Abstract:
The present invention provides a thin film transistor array panel comprising an insulating substrate; a gate line formed on the insulating substrate; a gate insulating layer formed on the gate line; a drain electrode and a data line having a source electrode formed on the gate insulating layer, the drain electrode being adjacent to the source electrode with a gap therebetween; and a pixel electrode coupled to the drain electrode, wherein at least one of the gate line, the data line, and the drain electrode comprises a first conductive layer comprising a conductive oxide and a second conductive layer comprising copper (Cu).

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. application Ser. No. 14/165,399, filed Jan. 27, 2014, which is a continuation of U.S. application Ser. No. 13/669,278, filed Nov. 5, 2012, which is a continuation of U.S. application Ser. No. 12/576,217, filed Oct. 8, 2009, (now U.S. Pat. No. 8,372,701), which is a divisional of U.S. patent application Ser. No. 11/228,852, (now U.S. Pat. No. 7,619,254), filed Sep. 16, 2005, which claims priority upon Patent Application No. 10-2004-0093887, filed in the Korean Intellectual Property Office, Republic of Korea, on Nov. 17, 2004, the entire contents of each of which are hereby incorporated herein by their references. 
     
    
     BACKGROUND 
       [0002]    1. (a) Field of the Invention 
         [0003]    The present description relates to a thin film transistor (TFT) array panel for a liquid crystal display (LCD) or an organic light emitting display (OLED), and a manufacturing method for the same. 
         [0004]    2. (b) Description of the Related Art 
         [0005]    Liquid crystal displays (LCDs) are one of the most widely used flat panel displays. An LCD includes a liquid crystal (LC) layer interposed between two panels provided with field-generating electrodes. The LCD displays images by applying voltages to the field-generating electrodes to generate an electric field in the LC layer that determines orientations of LC molecules therein to adjust the polarization of incident light. 
         [0006]    An LCD including two panels provided with field-generating electrodes respectively, wherein one panel has a plurality of pixel electrodes in a matrix and the other has a common electrode covering the entire surface of the panel, dominates the LCD market. 
         [0007]    The LCD displays images by applying a different voltage to each pixel electrode. For this purpose, thin film transistors (TFTs) having three terminals to switch voltages applied to the pixel electrodes are connected to the pixel electrodes, and gate lines to transmit signals for controlling the thin film transistors and data lines to transmit voltages applied to the pixel electrodes, are formed on a thin film transistor array panel. 
         [0008]    A TFT is a switching element for transmitting image signals from the data line to the pixel electrode in response to the scanning signals from the gate line. 
         [0009]    The TFT is applied to an active matrix organic light emitting display as a switching element for controlling respective light emitting elements. 
         [0010]    Meanwhile, chromium (Cr) is conventionally the dominating material for the gate lines and the data lines of a TFT array panel. 
         [0011]    Considering the trend of LCDs of increasing size, a material having low resistivity is urgently required since the lengths of the gate and data lines increase along with the LCD size. Accordingly, there are limitations to applying Cr to a large size LCD. 
         [0012]    Cu is a well-known substitute for Cr due to its low resistivity. However, the poor adhesiveness of Cu with a glass substrate and the difficulty in etching Cu are obstacles in applying Cu for use with gate and data lines. 
       SUMMARY 
       [0013]    Accordingly, it would be desirable to solve the above mentioned problems and to provide a thin film transistor array panel that has signal lines having low resistivity and good reliability. 
         [0014]    In accordance with the present invention, a thin film transistor array panel is provided. The thin film transistor array panel comprises an insulating substrate; a gate line formed on the insulating substrate; a gate insulating layer formed on the gate line; a drain electrode and a data line having a source electrode formed on the gate insulating layer, the drain electrode being adjacent to the source electrode with a gap therebetween; and a pixel electrode coupled to the drain electrode, wherein at least one of the gate line, the data line, and the drain electrode comprises a first conductive layer comprising a conductive oxide and a second conductive layer comprising copper (Cu). 
         [0015]    Here, the first conductive layer contains at least one material selected from ITO, ITON, IZO, and IZON. 
         [0016]    In accordance with the present invention, a manufacturing method of a thin film transistor array panel is provided. The manufacturing method comprises: forming a gate line having a gate electrode on an insulating substrate; depositing a gate insulating layer and a semiconductor layer on the gate line in sequence; forming a drain electrode and a data line having a source electrode on the gate insulating layer and the semiconductor layer, the drain electrode being adjacent to the source electrode with a gap therebetween; and forming a pixel electrode coupled to the drain electrode, wherein at least one step of the forming the gate line and the forming the data line and drain electrode comprises forming a conductive oxide layer and forming a conductive layer containing Cu. 
         [0017]    At least one step of the forming a gate line and the forming a data line and drain electrode may comprise a step of forming a conductive oxide layer after forming a conductive layer containing Cu. 
         [0018]    The conductive oxide layer may comprise IZO or ITO. 
         [0019]    The step of forming the conductive oxide layer may comprise exposing the conductive oxide layer to a nitrogen-containing gas. 
         [0020]    The step of forming the conductive oxide layer may comprise exposing the conductive oxide material to at least one of hydrogen (H 2 ) and water vapor (H 2 0). 
         [0021]    The step of forming the conductive oxide layer may be performed at a temperature between 25° C. to 150° C. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]      FIG. 1  is a layout view of a TFT array panel for an LCD according to an embodiment of the present invention; 
           [0023]      FIG. 2  is a sectional view of the TFT array panel shown in  FIG. 1  taken along the line II-II; 
           [0024]      FIGS. 3A ,  4 A,  5 A, and  6 A are layout views sequentially illustrating the intermediate steps of a method of manufacturing a TFT array panel for an LCD according to the embodiment of  FIGS. 1 and 2 ; 
           [0025]      FIG. 3B  is a sectional view of the TFT array panel shown in  FIG. 3A  taken along the line IIIb-IIIb′; 
           [0026]      FIG. 4B  is a sectional view of the TFT array panel shown in  FIG. 4A  taken along the line IVb-IVb′ in the step following the step shown in  FIG. 3B ; 
           [0027]      FIG. 5B  is a sectional view of the TFT array panel shown in  FIG. 5A  taken along the line Vb-Vb′ in the step following the step shown in  FIG. 4B ; 
           [0028]      FIG. 6B  is a sectional view of the TFT array panel shown in  FIG. 6A  taken along the line VIb-VIb′ in the step following the step shown in  FIG. 5B ; 
           [0029]      FIG. 7  is a layout view of a TFT array panel for an OLED according to another embodiment of the present invention; 
           [0030]      FIGS. 8A and 8B  are sectional views of the TFT array panel shown in  FIG. 7  taken along the line VIIIa-VIIIa′ and the line VIIIb-VIIIb′, respectively; 
           [0031]      FIGS. 9 ,  11 ,  13 ,  15 ,  17 ,  19 , and  21  are layout views of the TFT array panel shown in  FIGS. 7 to 8B  in intermediate steps of a manufacturing method according to an embodiment of the present invention; 
           [0032]      FIGS. 10A and 10B  are sectional views of the TFT array panel shown in  FIG. 9  taken along the lines Xa-Xa′ and Xb-Xb′; 
           [0033]      FIGS. 12A and 12B  are sectional views of the TFT array panel shown in  FIG. 11  taken along the lines XIIa-XIIa′ and XIIb-XIIb′; 
           [0034]      FIGS. 14A and 14B  are sectional views of the TFT array panel shown in  FIG. 13  taken along the lines XIVa-XIVa′ and XIVb-XIVb′; 
           [0035]      FIGS. 16A and 16B  are sectional views of the TFT array panel shown in  FIG. 15  taken along the lines XVIa-XVIa′ and XVIb-XVIb′; 
           [0036]      FIGS. 18A and 18B  are sectional views of the TFT array panel shown in  FIG. 17  taken along the lines XVIIIa-XVIIIa′ and XVIIIb-XVIIIb′; 
           [0037]      FIGS. 20A and 20B  are sectional views of the TFT array panel shown in  FIG. 19  taken along the lines XXa-XXa′ and XXb-XXb′; and 
           [0038]      FIGS. 22A and 22B  are sectional views of the TFT array panel shown in  FIG. 21  taken along the lines XXIIa-XXIIa′ and XXIIb-XXIIb′. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0039]    Preferred embodiments of the present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. The present invention may, however, be embodied in 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 scope of the invention to those skilled in the art. 
