KR20050066643A - Fabrication method of transreflective liquid crystal display device - Google Patents

Abstract

The present invention relates to a method of manufacturing a transflective liquid crystal display device, comprising: forming an active layer by applying a first mask, forming a gate line and a data line by applying a second mask, and applying a third mask Forming a contact hole and a pixel electrode and forming a reflective electrode by applying a fourth mask can reduce the number of masks applied to manufacture the liquid crystal display.

Description

Manufacturing method of transflective liquid crystal display {FABRICATION METHOD OF TRANSREFLECTIVE LIQUID CRYSTAL DISPLAY DEVICE}

The present invention relates to a method of manufacturing a switching element applied to a transflective liquid crystal display device, and more particularly, to a method of manufacturing a switching element of a transflective liquid crystal display device by applying a low mask.

Recently, with increasing interest in image display devices and increasing demand for using portable information carriers, lightweight panel displays (FPDs), which replace the existing display devices, the Cathode Ray Tube (CRT) Research and commercialization is actively being done. In particular, among such flat panel display devices, the liquid crystal display device is an apparatus for representing an image by using optical anisotropy of liquid crystal, and is applied to a notebook or a desktop monitor because of excellent resolution, color display, and image quality.

The liquid crystal display device is largely composed of a color filter substrate, which is a first substrate, an array substrate, which is a second substrate, and a liquid crystal layer formed between the color filter substrate and the array substrate.

In general, a thin film transistor is used as the switching element of the liquid crystal display, and amorphous silicon or polycrystalline silicon may be used as a channel layer of the thin film transistor. In particular, in order to manufacture a switching device that requires high-speed operating characteristics, polysilicon, which is significantly faster than amorphous silicon, is mainly used as a channel layer.

On the other hand, the manufacturing process of the liquid crystal display device basically requires a plurality of mask processes (ie, photolithography process) for the fabrication of the array substrate including a thin film transistor, the method of reducing the number of mask processes in terms of productivity This is required.

FIG. 1 is a plan view showing a structure of an array substrate of a general transflective liquid crystal display device. In an actual liquid crystal display device, N gate lines and M data lines intersect, where there are N × M pixels. For the sake of illustration, only one pixel is shown.

As shown in the drawing, the array substrate includes a reflective electrode 18 formed on a pixel region, a transmission region 30 formed on a portion of the pixel region, gate lines 16 and data lines arranged vertically and horizontally on the substrate. (17) and a thin film transistor, which is a switching element formed at the intersection of the gate line 16 and the data line 17. In the pixel region, a transparent pixel electrode 20 is formed.

The thin film transistor includes a gate electrode 21 connected to the gate line 16, a source electrode 22 connected to the data line 17, and a drain electrode 23 connected to a pixel electrode (not shown). In addition, the thin film transistor is supplied to a first insulating film (not shown), a second insulating film (not shown), and the gate electrode 21 for insulating the gate electrode 21 and the source / drain electrodes 22 and 23. An active layer 24 is formed to form a conductive channel between the source electrode 22 and the drain electrode 23 by the gate voltage.

At this time, the source electrode 22 is electrically connected to the source region of the active layer 24 through the first contact hole 40a formed in the first insulating film and the second insulating film, and the drain electrode 23 is active. It is in electrical connection with the drain region of layer 24. In addition, a third insulating film (not shown) having a second contact hole 40b is formed on the drain electrode 23, so that the drain electrode 23 and the pixel electrode 20 are formed through the second contact hole 40b. This is to be electrically connected.

Hereinafter, a manufacturing process of a conventional liquid crystal display device will be described in detail with reference to FIGS. 2A to 2F.

2A to 2F are flowcharts illustrating a manufacturing process along line II ′ of the liquid crystal display shown in FIG. 1.

First, as shown in FIG. 2A, an active layer 24 made of polysilicon is formed on a transparent substrate 10 such as glass using a photolithography process.

