Abstract:
A transflective type LCD device includes a substrate having gate and data lines crossing each other to define pixel regions, a reflective part and a transmitting part in each pixel region, a pixel electrode in the reflective part and the transmitting part of the pixel region, a reflective electrode in the reflective part of the pixel region, a thin film transistor having source and drain regions at a crossing of the gate and data lines for transmitting a signal of the data line to the pixel electrode in accordance with a signal of the gate line, and an electrode electrically connecting the source region of the thin film transistor with a data electrode of the data line.

Description:
This application claims the benefit of the Korean Application No. P2003-98921, filed on Dec. 29, 2003, which is hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a liquid crystal display (LCD) device, and more particularly, to a transflective type LCD device. 
     2. Discussion of the Related Art 
     Demands for various display devices have increased with development of information society. Accordingly, many efforts have been made to research and develop various flat display devices, such as liquid crystal display (LCD), plasma display panel (PDP), electroluminescent display (ELD), and vacuum fluorescent display (VFD). Some species of flat display devices have already been used as displays in various types of equipment. 
     Among the various flat display devices, liquid crystal display (LCD) devices have been most widely used due to the advantageous characteristics of thin profile, light weight, and low power consumption. Typically, a LCD device is provided as a substitute for a Cathode Ray Tube (CRT). In addition to mobile type LCD devices, such as a display for a notebook computer, LCD devices have been developed for computer monitors and televisions to receive and display broadcasting signals. 
     Despite various technical developments in the LCD technology for applications in different fields, research in enhancing the picture quality of the LCD device has been, in some respects, lacking as compared to other features and advantages of the LCD device. In order to use the LCD devices in various fields as a general display, LCD devices should have a high quality picture, such as high resolution and high luminance with a large-sized screen, while still maintaining a light weight, thin profile, and low power consumption. 
     Generally, the LCD device includes an LCD panel for displaying an image and a driver for supplying driving signals to the LCD panel. In addition, the LCD panel includes first and second substrates bonded to each other. A liquid crystal layer is formed in a cell gap between the first and second substrates. The first substrate (often referred to as a TFT array substrate) includes a plurality of gate lines arranged along a first direction at fixed intervals, a plurality of data lines arranged along a second direction perpendicular to the first direction at fixed intervals, a plurality of pixel electrodes arranged in a matrix-type configuration within pixel regions defined by crossings of the gate and data lines, and a plurality of thin film transistors enabled according to signals supplied to the gate lines for transmitting signals from the data lines to the pixel electrodes. Also, the second substrate (often referred to as a color filter array substrate) includes a black matrix layer that prevents light from portions of the first substrate except at the pixel regions, an R/G/B color filter layer for displaying various colors, and a common electrode for producing the image. 
     The LCD device does not emit light in and of itself. Thus, the LCD device requires an additional light source for emitting light. Especially, in the case of a transmitting type LCD device, it is necessary to provide an additional light source for emitting and guiding light at the rear of the LCD panel. However, the backlight is maintained in the turned-on state during driving the LCD device, thereby increasing power consumption of the LCD device. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is directed to a transflective type LCD device and a method for fabricating the same 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 transflective type LCD device and a method for fabricating the same, having a dual cell gap to decrease power consumption by using light emitted from a backlight in the dark surroundings, and using ambient light in the bright surroundings. 
     Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may 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 objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a transflective type LCD device includes a substrate having gate and data lines crossing each other to define pixel regions, a reflective part and a transmitting part in each pixel region, a pixel electrode in the reflective part and the transmitting part of the pixel region, a reflective electrode in the reflective part of the pixel region, a thin film transistor having source and drain regions at a crossing of the gate and data lines for transmitting a signal of the data line to the pixel electrode in accordance with a signal of the gate line, and an electrode electrically connecting the source region of the thin film transistor with a data electrode of the data line. 
