the optical patterning mask, from which the remaining transfer material of the transfer layer has been removed, deterioration of the transfer efficiency of the transfer material can be reduced. 
         [0037]    The effects according to the present invention are not limited to the contents as exemplified above, but further various effects are included in the description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0038]    The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings. 
           [0039]      FIG. 1  is a cross-sectional view of an optical patterning mask according to an embodiment of the present invention. 
           [0040]      FIG. 2  is a plan view of a reflective layer of  FIG. 1 . 
           [0041]      FIG. 3  is a cross-sectional view of an optical patterning mask according to another embodiment of the present invention. 
           [0042]      FIG. 4  is a cross-sectional view of an optical patterning mask according to still another embodiment of the present invention. 
           [0043]      FIG. 5  is a cross-sectional view of an optical patterning mask according to still another embodiment of the present invention. 
           [0044]      FIG. 6  is a cross-sectional view of an optical patterning mask according to still another embodiment of the present invention. 
           [0045]      FIG. 7  is a cross-sectional view of an optical patterning mask according to still another embodiment of the present invention. 
           [0046]      FIGS. 8 through 13  are cross-sectional views explaining a method for fabricating a display device using an optical patterning mask according to an embodiment of the present invention; and 
           [0047]      FIG. 14  is a cross-sectional view of an organic light emitting display device that is formed by the fabricating method illustrated in  FIGS. 8 through 13 . 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0048]    Advantages and features of the present invention and methods of accomplishing the same may be understood more readily by reference to the following detailed description of preferred embodiments and the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concept of the invention to those skilled in the art, and the present invention will only be defined by the appended claims. 
         [0049]    It will also be understood that when a layer is referred to as being “on” another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be present. The same reference numbers indicate the same components throughout the specification. 
         [0050]    It will be understood that, although the terms first, second, third etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention. 
         [0051]    Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. 
         [0052]      FIG. 1  is a cross-sectional view of an optical patterning mask according to an embodiment of the present invention, and  FIG. 2  is a plan view of a reflective layer of  FIG. 1 . 
         [0053]    Referring to  FIG. 1 , an optical patterning mask  100  according to an embodiment of the present invention includes a base substrate  110 , a reflective layer  120 , a thermal insulation layer  130 , a light absorption layer  140 , a protection layer  150 , a bank layer  160 , and a transfer layer  170 . 
         [0054]    The base substrate  110  may be a light permeable substrate that can transmit lamp light or laser light. For example, the base substrate  110  may be a glass substrate, a quartz substrate, or a synthetic resin substrate that is composed of a transparent polymer material, such as, polyester, poly acrylic, poly epoxy, polyethylene, polystyrene, or polyethylene terephthalate, having superior light permeability. The lamp light or laser light that has passed through the base substrate  110  may reach the light absorption layer  140  to generate heat in the light absorption layer  140 . 
         [0055]    The reflective layer  120  is formed on the base substrate  110 , and includes at least one opening OP as illustrated in  FIG. 2 . The reflective layer  120  may selectively provide the lamp light or the laser light that has passed through the base substrate  110  to a part of the light absorption layer  140  through the opening OP. The part of the light absorption layer  140  may be a portion that corresponds to a pattern layer that is formed through transferring a transfer material of the transfer layer  170  to a specific substrate using the optical patterning mask  100 . A reflective region of the reflective layer  120  except for the opening OP reflects the lamp light or the laser light that penetrates the base substrate  110  in the direction of the base substrate  110 . 
         [0056]    The reflective layer  120  may include a material having high reflectivity with respect to the lamp light or the laser light. Exemplary material could be selected from the group including aluminum, silver, platinum, copper, an alloy including aluminum, an alloy including silver, and indium oxide—tin oxide. The reflective layer  120  may be formed by depositing the above-described material using sputtering, electron beam deposition, or vacuum deposition and patterning the deposited material. 
         [0057]    The thermal insulation layer  130  is formed on the reflective layer  120  to cover the opening OP. The upper surface of the thermal insulating layer  130 , contacting with the light absorption layer  140 , may be flat. If a part of the light that is reflected by the reflective layer  120  is converted into heat and remains in the reflective layer  120 , the thermal insulation layer  130  prevents such heat from transferring to the light absorption layer  140 . Further, the light that has passed through the opening OP is converted into heat in the light absorption layer  140 , and the thermal isolation layer  130  intercepts the heat that is transferred in the direction of the base substrate  110 . For this, the thermal insulation layer  130  is formed of a material of low thermal conductivity. However, in order to pass the light that is provided through the opening OP of the reflective layer  120 , the thermal insulation layer  130  should be formed of a material having permeability. For example, the thermal insulation layer  130  may be made of any one of titanium oxide, silicon oxide, silicon nitride, silicon oxynitride, zirconium oxide, silicon carbide, and organic polymer, but is not limited thereto. The thermal insulation layer  130  may be formed by depositing the above-described material using the sputtering, the electron beam deposition, or the vacuum deposition. 