Next, as shown in FIG. 2B, the first insulating film 15a and the conductive metal film are sequentially deposited on the entire surface of the substrate 10 on which the active layer 24 is formed.

Next, the conductive metal film is patterned using a photolithography process to form the gate electrode 21 having the first insulating film 15a interposed therebetween.

Subsequently, source / drain regions 24a and 24b are formed by applying the gate electrode 21 as a mask to implant a high concentration of impurity ions of p + or n + into a predetermined region of the active layer 24. The source / drain regions 24a and 24b form for ohmic contact with the source / drain electrodes.

Next, as shown in FIG. 2C, the second insulating film 15b is deposited as an interlayer insulating film on the entire surface of the substrate 10 on which the gate electrode 21 is formed, and then the first insulating film 15a is formed through a photolithography process. And the second insulating layer 15b are partially removed to form a first contact hole 40a for electrical connection between the source / drain regions 24a and 24b and the source / drain electrode.

After that, as shown in FIG. 2D, a conductive electrode is deposited on the entire surface of the substrate 10 and then connected to the source region 24a through the first contact hole 40a using a photolithography process ( 22 and a drain electrode 23 connected to the drain region 24b are formed. At this time, a part of the conductive metal constituting the source electrode 22 is extended to form a data line.

Next, as shown in FIG. 2E, the third insulating film 15c, which is an organic insulating film such as acrylic, is deposited on the entire surface of the substrate 10, and the reflection efficiency is excellent on the third insulating film 15c. The reflecting plate 18 is formed. The reflecting plate 18 is formed for each unit pixel area and includes a transmission area so that a part of the reflection plate 18 is cut so that light propagated from the lower part can be transmitted.

Finally, as shown in FIG. 2F, a fourth insulating film 15d, which is an organic insulating film such as acrylic, is formed on the entire surface of the substrate 10 on which the third insulating film 15c is formed, and the drain electrode 23 is formed. The second contact hole 40b is formed in the upper portion of the second contact hole 40b. After forming the second contact hole 40b, a transparent conductive material such as indium tin oxide (ITO) is deposited on the contact hole and the fourth insulating layer 15d, and then a photolithography process is performed. The pixel electrode 30 is connected to the drain electrode 23 through the second contact hole 40b.

As described above, in the manufacture of the liquid crystal display device including the polysilicon thin film transistor, a photolithography process is performed to pattern an active pattern, a gate electrode, a first contact hole, a source / drain electrode, a reflector, a second contact hole, and a pixel electrode. in need.

The photolithography process is a series of processes in which a pattern drawn on a mask is transferred onto a substrate on which a thin film is deposited to form a desired pattern. The photolithography process includes a plurality of processes such as photoresist coating, exposure, and development. As a result, many photolithography processes have problems such as lowering the production yield and increasing the probability of defects in the formed thin film transistors.

In particular, the mask designed to form the pattern is very expensive, there is a problem that the manufacturing cost of the liquid crystal display device increases in proportion to the increase in the number of masks applied to the process.

An object of the present invention is to reduce the number of masks applied in manufacturing a liquid crystal display device using polysilicon as a channel layer of a thin film transistor to solve the above problems. It is also an object to reduce the manufacturing cost and improve the yield by reducing the number of masks applied to the manufacturing process.

In order to achieve the above object, the manufacturing process of the transflective liquid crystal display device of the present invention comprises the steps of forming an active layer on the substrate; Forming a gate line, a data line and a storage line on the active layer; Forming a source and a drain region in the active layer; Continuously forming an insulating layer and a pixel electrode material on the gate line, the data line and the storage line; Forming a pixel electrode and a contact hole by applying a mask on the pixel electrode material; And forming a reflective electrode on the pixel electrode.

In particular, the gate line, the data line and the storage line are formed on the same layer at the same time, the gate line and the storage line is formed in the step of forming the gate line and the storage line includes a separation region which is partially separated It is characterized by.