     In another aspect of the present invention, a method for fabricating a transflective type LCD device on a substrate having pixel regions includes forming a reflective part and a transmitting part in each pixel region, forming a pixel electrode in the reflective part and the transmitting part of the pixel region, forming a reflective electrode in the reflective part of the pixel region, forming a thin film transistor having source and drain regions at a crossing of the gate and data lines for transmitting a signal of the data line to the pixel electrode in accordance with a signal of the gate line, and forming an electrode electrically connecting the source region of the thin film transistor with a data electrode of the data line. 
     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 embodiment(s) of the invention and together with the description serve to explain the principle of the invention. 
         FIG. 1  is a plane view of one pixel region of a transflective type LCD device according to an embodiment of the present invention. 
         FIG. 2  is a cross-sectional view along I-I′ of  FIG. 1 . 
         FIG. 3A  to  FIG. 3F  are cross sectional views of a method for fabricating a transflective type LCD device according to an embodiment of the present invention. 
         FIG. 4  is a plane view of one pixel region of a transflective type LCD device according to an embodiment of the present invention. 
         FIG. 5  is a cross-sectional view along II-II′ of  FIG. 4 . 
         FIG. 6A  to  FIG. 6G  are cross sectional views of a method for fabricating a transflective type LCD device according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. Hereinafter, a transflective type LCD device according to embodiments of the present invention will be described with reference to the accompanying drawings. 
       FIG. 1  is a plane view of one pixel region of a transflective type LCD device according to an embodiment of the present invention.  FIG. 2  is a cross-sectional view along I-I′ of  FIG. 1 . 
     In the transflective type LCD device as shown in  FIG. 1  and  FIG. 2 , a gate line G is formed over a first substrate  350   a . A data line D is formed in perpendicular to the gate line G on the first substrate  350   a . Then, a plurality of pixel regions are formed at each crossing of the gate line G and the data line D. Each pixel region has a reflective part  101   a  and a transmitting part  101   b.    
     Between the first and second substrates  350   a  and  350   b , the data line D, a data electrode DE, a data insulating layer  108 , a semiconductor layer  103 , a gate insulating layer  105 , a gate electrode GE, a common electrode line C, an insulating interlayer  109 , and an organic insulating layer  106 , a reflective electrode R, a pixel electrode  104   b , and a transparent electrode  104   a  are formed. More specifically, the data electrode DE extends from the data line D and protrudes toward the pixel region. The data insulating layer  108  is formed over the entire surface of the first substrate  350   a  including the data line D and the data electrode DE. Then, the semiconductor layer  103  having source and drain regions  103   a  and  103   b  is formed on the data insulating layer  108 . The gate insulating layer  105  is formed over the entire surface of the first substrate  350   a  including the semiconductor layer  103 , and the gate electrode GE protruding the gate line G is formed on the gate insulating layer  105  corresponding to a channel region provided between the source and drain regions  103   a  and  103   b  of the semiconductor layer  103 . 
     The common electrode line C partially overlaps the semiconductor layer  103  and is parallel with the gate line G. The insulating interlayer  109  and the organic insulating layer  106  are sequentially formed on the entire surface of the first substrate  350   a  including the gate electrode GE and the common electrode line C. The reflective electrode R having an open portion A corresponding to the transmitting part  101   b  is formed on the organic insulating layer  106 . The pixel electrode  104   b  is connected with the drain region  103   b  of the semiconductor layer  103 , and is formed on the entire surface of the reflective electrode R including the transmitting part  101   b . The transparent electrode  104   a  connects the source region  103   a  of the semiconductor layer  103  with the data electrode DE. 
     A second substrate  350   b  is positioned opposite to the first substrate  350   a . A color filter  360  is formed on the second substrate. The color filter layer  360  receives light F 2  reflected from the reflective part  101   a  and light F 1  transmitted through the transmitting part  101   b  to display colors. 