         [0058]    The light absorption layer  140  is formed on the thermal insulation layer  130 . The light absorption layer  140  may be a light-heat conversion layer which absorbs and converts the light into heat that has passed through the base substrate  110 , the opening OP of the reflective layer  120 , and the thermal insulation layer  130 . The light absorption layer  140  may sublime and transfer the transfer material of the transfer layer  170  formed on the thermal absorption layer  140  by heat to the specific substrate to form the pattern layer. In this case, a portion of the transfer layer  170  that overlaps the bank layer  160  is not sublimed. 
         [0059]    The light absorption layer  140  may be formed of a material having low light reflectivity and high light absorbability. For example, the light absorption layer  140  may be formed of molybdenum (Mo), chromium (Cr), titanium (Ti), tin (Sn), tungsten (W), or an alloy thereof, but is not limited thereto. The light absorption layer  140  may be formed by depositing the above-described material using the sputtering, electron beam deposition, or the vacuum deposition. 
         [0060]    The protection layer  150  is formed on the light absorption layer  140 , and is formed in a position that overlaps the opening OP of the reflective layer  120 . The protection layer  150  can prevent an asher, for example, O 2  gas, from contacting with and reacting on a part of the light absorption layer  140  that is exposed after the transfer process of the optical patterning mask  100 . The asher gas is used to remove the residual transfer material of the transfer layer  170  remaining on the bank layer  160  after the transfer process. Since the light absorption layer  140  is formed to include a metal material, it may be damaged through oxidization reaction when it comes in contact with the O 2  gas. This may deteriorate the function of the light absorption layer  140 . The protection layer  150  can prevent the light absorption layer  140  from coming in contact with the O 2  gas. Accordingly, the protection layer  150  can prevent the light absorption layer  140  from being damaged, and thus can prevent deterioration of the light absorption layer  140 . Accordingly, when performing the transfer process using the cleaned optical patterning mask  100 , the protection layer  150  can keep the transfer efficiency of the transfer material longer. 
         [0061]    The protection layer  150  may be formed of the same material as the material of the bank layer  160  to be described later. The protection layer  150  may be formed of an inorganic material that does not react on the asher, for example, O 2  gas. For example, the protection layer  150  may be formed of at least one of silicon oxide, gallium oxide, aluminum oxide, zinc oxide, indium tin oxide, tin oxide, tungsten oxide, molybdenum oxide, chrome oxide, silicon nitride, aluminum nitride, and gallium nitride. 
         [0062]    On the other hand, the protection layer  150  can protect the light absorption layer  140  when the transfer material of the transfer layer  170  that remains on the bank layer  160  is removed after the transfer process of the optical patterning mask  100 . Further, the protection layer  150  is formed thinner than the bank layer  160  so that the heat of the light absorption layer  140  can be smoothly transferred to the transfer layer  170  during the transfer process of the optical patterning mask  100 . For example, the bank layer  160  may be about 1 μm or more thick, and the protection layer  150  may be about 7 nm to 50 nm thick. 
         [0063]    The protection layer  150  may be integrally formed with the bank layer  160  when the bank layer  160  is formed. The protection layer  150  and the bank layer  160  may be formed through a photolithography process. In this case, a dry etching process may be selected as an etching process of the photolithography to make the protection layer  150  thinner than the bank layer  160 . 
         [0064]    The bank layer  160  is formed on the light absorption layer  140  to expose the protection layer  150 , specifically, an upper surface of the protection layer  150 . That is, the bank layer  160  is formed on the reflective layer  120  except for the opening OP. The bank layer  160  may serve as a fence preventing the transfer material of the transfer layer  170  from being deposited on another region except for a determined position when transferring the transfer material of the transfer layer  170  by subliming it through heat of the light absorption layer  140 . In this case, the transfer layer  170  formed on the bank layer  160  is not sublimed. 
         [0065]    The bank layer  160  may be formed of at least one of silicon oxide, gallium oxide, aluminum oxide, zinc oxide, indium tin oxide, tin oxide, tungsten oxide, molybdenum oxide, chrome oxide, silicon nitride, aluminum nitride, and gallium nitride. 
         [0066]    The transfer layer  170  is formed on the protection layer  150  and the bank layer  160 . The transfer layer  170  is sublimed and transferred to the specific substrate by the heat of the light absorption layer  140  that is transferred through the protection layer  150 , but the portion that is formed on the bank layer  160  is not transferred to the specific substrate. Here, the portion of the transfer layer  170  that overlaps the opening OP of the reflective layer  120  may be flat. 
         [0067]    The transfer layer  170  is formed of a transfer material that includes the material of the pattern layer of the specific substrate. The transfer layer  170  may include an organic material of an organic material layer included in the organic light emitting display device that is a kind of display device, and for example, the transfer layer  170  may include any one of an organic light emitting layer (EML), an organic hole injection layer (HIL), an organic hole transport layer (HTL), an organic electron injection layer (EIL), and an organic electron transport layer (ETL). 
