Patent Publication Number: US-2006011222-A1

Title: Apparatus for treating substrates

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application claims the benefit of Korean Patent Application No. 2004-0059312, filed on Jul. 28, 2004, and No. 2004-0051225, filed on Jul. 1, 2004, in the Korean Intellectual Property Office, the disclosures of which are incorporated by reference herein in their entireties.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to an apparatus for treating a substrate, and more particularly, to an apparatus for treating a substrate by supplying a treating fluid to a substrate for washing and/or drying of the substrate.  
      2. Description of the Related Art  
      A liquid crystal display (LCD) comprises a liquid crystal panel which comprises a thin film transistor (TFT) substrate, a color filter substrate, and a liquid crystal layer sandwiched between both substrates. Since the liquid crystal panel does not emit light itself, a backlight unit may be located behind the TFT substrate to supply light to the liquid crystal panel. The transmittance of light from the backlight unit depends on the alignment of the liquid crystal layer.  
      In addition, the LCD may further comprise a driving circuit, a data driver and a gate driver to drive a pixel of the liquid crystal panel, wherein the data driver and the gate driver receive a driving signal from the driving circuit and then apply a driving voltage on a data line and a gate line within a display area respectively.  
      In making the TFT substrate and the color filter substrate, etching and developing are performed to form a pattern on the surface of the substrate. Further, washing and drying are performed before and/or after etching and developing.  
      In etching and developing, an etching solution and a developing solution are applied to the substrate to treat the substrate. A portion of the etching solution and the developing solution remain on the substrate after etching and developing. The remaining etching solution and developing solution are removed from the substrate through washing.  
      In washing, a washing fluid (for example, deionized water) is applied to the substrate. The remaining etching solution and developing solution are removed from the substrate by the washing fluid.  
      A portion of the washing fluid remains on the substrate after washing. The remaining washing fluid is removed through drying. In drying, an air flow is applied to the substrate. The air flow may be heated to increase the speed of drying.  
      However, as the size of the substrate increases, the lack of uniformity in the washing and drying steps also increases.  
     SUMMARY  
      Accordingly, in one aspect, an apparatus for treating a substrate that treats the substrate uniformly is provided.  
      Additional aspects and/or advantages provided by embodiments of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present invention.  
      The foregoing and/or other aspects of the present invention can be achieved by providing an apparatus for treating substrate comprising: a moving mechanism for moving a substrate; a high pressure spray unit comprising a first high pressure spray having a first nozzle portion disposed transverse to the direction of the moving direction of the substrate and a second high pressure spray having a second nozzle portion parallel to the first nozzle portion.  
      According to another aspect of the invention, at least one of the first nozzle portion and the second nozzle portion directs fluid at an oblique angle to the surface of the substrate.  
      According to another aspect of the invention, a treating fluid from the first high pressure spray is applied to the substrate prior to a treating fluid from the second high pressure spray, and the treating fluid from the first high pressure spray comprises air and the treating fluid from the second high pressure spray comprises water.  
      According to another aspect of the invention, a treating fluid from the first high pressure spray is applied to the substrate prior to application of a treating fluid from the second high pressure spray, and the treating fluid from the first high pressure spray comprises room-temperature air and the treating fluid from the second high pressure spray comprises heated air.  
      According to another aspect of the invention, the apparatus further comprises a widthwise high pressure spray having a widthwise nozzle portion disposed along the direction of movement of the substrate.  
      The foregoing and/or other aspects of the present invention can be also achieved by providing an apparatus for treating substrates comprising: a moving mechanism for moving a substrate; and a widthwise high pressure spray having a widthwise nozzle portion disposed along the direction of movement of the substrate.  
      According to another aspect of the invention, the apparatus further comprises a lengthwise high pressure spray having a lengthwise nozzle portion disposed transverse to the direction of movement of the substrate.  
      According to another aspect of the invention, a treating fluid from the widthwise high pressure spray and the lengthwise high pressure spray comprises water.  
      According to another aspect of the invention, the moving mechanism supports the substrate at an inclined angle, and the widthwise high pressure spray is disposed along an elevated edge of the substrate.  