     As shown in  FIG. 1 , the reflective electrode R partially overlaps the gate line G and the data line D. A transmitting hole H (shown in  FIG. 2 ) is formed below the open portion A of the reflective electrode R by removing portions of the data insulating layer  108 , the gate insulating layer  105 , the insulating interlayer  109 , and the organic insulating layer  106 . The transmitting hole H has a depth that exposes a portion of the first substrate  350   a . A cell gap depth d 2  from the bottom of transmitting hole H at the first substrate  350   a  to the second substrate  350   b  is twice as great as a cell gap d 1  from the top of the reflective part  101   a  of the first substrate  350   a  to the second substrate  350   b . The path of light F 1  passing through the transmitting hole H corresponds to the path of light F 2  reflected by the reflective electrode R of the reflective part. Thus, a phase difference of the light passing through the transmitting part  101   b  and the reflective part  101   a  is almost same. The aforementioned structure of having the two kinds of cell gap depths d 1  and d 2  is referred to as a dual cell gap structure. 
     The pixel electrode  104   b  is formed in the pixel region, and is electrically connected with the drain region  103   b  of the semiconductor layer  103  via a drain contact hole  102   b  penetrating through the gate insulating layer  105 , the insulating interlayer  109 , and the organic insulating layer  106 , as shown in  FIG. 2 . The transparent electrode  104   a  is formed on the data electrode DE and the source region  103   a  of the semiconductor layer  103  such that the transparent electrode  104   a  electrically connects the data electrode DE with the source region  103   a  of the semiconductor layer  103  via a source contact hole  102   a  and a data contact hole  102   c . The source contact hole  102   a  penetrates through the gate insulating layer  105 , the insulating interlayer  109 , and the organic insulating layer  106 . The data contact hole  102   c  penetrates through the data insulating layer  108 , the gate insulating layer  105 , the insulating interlayer  108 , and the organic insulating layer  106 . 
     The transflective type LCD device according to an embodiment of the present invention uses ambient light F 2  in the bright surroundings. That is, the light F 2  incident on the reflective part  101   a  is reflected from the reflective electrode R of the reflective part  101   a , and then the light passes through the color filter layer  360  of the second substrate  350   b , thereby displaying luminance. Otherwise, in dark surroundings, the transflective type LCD device according to an embodiment of the present invention uses the light F 1  emitted from a backlight (not shown). That is, the light F 1  emitted from the backlight unit passes through the transmitting hole H of the transmitting part  101   b , and the color filter layer  360  of the second substrate  350   b , thereby displaying luminance. 
     A method for fabricating the transflective type LCD device according to an embodiment of the present invention will be described while referring to  FIG. 3A  to  FIG. 3F  as follows.  FIG. 3A  to  FIG. 3F  are cross-sectional views of a method for fabricating the transflective type LCD device according to an embodiment of the present invention. 
     First, a first substrate  350   a  having a plurality of pixel regions is prepared. More particularly, each pixel region has a reflective part  101   a  and a transmitting part  101   b . Subsequently, as shown in  FIG. 3A , a metal layer, such as aluminum Al, is deposited on the first substrate  350   a , and selectively patterned by photolithography (using a first mask) to form the data line D and the data electrode DE extending from the data line D toward the pixel region. 
     Subsequently, as shown in  FIG. 3B , an insulating layer, such as silicon oxide SiO x  or silicon nitride SiN x  is formed over the entire surface of the first substrate  350   a  including the data line D and the data electrode DE. Also, a silicon layer is deposited over the entire surface of the data insulating layer  108 , and then is selectively patterned by photolithography (using a second mask) to form the island-shaped semiconductor layer  103  on the data insulating layer  108 . An insulating layer of silicon oxide (SiO x ) or silicon nitride (SiN x ) is deposited over the entire surface of the first substrate  350   a  including the semiconductor layer  103  to form the gate insulating layer  105 . 
     Referring to  FIG. 3C , a metal layer, such as aluminum (Al), aluminum neodymium (AlNd), and chrome (Cr), is deposited over the entire surface of the gate insulating layer  105 , and then is selectively patterned by photolithography (using a third mask) to form the gate line G perpendicular to the data line D and the gate electrode GE positioned on the gate insulating layer  105  in correspondence with the channel region of the semiconductor layer  103 . Simultaneously, the common electrode line C is formed on the gate insulating layer  105  to overlap the semiconductor layer  103 . 
