Patent Publication Number: US-7714967-B2

Title: Multi-domain liquid crystal display device and method for fabricating the same

Description:
This application is a Divisional of U.S. patent application Ser. No. 10/867,008, filed Jun. 15, 2004, now U.S. Pat. No. 7,463,322 and claims the benefit of Korean Patent Application No.; P2003-43945, filed in Korea on Jun. 30, 2003, which are hereby incorporated by reference in their entirety. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a liquid crystal display (LCD) device and a method for fabricating an LCD device, and more particularly, to a multi-domain liquid crystal display (LCD) device and a method for fabricating an LCD device. 
   2. Discussion of the Related Art 
   As demand for various types of display devices increases various flat display devices, such as liquid crystal display (LCD) devices, plasma display panel (PDP) devices, electroluminescent display (ELD) devices, and vacuum fluorescent display (VFD) devices, are being developed. Some of the flat display devices are commonly used due to characteristics of thin profile, light weight, and low power consumption, thereby substituting cathode ray tube (CRT) devices with the LCD devices. In addition, mobile type LCD devices, such as displays for notebook computers, are being developed, and LCD devices were developed for computer monitors and televisions. 
   Despite various technical developments within the LCD device technology, enhancement of picture quality of the LCD device has been lacking. Thus, in order to use the LCD devices as general display devices, the development of LCD devices having high image quality, such as high resolution and luminance, with large-sized screens is necessary while still maintaining light weight, thin profile, and low power consumption. Currently, multi-domain LCD devices having at least two different alignment directions within one pixel region have been developed to obtain LCD devices having wide viewing angles. 
     FIG. 1  is a schematic perspective view of an LCD device according to the related art. In  FIG. 1 , an LCD device includes first and second substrates  1  and  2 , and a liquid crystal layer  3  formed by injecting liquid crystal between the first and second substrates  1  and  2 . More specifically, the first substrate  1  includes a plurality of gate lines  4  arranged along a first direction at fixed intervals, a plurality of data lines  5  arranged along a second direction perpendicular with the gate lines at fixed intervals to define a plurality of pixel regions P, a plurality of pixel electrodes  6  each within the pixel regions defined by the plurality of gate and data lines, and a plurality of thin film transistors (TFTs) T being turned ON and OFF according to driving signals transmitted along the gate lines  4  for passing video signals transmitted along the data lines to the pixel electrodes  6 . 
   The second substrate includes a black matrix layer  7  for preventing light leakage within regions, except the pixel regions of the first substrate, and R/G/B color filter layers for producing colored light, and a common electrode  9 . Although not shown, alignment layers are formed on opposing surfaces of the first and second substrates  1  and  2  to align liquid crystal molecules of the liquid crystal layer  3  by a rubbing method. Accordingly, the thin film transistor T includes a gate electrode that protrudes from the gate line  4 , a gate insulating layer formed along an entire surface of the first substrate  1 , a source electrode that protrudes from the data line  5 , and a drain electrode opposing the source electrode. 
   The pixel electrode  6  is formed of transparent conductive metal having a high transmittance of light, such as indium-tin-oxide (ITO), and the liquid crystal layer  3  is formed of Twisted Nematic (TN) mode liquid crystal material, wherein the light oscillating along a longitudinal direction of the liquid crystal molecules has a first refractive index different from a second refractive index of the light oscillating along a direction vertical to the longitudinal direction of the liquid crystal molecules, thereby creating narrow viewing angles. Accordingly, instead of using the TN mode liquid crystal material, the liquid crystal layer is formed of Vertical Alignment (VA) mode liquid crystal material, whereby the liquid crystal molecules are aligned along different directions by distorting an electric field. 