         [0068]    The transfer layer  170  may be formed using a wet method, such as a spin coating method, a spray coating method, an ink jet printing method, a nozzle printing method, a deep coating method, a die coating method, a roll coating method, a blade coating method, a bar coating method, or a gravure coating method. Further, the transfer layer  170  may be formed using vacuum deposition or sputtering. 
         [0069]    The optical patterning mask  100  described above includes the protection layer  150  that is formed on the light absorption layer  140  that overlaps the opening OP of the reflective layer  120 . This prevents the asher gas used to remove the residual transfer material of the transfer layer  170  remaining on the bank layer  160  after the transfer process from contacting with and reacting on a part of the light absorption layer  140  that is exposed from the optical patterning mask  100 . 
         [0070]    This can prevent the light absorption layer  140  from being damaged, which reduces deterioration of the light absorption layer  140 . 
         [0071]    Further, when reusing the optical patterning mask  100  after removing the remaining transfer material of the transfer layer  170 , this can reduce deterioration of the transfer efficiency of the transfer material. 
         [0072]      FIG. 3  is a cross-sectional view of an optical patterning mask according to another embodiment of the present invention. 
         [0073]    Referring to  FIG. 3 , an optical patterning mask  200  according to another embodiment of the present invention includes a base substrate  110 , a reflective layer  120  including an opening OP, a thermal insulation layer  130 , a tapered layer  240 , a light absorption layer  250 , a protection layer  260 , a bank layer  160 , and a transfer layer  270 . 
         [0074]    The optical patterning mask  200  according to another embodiment of the present invention is similar to the optical patterning mask  100  of  FIG. 1  except that the tapered layer  240  is included, and the light absorption layer  250 , the protection layer  260 , and the transfer layer  270  are different to have tapered portion and inclination layers. Accordingly, explanation of the optical patterning mask  200  according to another embodiment of the present invention will be made around the tapered layer  240 , the light absorption layer  250 , the protection layer  260 , and the transfer layer  270 . 
         [0075]    The tapered layer  240  is arranged between the thermal insulation layer  130  and the light absorption layer  250 , and is formed to expose a portion of the thermal insulation layer  130  that overlaps the opening OP of the reflective layer  120 . The tapered layer  240  includes a tapered inclination portion  240   a  having an inclination shape in a portion that overlaps an edge portion of the opening OP. The tapered inclination portion  240   a  has an inclination shape in a portion of the transfer layer  270  that overlaps the edge portion of the opening OP. 
         [0076]    The tapered portion  240  may be formed of an inorganic material such as silicon oxide or an organic material such as polyimide. The tapered layer  240  may be formed through a photolithography process. 
         [0077]    The light absorption layer  250  is similar to the light absorption layer  140  of  FIG. 1 . However, the light absorption layer  250  includes an absorption inclination portion  250   a  having an inclination shape in a portion that overlaps the edge portion of the opening OP by the tapered inclination portion  240   a  of the tapered layer  240 . 
         [0078]    The protection layer  260  is similar to the protection layer  150  of  FIG. 1 . However, the protection layer  260  includes a protection inclination portion  260   a  having an inclination shape in a portion that overlaps the edge portion of the opening OP by the absorption inclination portion  250   a  of the light absorption layer  250 . 
         [0079]    The transfer layer  270  is similar to the transfer layer  170  of  FIG. 1 . However, the transfer layer  270  includes a transfer inclination portion  270   a  having an inclination shape in a portion that overlaps the edge portion of the opening OP by the protection inclination portion  260   a  of the protection layer  260 . 
         [0080]    The transfer material of the transfer inclination portion  270   a  may be heated and sublimed by heat of the absorption inclination portion  250   a . In this case, the transfer material of the transfer inclination portion  270   a  is sublimed in a vertical direction from the transfer inclination portion  270   a  that is inclined to a flat portion (a portion that is at the lowest position) of the transfer layer  270  that overlaps the opening OP of the reflective layer  120 , and is deposited on a region of the specific substrate on which the pattern layer is to be formed in a convex Gaussian shape. Accordingly, the transfer material of the transfer inclination portion  270   a  allows a pattern layer which may have a non-uniform thickness to be flat and to have uniform thickness, since the transfer material of the flat portion of the transfer layer  270  is sublimed in a vertical direction from the flat portion of the transfer layer  270  and is deposited on the region of the specific substrate on which the pattern layer is to be formed in a state where the center portion thereof is in the convex Gaussian shape. That is, an edge portion having a thin thickness in a portion formed by transferring the flat portion posited at the lowest position in the transfer layer  270  overlaps with an edge portion having a thin thickness in a portion formed by transferring the transfer inclination portion  270   a  in the transfer portion  270 , so that the pattern layer formed by transferring the transfer layer  270  may have uniform thickness. 
         [0081]    As described above, the optical patterning mask  200  according to another embodiment of the present invention includes the protection layer  260 , and thus in the case of reusing the optical patterning mask  200  after removing the remaining transfer material of the transfer layer  270 , deterioration of the transfer efficiency of the transfer material can be reduced. 