      The foregoing and/or other aspects of the present invention can be also achieved by providing an apparatus for treating substrates, comprising: a moving mechanism for moving a substrate in a first direction; and a washing module comprising a first high pressure spray unit. The first high pressure spray unit comprises: a first elongate spray nozzle extending across a length of the substrate transverse to the first direction, and a second elongate spray nozzle extending across a width of the substrate parallel to the first direction. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      These and other aspects and advantages of the present invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:  
       FIG. 1  is a cross-sectional view of an apparatus for treating substrate according to a first embodiment of the present invention;  
       FIG. 2  is a perspective view of a washing module according to the first embodiment of the present invention;  
       FIG. 3  is a cross-sectional view of an apparatus for treating substrate according to a second embodiment of the present invention;  
       FIG. 4  is a perspective view of a washing module according to the second embodiment of the present invention;  
       FIG. 5  is a cross-sectional view of an apparatus for treating substrate according to a third embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION  
      Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.  
      An apparatus for treating a substrate according to a first embodiment of the present invention will be described with reference to  FIGS. 1 and 2 .  
       FIG. 1  is a cross-sectional view of an apparatus  1  for treating a substrate according to the first embodiment of the present invention, and  FIG. 2  is a perspective view of a washing module according to the first embodiment of the present invention.  
      The apparatus  1  for treating a substrate comprises an etching module  200 , a washing module  300 , a drying module  400 , and a moving mechanism  500  for moving a substrate  100  to be treated.  
      In the etching module  200 , a portion of the metal layer, electrode layer, or insulating layer to be etched is exposed. A photoresist layer is formed on the portions that are not to be etched.  
      The etching module  200  comprises a spray module  210  for applying an etching solution  211  to the substrate  100 . A plurality of spray modules  210  may be provided to apply the etching solution  211  uniformly across the surface of the substrate  100 .  
      The composition of the etching solution  211  depends on the object to be etched. The etching solution  211  may comprise phosphoric acid, nitric acid, and acetic acid for aluminum or molybdenum, which is widely used for gate wiring or data wiring. The etching solution  211  may comprise fluoric acid and nitric acid for tantalum. The etching solution  211  may comprise ammonium nitrate, cesium, and nitric acid for chrome. The etching solution  211  may comprise hydrochloric acid, nitric acid, and iron chloride for ITO (indium tin oxide), which is used for pixel electrodes.  
      The etching module  200  further comprises an etching solution storage tank (not shown) and an etching solution supply mechanism (not shown) to supply the etching solution  211  from the etching solution storage tank to the spray module  210 .  
      The moving mechanism  500  is a conveyer belt type mechanism which moves the substrate  100  from the etching module  200  to the drying module  400 . The substrate  100  may have a rectangular shape, and the moving mechanism  500  may move the substrate  100  such that a longer side of the substrate  100  is parallel to the direction of movement of the substrate  100 . Further, the moving mechanism  500  may support the substrate  100  at an inclined angle so as to improve the ease and speed with which the etching solution  211  is removed from the upper surface of the substrate  100 .  
      The washing module  300  comprises a high pressure spray unit  310  and a spray module  320 .  
      The high pressure spray unit  310  comprises a first high pressure spray  311  having a first nozzle portion  312  extending laterally across the substrate  100  in a direction substantially perpendicular to the direction of travel of the substrate  100 . The high pressure spray unit  310  also comprises a second high pressure spray  315  having a second nozzle portion  316 , which extends laterally across the substrate  100  in a direction substantially parallel to the first nozzle portion  312 . The first high pressure spray  311  and the second high pressure spray  315  are formed as a single body. A treating fluid from the first high pressure spray  311  comprises a gas  313 , such as air, and a treating fluid from the second high pressure spray  315  comprises a washing fluid  317 , such as deionized water.  
      The first nozzle portion  312  is configured to direct the high-pressure air  313  in a direction substantially perpendicular to the surface of the substrate  100 . The second nozzle portion  316  is configured to direct the washing fluid  317  at a predetermined oblique angle to the surface of the substrate  100 .  
      A plurality of spray modules  320  may be provided to supply a washing fluid  321  as the treating fluid to the substrate  100 .  
      The moving mechanism  500  may support the substrate  100  at an inclined angle relative to the direction of movement of the substrate  100  while the substrate  100  is in the washing module  300 , as well as in the etching module  200 .  
      The washing module  300  further comprises a washing fluid storage tank (not shown), a washing fluid supply mechanism (not shown) to supply the washing fluid  317  and washing fluid  321  to the high pressure spray unit  310  and the spray module  320 , and a compressor (not shown) to supply compressed air to the high pressure spray unit  310 .  