     Next, both sides of the semiconductor layer  103  are exposed by using the gate electrode GE and the common electrode line C as a mask, and then impurity ions are implanted into the both sides of the semiconductor layer  103 . A middle portion of the semiconductor layer  103  that serves as a channel region is covered with the gate electrode GE. The sides of the semiconductor layer serve as the source and drain regions  103   a  and  103   b  after implantation of impurity ions. 
     Referring to  FIG. 3D , the insulating interlayer  109  and the organic insulating layer  106  are sequentially formed over the entire surface of the first substrate  350   a  including the gate electrode GE and the common electrode line C to planarize the surface over the first substrate  350   a.    
     After that, as shown in  FIG. 3E , portions of the gate insulating layer  105 , the organic insulating layer  106 , and the insulating interlayer  109  above the source and drain regions  103   a  and  103   b  of the semiconductor layer  103  are removed to form the source contact hole  102   a , the drain contact hole  102   b . At this time, portions of the gate insulating layer  105 , the organic insulating layer  106 , the insulating interlayer  109  and the data insulating layer  108  above the data electrode DE are removed to form the data contact hole  102   c  using a photo-lithographic process (using a fourth mask). The source contact hole  103   a  exposes a portion of the source region  103   a , the drain contact hole  102   b  exposes a portion of the drain region  103   b , and the data contact hole  102   c  exposes a portion of the data electrode DE, the gate insulating layer  105 , the insulating interlayer  109 , and the organic insulating layer  106 . During the process of forming the contact holes  102   a ,  102   b , and  102   c , the data insulating layer  108 , the gate insulating layer  105 , and the insulating interlayer, and the organic insulating layer  106 , corresponding to the transmitting part  101   b  of the pixel region, are also removed at the same time, thereby forming the transmitting hole H exposing a portion of the first substrate  350   a  in the transmitting part  101   b.    
     Next, as shown in  FIG. 3F , aluminum (Al) or aluminum neodymium (AlNd) is deposited over the entire surface of the first substrate  350   a  including the organic insulating layer  106 , and then patterned by photolithography (using a fifth mask), thereby forming the reflective electrode R having the open portion A corresponding to the transmitting hole H of the transmitting part  101   b  of the pixel region (using a fifth mask). At this time, the transmitting hole H of the transmitting part  101   b  and the source and drain contact holes  102   a  and  102   b  are patterned to form the reflective electrode R therein. 
     Then, a transparent conductive layer of indium tin oxide (ITO) is deposited over the entire surface of the first substrate  350   a  including the reflective electrode R and the source and drain contact holes  102   a  and  102   b , and is patterned by photolithography (using a sixth mask), thereby forming the pixel electrode  104   b  and the transparent electrode  104   a . At this time, the pixel electrode  104   b  is electrically connected with the drain region  103   b  exposed by the drain contact hole  102   b , and is formed over the entire surface of the pixel region including the transmitting hole H of the transmitting part  101   b . Also, the transparent electrode  104   a  electrically connects the data electrode DE exposed by the data contact hole  102   c  with the source region  103   a  of the semiconductor layer exposed by the source contact hole  102   a . In this case, the pixel electrode  104   b  and the transparent electrode  104   a  are formed at the same time, and are not connected with each other. 
     Subsequently, the first and second substrates  350   a  and  350   b  are bonded to each other, and liquid crystal is injected between the first and second substrates  350   a  and  350   b  to thereby form a liquid crystal layer between the first and second substrates. In the transflective type LCD device according to an embodiment of the present invention, the transparent electrode  104   a  is thin. Thus, the transparent electrode  104   a  may be damaged during the fabrication process. Further, the transparent electrode  104   a  has the disadvantageous characteristics of high contact resistance. To overcome this problem, the transparent electrode  104   a  may be formed of the same material as the reflective electrode R. 
     A transflective type LCD device according to an embodiment of the present invention will be described with reference to  FIGS. 4 and 5 .  FIG. 4  is a plane view of one pixel of a transflective type LCD device according to an embodiment of the present invention.  FIG. 5  is a cross-sectional view along II-II′ of  FIG. 4 . In the transflective type LCD device according to an embodiment of the present invention, a second substrate has the same structure as that of the transflective type LCD device of the embodiment of the present invention shown in  FIGS. 1 and 2 . Thus, the explanation of the second substrate will be omitted. 