         [0082]    Further, since the optical patterning mask  200  according to another embodiment of the present invention includes the tapered layer  240  having the tapered portion  240   a , the transfer inclination portion  270   a  can be formed in the portion of the transfer layer  270  that overlaps the edge portion of the opening OP. 
         [0083]    According to the optical patterning mask  200  according to another embodiment of the present invention, the transfer material of the transfer layer  270  that overlaps the opening OP is sublimed and transferred to the specific substrate, and thus the pattern layer can be formed in an entirely flat shape and with a uniform thickness. 
         [0084]      FIG. 4  is a cross-sectional view of an optical patterning mask according to still another embodiment of the present invention. 
         [0085]    Referring to  FIG. 4 , an optical patterning mask  300  according to still another embodiment of the present invention includes a base substrate  110 , a reflective layer  120  including an opening OP, a thermal insulation layer  330 , a light absorption layer  340 , a protection layer  260 , a bank layer  160 , and a transfer layer  270 . 
         [0086]    The optical patterning mask  300  according to still another embodiment of the present invention is similar to the optical patterning mask  200  of  FIG. 3  except that the thermal insulation layer  330  and the light absorption layer  340  are different from those of the optical patterning mask  200  of  FIG. 3 . Accordingly, explanation of the optical patterning mask  300  will be made about the thermal insulation layer  330  and the light absorption layer  340 . 
         [0087]    The thermal insulation layer  330  is similar to the thermal insulation layer  130  of  FIG. 3 . However, the thermal insulation layer  330  includes a groove g that is formed in a region of the upper surface, which comes in contact with the light absorption layer  340  and overlaps the opening OP of the reflective layer  120 . The cross-sectional shape of the groove g may be a reversed trapezoidal shape. Through the groove g, an inclination surface  330   a  having an inclination shape may be formed in a portion of the upper surface of the thermal insulation layer  330  that overlaps the opening OP. 
         [0088]    The light absorption layer  340  is similar to the light absorption layer  250  of  FIG. 3 . However, the light absorption layer  340  includes an absorption inclination portion  340   a  having the inclination shape in the portion that overlaps the edge portion of the opening OP by the inclination surface  330   a  of the thermal insulation layer  330 . Further, the light absorption layer  340  comes in contact with the whole upper surface of the thermal insulation layer  330 . 
         [0089]    As described above, the optical patterning mask  300  includes the protection layer  260 , and thus when reusing the optical patterning mask  300  after removing the remaining transfer material of the transfer layer  270 , deterioration of the transfer efficiency of the transfer material can be reduced. 
         [0090]    Further, since the optical patterning mask  300  includes the light absorption layer  330  having the absorption inclination surface  330   a , and thus the transfer inclination portion  270   a  can be formed in the portion of the transfer layer  270  that overlaps the edge portion of the opening OP. 
         [0091]    According to the optical patterning mask  300 , the transfer material of the transfer layer  270  that overlaps the opening OP is sublimed and transferred to the specific substrate, and thus the pattern layer can be formed in an entirely flat shape and with a uniform thickness. 
         [0092]      FIG. 5  is a cross-sectional view of an optical patterning mask according to still another embodiment of the present invention. 
         [0093]    Referring to  FIG. 5 , an optical patterning mask includes a base substrate  110 , a reflective layer  120  including an opening OP, a thermal insulation layer  130 , a light absorption layer  140 , a protection layer  450 , a bank layer  460 , and a transfer layer  170 . 
         [0094]    The optical patterning mask  400  according to still another embodiment of the present invention is similar to the optical patterning mask  100  of  FIG. 1  except that the protection layer  450  and the bank layer  460  are different from those of the optical patterning mask  100  of  FIG. 1 . Accordingly, explanation of the optical patterning mask  400  will be made about the protection layer  450  and the bank layer  460 . 
         [0095]    The protection layer  450  is similar to the protection layer  150  of  FIG. 1 . However, the protection layer  450  is formed entirely on the light absorption layer  450 . Further, the protection layer  450  is formed of a material that is different from the material of the bank layer  460  to be described later. That is, the protection layer  450  has an etching rate that is different from the etching rate of the bank layer  460 . Accordingly, the bank layer  460  may be formed to expose a portion of the protection layer  450  that overlaps the opening OP of the reflective layer  120  by using a simple wet etching process in lieu of a dry etching process. The dry etching process has more complicated process conditions in the photolithography. 
         [0096]    The protection layer  450  may be formed of a material having an etching rate that is different from the etching rate of the material that forms the bank layer  460 . It may be formed of an inorganic material that does not react to the asher, for example, O 2  gas, used to remove the transfer material of the transfer layer  170  remaining on the bank layer  460 . Exemplary material can be selected from the group including silicon oxide, gallium oxide, aluminum oxide, zinc oxide, indium tin oxide, tin oxide, tungsten oxide, molybdenum oxide, chrome oxide, silicon nitride, aluminum nitride, and gallium nitride. In this case, the protection layer  450  should be selected as a material that is not etched by the etching solution used to form the bank layer  460  and expose the portion of the protection layer  450  that overlaps the opening OP. 