     FIG. 2  is a cross sectional view of a unit pixel for a multi-domain LCD device according to the related art. In  FIG. 2 , upper and lower substrates  70  and  80  are formed to oppose each other, and a liquid crystal layer  90  is formed between the upper and lower substrates  70  and  80 . In addition, projections  60  are formed along inner facing surfaces of the upper and lower substrates  70  and  80 , wherein one projection  60  is formed at a center position of the inner surface of the upper substrate  70 , and the other projections  60  are formed on the left and right sides of the inner surface of the lower substrate  80 . If the projection  60  is formed of a material having a dielectric constant lower than a dielectric constant of the liquid crystal molecule  92 , the electric field  94  (arrow direction) is formed outward to the projection  60  of the upper substrate  70 . In addition, the liquid crystal molecules  92  are aligned in perpendicular to the electric field  94 , whereby the arrangement of the liquid crystal molecules is divided into first and second domains A and B. Thus, distortion of the electric field is attenuated as the difference of the dielectric constant between the projection  60  and the liquid crystal molecule  92  increases. Accordingly, as the projections  60  are formed of material having a dielectric constant greater than a dielectric constant of the liquid crystal molecule  92 , it is possible to obtain a stable multi-domain LCD device. 
   However, the related art multi-domain LCD device has the following disadvantages. In the related art multi-domain LCD device, the distortion of the electric field is formed by the projections formed on the inner surfaces of the lower and upper substrates. As a result, the aperture ratio lowers by the occupying area of the projections on the inner surfaces of the lower and upper substrates, thereby lowering the luminance. However, since the multi-domain LCD device requires rubbing fixation or electrode structures to determine the alignment direction of the liquid crystal molecules, complicated manufacturing processes are required that increase manufacturing costs. 
   SUMMARY OF THE INVENTION 
   Accordingly, the present invention is directed to a multi-domain LCD device and a method for fabricating a multi-domain LCD device that substantially obviates one or more problems due to limitations and disadvantages of the related art. 
   An object of the present invention is to provide a multi-domain LCD device having improve aperture ratio. 
   Another object of the present invention is to provide a method for fabricating a multi-domain LCD device having improve aperture ratio. 
   Another object of the present invention is to provide a method for fabricating a multi-domain LCD device having simplified manufacturing processes. 
   Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned from practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
   To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described, a multi-domain liquid crystal display (LCD) device includes a first substrate having a plurality of pixel regions each divided into at least first and second domains, a plurality of pixel electrodes each within one of the pixel regions of the first substrate, each of the pixel electrodes having a plurality of protrusions arranged along different directions within the at least first and second domains, a second substrate facing the first substrate, and a liquid crystal layer between the first and second substrates. 
   In another aspect, a multi-domain liquid crystal display (LCD) device includes a plurality of gate and data lines perpendicular to each other on a first substrate defining a plurality of pixel regions, each of the pixel regions divided into at least first and second domains, a plurality of thin film transistors each at a crossing portion of the gate and data lines, an insulating layer within each of the pixel regions and having a plurality of first protrusions arranged along different directions in each of the first and second domains of the pixel regions, a plurality of pixel electrodes on the insulating layer, each pixel electrode having a plurality of second protrusions corresponding to the first protrusions of the insulating layer, a second substrate having a black matrix layer and a color filter layer, and a liquid crystal layer between the first and second substrates. 
   In another aspect, a method for fabricating a multi-domain liquid crystal display (LCD) device includes preparing first and second substrates, the first substrate having a plurality of pixel regions each divided into at least first and second domains, forming a plurality of pixel electrodes in the pixel regions of the first substrate, each of the pixel electrodes having a plurality of protrusions arranged along different directions within one of the at least first and second domains, and forming a liquid crystal layer between the first and second substrates. 