         [0040]    In the drawings, the thicknesses of layers, films, and regions are exaggerated for clarity. Like numerals refer to like elements throughout. It will be understood that when an element such as a layer, film, region, or substrate is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present. 
         [0041]    Now, TFT array panels for an LCD and an OLED and manufacturing methods thereof according to embodiments of this invention will be described in detail with reference to the accompanying drawings. 
       Embodiment 1 
       [0042]    First, a TFT array panel for an LCD according to an embodiment of the present invention will be described in detail with reference to  FIGS. 1 and 2 . 
         [0043]      FIG. 1  is a layout view of a TFT array panel for an LCD according to an embodiment of the present invention, and  FIG. 2  is a sectional view of the TFT array panel shown in  FIG. 1  taken along the line II-II. 
         [0044]    A plurality of gate lines  121  for transmitting gate signals are formed on an insulating substrate  110 . The gate lines  121  are primarily formed in the horizontal direction and partial portions thereof form a plurality of gate electrodes  124 . Also, different partial portions thereof that extend in a lower direction form a plurality of expansions  127 . An end portion  129  of the gate line  121  has an expanded width for connection with an external device such as driving circuit. 
         [0045]    The gate line  121  has first layers  124   p ,  127   p , and  129   p  and second layers  124   q ,  127   q , and  129   q , and third layers  124   r ,  127   r , and  129   r . The first layers  124   p ,  127   p , and  129   p  comprise a conductive oxide such as ITO (indium tin oxide) or IZO (indium zinc oxide) and are formed on the substrate  110 . The second layers  124   q ,  127   q , and  129   q  comprise a Cu-containing metal such as Cu and a Cu alloy formed on the first layers  124   p ,  127   p , and  129   p . The third layers  124   r ,  127   r , and  129   r  comprise a conductive oxide such as ITO or IZO formed on the second layers  124   q ,  127   q , and  129   q.    
         [0046]    Here, the third layers  124   r ,  127   r , and  129   r  prevent the Cu of the second layers  124   q ,  127   q , and  129   q  from diffusing into a gate insulating layer  140  formed thereon. 
         [0047]    When a conductive oxide layer is disposed between a Cu layer and a substrate, adhesiveness between the Cu layer and the substrate is enhanced to prevent the Cu layer from peeling and lifting. 
         [0048]    When the conductive oxide layer comprises amorphous ITO, adhesiveness between the Cu layer and the substrate is significantly more enhanced. This is because the amorphous ITO layer formed at a low temperature subsequently undergoes a high temperature of about 200° C. during the formation of the gate insulating layer  140  and a semiconductor layer  151 , thereby resulting in the crystallization of the ITO layer. 
         [0049]    A Cu layer and a conductive oxide layer, such as an ITO layer or an IZO layer, can be etched by the same etching process. Since Cu is strongly affected by acid, it is etched very rapidly when exposed thereto. Accordingly, a weak acid is generally used to etch a Cu layer. However, since other metals, such as Mo, Cr, and Ti, are etched much more slowly than Cu, when such metals are applied as an underlayer of the Cu layer, two different etching conditions are applied to pattern those layers. In contrast, since the amorphous ITO or IZO is etched along with the Cu layer by the same etching process, they are simultaneously patterned to form the gate line  121 . 
         [0050]    The first layers  124   p ,  127   p , and  129   p  and the third layers  124   r ,  127   r , and  129   r  may comprise an ITON layer or IZON layer to prevent oxidation of Cu at the interfaces of the second layers  124   q ,  127   q , and  129   q , the first layers  124   p ,  127   p , and  129   p , and the third layers  124   r ,  127   r , and  129   r . The ITON layer or IZON layer is formed by exposing the ITO layer or IZO layer to a nitrogen atmosphere and prevents a rapid increase of resistance due to Cu oxidation. 
         [0051]    The lateral sides of the third layers  124   r ,  127   r , and  129   r , the second layers  124   q ,  127   q , and  129   q , and the first layers  124   p ,  127   p , and  129   p  are inclined relative to a surface of the substrate  110 , and the inclination angle thereof ranges from about 30 to 80 degrees. 
         [0052]    A gate insulating layer  140  preferably comprising silicon nitride (SiN x ) is formed on the gate lines  121 . 
         [0053]    A plurality of semiconductor stripes  151 , preferably comprising hydrogenated amorphous silicon (abbreviated to “a-Si”), are formed on the gate insulating layer  140 . Each semiconductor stripe  151  extends substantially in the longitudinal direction and is curved periodically. Each semiconductor stripe  151  has a plurality of projections  154  branching out toward the gate electrodes  124 . The width of each semiconductor stripe  151  becomes larger near the gate lines  121  such that the semiconductor stripe  151  covers large areas of the gate lines  121 . 
         [0054]    A plurality of ohmic contact stripes  161  and islands  165 , preferably comprising silicide or n+ hydrogenated a-Si heavily doped with an n-type impurity, are formed on the semiconductor stripes  151 . Each ohmic contact stripe  161  has a plurality of projections  163 , and the projections  163  and the ohmic contact islands  165  are located in pairs on the projections  154  of the semiconductor stripes  151 . 
         [0055]    The lateral sides of the semiconductor stripes  151  and the ohmic contacts  161  and  165  are tapered, and the inclination angles of the lateral sides of the semiconductor stripes  151  and the ohmic contacts  161  and  165  are preferably in a range of about 30-80 degrees. 