         [0097]    The bank layer  460  is similar to the bank layer  160  of  FIG. 1 . However, the bottom surface of the bank layer  460  comes in contact with the upper surface of the protection layer  450 . The bank layer  460  may be formed of a material having an etching rate that is different from the etching rate of the material that forms the protection layer  450 , and may be formed of any one selected from the group including silicon oxide, gallium oxide, aluminum oxide, zinc oxide, indium tin oxide, tin oxide, tungsten oxide, molybdenum oxide, chrome oxide, silicon nitride, aluminum nitride, and gallium nitride. In this case, the bank layer  460  should be formed of a material that can be etched by the etching solution used to expose the portion of the protection layer  450  that overlaps the opening OP of the reflective layer  120 . 
         [0098]    As described above, the optical patterning mask  400  includes the protection layer  450 , and thus when reusing the optical patterning mask  400  after removing the remaining transfer material of the transfer layer  170 , deterioration of the transfer efficiency of the transfer material can be reduced. 
         [0099]    Further, the optical patterning mask  400  makes the protection layer  450  and the bank layer  460  out of different materials, which can simplify the manufacturing process of the bank layer  450 . 
         [0100]      FIG. 6  is a cross-sectional view of an optical patterning mask  500  according to still another embodiment of the present invention. 
         [0101]    Referring to  FIG. 6 , an optical patterning mask  500  includes a base substrate  110 , a reflective layer  120  including an opening OP, a thermal insulation layer  130 , a tapered layer  240 , a light absorption layer  250 , a protection layer  550 , a bank layer  460 , and a transfer layer  270 . 
         [0102]    The optical patterning mask  500  is similar to the optical patterning mask  400  of  FIG. 5  except that the tapered layer  240  is included, and the light absorption layer  250 , the protection layer  550 , and the transfer layer  270  are different from those of the optical patterning mask  400  of  FIG. 5 . Accordingly, explanation of the optical patterning mask  500  will be made about the tapered layer  240 , the light absorption layer  250 , the protection layer  550 , and the transfer layer  270 . 
         [0103]    Since the tapered layer  240  and the light absorption layer  250  have been described in detail with reference to  FIG. 3 , the duplicate explanation thereof will not be repeated. 
         [0104]    The protection layer  550  is similar to the protection layer  450  of  FIG. 5 . However, the protection layer  550  includes a protection inclination portion  550   a  having an inclination shape in a portion that overlaps the edge portion of the opening OP by the absorption inclination portion  250   a  of the light absorption layer  250 . Further, the protection layer  550  comes in contact with the whole upper surface of the light absorption layer  250 . 
         [0105]    Since the transfer layer  270  has been described in detail with reference to  FIG. 3 , the duplicate explanation thereof will be omitted. 
         [0106]    As described above, the optical patterning mask  500  includes the protection layer  550 . This may reduce deterioration of the transfer efficiency of the transfer material, when reusing the optical patterning mask  500  after removing the remaining transfer material of the transfer layer  270 . 
         [0107]    Further, the optical patterning mask  500  can simplify the process of manufacturing the bank layer  460  by forming the protection layer  550  and the bank layer  460  out of different materials. 
         [0108]    Further, the optical patterning mask  500  including the tapered layer  540  with the tapered portion  240   a  can form the transfer inclination portion  270   a  in the portion of the transfer layer  270  that overlaps the edge portion of the opening OP. 
         [0109]    According to the optical patterning mask  500 , the transfer material of the transfer layer  270  that overlaps the opening OP is sublimed and transferred to the specific substrate, and thus the pattern layer can be formed in an entirely flat shape and with a uniform thickness. 
         [0110]      FIG. 7  is a cross-sectional view of an optical patterning mask according to still another embodiment of the present invention. 
         [0111]    Referring to  FIG. 7 , an optical patterning mask  600  according to still another embodiment of the present invention includes a base substrate  110 , a reflective layer  120  including an opening OP, a thermal insulation layer  330 , a light absorption layer  340 , a protection layer  650 , a bank layer  460 , and a transfer layer  270 . 
         [0112]    The optical patterning mask  600  is similar to the optical patterning mask  400  of  FIG. 5  except that thermal insulation layer  330 , the light absorption layer  340 , the protection layer  650 , and the transfer layer  270  are different from those of the optical patterning mask  400  of  FIG. 5 . Accordingly, explanation of the optical patterning mask  600  according to still another embodiment of the present invention will be made about the thermal insulation layer  330 , the light absorption layer  340 , the protection layer  650 , and the transfer layer  270 . 
         [0113]    Since the thermal insulation layer  330  and the light absorption layer  340  have been described in detail with reference to  FIG. 4 , the duplicate explanation thereof will not be repeated. 
