Patent Abstract:
A liquid crystal display is provided, which includes: a first substrate; a first signal line formed on the first substrate; a second signal line formed on the first substrate and intersecting the first signal line; a pixel electrode including a plurality of partitions; a thin film transistor connected to the gate line, the data line, and the pixel electrode; a second substrate facing the second substrate; a common electrode formed on the second substrate and having an opening facing the first or the second signal line; and first and second domain defining members that define a plurality of domains in the liquid crystal display and are dispose on the first and the second substrates, respectively, the second domain defining member disposed on the second substrate and separated from the opening.

Full Description:
BACKGROUND OF THE INVENTION 
   (a) Field of the Invention 
   The present invention relates to a liquid crystal display. 
   (b) Description of the Related Art 
   A liquid crystal display (LCD) is one of the most widely used flat panel displays. An LCD includes two panels provided with field-generating electrodes such as pixel electrodes and a common electrode and a liquid crystal (LC) layer interposed therebetween. The LCD displays images by applying voltages to the field-generating electrodes to generate an electric field in the LC layer, which determines orientations of LC molecules in the LC layer to adjust polarization of incident light. 
   Among the LCDs, a vertical alignment (VA) mode LCD, which aligns LC molecules such that the long axes of the LC molecules are perpendicular to the panels in absence of electric field, is spotlighted because of its high contrast ratio and wide viewing angle. 
   The wide viewing angle of the VA mode LCD can be realized by cutouts in the field-generating electrodes and protrusions on the field-generating electrodes. Since the cutouts and the protrusions can determine the tilt directions of the LC molecules, the tilt directions can be distributed into several directions by using the cutouts and the protrusions such that the viewing angle is widened. In particular, a patterned VA (PVA) mode LCD employing the cutouts is preferred as a substitute of an in-plane switching (IPS) mode LCD. 
   The PVA mode LCD has a fast response time compared with a twisted nematic (TN) mode LCD since the motions of the LC molecules only include elastic splay or bend without twist. 
   In the meantime, the LCD also includes a plurality of switching elements for applying voltages to the field-generating electrodes and a plurality of signal lines such as gate lines and data lines connected to the switching elements. The signal lines make capacitive coupling with other signal lines and the common electrode, which serves as a load exerted on the signal lines to yield signal delay as well as their own resistances. In particular, the coupling between the data lines and the common electrode drives liquid crystal molecules disposed therebetween to cause light leakage near the data lines, thereby deteriorating the light leakage. In order to prevent the light leakage, a black matrix may be wide to reduce the aperture ratio. 
   SUMMARY OF THE INVENTION 
   A liquid crystal display is provided, which includes: a first substrate; a first signal line formed on the first substrate; a second signal line formed on the first substrate and intersecting the first signal line; a pixel electrode including a plurality of partitions; a thin film transistor connected to the gate line, the data line, and the pixel electrode; a second substrate facing the second substrate; a common electrode formed on the second substrate and having an opening facing the first or the second signal line; and first and second domain defining members that define a plurality of domains in the liquid crystal display and are dispose on the first and the second substrates, respectively, the second domain defining member disposed on the second substrate and separated from the opening. 
   The first domain defining member may include a first cutout provided at the pixel electrode and the second domain defining member may include a second cutout provided at the common electrode. 
   A distance between the second cutout and the opening preferably ranges from about three to six microns. 
   A liquid crystal display is provided, which includes: a first substrate; a gate line formed on the first substrate; a gate insulating layer formed on the gate line; a semiconductor layer formed on the gate insulating layer; a data line formed on the gate insulating layer and intersecting the gate line; a drain electrode formed on the semiconductor layer at least in part; a pixel electrode connected to the drain electrode and having a first cutout; a second substrate facing the first substrate; and a common electrode formed on the second substrate and having a second cutout facing the pixel electrode and a first opening that faces the gate line or the data line. 
   The liquid crystal display may further include a storage electrode line located on the same plane as the gate line and overlapping the pixel electrode. 
   The common electrode may further have a second opening separated from the first opening along the gate lines or the data line. 
   Distances between the second cutout and the first and the second openings and between the first opening and the second opening may range from about three to six microns. 
   The liquid crystal display may further include a plurality of ohmic contacts disposed between the semiconductor layer and the data line and between the semiconductor layer and the drain electrode. 
   The ohmic contacts and the semiconductor layer may extend along the data line and the drain electrode. 