     As shown in  FIG. 4  and  FIG. 5 , the transflective type LCD device includes a substrate  650 , a buffer layer  700 , a data line D′, a data electrode DE′, a data insulating layer  408 , a semiconductor layer  403 , a gate insulating layer  405 , a gate line G′, a gate electrode GE′, a common electrode line C′, an insulating interlayer  409 , an organic insulating layer  406 , source and drain contact holes  402   a  and  402   b , a data contact hole  402   c , a transmitting hole H′, a first reflective electrode R 1  a second reflective electrode R 2 , and a pixel electrode  601 . The substrate  650  has a plurality of pixel regions. Each pixel region has a reflective part  401   a  and a transmitting part  401   b . The buffer layer  700  is formed on the entire surface of the substrate  650 . The buffer layer  700  may be one of a silicon nitride (SiN x ) layer and a silicon nitro-oxide (SiNxOy) layer. The data line D′ is formed on the buffer layer  700 , the data electrode DE′ extends from the data line D′ and protrudes into the pixel region, and the data insulating layer  408  is formed over the entire surface of the substrate  650  including the data line D′ and the data electrode DE′. 
     Then, the semiconductor layer  403  having source and drain regions  403   a  and  403   b  is formed on the data insulating layer  408 . The gate insulating layer  405  is formed over the entire surface of the substrate  650  including the semiconductor layer  403 . After that, the gate line G′ is formed perpendicular to the data line D′ on the gate insulating layer  405 , and the gate electrode GE′ protruding from the gate line G′ is formed on the gate insulating layer  405  above a channel region of the semiconductor layer  403 . The common electrode line C′ partially overlaps the semiconductor layer  403  and is formed on the gate insulating layer  405 . Thereafter, the insulating interlayer  409  and the organic insulating layer  406  are sequentially formed over an entire surface of the gate insulating layer  405  including the gate electrode GE′ and the common electrode line C′. 
     The source and drain contact holes  402   a  and  402   b  penetrate through the organic insulating layer  406 , the insulating interlayer  409 , and the gate insulating layer  405  to expose portions of the source and drain regions  403   a  and  403   b  of the semiconductor layer  403 . Also, the data contact hole  402   c  penetrates through the organic insulating layer  406 , the insulating interlayer  409 , the gate insulating layer  405 , and the data insulating layer  408  to exposes a portion of the data electrode DE′. The transmitting hole H′ penetrates through the gate insulating layer  405 , the data insulating layer  408 , the insulating interlayer  409  and the organic insulating layer  406  formed in the transmitting part  401   b  of the substrate  650 , and exposes some of the substrate  650 . 
     The first reflective electrode R 1  electrically connects the source region  403   a  of the semiconductor layer  403  with the data electrode DE′ through the source and data contact holes  402   a  and  402   c . The second reflective electrode R 2  is formed on the organic insulating layer  406  in the reflective part. The second reflective electrode R 2  contacts the drain region  403   b  via the drain contact hole  402   b . The pixel electrode  601  is formed on the second reflective electrode R 2  including the transmitting hole H′ of the transmitting part  401   b  in the pixel region. 
     During an etching process of forming the transmitting hole H′, the buffer layer  700  prevents the substrate from being etched. That is, since the transmitting hole H′ has a large size, the organic insulating layer  406 , the insulating interlayer  409 , the gate insulating layer  405 , and the data insulating layer  408  are etched in a large range during the etching process of forming the transmitting hole H′. Accordingly, the surface of the substrate  650  may be etched by an etchant such that the substrate  650  may be damaged. In this respect, the buffer layer  700  between the gate insulating layer  405  and the substrate  650  prevents the etchant from contacting the surface of the substrate  650 , thereby preventing the substrate  650  from being damaged by the etchant. 