         [0056]    A plurality of data lines  171 , a plurality of drain electrodes  175 , and a plurality of storage capacitor conductors  177  are formed on the ohmic contacts  161  and  165  and the gate insulating layer  140 . 
         [0057]    The data lines  171 , for transmitting data voltages, extend substantially in the longitudinal direction and intersect the gate lines  121  to define pixel areas arranged in a matrix. Each data line  171 A has a plurality of branches which project toward the drain electrodes  175 , forms a plurality of source electrodes  173 , and has an end portion  179  having an enlarged width. Each pair of the source electrodes  173  and the drain electrodes  175  are separated from each other at the gate electrodes  124 , and oppose each other. 
         [0058]    The data line  171 , the drain electrode  175 , and the storage capacitor conductor  177  have first layers  171   p ,  175   p , and  177   p , second layers  171   q ,  175   q , and  177   q , and third layers  171   r ,  175   r , and  177   r . The first layers  171   p ,  175   p , and  177   p  and the third layers  171   r ,  175   r , and  177   r  are respectively disposed at lower and upper sides of the second layers  171   q ,  175   q , and  177   q . The first layers  171   p ,  175   p , and  177   p  and the third layers  171   r ,  175   r , and  177   r  comprise a conductive oxide. The second layers  171   q ,  175   q , and  177   q  comprise a Cu containing metal, such as Cu or a Cu alloy. 
         [0059]    The first layers  171   p ,  175   p , and  177   p  and the third layers  171   r ,  175   r , and  177   r  may comprise ITO or IZO. Here the first layers  171   p ,  175   p , and  177   p  and the third layers  171   r ,  175   r , and  177   r  of a conductive oxide prevent Cu of the second layers  171   q ,  175   q , and  177   q  from diffusing into the semiconductor layer  151  and a pixel electrode  190  formed thereon. When the conductive oxide layer comprises ITO, amorphous ITO is preferable. Since the amorphous ITO or IZO is etched along with Cu by the same etching process, they are simultaneously patterned to form the data lines  171  having a smooth profile. 
         [0060]    The first layers  171   p ,  175   p , and  177   p  and the third layers  171   r ,  175   r , and  177   r  preferably comprise an ITON layer or IZON layer to prevent oxidation of Cu at the interface of the second layers  171   q ,  175   q , and  177   q  and the first and third layers  171   p ,  175   p ,  177   p ,  171   r ,  175   r , and  177   r . The ITON layer or IZON layer is formed by exposing the ITO layer or IZO layer to a nitrogen atmosphere, and helps to prevent a rapid increase of resistance due to Cu oxidation. 
         [0061]    A gate electrode  124 , a source electrode  173 , and a drain electrode  175 , along with a projection  154  of a semiconductor stripe  151 , forms a TFT having a channel formed in the projection  154  disposed between the source electrode  173  and the drain electrode  175 . The storage capacitor conductor  177  overlaps with the expansion  127  of the gate line  121 . 
         [0062]    The data lines  171 , the drain electrodes  175 , and the storage capacitor conductor  177  have tapered lateral sides, and the inclination angles of the lateral sides are in a range of about 30-80 degrees. 
         [0063]    The ohmic contacts  161  and  165  are only interposed between the semiconductor stripe  151  and the data line  171  and between the drain electrode  175  and the projection  154  of the semiconductor stripe  151  in order to reduce contact resistance therebetween. 
         [0064]    The semiconductor stripe  151  is partially exposed at the location between the source electrode  173  and the drain electrode  175  and at the other places not covered by the data line  171  and the drain electrode  175 . Most of the semiconductor stripe  151  is narrower than the data line  171 , but the width of the semiconductor stripe  151  broadens near a location where the semiconductor stripe  151  and the gate line  121  meet each other in order to prevent disconnection of the data line  171 . 
         [0065]    On the data line  171 , the drain electrode  175 , the storage capacitor conductor  177 , and the exposed region of the semiconductor stripe  151 , a passivation layer  180  is provided, which comprises an organic material having substantial planarization properties and photosensitivity or an insulating material with a low dielectric constant, such as a-Si:C:O, a-Si:O:F, etc. This passivation layer  180  may be formed by plasma enhanced chemical vapor deposition (PECVD). To prevent the organic material of the passivation layer  180  from contacting the semiconductor stripes  151  exposed between the data line  171  and the drain electrode  175 , the passivation layer  180  can be structured in a way that an insulating layer made of SiN x  or SiO 2  is additionally formed under the organic material layer. 
         [0066]    In the passivation layer  180 , a plurality of contact holes  181 ,  185 ,  187 , and  182  are formed to expose an end portion  129  of the gate line  121 , the drain electrode  175 , the storage capacitor conductor  177 , and an end portion  179  of the data line  171 , respectively. 
         [0067]    A plurality of pixel electrodes  190  and a plurality of contact assistants  81  and  82 , which comprise IZO or ITO, are formed on the passivation layer  180 . 
         [0068]    Since the pixel electrode  190  is physically and electrically connected with the drain electrode  175  and the storage capacitor conductor  177  through the contact holes  185  and  187 , respectively, the pixel electrode  190  receives the data voltage from the drain electrodes  175  and transmits it to the storage capacitor conductor  177 . 
         [0069]    The pixel electrode  190  to which the data voltage is applied generates an electric field with a common electrode (not illustrated) of the opposite panel (not illustrated) to which a common voltage is applied, so that the liquid crystal molecules in the liquid crystal layer are rearranged. 
         [0070]    Also, as mentioned above, the pixel electrode  190  and the common electrode form a capacitor to store and preserve the received voltage after the TFT is turned off. This capacitor will be referred to as a “liquid crystal capacitor.” To enhance the voltage storage capability, another capacitor is provided, which is connected with the liquid crystal capacitor in parallel and will be referred to as a “storage capacitor.” The storage capacitor is formed at an overlapping portion of the pixel electrode  190  and the adjacent gate line  121 , which will be referred to as the “previous gate line.” The expansion  127  of the gate line  121  is provided to ensure the largest possible overlap area and thus to increase the storage capacity of the storage capacitor. The storage capacitor conductor  177  is connected to the pixel electrode  190  and overlaps with the expansion  127 , and is provided below the passivation layer  180  so that the pixel electrode  190  is in close proximity to the previous gate line  121 . 
         [0071]    The contact assistants  81  and  82  are respectively connected to the end portions  129  and  179  of the gate line  121  and the data line  171 . The contact assistants  81  and  82  respectively provide protection and supplement adhesion between the end portion  129  of the gate line  121  and the exterior devices, such as the driving integrated circuit, and between the end portion  179  of the data line  171  and the exterior devices. Applying the contact assistants  81  and  82  is optional since they are not essential elements. 