   The semiconductor layer may have substantially the same planar shape as the data line and the drain electrode except for a portion disposed between the data line and the drain electrode. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more apparent by describing embodiments thereof in detail with reference to the accompanying drawings in which: 
       FIG. 1  is a layout view of a TFT array panel of an LCD according to an embodiment of the present invention; 
       FIG. 2  is a layout view of cutouts of a common electrode panel of an LCD according to an embodiment of the present invention; 
       FIG. 3  is a layout view of an LCD including the TFT array panel shown in  FIG. 1  and the common electrode panel shown in  FIG. 2 ; 
       FIG. 4  is a sectional view of the LCD shown in  FIG. 3  taken along the line IV–IV′; 
       FIG. 5  is a layout view of an LCD according to another embodiment of the present invention; and 
       FIG. 6  is a sectional view of the LCD shown in  FIG. 5  taken along the line VI–VI′. 
   

   DETAILED DESCRIPTION OF EMBODIMENTS 
   The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. 
   In the drawings, the thickness 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. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present. 
   Now, liquid crystal displays according to embodiments of the present invention will be described with reference to the accompanying drawings. 
     FIG. 1  is a layout view of a TFT array panel of an LCD according to an embodiment of the present invention,  FIG. 2  is a layout view of cutouts of a common electrode panel  200  of an LCD according to an embodiment of the present invention,  FIG. 3  is a layout view of an LCD including the TFT array panel shown in  FIG. 1  and the common electrode panel shown in  FIG. 2 , and  FIG. 4  is a sectional view of the LCD shown in  FIG. 3  taken along the line IV–IV′. 
   An LCD according to an embodiment of the present invention will be described in detail with reference to  FIGS. 1–4 . 
     FIG. 1  is a layout view of a TFT array panel of an LCD according to an embodiment of the present invention,  FIG. 2  is a layout view of cutouts of a common electrode panel of an LCD according to an embodiment of the present invention,  FIG. 3  is a layout view of an LCD including the TFT array panel shown in  FIG. 1  and the common electrode panel shown in  FIG. 2 , and  FIG. 4  is a sectional view of the LCD shown in  FIG. 3  taken along the line IV–IV′. 
   An LCD according to an embodiment of the present invention includes a TFT array panel  100 , a common electrode panel  200 , and a LC layer  3  interposed between the panels  100  and  200  and containing a plurality of LC molecules aligned substantially vertical to surfaces of the panels  100  and  200 . 
   The TFT array panel  100  is now described in detail with reference  FIGS. 1 ,  3  and  4 . 
   A plurality of gate lines  121  and a plurality of storage electrode lines  131  are formed on an insulating substrate  110  such as transparent glass. 
   The gate lines  121  extend substantially in a transverse direction and are separated from each other and transmit gate signals. Each gate line  121  includes a plurality of projections forming a plurality of gate electrodes  123  and an end portion having a large area for connection with an external driving circuit. 
   Each storage electrode line  131  extends substantially in the transverse direction and includes a plurality of sets of two longitudinal branches forming first and second storage electrodes  133   a  and  133   b  and a transverse branch forming a third storage electrode  133   c  connected between the first storage electrode  133   a  and the second storage electrode  133   b . Each of the first storage electrodes  133   a  has a free end portion and a fixed end portion connected to the storage electrode line  131 , and the fixed end portion has a projection. Each of the third storage electrodes  133   c  forms a mid-line between two adjacent gate lines  121 . The storage electrode lines  131  are supplied with a predetermined voltage such as a common voltage, which is applied to a common electrode  270  on the common electrode panel  200  of the LCD. Each storage electrode line  131  may include a pair of stems extending in the transverse direction. 
   The gate lines  121  and the storage electrode lines  131  is preferably made of Al containing metal such as Al and Al alloy, Ag containing metal such as Ag and Ag alloy, Cu containing metal such as Cu and Cu alloy, MgSO containing metal such as MgSO and MgSO alloy, Cr, Ti or Ta. The gate lines  121  and the storage electrode lines  131  may have a multi-layered structure including two films having different physical characteristics, a lower film (not shown) and an upper film (not shown). The upper film is preferably made of low resistivity metal including Al containing metal such as Al and Al alloy for reducing signal delay or voltage drop in the gate lines  121  and the storage electrode lines  131 . On the other hand, the lower film is preferably made of material such as Cr, MgSO and MgSO alloy, which has good contact characteristics with other materials such as indium tin oxide (ITO) or indium zinc oxide (IZO). A good exemplary combination of the lower film material and the upper film material is Cr and Al—Nd alloy. 