      The drying module  400  comprises a high pressure spray unit  410 . The high pressure spray unit  410  comprises a first high pressure spray  411  having a first nozzle portion  412  extending laterally across the substrate  100  in a direction substantially perpendicular to the direction of travel of the substrate  100 . The high pressure spray unit  410  also comprises a second high pressure spray  415  having a second nozzle portion  416 , which extends laterally across the substrate  100  in a direction substantially parallel to the first nozzle portion  412 . The first high pressure spray  411  and the second high pressure spray  415  are formed as a single body. A treating fluid from the first high pressure spray  411  comprises room temperature air  413  and a treating fluid from the second high pressure spray  415  comprises heated air  417 .  
      The first nozzle portion  412  is configured to supply the room temperature air  413  in a direction substantially perpendicular to the surface of the substrate  100 . The second nozzle portion  416  is configured to supply the heated air  417  at a predetermined oblique angle to the surface of the substrate  100 .  
      A method of forming gate wiring on the substrate  100  using the apparatus for treating a substrate according to the first embodiment of the present invention will be described.  
      A gate metal layer is deposited on an insulating substrate. A photoresist solution is coated on the gate metal layer. A photoresist layer is formed by a removing solvent in the photoresist solution using a soft-bake process. A mask is used to expose portions of the photoresist layer to light in a predetermined pattern. The photoresist layer is then developed to form a photoresist pattern on the gate metal layer. The portions of the gate metal layer not covered by the photoresist pattern are removed using the following process.  
      In the etching module  200 , the spray module  210  applies the etching solution  211  to the surface of the substrate  100 . The etching solution  211  may comprise phosphoric acid, nitric acid, and acetic acid when the gate metal layer is formed of aluminum or molybdenum. The portions of the gate metal layer gate metal layer not covered by the photoresist pattern are etched by the etching solution  211 . The portions of the gate metal layer covered by the photoresist pattern remain to form the gate wiring.  
      Next, the moving mechanism  500  moves the substrate  100  having the etched gate metal layer to the washing module  300 . The moving mechanism  500  may support the substrate  100  at an inclined angle.  
      Portions of the gate metal layer material separated from the substrate  100  during the etching process and portions of the etching solution  211  which remain on the substrate  100  are removed in the washing module  300 . The washing fluid  317  from the second high pressure spray  315  is applied to the substrate  100  in large volumes to remove the remaining gate metal layer material and etching solution  211 , before the washing fluid  321  from the spray module  320  is applied. The air  313  from the first high pressure spray  311  prevents the washing fluid  317  from flowing backward to the etching module  200 , thereby helping to prevent the concentration of the etching solution  211  in the etching module  200  from changing and to prevent the etching process from becoming unstable.  
      In the washing module  300 , the first high pressure spray  311  supplies the air  313  and the second high pressure spray  315  supplies the washing fluid  317  to the substrate  100 . As the first high pressure spray  311  and the second high pressure spray  315  are formed as a single body, the interval between the supplying of the air  313  and the supplying of the washing fluid  317  is short. Accordingly, the washing of the substrate  100  is performed in a short time and in a uniform fashion, thus reducing the generation of spots on the substrate  100 . Further, the high pressure spray unit  310  used to supply the air  313  and the washing fluid  317  is compact and does not consume an excessive amount of space.  
      The washing fluid  317  from the second high pressure spray  315  is applied to the substrate  100  at a predetermined oblique angle to the surface of the substrate  100 . Accordingly, an interval is provided between areas of the substrate  100  being supplied with the washing fluid  317  and the air  313 . This interval prevents the washing fluid  317  from flowing backward into the etching module  200 .  
      The high pressure spray unit  310  removes the etching solution and the etched gate metal layer material from the substrate  100  quickly. In addition, the spray module  320  further supplies the washing fluid  321  to wash the substrate  100 .  
      Next, the moving mechanism  500  moves the substrate  100  from the washing module  300  to the drying module  400 .  
      In the drying module  400 , the first high pressure spray  411  directs pressurized room temperature air  413  to surface of the substrate  100 . Next, the second high pressure spray  415  directs pressurized heated air  417  to the surface of the substrate  100 . As the first high pressure spray  411  and the second high pressure spray  415  are formed as a single body, the interval between the supplying of the room temperature air  413  and the supplying of the heated air  417  is short. Accordingly, the drying of the substrate  100  is performed in a short time and in a uniform fashion, thus reducing the generation of spots on the substrate  100 . Further, the high pressure spray unit  410  used to supply the room temperature air  413  and the heated air  417  is compact and does not consume an excessive amount of space.  
      The high pressure spray unit  310 ,  410  may be modified in various ways. The high pressure spray unit  310 ,  410  may comprise 3 or more high pressure sprays. The high pressure spray units  310 ,  410  may supply washing fluid or air only.  