   In another aspect, a method for fabricating a multi-domain liquid crystal display (LCD) device includes forming a plurality of gate and data lines perpendicular to each other on a first substrate to define a plurality of pixel regions, each of the pixel regions includes at least first and second domains, forming a gate insulating layer along an entire surface of the substrate including the gate lines, forming a plurality of semiconductor layers on the gate insulating layer, each semiconductor layer disposed above a gate electrode corresponding to the gate lines, forming source and drain electrodes on each of the semiconductor layers, the source electrode extending from one of the data lines, forming an insulating layer on the first substrate, etching the insulating layer to form a plurality of first protrusions having first major-axes directions within the at least first domain and to form a plurality of second protrusions having second major-axes directions within the at least second domain, each of the first major-axes directions being different from each of the second major-axes directions, forming a plurality of pixel electrodes on the plurality of first protrusions and the plurality of second protrusions, forming a first alignment layer along an entire surface of the first substrate including the pixel electrodes, forming a black matrix layer and a color filter layer on a second substrate, attaching the first and second substrates together, and forming a liquid crystal layer between the first and second substrates. 
   It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiments of the invention and together with the description serve to explain the principle of the invention. In the drawings: 
       FIG. 1  is a schematic perspective view of an LCD device according to the related art; 
       FIG. 2  is a cross sectional view of a unit pixel for a multi-domain LCD device according to the related art; 
       FIG. 3  is a schematic perspective view of an exemplary multi-domain LCD device according to the present invention; 
       FIG. 4A  is a cross sectional view along II-II′ of  FIG. 3  of liquid crystal molecules in a multi-domain LCD device according to the present invention; 
       FIG. 4B  is a cross sectional view along II-II′ of  FIG. 3  of liquid crystal molecules in a multi-domain LCD device according to the present invention; 
       FIG. 5  is a schematic perspective view of liquid crystal molecules in a multi-domain LCD device according to the present invention; 
       FIG. 6A  is a diagram of liquid crystal molecules in a multi-domain LCD device according to the present invention; 
       FIG. 6B  is a diagram of liquid crystal molecules in a multi-domain LCD device according to the first embodiment of the present invention; 
       FIG. 7A  to  FIG. 7E  are cross sectional views of an example method of fabricating a multi-domain LCD device according to the present invention; and 
       FIG. 8  is a schematic perspective view of another exemplary multi-domain LCD device according to the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. 
     FIG. 3  is a perspective view schematically illustrating a multi-domain LCD device according to the first embodiment of the present invention, and  FIG. 4A  is a cross sectional view along II-II′ of  FIG. 3  of liquid crystal molecules in a multi-domain LCD device according to the present invention, and  FIG. 4B  is a cross sectional view along II-II′ of  FIG. 3  of liquid crystal molecules in a multi-domain LCD device according to the present invention. In  FIG. 4A , a state of liquid crystal molecules is shown when an electric field is not applied in a multi-domain LCD device according to the present invention. In  FIG. 4B , a state of liquid crystal molecules is shown when an electric field is applied in a multi-domain LCD device according to the present invention. 
   In  FIGS. 3 ,  4 A, and  4 B, a multi-domain LCD device may include a first substrate and a second substrate  300   a  and  300   b . Although not specifically shown, but similar to the structures shown in  FIG. 1 , the first substrate  300   a  may include a plurality of orthogonal gate and data lines, which may define a plurality of pixel regions, pixel electrodes formed in the pixel regions, and a plurality of TFTs at respective crossing portions of the gate and data lines. The plurality of TFTs may be turned ON/OFF according driving signals transmitted along the gate lines to provide video signals transmitted along the data lines to the respective pixel electrodes. 
   In  FIGS. 3 ,  4 A, and  4 B, each of the pixel regions may be divided into first and second domains  301   a  and  301   b . Accordingly, a pixel electrode (i.e., reflective electrode)  302  may include a plurality of protrusions  309   a  and  309   b , may be formed within the first and second domains  301   a  and  301   b . In addition, the protrusions  309   a  of the first domain  301   a  may be arranged differently from the protrusions  309   b  of the second domain  301   b.    
   The second substrate  300   b  may be formed to oppose the first substrate  300   a . The second substrate  300   b  may include a black matrix layer (not shown) for preventing light leakage within regions, except the pixel regions of the first substrate  300   a , an R/G/B color filter layer  305  for producing colored light, a common electrode  304 , and a second alignment layer  303   b  to provide vertical alignment of liquid crystal molecules. Accordingly, liquid crystal layers  307   a  and  307   b  may be formed between the first and second substrates  300   a  and  300   b.    