   In addition, the lateral sides of the gate lines  121  and the storage electrode lines  131  are inclined relative to a surface of the substrate, and the inclination angle thereof ranges about 20–80 degrees. 
   A gate insulating layer  140  preferably made of silicon nitride (SiNx) is formed on the gate lines  121  and the storage electrode lines  131 . 
   A plurality of semiconductor stripes  151  preferably made of 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  branched out toward the gate electrodes  123 . 
   A plurality of ohmic contact stripes and islands  161  and  165  preferably made of silicide or n+ hydrogenated a-Si heavily doped with n type impurity such as phosphorous 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 . 
   The lateral sides of the semiconductor stripes  151  and the ohmic contacts  161  and  165  are inclined relative to a surface of the substrate, and the inclination angles thereof are preferably in a range between about 30–80 degrees. 
   A plurality of data lines  171 , a plurality of drain electrodes  175  separated from the data lines  171 , and a plurality of isolated metal pieces  172  are formed on the ohmic contacts  161  and  165  and the gate insulating layer  140 . 
   The data lines  171  for transmitting data voltages extend substantially in the longitudinal direction and intersect the gate lines  121  and the storage electrode lines  131 . Each data line  171  is disposed between the first and the second storage electrodes  133   a  and  133   b  in adjacent sets of the branches  133   a – 133   c  of the storage electrode lines  131  and it includes an end portion  179  having a large area for contact with another layer or an external device. A plurality of branches of each data line  171 , which project toward the drain electrodes  175 , form a plurality of source electrodes  173 . Each drain electrode  175  includes an end portion  179  having a large area for contact with another layer and each source electrode  173  is curved to partly enclose another end portion of the drain electrode  175 . A gate electrode  123 , a source electrode  173 , and a drain electrode  175  along with a projection  154  of a semiconductor stripe  151  form a TFT having a channel formed in the projection  154  disposed between the source electrode  173  and the drain electrode  175 . 
   The metal pieces  172  are disposed on the gate lines  121  near the end portions of the storage electrodes  133   a.    
   The data lines  171 , the drain electrodes  175 , and the metal pieces  172  are preferably made of refractory metal such as Cr, MgSO containing metal, Ti and Ti, or Al containing metal and they may also have a multilayered structure including a lower film (not shown) preferably made of MgSO, MgSO alloy or Cr and an upper film (not shown) located thereon and preferably made of Al containing metal. 
   Like the gate lines  121  and the storage electrode lines  131 , the data lines  171  and the drain electrodes  175  have tapered lateral sides, and the inclination angles thereof range about 30–80 degrees. 
   The ohmic contacts  161  and  165  are interposed only between the underlying semiconductor stripes  151  and the overlying data lines  171  and the overlying drain electrodes  175  thereon and reduce the contact resistance therebetween. The semiconductor stripes  151  include a plurality of exposed portions, which are not covered with the data lines  171  and the drain electrodes  175 , such as portions located between the source electrodes  173  and the drain electrodes  175 . 
   A passivation layer  180  is formed on the data lines  171 , the drain electrodes  175 , and the exposed portions of the semiconductor stripes  151 . The passivation layer  180  is preferably made of photosensitive organic material having a good flatness characteristic, low dielectric insulating material having 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), or inorganic material such as silicon nitride. 
   The passivation layer  180  has a plurality of contact holes  181  and  183  exposing the end portions of the drain electrodes  175  and the end portions  179  of the data lines  171 , respectively. The passivation layer  180  and the gate insulating layer  140  have a plurality of contact holes  182 ,  184  and  185  exposing the end portions  125  of the gate lines  121 , the projections of the free end portions of the first storage electrodes  133   a , and portions of the storage electrode lines  131  near the fixed end portions of the first storage electrodes  133   a , respectively. The contact holes  181 – 185  have a shape of polygon or a circle, and sidewalls of the contact holes  181 – 185  are tapered. Each of the contact holes  182  and  183  exposing the end portions  125  and  179  preferably has an area ranging from about 0.5 mm×15 μm to about 2 mm×60 μm. 
   A plurality of pixel electrodes  190 , a plurality of contact assistants  95  and  97 , and a plurality of storage connections  91 , which are preferably made of ITO or IZO, are formed on the passivation layer  180 . 
   The pixel electrodes  190  are physically and electrically connected to the drain electrodes  175  through the contact holes  181  such that the pixel electrodes  190  receive the data voltages from the drain electrodes  175 . 