     For example, the first and second reflective electrodes R 1  and R 2  may be formed of a metal material having high reflectance, low contact resistance, and high degree of strength, such as aluminum (Al), and aluminum neodymium (AlNd). The first reflective electrode R 1  electrically connects the source region  403   a  of the semiconductor layer  403  with the data electrode DE′ via the data contact hole  402   c  and the source contact hole  402   a . As described above, the first reflective electrode R 1  is formed of a metal material having low resistance such that the first reflective electrode R 1  is connected with the source region  403   a  and the data line D′ with a low contact resistance. Accordingly, electric signals provided from the data line D′ are easily transmitted to the source region  403   a  of the semiconductor layer  403 . 
     The first and second reflective electrodes R 1  and R 2  have uneven surfaces  500  to reflect the external light incident on the first and second reflective electrodes R 1  and R 2  diffusively. Also, the second reflective electrode R 2  has an open portion A′ corresponding to the transmitting hole H′ of the transmitting part  401   b , and the second reflective electrode R 2  partially overlaps portions of the gate line G′ and the data line D′. 
     A method for fabricating the transflective type LCD device according to an embodiment of the present invention will be described with reference  FIGS. 6A to 6G .  FIG. 6A  to  FIG. 6G  are cross-sectional views of a method for fabricating the transflective type LCD device according to an embodiment of the present invention. 
     First, the substrate  650  having the plurality of pixel regions is prepared. Each pixel region has a reflective part  401   a  and a transmitting part  401   b . Subsequently, as shown in  FIG. 6A , the buffer layer  700 , such as silicon nitride (SiNx) and silicon nitro-oxide (SiNxOy), is formed on the entire surface of the substrate  650 . The buffer layer  700  is formed to prevent the substrate  650  from being damaged by the etchant during the process of forming the transmitting hole H′. 
     After that, as shown in  FIG. 6B , the metal layer of aluminum (Al) is deposited over the entire surface of the substrate  650  including the buffer layer  700 , and then selectively patterned by photolithography (using a first mask), thereby forming the data line D′ and the data electrode DE′. 
     Referring to  FIG. 6C , the data insulating layer  408  is formed over the entire surface of the substrate  650  including the data line D′ and the data electrode DE′. Then, a silicon layer is deposited over the entire surface of the substrate  650  including the data insulating layer  408 , and selectively patterned by photolithography (using a second mask), thereby forming the island-shaped semiconductor layer  403 . 
     Subsequently, as shown in  FIG. 6D , an insulating layer, such as silicon oxide and silicon nitride, is formed over the entire surface of the substrate  650  including the semiconductor layer  403 , thereby forming the gate insulating layer  405 . Thereafter, a metal layer, such as aluminum (Al), aluminum neodymium (AlNd), and chrome (Cr), is formed over the entire surface of the substrate  650  including the gate insulating layer  405 , and then selectively patterned by photolithography (using a third mask), thereby forming the gate line G′ and positioning the gate electrode GE of the gate line G on the gate insulating layer  405  in correspondence with the channel region of the semiconductor layer  403 . Simultaneously, the common electrode line C′ is formed in parallel with the gate line G′ to overlap the semiconductor layer  403 . 
     Next, impurity ions are implanted into the semiconductor layer  403  using the gate electrode GE′ and the common electrode line C′ as a mask. Exposed side portions of the semiconductor layer  403  are formed as the source and drain regions  403   a  and  403   b  by implantation of impurity ions. Thus, a middle portion of the semiconductor layer  403 , covered with the gate electrode GE′ is formed as a channel region. 
     Subsequently, as shown in  FIG. 6E , the insulating interlayer  409  and the organic insulating layer  406  are sequentially formed over the entire surface of the substrate  650  including the gate electrode GE′ and the common electrode line C′ to planarize the surface over the substrate  650 . 