   Formation of the plurality of protrusions  309   a  and  309   b  within the pixel electrode  302  may first include forming an insulating layer  306  on first the substrate  300   a , and forming the pixel electrode  302  on in the insulating layer  306 . Accordingly, the pixel electrodes  302  may have the plurality of protrusions  309   a  and  309   b  formed on the insulating layer  306 . 
   Next, a first alignment layer  303   a  may be formed on the pixel electrodes  302  including the plurality of protrusions  309   a  and  309   b . The plurality of protrusions  309   a  and  309   b  may each have an elliptical shape having long-axis (major-axis) and short-axis (minor-axis) directions. In addition, the major-axis direction of the protrusions  309   a  formed within the first domain  301   a  of the first substrate  300   a  may cross the major-axis direction of the protrusions  309   b  formed within the second domain  301   b  of the first substrate  300   a.    
   In  FIGS. 4A and 4B , the elliptical-shaped protrusions  309   a  formed within the first domain  301   a  may have widths corresponding to the minor-axis direction, and the elliptical-shaped protrusions  309   b  formed within the second domain  301   b  may have widths corresponding the major-axis direction. In addition, the protrusions  309   a  and  309   b  may be compactly formed at irregular intervals in order to provide diffused reflection of incident light. However, the plurality of protrusions  309   a  or  309   b  formed within the same domain  301   a  or  301   b  of one pixel region may have their major-axes formed along one direction. Thus, an additional alignment process for aligning liquid crystal molecules of the liquid crystal layers  307   a  and  307   b  to the first and second alignment layers  303   a  and  303   b  may not be necessary. 
   When images are displayed by reflection of the incident light within the color filter layer  305  without using an additional backlight device, the pixel electrodes  302  of the first substrate  300   a  may be formed of metal having a relatively high reflectivity. In a transmitting-type LCD device using an additional backlight device, the pixel electrodes  302  of the first substrate  300   a  may be formed of a transparent electrode material. Accordingly, the pixel electrode  302  formed of the relatively high reflectivity metal may be more advantageous than the transparent electrode material. For example, if the pixel electrode  302  is formed of the relatively high reflectivity metal, the plurality of protrusions  309   a  and  309   b  formed within the pixel electrode  302  diffuse and reflect the incident light, thereby obtaining uniform luminance along an entire surface of the color filter layer  305 . 
   When a voltage is supplied to the pixel electrode  302  and the common electrode  304 , an electric field may be formed between the pixel electrode  302  and the common electrode  304 . Accordingly, the electric field affects the major-axes direction of the liquid crystal molecules within the liquid crystal layers  307   a  and  307   b , wherein the liquid crystal layers  307   a  and  307   b  may be formed of negative-type liquid crystal material. For example, when the electric field is not supplied to the pixel electrode  302  and the common electrode  304 , the liquid crystal molecules of the liquid crystal layers  307   a  and  307   b  may be aligned along a direction vertical to the first and second alignment layers  303   a  and  303   b . Conversely, when the electric field is supplied to the pixel electrode  302  and the common electrode  304 , the liquid crystal molecules of the liquid crystal layers  307   a  and  307   b  may be aligned along a direction parallel to the first and second alignment layers  303   a  and  303   b.    
   In  FIG. 4A , when the voltage is not supplied to the pixel electrode  302  and the common electrode  304 , the electric field is not formed between the pixel electrode  302  and the common electrode  304 . Accordingly, the major-axes of the liquid crystal molecules of the liquid crystal layers  307   a  and  308   b  formed in the first and second domains  301   a  and  301   b  may be aligned along a direction vertical to the first and second alignment layers  303   a  and  303   b . For example, the first alignment layer  303   a  formed within the first domain  301  of the first substrate  300   a  may be formed having a shape similar to a shape of the elliptical protrusion  309   a  formed below the first alignment layer  303   a , whereby the first alignment layer  303   a  may have the similar inclined side surfaces as inclined surfaces of the protrusions  309   a . Thus, the major-axes of the liquid crystal molecules adjacent to the first alignment layer  303   a  may be arranged along the direction vertical to the inclined surfaces of the first alignment layer  303   a  due to a vertical alignment restrictive force. 