   The pixel electrodes  190  supplied with the data voltages generate electric fields in cooperation with the common electrode  270 , which reorient liquid crystal molecules in the liquid crystal layer  3 . 
   A pixel electrode  190  and the common electrode  270  form a liquid crystal capacitor, which stores applied voltages after turn-off of the TFT. An additional capacitor called a “storage capacitor,” which is connected in parallel to the liquid crystal capacitor, is provided for enhancing the voltage storing capacity. The storage capacitors are implemented by overlapping the pixel electrodes  190  with the storage electrode lines  131  including the storage electrodes  133   a – 133   c.    
   Each pixel electrode  190  is chamfered at its four corners and the chamfered edges of the pixel electrode  190  make an angle of about 45 degrees with the gate lines  121 . 
   Each pixel electrode  190  has a lower cutout  191 , a center cutout  192 , and an upper cutout  193 , which partition the pixel electrode  190  into a plurality of partitions. The cutouts  191 ,  192  and  193  substantially have an inversion symmetry with respect to a third storage electrode  133   c.    
   The lower and the upper cutouts  191  and  193  obliquely extend approximately from a right edge of the pixel electrode  190  approximately to a left edge of the pixel electrode  190 , and they are disposed at lower and upper halves of the pixel electrode  190 , respectively, which can be divided by the third storage electrode  133   c . The lower and the upper cutouts  191  and  193  make an angle of about 45 degrees to the gate lines  121 , and they extend perpendicular to each other. 
   The center cutout  192  extends along the third storage electrode  133   c  and has an inlet from the right edge of the pixel electrode  190 , which has a pair of inclined edges substantially parallel to the lower cutout  191  and the upper cutout  193 , respectively. 
   Accordingly, the lower half of the pixel electrode  190  is also partitioned into two lower partitions by the lower cutout  191  and the upper half of the pixel electrode  190  is partitioned into two upper partitions by the upper cutout  193 . The number of partitions or the number of the cutouts is varied depending on the design factors such as the size of pixels, the ratio of the transverse edges and the longitudinal edges of the pixel electrodes, the type and characteristics of the liquid crystal layer  3 , and so on. 
   The contact assistants  95  and  97  are connected to the end portions  125  of the gate lines  121  and the end portions  179  of the data lines  171  through the contact holes  182  and  183 , respectively. The contact assistants  95  and  97  are not requisites but preferred to protect the end portions  125  and  179  and to complement the adhesiveness of the end portions  125  and  179  and external devices. 
   The storage connections  91  cross over the gate lines  121  and they are connected to the exposed projection of the fixed end portions of the first storage electrodes  133   a  and the exposed portions of the storage electrode lines  131  respectively through the contact holes  184  and  185  opposite each other with respect to the gate lines  121 . The storage connections  91  overlaps the metal pieces  172  and they may be electrically connected to the metal pieces  172 . The storage electrode lines  131  including the storage electrodes  133   a – 133   c  along with the storage connections  91  and the metal pieces  172  are used for repairing defects in the gate lines  121 , the data lines  171 , or the TFTs. The electrical connection between the gate lines  121  and the storage electrode lines  131  for repairing the gate lines  121  is obtained by illuminating the cross points of the gate lines  121  and the storage connections  91  by a laser beam to electrically connect the gate lines  121  to the storage connections  91 . In this case, the metal pieces  172  enhance the electrical connection between the gate lines  121  and the storage connections  91 . 
   The description of the common electrode panel  200  follows with reference to  FIGS. 2–4 . 
   A light blocking member  220  called a black matrix for preventing light leakage is formed on an insulating substrate  210  such as transparent glass. The light blocking member  220  may include a plurality of openings that face the partitions  191   a  and  191   b  of the pixel electrodes  191  and may have substantially the same shape as the partitions  191   a  and  191   b . Otherwise, the light blocking member  220  may include oblique linear portions corresponding to the data lines  171  and other portions corresponding to the TFTs. 
   A plurality of red, green and blue color filters  230  are formed on the substrate  210  and they are disposed substantially in the areas enclosed by the light blocking member  220 . The color filters  230  may extend substantially along the longitudinal direction along the pixel electrodes  191 . The color filters  230  may represent one of the primary colors such as red, green and blue colors. 
   An overcoat  250  is formed on the color filters  230 . 
   A common electrode  270  preferably made of transparent conductive material such as ITO and IZO is formed on the overcoat  250 . 