         [0072]    A method of manufacturing a TFT array panel will be now described in detail with reference to  FIGS. 3A to 6B  as well as  FIGS. 1 and 2 . 
         [0073]    At first, as shown in  FIGS. 3A and 3B , a first layer of a conductive oxide, such as ITO or IZO, a second layer of a Cu-containing metal, and a third layer of a conductive oxide, such as ITO or IZO, are formed on an insulating substrate  110 . 
         [0074]    The first layer and the second layer may be deposited by co-sputtering. Two targets are installed in the same sputtering chamber for the co-sputtering. One target comprises a conductive oxide, such as ITO or IZO. The other target comprises a Cu-containing metal, such as Cu or a Cu-alloy. Hereinafter, examples of an ITO target and a Cu target will be described. 
         [0075]    The co-sputtering is performed as follows. 
         [0076]    At first, in order to deposit a first ITO layer, power is applied to the ITO target while no power is applied to the Cu target. The sputtering is performed at a temperature between 25° C. and 150° C. while supplying hydrogen gas (H 2 ) or water vapor (H 2 0). Such conditions result in the formation of an amorphous ITO layer. The ITO layer has a thickness of 50 Å to 500 Å. 
         [0077]    Next, a Cu layer is deposited by switching the power to be applied to the Cu target and not to be applied to the ITO target. The Cu layer has a thickness of 50 Å to 2,000 Å. 
         [0078]    Next, a second ITO layer is deposited by switching the power to be applied again to the ITO target and not to be applied to the Cu target. The sputtering is performed at a temperature between 25° C. and 150° C. while supplying hydrogen gas (H 2 ) or water vapor (H 2 0). Such conditions result in the formation of an amorphous ITO layer. The second ITO layer has a thickness of 50 Å to 500 Å. 
         [0079]    Nitrogen gas (N 2 ), nitrous oxide (N 2 0), or ammonia (NH 3 ) may be applied while sputtering the ITO target to form an ITON layer. 
         [0080]    When a conductive oxide layer is disposed between a Cu layer and a substrate, adhesiveness between the Cu layer and the substrate is enhanced. The conductive oxide layer applied on top of the Cu layer prevents the Cu from diffusing into a gate insulating layer  140  which will be formed thereon. 
         [0081]    When the conductive oxide layer comprises amorphous ITO, adhesiveness between the Cu layer and the substrate  110  is significantly enhanced. This is because the amorphous ITO layer formed at a low temperature undergoes a high temperature of about 200° C. during the formation of the gate insulating layer  140  and a semiconductor layer  151 , thereby resulting in the crystallization of the ITO layer. 
         [0082]    An amorphous ITO layer or an amorphous IZO layer can be etched by a weak acid. Since Cu is strongly affected by an acid, it is etched very fast therewith. Accordingly, a weak acid is generally used to etch a Cu layer. However, since other metals such as Mo, Cr, and Ti are etched much more slowly than Cu, when such metals are applied as an underlayer of the Cu layer, two different etching conditions are applied to pattern those layers. In contrast, since the amorphous ITO or IZO can be etched along with the Cu layer by a weak acid, the layers can be simultaneously patterned to form the gate line  121 . 
         [0083]    As in the above descriptions, when an amorphous ITO or IZO layer is disposed between a Cu layer and a substrate, the adhesiveness between the Cu layer and the substrate and etching efficiency is enhanced. The amorphous ITO or IZO layer prevents diffusion of Cu to other layers. 
         [0084]    When nitrogen gas (N 2 ), nitrous oxide (N 2 0), or ammonia (NH 3 ) is supplied during sputtering of the ITO or IZO target, an ITON or IZON layer is formed to prevent oxidation of the Cu layer at the interface. 
         [0085]    Then, a photoresist is coated on the second ITO layer and is illuminated with a light through a photo-mask. Next, the illuminated photoresist is developed. 
         [0086]    The two ITO layers and the Cu layer are simultaneously etched to form a plurality of gate lines  121  using an etchant, such as, e.g., hydrogen peroxide (H 2 O 2 ) or a common etchant containing an appropriate amount of phosphoric acid (H 2 PO 3 ), nitric acid (HNO 3 ), and acetic acid (CH 3 COOH). 
         [0087]    Through the above-described processes, as shown in  FIGS. 3A and 3B , a plurality of gate lines  121  having a plurality of gate electrodes  124 , expansions  127 , and end portions  129  are formed. 
         [0088]    Referring to  FIGS. 4A and 4B , after sequential deposition of a gate insulating layer  140 , an intrinsic a-Si layer, and an extrinsic a-Si layer, the extrinsic a-Si layer and the intrinsic a-Si layer are photo-etched to form a plurality of extrinsic semiconductor stripes  161  and a plurality of intrinsic semiconductor stripes  151  respectively having projections  164  and  154 . The gate insulating layer  140  preferably comprises silicon nitride having a thickness of about 2,000 Å to about 5,000 Å, and the deposition temperature is preferably in a range between about 250° C. and about 500° C. 
         [0089]    Since this process is performed at a high temperature of over 200° C., the amorphous ITO of the gate line  121  is crystallized. 
         [0090]    Next, a first layer of a conductive oxide, such as ITO, a second layer of a Cu-containing metal, and a third layer of a conductive oxide, such as ITO, are sequentially deposited on the extrinsic semiconductor stripes  161 . 
         [0091]    The first layer and the third layer of a conductive oxide prevent the Cu of the second layer from diffusing into the semiconductor layer  151  and a pixel electrode  190  which will be formed thereon. 
         [0092]    The first layer and the third layer may comprise ITO or IZO. When the first layer and the third layer are formed of ITO, the sputtering is performed at a temperature between 25° C. and 150° C. while supplying hydrogen gas (H 2 ) or water vapor (H 2 0). This operating condition results in the formation of an amorphous ITO layer. 
         [0093]    Since the amorphous ITO or IZO can be etched along with the Cu layer by a weak acid, the layers can be simultaneously patterned. 
         [0094]    When nitrogen gas (N 2 ), nitrous oxide (N 2 O), or ammonia (NH 3 ) is supplied during sputtering of the ITO or IZO target, an ITON or IZON layer is formed for preventing oxidation of the Cu layer at the interface. 
         [0095]    The first and third layers are formed to have a thickness of about 50 Å to 500 Å and the second layer is formed to have a thickness of about 1,500 Å to 3,000 Å. 
         [0096]    Then, a photoresist is coated on the third layer and is illuminated with a light through a photo-mask. Next, the illuminated photoresist is developed. 
         [0097]    The first to third layers are simultaneously etched to form a plurality of data lines  171  using an etchant, such as, e.g., hydrogen peroxide (H 2 O 2 ) or a common etchant containing an appropriate amount of phosphoric acid (H 2 PO 3 ), nitric acid (HNO 3 ), and acetic acid (CH 3 COOH). 