   Along a direction from the first alignment layer  303   a  to the second alignment layer  303   b , the major-axes of the liquid crystal molecules may be changed to be aligned along a direction vertical to the second alignment layer  303   b  due to a vertical alignment force of the second alignment layer  303   b . Similarly, along the direction from the first alignment layer  303   a  to the second alignment layer  303   b , the major-axes of the liquid crystal molecules formed within the second domain  301   b  may be aligned along a direction vertical to the second alignment layer  303   b . Accordingly, there may be no difference in the major-axes directions of the liquid crystal molecules between the first and second domains  301   a  and  301   b.    
   When the voltage is supplied to the pixel electrode  302  and the common electrode  304 , the electric field  308  may be formed between the pixel electrode  302  and the common electrode  304 . Then, as shown in  FIG. 4B , the major-axes of the liquid crystal molecules formed within the first and second domains  301   a  and  301   b  may be changed to be aligned along a direction vertical to the electric field  308 . For example, as shown in  FIG. 5 , the major-axes directions  310   a  of the elliptical protrusions  309   a  within the first domain  301   a  may cross the major-axes directions  310   b  of the elliptical protrusion  309   b  within the second domain  301   b . Accordingly, the major-axes directions of the liquid crystal molecules  311   a  along the major-axes directions  310   a  of the elliptical protrusions  309   a  within the first domain  301   a  may cross the major-axes directions of the liquid crystal molecules  311   b  along the major-axes directions  310   b  of the elliptical protrusions  309   b  within the second domain  301   b . Thus, the major-axes directions of the liquid crystal molecules adjacent to the first and second alignment layers  303   a  and  303   b  may be effected by the vertical alignment restrictive forces while having less of an effect from the electric field  308 , whereby the liquid crystal molecules adjacent to the first and second alignment layers  303   a  and  303   b  may be maintained in an initial alignment state. As a result, the liquid crystal molecules may be aligned differently within the two domains  301  and  301   b , thereby obtaining a multi-domain LCD device. 
     FIG. 6A  is a diagram of liquid crystal molecules in a multi-domain LCD device according to the present invention; 
     FIG. 6B  is a diagram of liquid crystal molecules in a multi-domain LCD device according to the present invention, wherein the multi-domain LCD device may be shown in  FIGS. 4A  and/or  4 B.  FIG. 6A  shows light transmittance of liquid crystal molecules when an electric field is not applied in a multi-domain LCD device according to the present invention.  FIG. 6B  shows light transmittance of liquid crystal molecules when an electric field is applied in a multi-domain LCD device according to the present invention. Accordingly,  FIGS. 6A and 6B  demonstrate any one of the first and second domains  301   a  and  301   b.    
   In  FIG. 6A , before applying an electric field via pixel and common electrodes  302  and  304 , the major-axes of the liquid crystal molecules may be aligned along a direction vertical to first and second substrates  300   a  and  300   b . Accordingly, the elliptical protrusions  309   a  or  309   b  may be formed below the first alignment layer  303   a , whereby the first alignment layer  303  may have inclined surfaces similar to inclined surfaces of the protrusions  309   a  or  309   b . Thus, the major-axes of the liquid crystal molecules adjacent to the first alignment layer  303   a  may be vertical to the inclined surfaces of the first alignment layer  303   a , wherein the major-axes of the liquid crystal molecules corresponding to both inclined surfaces of the first alignment layer  303   a  may be formed at an angle of about ±10° to the first substrate  300   a . In addition, the major-axes of the liquid crystal molecules corresponding to uppermost (i.e., flat) surfaces of the first alignment layer  303   a  may be formed at an angle of about 90° to the first substrate  300   a . As shown in  FIGS. 4A and 4B , the second alignment layer  303   b  of the second substrate  300   b  may include a flat surface having no elliptical protrusions  309   a  and  309   b  (in  FIG. 5 ), whereby the major-axes of the liquid crystal molecules adjacent to the second alignment layer  303   b  may be formed at an angle of about 90° to the second substrate  300   b . When no electric field is applied, transmittance of the liquid crystal layer is approximately 0, thereby displaying a black state. 