   The common electrode  270  has a plurality of sets of cutouts  271 – 273  and a plurality of openings  279 . 
   A set of cutouts  271 – 273  face a pixel electrode  190  and include a lower cutout  271 , a center cutout  272 , and an upper cutout  273 . Each of the cutouts  271 – 273  is disposed between adjacent cutouts  191 – 193  of the pixel electrode  190  or between a cutout  191  or  193  and a chamfered edge of the pixel electrode  190 . In addition, each of the cutouts  271 – 273  has at least an oblique portion extending parallel to the lower cutout  191  or the upper cutout  193  of the pixel electrode  190 , and the distances between adjacent two of the cutouts  271 – 273  and  191 – 193 , the oblique portions thereof, the oblique edges thereof, and the chamfered edges of the pixel electrode  190 , which are parallel to each other, are substantially the same. The cutouts  271 – 293  substantially have an inversion symmetry with respect to a third storage electrode  133   c.    
   Each of the lower and upper cutouts  271  and  273  includes an oblique portion extending approximately from a left edge of the pixel electrode  190  approximately to a lower or upper edge of the pixel electrode  190 , and transverse and longitudinal portions extending from respective ends of the oblique portion along edges of the pixel electrode  190 , overlapping the edges of the pixel electrode  190 , and making obtuse angles with the oblique portion. 
   The center cutout  272  includes a central transverse portion extending approximately from the left edge along the third storage electrode  133   c , a pair of oblique portions extending from an end of the central transverse portion approximately to a right edge of the pixel electrode and making obtuse angles with the central transverse portion, and a pair of terminal longitudinal portions extending from the ends of the respective oblique portions along the right edge of the pixel electrode  190 , overlapping the right edge of the pixel electrode  190 , and making obtuse angles with the respective oblique portions. 
   The number of the cutouts  271 – 273  may be varied depending on the design factors, and the light blocking member  220  may also overlap the cutouts  271 – 273  to block the light leakage through the cutouts  271 – 273 . 
   Each opening  279  extends along a data line  171  to overlap the data line  171  and it is disposed between adjacent sets of the cutouts  271 – 278 . Some openings  279  meet the gate lines  121  while the other openings  279  do not meet the gate lines  121 . The number of the openings  279  that are disposed between adjacent two gate lines  121  is one but it may be at least two. 
   The openings  279  reduce the load exerted on the data lines  171  and thus the delay of the data voltages flowing in the data lines  171 , which is generated by the parasitic capacitance formed by the overlap of the common electrode  270  and the data lines  171 . The reduction of the load on the data lines  171  enlarges the freedom of the selection of the material for the data lines  171  and the resolution of the LCD. 
   The openings  279  also decrease the variation of the capacitance of the liquid crystal capacitor due to the data voltages carried by the data lines  171 , thereby decreasing vertical crosstalk that are firstly generated under the poor charging capacity of the liquid crystal capacitor. Accordingly, the charging capacity is improved. 
   In addition, the openings  279  reduce the lateral light leakage due to the lateral crosstalk of the data signals. The reduction of the lateral light leakage enables to decrease the width of the light blocking member  220 , thereby increasing aperture ratio. 
   Referring to  FIG. 2 , the distance between the openings  279  denoted by (a) and the distance between the openings  279  and the cutouts  271 – 273  denoted by (b) are preferably larger than the resolution of an exposer used in photolithography process, and more preferably, they are equal to about 3–6 microns. The portions of the common electrode  270  between the openings  279  and between the openings  279  and the cutouts  271 – 273  form various signal paths for the common voltage. 
   Homeotropic alignment layers  21  and  22  are coated on inners surfaces of the panels  100  and  200 , and polarizers  12  and  22  are provided on outer surfaces of the panels  100  and  200  such that their polarization axes may be crossed and one of the transmissive axes may be parallel to the gate lines  121 . One of the polarizers may be omitted when the LCD is a reflective LCD. 
   The LCD may further include at least one retardation film for compensating the retardation of the LC layer  3 . 
   The LC molecules in the LC layer  3  are aligned such that their long axes are vertical to the surfaces of the panels  100  and  200 . The liquid crystal layer  3  has negative dielectric anisotropy. 