         [0098]    Through the above-described processes, as shown in  FIGS. 5A and 5B , a plurality of data lines  171  having a plurality of source electrodes  173 , a plurality of drain electrodes  175 , an end portion  179 , and storage capacitor conductors  177  are formed. 
         [0099]    Next, portions of the extrinsic semiconductor stripes  161 , which are not covered with the data lines  171  and the drain electrodes  175 , are removed by etching to form a plurality of ohmic contacts  163  and  165  and to expose portions of the intrinsic semiconductor stripes  151 . Oxygen plasma treatment may follow thereafter in order to stabilize the exposed surfaces of the semiconductor stripes  151 . 
         [0100]    Referring to  FIGS. 6A and 6B , a passivation layer  180  is deposited and dry etched along with the gate insulating layer  140  to form a plurality of contact holes  181 ,  185 ,  187 , and  182 . The gate insulating layer  140  and the passivation layer  180  are preferably etched under an etch condition having substantially the same etch ratio for both the gate insulating layer  140  and the passivation layer  180 . 
         [0101]    When the passivation layer comprises a photosensitive material, the contact holes can be formed using only photolithography, without a subsequent etching step. 
         [0102]    Next, an indium tin oxide (ITO) layer is deposited on the passivation layer  180  to a thickness of about 400 Å to 1500 Å and is patterned to form a plurality of pixel electrodes  190  and contact assistants  81  and  82 . 
         [0103]    In the present embodiment, ITO is the primary conductive oxide, but another conductive oxide such as IZO may also be applied as a conductive oxide of the present invention. 
         [0104]    In the present embodiment, conductive oxide layers are disposed on lower and upper sides of a Cu layer. However, one of the upper and lower conductive oxide layers may be omitted. 
       Embodiment 2 
       [0105]    Now, a TFT panel for an active matrix organic light emitting display (AM-OLED) according to another embodiment of the present invention will be described. 
         [0106]      FIG. 7  is a layout view of a TFT array panel for an OLED according to another embodiment of the present invention.  FIGS. 8A and 8B  are sectional views of the TFT array panel shown in  FIG. 7  taken along the line VIIIa-VIIIa′ and the line VIIIb-VIIIb′, respectively. 
         [0107]    A plurality of gate conductors that include a plurality of gate lines  121 , including a plurality of first gate electrodes  124   a  and a plurality of second gate electrodes  124   b , are formed on an insulating substrate  110  such as transparent glass. 
         [0108]    The gate lines  121  transmitting gate signals extend substantially in a transverse direction and are separated from each other. The first gate electrodes  124   a  protrude upward, as viewed from the perspective shown in  FIG. 7 . The gate lines  121  may extend to be connected to a driving circuit (not shown) integrated on the substrate  110 . Alternatively, the gate lines  121  may have an end portion (not shown) having a large area for connection with another layer or an external driving circuit mounted on the substrate  110  or on another device such as a flexible printed circuit film (not shown) that may be attached to the substrate  110 . 
         [0109]    Each of the second gate electrodes  124   b  is separated from the gate lines  121  and includes a storage electrode  133  extending substantially in a transverse direction between two adjacent gate lines  121 . 
         [0110]    The gate lines  121 , the first and second gate electrodes  124   a  and  124   b , and the storage electrodes  133  have first layers  124   ap,    124   bp , and  133   p  and second layers  124   aq ,  124   bq , and  133   q  formed on the first layers  124   ap,    124   bp , and  133   p , and third layers  124   ar ,  124   br ,  133   r  formed on the second layers  124   aq ,  124   bq , and  133   q . The first layers  124   ap,    124   bp , and  133   p  comprise a conductive oxide such as ITO or IZO. The second layers  124   aq ,  124   bq , and  133   q  comprise a Cu-containing metal such as Cu or a Cu alloy. The third layers  124   ar ,  124   br ,  133   r  comprise a conductive oxide such as ITO or IZO. 
         [0111]    Here, the third layers  124   ar ,  124   br ,  133   r  prevent the Cu of the second layers  124   aq ,  124   bq , and  133   q  from diffusing into a gate insulating layer  140  formed thereon. 
         [0112]    When a conductive oxide layer is disposed between a Cu layer and a substrate, adhesiveness between the Cu layer and the substrate is enhanced to prevent the Cu layer from peeling and lifting. 
         [0113]    When the conductive oxide layer comprises amorphous ITO, adhesiveness between the Cu layer and the substrate is significantly enhanced. This is because the amorphous ITO layer formed at a low temperature undergoes a high temperature of about 200° C. during the formation of the gate insulating layer  140  and a semiconductor layer  151 , thereby resulting in the crystallization of the ITO layer. 
         [0114]    A Cu layer and a conductive oxide layer such as an ITO layer or an IZO layer can be etched by the same etching process. Since Cu is strongly affected by acid, it is etched very rapidly when exposed thereto. Accordingly, a weak acid is generally used to etch a Cu layer. However, since other metals such as Mo, Cr, and Ti are etched much more slowly than Cu, when such metals are applied as an underlayer of the Cu layer, two different etching conditions are applied to pattern those layers. In contrast, since the amorphous ITO or IZO is etched along with the Cu layer by the same etching process, they are simultaneously patterned to form the gate line  121 . 
         [0115]    The first layers  124   ap,    124   bp , and  133   p  and the third layers  124   ar ,  124   br , and  133   r  may comprise an ITON layer or IZON layer to prevent oxidation of Cu at the interfaces of the second layers  124   aq ,  124   bq , and  133   q , the first layers  124   ap,    124   bp , and  133   p , and the third layers  124   ar ,  124   br , and  133   r . The ITON layer or IZON layer is formed by exposing the ITO layer or IZO layer to a nitrogen atmosphere, and helps to prevent a rapid increase of resistance due to Cu oxidation. 
         [0116]    In addition, the lateral sides of the gate conductors  121  and  124   b  are inclined relative to a surface of the substrate  110 , and the inclination angle thereof ranges from about 30 to 80 degrees. 
         [0117]    A gate insulating layer  140 , preferably comprising silicon nitride (SiN x ), is formed on the gate conductors  121  and  124   b.    
         [0118]    A plurality of semiconductor stripes  151  and islands  154   b , preferably comprising hydrogenated amorphous silicon (abbreviated to “a-Si”) or polysilicon, are formed on the gate insulating layer  140 . Each semiconductor stripe  151  extends substantially in the longitudinal direction and has a plurality of projections  154   a  branching out toward the first gate electrodes  124   a . Each semiconductor island  154   b  crosses a second gate electrode  124   b  and includes a portion  157  overlapping the storage electrode  133  of the second gate electrode  124   b.    