      An apparatus for treating a substrate according to a second embodiment of the present invention will be described with reference to  FIGS. 3 and 4 .  
       FIG. 3  is a cross-sectional view of the apparatus for treating a substrate according to the second embodiment of the present invention, and  FIG. 4  is a perspective view of a washing module according to the second embodiment of the present invention.  
      The washing module  300  comprises a spray module  320 , a widthwise high pressure spray  330 , and a lengthwise high pressure spray  340 . The widthwise high pressure spray  330  and the lengthwise high pressure spray  340  are positioned perpendicular to each other.  
      The widthwise high pressure spray  330  comprises a widthwise nozzle portion  331  disposed along the direction of movement of the substrate  100 . The widthwise high pressure spray  330  supplies a washing fluid  332  as a treating fluid to the substrate  100 . The widthwise high pressure spray  330  is disposed near an edge of the substrate  100 . The moving mechanism  500  supports the substrate  100  at an inclined angle with the edge of the substrate  100  adjacent to the widthwise high pressure spray  330  being positioned at a higher elevation than the opposite edge of the substrate  100 , as shown in  FIG. 4 . The length L 1  of the widthwise nozzle portion  331  may be about 50% of the length L 2  of the long side of the substrate  100 .  
      The lengthwise high pressure spray  340  comprises a lengthwise nozzle portion  341  extending laterally across the substrate  100  in a direction substantially perpendicular to the direction of travel of the substrate  100 . The lengthwise high pressure spray  340  supplies a washing fluid  342  as the treating fluid to the substrate  100 . The length L 3  of the lengthwise nozzle portion  341  may be a little longer than the length L 4  of the short side of the substrate  100 .  
      The widthwise high pressure spray  330  and the lengthwise high pressure spray  340  may be modified in various ways. For example, the widthwise nozzle portion  331  may be formed by a plurality of injecting holes arranged in a row. A plurality of the widthwise high pressure sprays  330  and the lengthwise high pressure sprays  340  may be provided. The widthwise high pressure spray  330  and the lengthwise high pressure spray  340  may be formed as a single body.  
      A method of treating the substrate  100  using the apparatus for treating a substrate according to a second embodiment of the present invention will be described, with particular focus on the washing module  300 .  
      In the washing module  300 , the washing fluid  332  and washing fluid  342  are applied to the substrate  100  from the widthwise nozzle portion  331  of the widthwise high pressure spray  300  and the lengthwise nozzle portion  341  of the lengthwise high pressure spray  340 , respectively. The washing fluid  332  and washing fluid  342  remove the etching solution  211  and the portions of the gate metal layer etched by the etching solution  211  from the substrate  100 .  
      The moving mechanism  500  supports the substrate  100  at a predetermined inclined angle Θ. The widthwise high pressure spray  330  is positioned along the elevated edge of the substrate  100 . Due to the incline of the substrate  100 , the washing fluid  331  applied from the widthwise nozzle portion  331  flows downwards across the upper face of the inclined substrate  100  towards the lowered edge of the substrate  100 .  
      As the washing fluid  332  and washing fluid  342  is applied by the lengthwise high pressure spray  340  together with the widthwise high pressure spray  330 , the etching solution  211  and the portions of the gate metal layer etched by the etching solution  211  are quickly removed from the substrate  100 . In addition, the residual time of that the etching solution  211  remains on the surface of the substrate remains substantially uniform at all positions across the face of the substrate  100 .  
      The widthwise high pressure spray  330  and the lengthwise high pressure spray  340  quickly remove the etching solution  211  and the etched gate metal layer from the substrate  100 , and then the spray module  320  further applies additional washing fluid  321  to wash the substrate  100 .  
       FIG. 5  is a cross-sectional view of an apparatus for treating a substrate according to a third embodiment of the present invention.  
      A high pressure spray unit  310 , a widthwise knife unit  330 , and a spray module  320  are disposed sequentially along the direction of movement of a substrate  100 . The high pressure spray unit  310  prevents washing fluid from the washing module  300  from flowing backward into the etching module  200 . In addition, the widthwise high pressure spray unit  330  sprays washing fluid  332  to quickly remove the etching solution  211  from the substrate  100 .  
      The present invention is not limited to treating etched substrates, and may also be applied in other embodiments to treating developed substrates.  
      The present invention is not limited to manufacturing substrates for liquid crystal displays, and may also be applied to semiconductor manufacturing processes, such as the manufacturing of semiconductor wafers and substrates for flat panel displays, such as organic light emitting diodes.  
      Although various embodiments of the present invention have been shown and described, it will be appreciated by those of ordinary skill in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.