   The cutouts  191 – 193  and  271 – 273  controls the tilt directions of the LC molecules in the LC layer  3 . That is, the liquid crystal molecules in each region called domain defined by adjacent cutouts  191 – 193  and  271 – 273  or by the cutout  272  or  273  and the chamfered edge of the pixel electrode  190  are tilted in a direction perpendicular to the extension direction of the cutouts  191 – 193  and  271 – 273 . It is apparent that the domains have two long edges extending substantially parallel to each other and making an angle of about 45 degrees with the gate line  121 . 
   At lease one of the cutouts  191 – 193  and  271 – 273  can be substituted with protrusions or depressions. 
   The shapes and the arrangements of the cutouts  191 – 193  and  271 – 273  and the openings  279  may be modified. For example, the openings  279  may be formed along the gate lines  121  instead of the data lines  171 . 
   A method of manufacturing the TFT array panel shown in  FIGS. 1–4  according to an embodiment of the present invention will be now described in detail. 
   A conductive film preferably made of Cr or MgSO alloy or Al are deposited and photo-etched to form a plurality of gate lines  121  including a plurality of gate electrodes  123  and end portions  125  and a plurality of storage electrode lines  131  including a plurality of storage electrodes  133   a – 133   c.    
   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 and a plurality of intrinsic semiconductor stripes  151  including a plurality of projections  154  on the gate insulating layer  140 . 
   Subsequently, a conductive film preferably made of Cr or MgSO alloy or Al are deposited and photo-etched to form a plurality of date lines  171  including a plurality of source electrodes  173  and end portions  179 , a plurality of drain electrodes  175 , and a plurality of metal pieces  172 . 
   Thereafter, portions of the extrinsic semiconductor stripes, which are not covered with the data lines  171  and the drain electrodes  175 , are removed to complete a plurality of ohmic contact stripes  161  including a plurality of projections  163  and a plurality of ohmic contact islands  165  and to expose portions of the intrinsic semiconductor stripes  151 . Oxygen plasma treatment preferably follows in order to stabilize the exposed surfaces of the semiconductor stripes  151 . 
   A passivation layer  180  is formed by chemical vapor deposition of a-Si:C:O or a-Si:O:F, by deposition of an inorganic insulator such as silicon nitride, or by coating of an organic insulator such as acrylic material. An a-Si:C:O film may be deposited by using a gas mixture containing source gases of SiH(CH 3 ) 3 , SiO 2 (CH 3 ) 4 , (SiH) 4 O 4 (CH 3 ) 4  or Si(C 2 HsO) 4 , oxidants of N 2 O or O 2 , and Ar or He. An a-Si:O:F film may be deposited by using a gas mixture of SiH 4 , SiF 4 , O 2 , etc., and CF 4  gas may be added as an additional source of fluorine. 
   The passivation layer  180  and the gate insulating layer  140  are photo-etched to form a plurality of contact holes  181 – 185  exposing the drain electrodes  175 , the end portions  125  of the gate lines  121 , the end portions  179  of the data lines  171 , the storage electrodes  133   a , and the storage electrode lines  131 . 
   Finally, a plurality of pixel electrodes  190 , a plurality of contact assistants  95  and  97 , and a plurality of storage connections  91  are formed on the passivation layer  180  and on the exposed portions of the drain electrodes  175 , the end portions  125  and  179 , the storage electrodes  133   a , and the storage electrode lines  131  by sputtering and photo-etching an IZO or ITO layer. The TFT array panel may be preheated with nitrogen gas before the IZO or ITO layer is deposited in order for preventing the formation of metal oxides on exposed portions of metal layers through the contact holes  181 – 185 . 
   An LCD according to another embodiment of the present invention will be described in detail with reference to  FIGS. 5 and 6 . 
     FIG. 5  is a layout view of an LCD according to another embodiment of the present invention, and  FIG. 6  is a sectional view of the LCD shown in  FIG. 5  taken along the line VI–VI′. 
   Referring to  FIGS. 5 and 6 , an LCD according to this embodiment also includes a TFT array panel  100 , a common electrode panel  200 , and a LC layer  3  interposed therebetween. 
   Layered structures of the panels according to this embodiment are almost the same as those shown in  FIGS. 1–4 . 