         [0114]    The protection layer  650  is similar to the protection layer  450  of  FIG. 5 . However, the protection layer  650  includes a protection inclination portion  650   a  having an inclination shape in a portion that overlaps the edge portion of the opening OP by the inclination portion  340   a  of the light absorption layer  340 . Further, the protection layer  650  comes in contact with the whole upper surface of the light absorption layer  350 . 
         [0115]    Since the transfer layer  270  has been described in detail with reference to  FIG. 3 , the duplicate explanation thereof will be omitted. 
         [0116]    As described above, the optical patterning mask  600  includes the protection layer  650 . This can reduce deterioration of the transfer efficiency of the transfer material when reusing the optical patterning mask  600  after removing the remaining transfer material of the transfer layer  270 . 
         [0117]    Further, the optical patterning mask  600  forms the protection layer  650  and the bank layer  460  out of different materials, which may simplify the manufacturing process of the bank layer  460 . 
         [0118]    Further, since the optical patterning mask  600  includes the light absorption layer  330  having the absorption inclination surface  330   a , the transfer inclination portion  270   a  can be formed in the portion of the transfer layer  270  that overlaps the edge portion of the opening OP. 
         [0119]    The optical patterning mask  600  can subline and transfer the transfer material of the transfer layer  270  that overlaps the opening OP to the specific substrate, and thus can form the pattern layer in an entirely flat shape and with a uniform thickness. 
         [0120]    Hereinafter, an exemplary method for fabricating a display device using an optical patterning mask according to the embodiments of the present invention as described above will be described. 
         [0121]      FIGS. 8 through 13  are cross-sectional views explaining a method for fabricating a display device using an optical patterning mask according to an embodiment of the present invention. 
         [0122]    Referring to  FIG. 8 , an optical patterning mask  100  is prepared to include a base substrate  110 , a reflective layer  120  formed on the base substrate  110  and including an opening OP, a thermal insulation layer  130  formed on the reflective layer  120  to cover the opening OP, a light absorption layer  140  formed on the thermal insulation layer  130 , a protection layer  150  formed in a region that overlaps the opening OP on the light absorption layer  140 , a bank layer  160  formed on the light absorption layer to expose the protection layer  150 , and a transfer layer  170  formed on the protection layer  150  and the bank layer  160 . The protection layer  150  is thinner than the bank layer  160 . Since the optical patterning mask  100  has been described in detail, the duplicate explanation thereof will be omitted.  FIG. 8  illustrates the optical patterning mask  100  of  FIG. 1 . However, optical patterning masks  200 ,  300 ,  400 ,  500 ,  600 , and  700  as illustrated in  FIGS. 3 to 7  may be used. 
         [0123]    Then, referring to  FIG. 9 , a substrate  11  of an organic light emitting display device  10  is arranged on an upper portion of the optical patterning mask  100  so that the transfer layer  170  of the optical patterning mask  100  faces the display device, for example, a first electrode E 1  of the substrate  11  of the organic light emitting display device  10 . The transfer layer  170  of the optical patterning mask  100  includes, for example, an organic material. The first electrode E 1  is exposed through an opening POP of a pixel-defining layer  12  that partitions respective pixels on the substrate  11 . 
         [0124]    Then, referring to  FIG. 10 , an organic material layer, for example, a light emitting layer EML, is formed by transferring a transfer material of the transfer layer  170 , which is positioned on the light absorption layer  140  and the protection layer  150  that overlaps the opening OP of the reflective layer  120 , onto the first electrode E 1  of the first substrate  11  of the organic light emitting display device  10  through irradiation of light from a lower portion of the base substrate  110 . Here, the transfer layer  170  may include an organic light emitting layer (EML) of the organic light emitting display device. 
         [0125]    Specifically, the light that is irradiated from the lower portion of the base substrate  110  penetrates the base substrate  110  and the thermal insulation layer  130  through the opening of the reflective layer  120 , and then is absorbed in the light absorption layer  140 . A reflective region of the reflective layer  120  except for the opening OP reflects the light that penetrates the base substrate  110  in the direction of the base substrate  110 . The light that is absorbed in the light absorption layer  140  is converted into heat, and the heat is transferred to the transfer layer  170  through the protection layer  150 . Accordingly, the organic light emitting layer of the transfer layer  170  is sublimed and deposited on the first electrode E 1  of the first substrate  11  of the organic light emitting display device  10 . As a result, the light emitting layer EML is formed on the first electrode E 1  of the first substrate  11  of the organic light emitting display device as shown in  FIG. 11 . 
         [0126]    Then, referring to  FIG. 12 , the transfer material of the transfer layer  170  that remains on the bank layer  160  is removed by injecting O 2  gas energy into the upper portion of the bank layer  160  after the light emitting layer EML is formed. In this case, the protection layer  150  can protect the light absorption layer  150  from the O 2  gas energy. As illustrated in  FIG. 13 , the optical patterning mask  100 , from which the transfer material of the transfer layer  170  that remains on the upper portion of the bank layer  160  has been removed, can be reused. 