         [0119]    A plurality of ohmic contact stripes  161  and ohmic contact islands  163   b ,  165   a , and  165   b , which preferably comprise silicide or n+ hydrogenated a-Si heavily doped with an n-type impurity such as phosphorous, are formed on the semiconductor stripes  151  and islands  154   b . Each ohmic contact stripe  161  has a plurality of projections  163   a , and the projections  163   a  and the ohmic contact islands  165   a  are located in pairs on the projections  154   a  of the semiconductor stripes  151 . The ohmic contact islands  163   b  and  165   b  are located in pairs on the semiconductor islands  154   b.    
         [0120]    The lateral sides of the semiconductor stripes  151  and islands  154   b  and the ohmic contacts  161 ,  163   b ,  165   b , and  165   b  are inclined relative to a surface of the substrate, and the inclination angles thereof are preferably in a range between about 30-80 degrees. 
         [0121]    A plurality of data conductors including a plurality of data lines  171 , a plurality of voltage transmission lines  172 , and a plurality of first and second drain electrodes  175   a  and  175   b  are formed on the ohmic contacts  161 ,  163   b ,  165   b , and  165   b  and the gate insulating layer  140 . 
         [0122]    The data lines  171  for transmitting data signals extend substantially in the longitudinal direction and intersect the gate lines  121 . Each data line  171  includes a plurality of first source electrodes  173   a , an end portion having a large area for contact with another layer or an external device. The data lines  171  may be directly connected to a data driving circuit for generating the gate signals, which may be integrated on the substrate  110 . 
         [0123]    The voltage transmission lines  172  for transmitting driving voltages extend substantially in the longitudinal direction and intersect the gate lines  121 . Each voltage transmission line  172  includes a plurality of second source electrodes  173   b . The voltage transmission lines  172  may be connected to each other. The voltage transmission lines  172  overlap the storage region  157  of the semiconductor islands  154   b.    
         [0124]    The first and the second drain electrodes  175   a  and  175   b  are separated from the data lines  171  and the voltage transmission lines  172 , and from each other. Each pair of the first source electrodes  173   a  and the first drain electrodes  175   a  are disposed opposite each other with respect to a first gate electrode  124   a , and each pair of the second source electrodes  173   b  and the second drain electrodes  175   b  are disposed opposite each other with respect to a second gate electrode  124   b.    
         [0125]    A first gate electrode  124   a , a first source electrode  173   a , a first drain electrode  175   a , and a projection  154   a  of a semiconductor stripe  151  form a switching TFT having a channel formed in the projection  154   a  disposed between the first source electrode  173   a  and the first drain electrode  175   a . Meanwhile, a second gate electrode  124   b , a second source electrode  173   b , a second drain electrode  175   b , and a semiconductor island  154   b  form a driving TFT having a channel formed in the semiconductor island  154   b  disposed between the second source electrode  173   b  and the second drain electrode  175   b.    
         [0126]    The data conductors  171 ,  172 ,  175   a , and  175   b  preferably have first layers  171   p ,  172   p ,  175   ap , and  175   bp , second layers  171   q ,  172   q ,  175   aq , and  175   bq , and third layers  171   r ,  172   r ,  175   ar , and  175   br . The second layers  171   q ,  172   q ,  175   ap , and  175   bp  comprise a Cu-containing metal such as Cu or a Cu alloy. The first layers  171   p ,  172   p ,  175   ap , and  175   bp  and third layers  171   r ,  172   r ,  175   ar , and  175   br  are respectively disposed at lower and upper sides of the second layers  171   q ,  172   q ,  175   aq , and  175   bq . The first layers  171   p ,  172   p ,  175   ap , and  175   bp  and the third layers  171   r ,  172   r ,  175   ar , and  175   br  comprise a conductive oxide. 
         [0127]    The first layers  171   p ,  172   p ,  175   ap , and  175   bp  and the third layers  171   r ,  172   r ,  175   ar , and  175   br  may comprise ITO or IZO. Here, the first layers  171   p ,  172   p ,  175   ap , and  175   bp  and the third layers  171   r ,  172   r ,  175   ar , and  175   br  comprise a conductive oxide to prevent the Cu of the second layers  171   q ,  172   q ,  175   aq , and  175   bq  from diffusing into the semiconductor layer  151  and a pixel electrode  190  formed thereon. When the conductive oxide layer comprises ITO, amorphous ITO is preferable. Since the amorphous ITO or IZO is etched along with Cu by the same etching process, the layers are simultaneously patterned to form the data lines  171  having a smooth profile. 
         [0128]    The first layers  171   p ,  172   p ,  175   ap , and  175   bp  and the third layers  171   r ,  172   r ,  175   ar , and  175   br  preferably comprise an ITON layer or IZON layer to prevent oxidation of Cu at the interface of the second layers  171   q ,  172   q ,  175   aq , and  175   bq  and the first and third layers  171   p ,  172   p ,  175   ap,    175   bp ,  171   r ,  172   r ,  175   ar , and  175   br . The ITON layer or IZON layer is formed by exposing the ITO layer or IZO layer to a nitrogen atmosphere, and it prevents a rapid increase of resistance due to Cu oxidation. 
         [0129]    Like the gate conductors  121  and  124   b , the data conductors  171 ,  172 ,  175   a , and  175   b  have tapered lateral sides relative to the surface of the substrate  110 , and the inclination angles thereof range from about 30 to 80 degrees. 
         [0130]    The ohmic contacts  161 ,  163   b ,  165   b , and  165   b  are interposed only between the underlying semiconductor stripes  151  and islands  154   b  and the overlying data conductors  171 ,  172 ,  175   a , and  175   b  thereon, and reduce the contact resistance therebetween. The semiconductor stripes  151  include a plurality of exposed portions that are not covered with the data conductors  171 ,  172 ,  175   a , and  175   b.    
         [0131]    Most of the semiconductor stripe  151  is narrower than the data line  171 , but the width of the semiconductor stripe  151  broadens near a location where the semiconductor stripe  151  and the gate line  121  meet each other in order to prevent disconnection of the data line  171 , as mentioned above. 
         [0132]    A passivation layer  180  is formed on the data conductors  171 ,  172 ,  175   a , and  175   b  and the exposed portions of the semiconductor stripes  151  and islands  154   b . The passivation layer  180  preferably comprises an inorganic material, such as silicon nitride or silicon oxide, a photosensitive organic material having good flatness characteristics, or a low dielectric insulating material having a dielectric constant lower than 4.0, such as a-Si:C:O and a-Si:O:F, formed by plasma enhanced chemical vapor deposition (PECVD). The passivation layer  180  may include a lower film of an inorganic insulator and an upper film of an organic insulator. 
         [0133]    The passivation layer  180  has a plurality of contact holes  189 ,  183 ,  185 ,  181 , and  182  exposing portions of the first drain electrode  175   a , a second gate electrode  124   b , the second drain electrode  175   b , and the end portions  129  and  179  of the gate line  121  and the data line  171 , respectively. 