     Referring to  FIG. 6F , the source contact hole  402   a  and the drain contact hole  402   b  are formed by removing portions of the gate insulating layer  405 , the organic insulating layer  406 , and the insulating interlayer  409  above the source region  403   a  and drain region  403   b  using a photolithography process (using a fourth mask). In this process, the data contact hole  402   c  is also formed by removing portions of the gate insulating layer  405 , the organic insulating layer  406 , the insulating interlayer  409 , and the data insulating layer  408  above the data electrode DE′ using a photolithography process (using a fourth mask). More specifically, the source contact hole  403   a  exposes a portion of the source region  403   a , the drain contact hole  403   b  exposes a portion of the drain region  403   b , and the data contact hole  402   c  exposes a portion of the data electrode DE′. During the process of forming the respective contact holes  402   a ,  402   b , and  402   c , the data insulating layer  408 , the gate insulating layer  405 , and the insulating interlayer  409 , and the organic insulating layer  406 , corresponding to the transmitting part  401   b  of the pixel region, are removed at the same time, thereby forming the transmitting hole H′ and exposing the buffer layer  700  of the transmitting part  401   b . At this time, the buffer layer  700  prevents the substrate  650  from being damaged by the etchant used for the process of forming the transmitting hole H′. That is, since the etchant could have penetrated into the substrate  650  by excessive etching, the buffer layer  700  is formed between the substrate  650  and the gate insulating layer  405  to prevent the etchant from penetrating into the substrate  650 . In this case, the organic insulating layer  406  may have the uneven surface  500  formed by photolithography (a fifth mask). 
     After that, as shown in  FIG. 6G , aluminum (Al) or aluminum neodymium (AlNd) is deposited over the entire surface of the substrate  650  including the organic insulating layer  406 , and patterned by photolithography (using a sixth mask), thereby forming the first reflective electrode R 1  and the second reflective electrode R 2 . The first reflective electrode R 1  electrically connects the source region  403   a  of the semiconductor layer  403  with the data electrode DE′ through the data contact hole  402   c  and the source contact hole  402   a . The second reflective electrode R 2  electrically connects the drain region  403   b  of the semiconductor layer  403  through the drain contact hole  402   b . Also, the second reflective electrode R 2  has the open part A′ corresponding to the transmitting hole H′ of the transmitting part of the pixel region. In this case, the second reflective electrode R 2  is not formed in the transmitting hole H′ of the transmitting part  401   b.    
     The first and second reflective electrodes R 1  and R 2  are formed on the organic insulating layer  406  having the uneven surface  500  such that the first and second reflective electrodes R 1  and R 2  have an uneven surface. The uneven surface  500  of the first and second reflective electrodes R 1  and R 2  diffusively reflects light in the reflective part  401   a  such that the light is not concentrated at one point. 
     Next, the transparent conductive layer of ITO is deposited over the entire surface of the organic insulating layer  406  including the first and second reflective electrodes R 1  and R 2 , and the source and drain contact holes  402   a  and  402   b . The transparent conductive layer of ITO is then patterned by photolithography (using a seventh mask) to form the pixel electrode  601  on the second reflective electrode R 2  such that the pixel electrode  601  is electrically connected with the drain region  403   b  of the semiconductor layer  403  via the second reflective electrode  403   b . In this case, the pixel electrode  601  is formed in the pixel region including the transmitting hole H′ of the transmitting part  401   b.    
     The transflective type LCD device according to an embodiment of the present invention, which has the reflective electrodes R 1  and R 2  with an uneven surface  500 , requires 7 masks. Thus, the fabrication process according to the embodiment of the present invention shown in  FIGS. 3A to 3F  requires one more mask as compared with the fabrication process according to the embodiment of the present invention shown in  6 A to  6 G that uses 6 masks. However, since the reflective electrodes R 1  and R 2  have the uneven surface  500 , the efficiency in scattering the light is improved. 
     As mentioned above, the transflective type LCD device according to embodiments of the present invention and the method for fabricating the same have the following advantages. A buffer layer of silicon nitride or silicon nitride-oxide is formed between the substrate and the gate insulating layer to prevent the substrate from being damaged by the etchant used for etching the gate insulating layer and the organic insulating layer for formation of the transmitting hole of the transmitting part. Also, the reflective electrode is formed of the metal material having low contact resistance and high degree of strength such that electric signals are easily transmitted between the source region of the semiconductor layer and the data line. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.