         [0127]    On the other hand,  FIG. 11  illustrates that the light emitting layer EML is formed on the first electrode E 1  of the first substrate  11  of the organic light emitting display device  10  using the optical patterning mask  100 . However, any one of a hole injection layer (HIL in  FIG. 14 ), a hole transport layer (HTL in  FIG. 14 ), an electron injection layer (EIL), and an electron transport layer (ETL) may also be formed. In this case, the transfer layer  170  may include at least one selected from the group including an organic hole injection layer (HIL), an organic hole transport layer (HTL), an organic electron injection layer (EIL), and an organic electron transport layer (ETL). 
         [0128]    Hereinafter, the structure of a display device, for example, an organic light emitting display device  100 , which is fabricated using the optical patterning mask, will be described in detail. 
         [0129]      FIG. 14  is a cross-sectional view of an organic light emitting display device that is formed by the fabricating method illustrated in  FIGS. 8 through 13 . 
         [0130]    Referring to  FIG. 14 , an organic light emitting display device  10  includes a substrate  11 , a semiconductor layer AP, a gate electrode GE, a source electrode SE, a drain electrode DE, a gate insulating layer  13 , an interlayer insulating layer  14 , a planarization layer  15 , a pixel-defining layer  12 , a first electrode E 1 , a hole injection layer HIL, a hole transport layer HTL, a light emitting layer EML, an electron transport layer ETL, an electron injection layer EIL, and a second electrode E 2 . 
         [0131]    The substrate  11  may be formed of a transparent insulating material. For example, the substrate  11  may be formed of glass, quartz, ceramic, or plastic. The substrate  11  may be in a flat plate shape. In some embodiments, the substrate  11  may be formed of a material that is easily bendable. The substrate  11  may support other constructions arranged on the substrate  11 . 
         [0132]    The semiconductor layer AP may be arranged on the upper portion of the substrate  11 . The semiconductor layer AP may be formed of an amorphous silicon layer or a polycrystalline silicon layer. The semiconductor layer AP may include a channel region that is not doped with an impurity, and a source region and a drain region which are arranged on both sides of the channel region to be p+-doped, and come in contact with the source electrode SE and the drain electrode DE, respectively. The impurity doped in the semiconductor layer AP may be a P-type impurity including boron (B), and for example, B 2 H 6  may be used as the impurity. Various kinds of impurities may be doped in the semiconductor layer AP according to embodiments. 
         [0133]    The gate insulating layer  13  may be arranged on the upper portion of the semiconductor layer AP. The gate insulating layer  13  may insulate the gate electrode GE and the semiconductor layer AP from each other. The gate insulating layer  13  may be formed of silicon nitride (SiN x ) or silicon oxide (SiO 2 ). 
         [0134]    The gate electrode GE may be arranged on the gate insulating layer  13  to overlap at least a part of the semiconductor layer AP. By applying a voltage to the gate electrode GE, it can be controlled whether the semiconductor layer AP is conductive or non-conductive. For example, if a relatively high voltage is applied to the gate electrode GE, the semiconductor layer AP has conductivity and makes the drain electrode DE and the source electrode SE electrically connected to each other. If a relatively low voltage is applied to the gate electrode GE, the semiconductor layer AP has non-conductivity, and makes the drain electrode DE and the source electrode SE insulated from each other. 
         [0135]    The interlayer insulating layer  14  may be arranged on the upper portion of the gate electrode GE. The interlayer insulating layer  14  may cover the gate electrode GE to insulate the gate electrode GE from the source electrode SE and the drain electrode. The interlayer insulating layer  14  may be formed of silicon nitride (SiN x ) or silicon oxide (SiO 2 ). 
         [0136]    The source electrode SE and the drain electrode DE may be arranged on the upper portion of the interlayer insulating layer  14 . The source electrode SE and the drain electrode DE may be connected to the semiconductor layer AP by through-holes formed to penetrate the interlayer insulating layer  14  and the gate insulating layer  13 . 
         [0137]    The source electrode SE, the drain electrode DE, the gate electrode GE, and the semiconductor layer AP may form a thin film transistor TR, and the thin film transistor TR may determine whether to transfer a signal that is transferred to the source electrode SE to the drain electrode DE according to the voltage applied to the gate electrode GE. 
         [0138]    The planarization layer  15  may be formed on upper portions of the interlayer insulating layer  14 , the source electrode SE, and the drain electrode DE. In order to heighten the light emitting efficiency of the light emitting layer EML that is arranged on the planarization layer  15 , the planarization layer  15  may form a flat surface by eliminating a step height of the upper portions of the source electrode SE and the drain electrode DE. 
         [0139]    The planarization layer  15  may be formed of at least one of polyacrylates resin, epoxy resin, phenolicresin, polyamides resin, polyimides resin, unsaturated polyesters resin, poly phenylenethers resin, poly phenylenesuffides resin, and benzocyclobutene (BCB). 
         [0140]    A via hole may be formed on the planarization layer  15 , and through the via hole, the first electrode E 1  comes in contact with the drain electrode DE to be electrically connected thereto. 