         [0134]    The contact holes  181  and  182  expose the end portions  129  and  179  of the gate line  121  and the data line  171  to provide a connection between the gate line  121  and the data line  171  and external driving circuits. Anisotropic conductive films are disposed between the output terminals of the external driving circuit and the end portions  129  and  175  to assist the electrical connection and physical adhesion. However, when driving circuits are directly fabricated on the substrate  110 , contact holes are not formed. In embodiments where the gate driving circuits are directly fabricated on the substrate  110 , while the data driving circuits are formed as separate chips, only the contact hole  181  exposing the end portion  179  of the data line  171  is formed. 
         [0135]    A plurality of pixel electrodes  190 , a plurality of connecting members  192 , and a plurality of contact assistants  81  and  82  are formed on the passivation layer  180 . 
         [0136]    The pixel electrodes  190  are connected to the second drain electrodes  175   b  through the contact holes  185 . The connecting member  192  connects the first drain electrode  175   a  and the second gate electrode  124   b  through the contact holes  189  and  183 . The contact assistants  81  and  82  are connected to the end portions  81  and  82  of the gate line  121  and the data line  171  through the contact holes  181  and  182 , respectively. 
         [0137]    The pixel electrode  190 , the connecting member  192 , and the contact assistants  81  and  82  comprise a transparent conductor such as ITO or IZO. 
         [0138]    A partition  803 , an auxiliary electrode  272 , a plurality of light emitting members  70 , and a common electrode  270  are formed on the passivation layer  180 , and on the pixel electrodes  190 . 
         [0139]    The partition  803  comprises an organic or inorganic insulating material and forms frames of organic light emitting cells. The partition  803  is formed along boundaries of the pixel electrodes  190  and defines a space for filling with an organic light emitting material. 
         [0140]    The light emitting member  70  is disposed on the pixel electrode  190  and surrounded by the partition  803 . The light emitting member  70  comprises one light-emitting material that emits red, green, or blue light. Red, green, and blue light emitting members  70  are sequentially and repeatedly disposed. 
         [0141]    The auxiliary electrode  272  has substantially the same planar pattern as the partition  803 . The auxiliary electrode  272  contacts the common electrode  270  to reduce resistance of the common electrode  270 . 
         [0142]    The common electrode  270  is formed on the partition  803 , the auxiliary electrode  272 , and the light emitting member  70 . The common electrode  270  comprises a metal such as Al, which has low resistivity. This embodiment illustrates a back-emitting OLED. However, in embodiments incorporating a front-emitting OLED or a dual-sides-emitting OLED, the common electrode  270  comprises a transparent conductor such as ITO or IZO. 
         [0143]    A method of manufacturing the TFT array panel shown in  FIGS. 7 to 8B  according to an embodiment of the present invention will now be described in detail with reference to  FIGS. 9A to 22B  as well as  FIGS. 7 to 8B . 
         [0144]      FIGS. 9 ,  11 ,  13 ,  15 ,  17 ,  19 , and  21  are layout views of the TFT array panel shown in  FIGS. 7 to 8B  in intermediate steps of a manufacturing method according to an embodiment of the present invention.  FIGS. 10A and 10B  are sectional views of the TFT array panel shown in  FIG. 9  taken along the lines Xa-Xa′ and Xb-Xb′.  FIGS. 12A and 12B  are sectional views of the TFT array panel shown in  FIG. 11  taken along the lines XIIa-XIIa′ and XIIb-XIIb′.  FIGS. 14A and 14B  are sectional views of the TFT array panel shown in  FIG. 13  taken along the lines XIVa-XIVa′ and XIVb-XIVb′.  FIGS. 16A and 16B  are sectional views of the TFT array panel shown in  FIG. 15  taken along the lines XVIa-XVIa′ and XVIb-XVIb′.  FIGS. 18A and 18B  are sectional views of the TFT array panel shown in  FIG. 17  taken along the lines XVIIIa-XVIIIa′ and XVIIIb-XVIIIb′.  FIGS. 20A and 20B  are sectional views of the TFT array panel shown in  FIG. 19  taken along the lines XXa-XXa′ and XXb-XXb′.  FIGS. 22A and 22B  are sectional views of the TFT array panel shown in  FIG. 21  taken along the lines XXIIa-XXIIa′ and XXIIb-XXIIb′. 
         [0145]    First, as shown in  FIGS. 9 and 10B , a first layer of a conductive oxide such as ITO or IZO, a second layer of a Cu-containing metal, and a third layer of a conductive oxide such as ITO or IZO are formed on an insulating substrate  110 . 
         [0146]    The first layer and the second layer may be deposited by co-sputtering. Two targets are installed in the same sputtering chamber for the co-sputtering. One target comprises a conductive oxide such as ITO or IZO, and the other target comprises a Cu-containing metal such as Cu or a Cu-alloy. Hereinafter, examples of an ITO target and a Cu target will be described. 
         [0147]    The co-sputtering is performed as follows. 
         [0148]    At first, in order to deposit a first ITO layer, power is applied to the ITO target while no power is applied to the Cu target. The sputtering is performed at a temperature between 25° C. and 150° C. while supplying hydrogen gas (H 2 ) or water vapor (H 2 0). Such condition result in the formation of an amorphous ITO layer. The ITO layer has a thickness of 50 Å to 500 Å. 
         [0149]    Next, a Cu layer is deposited by switching the power to be applied to the Cu target and not to be applied to the ITO target. The Cu layer has a thickness of 50 Å to 2,000 Å. 
         [0150]    Next, a second ITO layer is deposited by switching the power to be applied again to the ITO target and not to be applied to the Cu target. The sputtering is performed at a temperature between 25° C. and 150° C. while supplying hydrogen gas (H 2 ) or water vapor (H 2 0). Such conditions result in the formation of an amorphous ITO layer. The second ITO layer has a thickness of 50 Å to 500 Å. 
         [0151]    Nitrogen gas (N 2 ), nitrous oxide (N 2 0), or ammonia (NH 3 ) may be applied during sputtering of the ITO target to form an ITON layer. 
         [0152]    When a conductive oxide layer is disposed between a Cu layer and a substrate, adhesiveness between the Cu layer and the substrate is enhanced. The conductive oxide layer applied on top of the Cu layer prevents the Cu from diffusing into a gate insulating layer  140  which will be formed thereon. 
         [0153]    When the conductive oxide layer comprises amorphous ITO, adhesiveness between the Cu layer and the substrate  110  is significantly enhanced. This is because the amorphous ITO layer formed at a low temperature undergoes a high temperature of about 200° C. during the formation of the gate insulating layer  140  and a semiconductor layer  151 , thereby resulting in the crystallization of the ITO layer. 
         [0154]    An amorphous ITO layer or an amorphous IZO layer can be etched by a weak acid. Since Cu is strongly affected by acid, it is etched very fast therewith. Accordingly, a weak acid is generally used to etch a Cu layer. However, since other metals such as Mo, Cr, and Ti are etched much more slowly than Cu, when such metals are applied as an underlayer of the Cu layer, two different etching conditions are applied to pattern those layers. In contrast, since the amorphous ITO or IZO can be etched along with the Cu layer by a weak acid, the layers can be simultaneously patterned to form the gate line  121 , the second gate electrode  124   b , and the voltage transmission line  172 . 