   Regarding the TFT array panel, a plurality of gate lines  121  including a plurality of gate electrodes  123  and a plurality of storage electrode lines  131  including a plurality of storage electrodes  133   a – 133   b  are formed on a substrate  110 , and a gate insulating layer  140 , a plurality of semiconductor stripes  151  including a plurality of projections  154 , and a plurality of ohmic contact stripes  161  including a plurality of projections  163  and a plurality of ohmic contact islands  165  are sequentially formed thereon. A plurality of data lines  171  including a plurality of source electrodes  173  and a plurality of drain electrodes  175  are formed on the ohmic contacts  161  and  165 , and a passivation layer  180  is formed thereon. A plurality of contact holes  181   184  and  185  are provided at the passivation layer  180  and the gate insulating layer  140 , and a plurality of pixel electrodes  190  and a plurality of storage connections  91  are formed on the passivation layer  180 . An alignment layer  11  is coated on an inner surface of the TFT array panel  100 , and a polarizer  12  is disposed on an outer surface of the TFT array panel  100 . 
   Regarding the common electrode panel, a light blocking member  220 , a plurality of color filters  230 , an overcoat  250 , and a common electrode  270  are formed on an insulating substrate  210 . An alignment layer  21  is coated on an inner surface of the common electrode panel  100 , and a polarizer  22  is disposed on an outer surface of the common electrode panel  100 . 
   Different from the LCD shown in  FIGS. 1–4 , the semiconductor stripes  151  have almost the same planar shapes as the data lines  171  and the drain electrodes  175  as well as the underlying ohmic contacts  161  and  165 . However, the projections  154  of the semiconductor stripes  151  include some exposed portions, which are not covered with the data lines  171  and the drain electrodes  175 , such as portions located between the source electrodes  173  and the drain electrodes  175 . 
   In addition, there is no storage electrode connecting the storage electrodes  133   a  and  133   b.    
   Each pixel electrode  190  is chamfered at its left corners but not chamfered at its right corners and the chamfered edges of the pixel electrode  190  make an angle of about 45 degrees with the gate lines  121 . 
   Each pixel electrode  190  has a plurality of lower cutouts  191 – 193 , upper cutouts  196 – 198 , and center cutouts  194  and  195 , which partition the pixel electrode  190  into a plurality of partitions. The lower and the upper cutouts  191 – 193  and  196 – 198  are disposed at lower and upper halves of the pixel electrode  190 , respectively, and the center cutouts  194  and  195  is located between the lower cutouts  191 – 193  and the upper cutouts  196 – 198 . The cutouts  191 – 198  substantially have an inversion symmetry with respect to a transverse center line of the pixel electrode  190  that divides the lower and the upper halves of the pixel electrode  190 . 
   The lower and the upper cutouts  191 – 193  and  196 – 198  make an angle of about 45 degrees to the gate lines  121 , and the lower cutouts  191 – 193 , which extend substantially parallel to each other and to the chamfered lower edge of the pixel electrode  190 , extend substantially perpendicular to the upper cutouts  196 – 198 , which extend substantially parallel to each other and to the chamfered upper edge of the pixel electrode  190 . 
   The cutouts  191  and  198  extend approximately from a left longitudinal edge of the pixel electrode  190  approximately to transverse edges of the pixel electrode  190 . The cutouts  192  and  197  extend approximately from the left edge of the pixel electrode  190  approximately to the unchamfered right corners of the pixel electrode  190 . The cutouts  193  and  196  extend approximately from left corners of the upper and lower halves of the pixel electrode  190  approximately to a right longitudinal edge of the pixel electrode  190 . 
   The center cutout  194  includes a transverse portion extending along the transverse center line of the pixel electrode  190  and a pair of oblique portions extending from the transverse portion to the right edge of the pixel electrode  190  and extending substantially parallel to the lower cutouts  191 – 193  and the upper cutouts  196 – 198 , respectively. The center cutout  195  extends along the transverse center line of the pixel electrode  190  and has an inlet from the right edge of the pixel electrode  190 , which has a pair of inclined edges substantially parallel to the lower cutouts  191 – 193  and the upper cutouts  196 – 198 , respectively. 
   Accordingly, the lower half of the pixel electrode  190  is partitioned into five lower partitions by the lower cutouts  191 – 193  and the center cutout  194  and the upper half of the pixel electrode  190  is also partitioned into five upper partitions by the upper cutouts  196 – 198  and the center cutout  194 . 
   The common electrode  270  has a plurality of sets of cutouts  271 – 278  and a plurality of openings  279 . 