The forming of the pixel electrode and the contact hole may include forming a photosensitive organic layer on the pixel electrode material; Etching the pixel electrode material to form a pixel electrode; Ashing the photosensitive organic film; And removing the insulating film on the source and drain regions.

Hereinafter, the structure of the transflective liquid crystal display according to the first embodiment of the present invention will be described with reference to FIG. 3 through a plan view, and the manufacturing process thereof through FIG. 4.

As shown in FIG. 3, in the transflective liquid crystal display of the present invention, the gate line 304a and the storage line 305a are arranged in parallel on the substrate, and the gate line 304a and the storage line 305a are mutually arranged. Vertical data lines 306a are arranged. The gate line 304a and the storage line 305a have isolation regions in which portions thereof are disconnected, and the data lines 306a pass through the isolation regions. Therefore, the gate line 304a and the storage line 305a are formed on the same layer as the data line 306a but are electrically insulated from each other.

In addition, the gate line 304a including the isolation region is connected to each other through the contact holes 310c and 310d and by the reflective electrode 309. The storage line 305a including the isolation region is also connected to each other by a reflective electrode through a contact hole like the gate line 304a.

On the other hand, a reflective electrode 309 is formed in the unit pixel area defined by the gate line 304a and the data line 306a, and a part of the reflective electrode 309 is cut away to transmit a transmissive area of the transflective liquid crystal display. 360 is formed. The reflective electrode 309 is connected to each other through the drain electrode of the thin film transistor switching unit pixels and the second contact hole 310b.

On the other hand, an active layer 302 constituting a channel layer of a thin film transistor is formed on one side of the pixel region as the switching element. The active layer 302 is made of polysilicon and has source and drain regions formed by ion implantation.

In addition, a storage electrode 305 for forming a capacitor is formed on the active layer 302, and the storage electrode 305 is formed on the same layer as the gate line and the data line.

On the other hand, the pixel electrode for applying the electric field to the liquid crystal is formed over the entire pixel region, although not shown in the figure.

Hereinafter, the manufacturing process of the transflective liquid crystal display device of the present invention having the above structure will be described with the cut lines J-J 'and K-K' shown in FIG.

As shown in FIG. 4A, an active layer 302 is formed on a transparent substrate 301 such as glass.

As shown in FIG. 4A, an active layer 302 made of polysilicon is formed on the transparent substrate 301.

Prior to forming the active layer, a buffer layer of a silicon oxide film (Si0 ₂ ) or a silicon nitride film (SiNx) is formed to prevent diffusion of impurities in the substrate 301 into the silicon layer, which may occur during crystallization of amorphous silicon. can do.

The forming of the active layer may include forming an amorphous silicon layer on the substrate 301, heating the amorphous silicon layer to dehydrogenating it, crystallizing the amorphous silicon layer, and patterning the crystallized silicon layer. Ning consists of steps.

In more detail, the amorphous silicon layer is formed to a predetermined thickness on the substrate 301 on which the buffer layer (not shown) is formed by a plasma enhanced chemical vapor deposition (PECVD) method.

Next, a dehydrogenation process of removing hydrogen contained in the amorphous silicon layer formed first is performed. That is, the amorphous silicon layer is placed in a heating furnace to remove hydrogen by heating at about 400 ℃. The amorphous silicon layer is formed in an amorphous state in which the bonds of molecules are unstable in the formation process, and each molecule has an excess bond group, and hydrogen ions are bonded to the bond group. The hydrogen ions act as a defect in the process of crystallizing amorphous silicon and are removed in advance because they may explode and damage the silicon layer during the process of crystallization.

After the dehydrogenation process, the process of crystallizing the amorphous silicon layer is performed. As the crystallization method, a heating method of heating the amorphous silicon layer in a high temperature furnace and a laser crystallization method of heating and crystallizing the amorphous silicon layer instantaneously using excimer laser energy may be used.