   In  FIG. 6B , when applying an electric field to the liquid crystal molecules, the major-axes of the liquid crystal molecules may be aligned vertical to the electric field direction, thereby improving light transmittance. Since the major-axes of the liquid crystal molecules corresponding to the inclined surfaces of the first alignment layer  303   a  have a certain alignment direction with respect to the first substrate  300   a , the liquid crystal molecules are inclined along a constant direction by applying the electric field, thereby obtaining a normal light transmittance. However, the liquid crystal molecules on the uppermost (flat) surfaces of the first alignment layer  303   a  may not be inclined with respect to the first substrate  300   a , for example, at an angle of about 90°. Thus, when the electric field is applied to the liquid crystal molecules, the liquid crystal molecules may be irregularly inclined. Accordingly, an area having the irregularly inclined liquid crystal molecule may have a disclination line, wherein it is not possible to control the alignment of the liquid crystal molecules, thereby lowering the light transmittance. However, the area having the disclination line is negligible as compared with normal operation areas, so that the light transmittance may not be significantly affected by the area having the disclination line. 
     FIG. 7A  to  FIG. 7E  are cross sectional views of an example method of fabricating a multi-domain LCD device according to the present invention. In  FIG. 7A , a gate electrode (not shown) having a gate electrode  901  may be formed on a first substrate  900   a , and a gate insulating layer  902  may be formed along an entire surface of the first substrate  900   a  including the gate electrode  901 . Next, a semiconductor layer  903  may be formed on the gate insulating layer  902  above the gate electrode  901 . In addition, a data line (not shown) having source and drain electrodes  904   a  and  904   b  overlapped with both sides of the semiconductor layer  903  may be formed on the gate insulating layer  902  along a direction perpendicular to the gate line. Then, an organic insulating layer  803  for planarization and transmittance may be formed on the gate insulating layer  902  including the source and drain electrodes  904   a  and  904   b.    
   In  FIG. 7B , a photoresist (not shown) may be deposited on the organic insulating layer  803 , and then selectively removed by photolithographic processes, thereby forming a plurality of protrusions within first and second domains  801   a  and  801   b . The protrusions within the first domain  801   a  may have widths that are different from widths of the protrusions within the second domain  801   b . As shown in  FIG. 3 , the plurality of protrusions may each have an elliptical shape having major-axes and minor-axes, wherein the major-axes direction of the protrusions within the first domain  801   a  may cross the major-axes direction of the protrusions within the second domain  801   b . In  FIGS. 7B to 7E , the plurality of protrusions within the first domain  801   a  each may have a width along the minor-axes direction, and the plurality of protrusions within the second domain  801   b  each may have a width along the major-axes direction. 
   In  FIG. 7C , portions of the organic insulating layer  803  may be selectively removed above the drain electrode  904   b , thereby forming a contact hole. Then, a pixel electrode  804  may be formed on the organic insulating layer  803  of the pixel region to be connected to the drain electrode  904   b  through the contact hole. Since the organic insulating layer  803  may include the plurality of protrusions, the pixel electrodes  804  may be formed to each have shapes corresponding to the plurality of protrusions. The pixel electrode  804  may be formed of a metal material having high reflectivity, or of a transparent conductive material, such indium-tin-oxide (ITO). 