   A set of cutouts  271 – 278  face a pixel electrode  190  and include a plurality of lower and upper cutouts  271 – 273  and  276 – 278  and center cutouts  274  and  275 . Each of the cutouts  271 – 278  is disposed between adjacent cutouts  191 – 198  of the pixel electrode  190  or between a cutout  191  or  198  and a chamfered edge of the pixel electrode  190 . In addition, each of the cutouts  271 – 278  has at least an oblique portion extending parallel to the lower cutouts  191 – 193  or the upper cutouts  196 – 198  of the pixel electrode  190 , and the distances between adjacent two of the cutouts  271 – 278  and  191 – 198 , the oblique portions thereof, the oblique edges thereof, and the chamfered edges of the pixel electrode  190 , which are parallel to each other, are substantially the same. The cutouts  271 – 278  substantially have an inversion symmetry with respect to a transverse center line of the pixel electrode  190 . 
   Each of the cutouts  271 ,  272 ,  278  and  277  has an oblique portion extending approximately from a left edge of the pixel electrode  190  approximately to a lower or upper edge of the pixel electrode  190  and transverse and longitudinal portions extending from respective ends of the oblique portion along edges of the pixel electrode  190 , overlapping the edges of the pixel electrode  190 , and making obtuse angles with the oblique portion. Each of the cutouts  273  and  276  has an oblique portion extending approximately from the left edge of the pixel electrode  190  approximately to a right edge of the pixel electrode  190  and a pair of longitudinal portions extending from respective ends of the oblique portion along the left and the right edges of the pixel electrode  190 , overlapping the left and the right edges of the pixel electrode  190 , and making obtuse angles with the oblique portion. Each of the cutouts  274  and  275  has a central transverse portion extending along the transverse center line of the pixel electrode  190 , a pair of oblique portions extending from the transverse portion approximately to the right edge of the pixel electrode  190  and making obtuse angles with the central transverse portion, and a pair of terminal transverse portions extending from the respective oblique portions along the right edge of the pixel electrode  190 , overlapping the right edge of the pixel electrode  190 , and making an obtuse angle with the respective oblique portions. 
   Each opening  279  extends along a data line  171  to overlap the data line  171  and it is disposed between adjacent sets of the cutouts  271 – 278 . Some openings  279  meet the gate lines  121  while the other openings  279  do not meet the gate lines  121 . The number of the openings  279  that are disposed between adjacent two gate lines  121  is three. 
   The contact holes  182  and  183  and the contact assistants  95  and  97  shown in  FIGS. 1–4  can be omitted when driving circuits for applying signals to the gate lines  121  or the data lines  171  are formed on the TFT panel  100  along with the TFTs. 
   A manufacturing method of the TFT array panel according to an embodiment simultaneously forms the data lines  171 , the drain electrodes  175 , the semiconductors  151 , and the ohmic contacts  161  and  165  using one photolithography process. 
   A photoresist pattern for the photolithography process has position-dependent thickness, and in particular, it has first and second portions with decreased thickness. The first portions are located on wire areas that will be occupied by the data lines  171  and the drain electrodes  175  and the second portions are located on channel areas of TFTs. 
   The position-dependent thickness of the photoresist is obtained by several techniques, for example, by providing translucent areas on the exposure mask  300  as well as transparent areas and light blocking opaque areas. The translucent areas may have a slit pattern, a lattice pattern, a thin film(s) with intermediate transmittance or intermediate thickness. When using a slit pattern, it is preferable that the width of the slits or the distance between the slits is smaller than the resolution of a light exposer used for the photolithography. Another example is to use reflowable photoresist. In detail, once a photoresist pattern made of a reflowable material is formed by using a normal exposure mask only with transparent areas and opaque areas, it is subject to reflow process to flow onto areas without the photoresist, thereby forming thin portions. 
   As a result, the manufacturing process is simplified by omitting a photolithography step. 
   Many of the above-described features of the LCD shown in  FIGS. 1–4  may be appropriate to the LCD shown in  FIGS. 5 and 6 . 
   As described above, the openings  279  reduce the delay of the data voltages flowing in the data lines  171 , which is generated by the parasitic capacitance formed by the overlap of the common electrode  270  and the data lines  171 . The openings  270  also decrease the variation of the capacitance of the liquid crystal capacitor due to the data voltages carried by the data lines  171  and lateral light leakage due to the crosstalk of the data signals. The reduction of the lateral light leakage enables to decrease the width of the light blocking member  220 , thereby increasing the aperture ratio. 
   While the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art will appreciate that various modifications and substitutions can be made thereto without departing from the spirit and scope of the present invention as set forth in the appended claims. 
   For example, the arrangements of the cutouts and the openings of the pixel electrodes and the common electrode may be modified and protrusions are provided instead of the cutouts.

Technology Classification (CPC): 6