         [0155]    As in the above descriptions, when an amorphous ITO or IZO layer is disposed between a Cu layer and a substrate, the adhesiveness between the Cu layer and the substrate etching efficiency is enhanced. The amorphous ITO or IZO layer prevents diffusion of Cu to another layer. 
         [0156]    When nitrogen gas (N 2 ), nitrous oxide (N 2 0), or ammonia (NH 3 ) is supplied during sputtering of the ITO or IZO target, an ITON or IZON layer is formed to prevent oxidation of the Cu layer at the interface. 
         [0157]    Then, a photoresist is coated on the second ITO layer and is illuminated with a light through a photo-mask. Next, the illuminated photoresist is developed. 
         [0158]    The two ITO layers and the Cu layer are simultaneously etched using an etchant to form a plurality of gate lines  121 , the second gate electrode  124   b , and the voltage transmission line  172 . The etchant may be one of hydrogen peroxide (H 2 O 2 ) or a common etchant containing an appropriate amount of phosphoric acid (H 2 PO 3 ), nitric acid (HNO 3 ), and acetic acid (CH 3 COOH). 
         [0159]    Referring to  FIGS. 11-12B , after sequential deposition of a gate insulating layer  140 , an intrinsic a-Si layer, and an extrinsic a-Si layer, the extrinsic a-Si layer and the intrinsic a-Si layer are photo-etched to form a plurality of extrinsic semiconductor stripes  164  and a plurality of intrinsic semiconductor stripes  151  and islands  154   b  including projections  154   a  on the gate insulating layer  140 . The gate insulating layer  140  preferably comprises silicon nitride having a thickness of about 2,000 Å to about 5,000 Å, and the deposition temperature is preferably in a range of about 250° C. to about 500° C. 
         [0160]    Since this process is performed at a high temperature of over 200° C., the amorphous ITO of the gate line  121  is crystallized. 
         [0161]    Next, referring to  FIGS. 13 to 14B , a first layer of a conductive oxide such as ITO, a second layer of a Cu-containing metal, and a third layer of a conductive oxide such as ITO are sequentially deposited on the extrinsic semiconductor stripes  161 . The first layer and the third layer of a conductive oxide prevent the Cu of the second layer from diffusing into the semiconductor layer  151  and a pixel electrode  190  which will be formed thereon. 
         [0162]    The first layer and the third layer may comprise ITO or IZO. When the first layer and the third layer are formed of ITO, the sputtering is performed at a temperature between 25° C. and 150° C. while supplying hydrogen gas (H 2 ) or water vapor (H 2 0). This operating condition results in the formation of an amorphous ITO layer. 
         [0163]    Since the amorphous ITO or IZO can be etched along with the Cu layer by a weak acid, the layers can be simultaneously patterned. 
         [0164]    When nitrogen gas (N 2 ), nitrous oxide (N 2 0), or ammonia (NH 3 ) is supplied during sputtering of the ITO or IZO target, an ITON or IZON layer is formed for preventing oxidation of the Cu layer at the interface. 
         [0165]    The first and third layers are formed to have a thickness of about 50 Å to 500 Å, and the second layer is formed to have a thickness of about 1,500 Å to 3,000 Å. 
         [0166]    Then, a photoresist is coated on the third layer and is illuminated with a light through a photo-mask. Next, the illuminated photoresist is developed. 
         [0167]    The first to third layers are simultaneously etched to form a plurality of data lines  171  using an etchant, such as, e.g., hydrogen peroxide (H 2 O 2 ) or a common etchant containing an appropriate amount of phosphoric acid (H 2 PO 3 ), nitric acid (HNO 3 ), and acetic acid (CH 3 COOH). 
         [0168]    Through the above-described processes, as shown in  FIGS. 13 to 14B , a plurality of data lines  171  having a plurality of first source electrodes  173   a , a plurality of first and second drain electrodes  175   a  and  175   b , and a plurality of voltage transmission lines  172  having second source electrodes  173   b  are formed. 
         [0169]    Before or after removing the photoresist, portions of the extrinsic semiconductor stripes  164 , which are not covered with the data conductors  171 ,  172 ,  175   a , and  175   b , are removed by etching to form a plurality of ohmic contact stripes  161  including projections  163   a  and a plurality of ohmic contact islands  163   b ,  165   a , and  165   b , and to expose portions of the intrinsic semiconductor stripes  151  and islands  154   b.    
         [0170]    Oxygen plasma treatment may follow thereafter in order to stabilize the exposed surfaces of the semiconductor stripes  151 . 
         [0171]    Referring to  FIGS. 15 to 16B , a passivation layer  180  is formed of an organic insulating material or an inorganic insulating material. Since this process is performed in a high temperature of over 200° C., the amorphous ITO of the data conductors  171 ,  172 ,  175   a , and  175   b  is crystallized. 
         [0172]    The passivation layer  180  is patterned to form a plurality of contact holes  189 ,  185 ,  183 ,  181 , and  182  exposing the first and second drain electrodes  175   a  and  175   b , the second gate electrodes  124   b , an end portion  129  of the gate line  121 , and an end portion  179  of the data line  171 . 
         [0173]    Referring to  FIGS. 17 to 18B , a plurality of pixel electrodes  190 , a plurality of connecting members  192 , and contact assistants  81  and  82  comprising ITO or IZO are formed on the passivation layer  180 . 
         [0174]    Referring to  FIGS. 19-20B , a partition  803  and an auxiliary electrode  272  may be formed using a single photolithography step followed by a single etching step. 
         [0175]    Finally, a plurality of organic light emitting members  70 , preferably comprising multiple layers, are formed in the openings by deposition or inkjet printing following masking, and a common electrode  270  is subsequently formed as shown in  FIGS. 21-22B . 
         [0176]    In accordance with the present invention, since a conductive oxide layer is disposed between a Cu layer and a substrate, the adhesion between the Cu layer and the substrate and etching efficiency is enhanced. In addition, the conductive oxide layer prevents diffusion of the Cu to another layer. Accordingly, reliability of the signal lines is improved. 
         [0177]    In the present embodiment, ITO is the primary conductive oxide, but another conductive oxide such as IZO may also be applied as a conductive oxide of the present invention. 
         [0178]    In the present embodiment, conductive oxide layers are disposed on lower and upper sides of a Cu layer. However, one of the upper and lower conductive oxide layers may be omitted. 
         [0179]    Although preferred embodiments of the present invention have been described in detail hereinabove, it should be clearly understood that many variations and/or modifications of the basic inventive concepts herein taught, which may appear to those skilled in the present art, will still fall within the spirit and scope of the present invention, as defined in the appended claims.