   In  FIG. 7D , a first alignment layer  805   a  may be formed along an entire surface of the first substrate  900   a  including the pixel electrode  804 . The first alignment layer  805   a  may be formed using one of a spinning, spraying, dipping, or printing methods, and may be formed of polyamide or polyimide group compound materials, such as polyvinylalcohol (PVA), polyamic acid material, or may be formed of photoreactive materials, such as polyvinylcinnamate (PVCN), polysiloxanecinnamate (PSCN), or cellulosecinnamate (CelCN). The first alignment layer  805   a  may be formed to provide a vertical alignment of the liquid crystal molecules within the liquid crystal layer, wherein additional alignment processes may not be necessary. 
   In  FIG. 7E , a black matrix layer  906  may be formed on a second substrate  900   b  to prevent light leakage on portions, except for the pixel regions, and a color filter layer  907  may be formed to produce colored light within the pixel regions. In addition, a common electrode  908  may be formed along an entire surface of the second substrate  900   b  including the color filter layer  907 , and a second alignment layer  805   b  may be formed on the common electrode  908 . The second alignment layer  805   b  may be formed of the same material as the first alignment layer  805   a , wherein the second alignment layer  805   b  may not require additional alignment processes. 
   Although not shown, a plurality of spacers and sealant material may be formed on one or both of the first and/or second substrate  900   a  and/or  900   b , and the first and second substrates  900   a  and  900   b  may be bonded to each other. Then, the liquid crystal layer  806  having the liquid crystal molecules aligned along the vertical direction may be formed between the first and second substrates  900   a  and  900   b . When an inlet is formed within the sealant, the first and second substrates  900   a  and  900   b  may be bonded to each other by the sealant while being maintained in a vacuum state. Accordingly, the inlet may be dipped into a vessel having liquid crystal material, whereby the liquid crystal may be injected between the first and second substrates  900   a  and  900   b  by osmotic action, thereby forming the liquid crystal layer  806 . Alternatively, the liquid crystal material may dispersed on one of the first and second substrates  900   a  and  900   b , and then the first and second substrates  900   a  and  900   b  may be bonded to each other. 
     FIG. 8  is a schematic perspective view of another exemplary multi-domain LCD device according to the present invention. In  FIG. 8 , one pixel region may be divided into first, second, third, and fourth domains  701   a ,  701   b ,  701   c , and  701   d , and a plurality of elliptical protrusions  800   a ,  800   b ,  800   c , and  800   d  may be formed within the respective first, second, third, and fourth domains  701   a ,  701   b ,  701   c , and  701   d . Accordingly, the major axes directions of the plurality of protrusions  800   a ,  800   b ,  800   c , and  800   d  may be different within each of the first, second, third, and fourth domains  701   a ,  701   b ,  701   c , and  701   d , thereby obtaining a multi-domain LCD device having at least four domains. Of course, an LCD device according to the present invention may be provided having an increased number of domains, such as 6, 8, 10, . . . . 
   The elliptical protrusions  800   a  of the first domain  701   a  may have major-axes directions similar to major-axes directions of the elliptical protrusions  800   c  of the third domain  701   c . Similarly, the elliptical protrusions  800   b  may have major-axes directions similar to major-axes directions of the elliptical protrusions  800   d  of the fourth domain  701   d . In addition, the major-axes directions of the protrusions  800   a  and  800   c  within the first or third domain  701   a  or  701   c  may have a direction vertical to the major-axes directions of the protrusions  800   b  and  800   d  within the second or fourth domain  701   b  or  701   d . Moreover, the major-axes directions within each of the first, second, third, and fourth domains  701   a ,  701   b ,  701   c , and  701   d  may be different. 
   According to the present invention, A plurality of protrusions of a pixel electrode may be aligned along different directions within different domains of a pixel region to obtain a multi-domain LCD device having high aperture ratio and without requiring additional structures. In addition, a simplified fabrication process may be achieved, thereby decreasing manufacturing costs. Furthermore, a reflective- or transmitting-type multi-domain LCD device may be fabricated according to materials of a pixel electrode, thereby improving efficiency. 
   It will be apparent to those skilled in the art that various modifications and variations can be made in the multi-domain liquid crystal display device and method for fabricating a multi-domain liquid crystal display device of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.