         [0141]    The first electrode E 1  may be arranged on the upper portion of the planarization layer  15  and the lower portion of the light emitting layer EML. The first electrode E 1  may be electrically connected to the drain electrode DE through the via hole to transfer the signal that is applied to the drain electrode DE to the lower portion of the light emitting layer EML. 
         [0142]    The first electrode E 1  may be formed of a reflection type conductive material, a transparent conductive material, or a semi-transparent conductive material. For example, the reflection type conductive material may be lithium (Li), calcium (Ca), lithium fluoride/calcium (LiF/Ca), lithium fluoride/aluminum (LiF/Al), aluminum (Al), silver (Ag), magnesium (Mg), or gold (Au), and the transparent conductive material may be ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), ZnO (Zinc Oxide), or In 2 O 3  (Indium Oxide). The semi-transparent conductive material may be a co-deposition material including at least one of magnesium (Mg) and silver (Ag), or at least one material of magnesium (Mg), silver (Ag), calcium (Ca), lithium (Li), and aluminum (Al). 
         [0143]    The pixel-defining layer  12  may be arranged on the upper portion of the planarization layer  15 . The pixel-defining layer  12  may partition a plurality of pixels included in the organic light emitting display device  10 , and may include an opening POP. The first electrode E 1  may be exposed to the upper portion of the pixel-defining layer  12  through the opening POP. On the upper portion of the first electrode E 1  in the opening POP, a hole injection layer (HIL), a hole transport layer (HTL), a light emitting layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL) may be arranged. 
         [0144]    The hole injection layer (HIL) may be formed on the first electrode EL that is exposed through the opening POP of the pixel-defining layer  12  to cover the whole pixel-defining layer  12 . The hole injection layer (HIL) is a buffer layer that lowers a energy barrier between the first electrode E 1  and the hole transport layer (HTL), and serves to make holes that are provided from the first electrode E 1  easily injected into the hole transport layer (HTL). The hole injection layer  130  may be made of an organic compound, for example, MTDATA(4,4′,4″-tris(3-methylphenylphenylamino)triphenylamine), CuPc(copper phthalocyanine) or PEDOT/PSS(poly(3,4-ethylenedioxythiphene, polystyrene sulfonate), but is not limited thereto. 
         [0145]    The hole transport layer (HTL) is formed on the hole injection layer (HIL). The hole transport layer (HTL) serves to transfer the holes that are provided through the hole injection layer (HIL) to the light emitting layer (EML). The hole transport layer (HTL) may be made of an organic compound, for example, TPD(N,N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1′-bi-phenyl-4,4′-diamine) or NPB(N,N′-di(naphthalen-1-yl)-N,N′-diphenyl-benzidine), but is not limited thereto. 
         [0146]    The light emitting layer EML is formed on the hole transport layer HTL. The light emitting layer EML recombine the holes provided from the first electrode E 1  and the electrons provided from the second electrode E 2  to emit light. More specifically, if the holes and electrons are provided to the light emitting layer EML, the holes and the electrons are combined to form excitons, and as the excitons change from an excited state to a ground state, the light emitting layer EML emits light. The light emitting layer EML may include a red light emitting layer that emits red light, a green light emitting layer that emits green light, and a blue light emitting layer that emits blue light. 
         [0147]    The electron transport layer (ETL) is formed on the light emitting layer EML, and serves to transfer the electrons provided from the second electrode E 2  to the light emitting layer (EML). The electron transport layer (ETL) may be made of an organic compound, for example, a material of Bphen(4,7-diphenyl-1,10-phenanthroline)), BAlq, Alq3 (Tris(8-quinolinorate)aluminum), Bebq 2 (berylliumbis(benzoquinolin-10-olate), or TPBI, but is not limited thereto. 
         [0148]    The electron injection layer (EIL) is formed on the electron transport layer (ETL), and serves to make the electrons provided from the second electrode E 2  easily injected into the electron transport layer (ETL) as a buffer layer that lowers an energy barrier between the electron transport layer (ETL) and the second electrode E 2 . The electron injection layer (EIL) may be formed of, for example, LiF or CsF, but is not limited thereto. 
         [0149]    The second electrode E 2  may be arranged on the upper portion of the electron injection layer (EIL). The second electrode E 2  may be formed of the same material as the material of the first electrode E 1 , but is not limited thereto. In some embodiments, the second electrode E 2  may be a common electrode that is arranged on a plurality of pixels included in the organic light emitting display device. In some embodiments, the second electrode E 2  may be arranged on front surfaces of the upper portion of the electron injection layer (EIL) and the upper portion of the pixel-defining layer  12 . Light emission of the light emitting layer (EML) may be controlled according to current that flows between the first electrode E 1  and the second electrode E 2 . 
         [0150]    In concluding the detailed description, those skilled in the art will appreciate that many variations and modifications can be made to the preferred embodiments without substantially departing from the principles of the present invention. Therefore, the disclosed preferred embodiments of the invention are used in a generic and descriptive sense only and not for purposes of limitation.