In particular, since the laser crystallization method can greatly increase the grain size during the crystallization process, it is possible to greatly improve the electric mobility compared to the crystallization method by the heating method in terms of electric mobility. effective.

After crystallizing the amorphous silicon layer, the polysilicon layer is patterned as an active layer by applying a first mask. The active layer patterning process may be formed by a photolithography process.

That is, the photosensitive film is coated on the polysilicon layer and the first mask is applied on the photosensitive film to perform an exposure process, a developing process, and a polysilicon layer etching process. The polysilicon layer may be effectively patterned by dry etching.

After the active layer 302 is formed, as shown in FIG. 4B, a first insulating film 303a including a silicon oxide film or a silicon nitride film is formed on the entire surface of the substrate including the active layer 302 layer by PECVD. Form.

In addition, a conductive layer is formed on the first insulating film 303a by a sputtering method. The conductive layer may be formed of aluminum (Al) or molybdenum (Mo) to form a gate line, a data line, and a storage line, and a double layer of aluminum and molybdenum may be used.

After the conductive layer is formed on the first insulating layer 303a, a photosensitive film (not shown) is coated on the conductive layer, a second mask is applied, and a photolithography is performed to etch the gate electrode 304, the storage electrode 305, and The source electrode 306 is formed at the same time.

In this case, the gate line including the gate electrode 304 and the data line including the source electrode 306 vertically intersect each other, and a portion of the gate line is disposed so that the gate line and the data line are not electrically connected to each other at an intersection area. The removed gate line isolation region is formed. Since the storage line including the storage electrode 305 is also formed on the substrate 301 in parallel with the gate line, a connection with a data line may occur, so that a part of the storage line is also removed to form an isolation region. . 4B illustrates a process of forming the gate line 304a and the data line 306a of the isolation region using the K-K ′ line of FIG. 3 as a cutting line, and the data line 306a formed in the isolation region of the gate line. You can see a cross section of

After the gate electrode, the source electrode, and the storage electrode are formed, the active layer 302 is formed by applying the gate electrode 304, the source electrode 306, and the storage electrode 305 formed on the active layer 302 as a mask. The source 320 and the drain region 330 are formed. The source 320 and the drain region 330 may be formed by implanting impurity ions on the active layer. In order to form a P-type thin film transistor, group 3 ions may be used as impurities to be implanted. In order to form an N-type thin film transistor, ions of Group 5 may be used as impurities to be implanted.

Forming the source 302 and the drain region 330 in the active layer 302 allows the ohmic contact with the source and drain electrodes by metalizing the active layer by injecting impurities into the active layer. For sake.

After the source and drain regions are formed by ion implantation, a second insulating layer 303b is formed on the gate electrode 304, the source electrode 306, and the storage electrode 305, as shown in FIG. 4C. do. The second insulating layer 303b may be formed of a silicon oxide film or a silicon nitride film as an interlayer insulating layer, or a double layer of a silicon oxide film or a silicon nitride film may be used.

After forming the second insulating layer, hydrogenation heat treatment is performed to stabilize the damaged active layer 302 during the process. The hydrogenation heat treatment is to stabilize the polysilicon layer by injecting hydrogen ions into the active layer to combine hydrogen with the excess bond in the polysilicon generated during the process.

After the hydrogenation heat treatment process, as illustrated in FIG. 4C, a pixel electrode material is formed on the second insulating layer 303b. The pixel electrode material is a transparent electrode material made of indium tin oxide (ITO) or indium zinc oxide (IZO), and may be formed on the second insulating layer 303b by a sputtering method.

After the pixel electrode material 307 is formed, the pixel electrode material is patterned to form a pixel electrode, and contact holes are formed on the source and drain regions.

First, to form a pixel electrode, as shown in FIG. 4D, a photosensitive organic layer 308 is formed on the pixel electrode material 307 and a mask is applied to perform a first exposure and development process. The first exposure and development process is to roughen the surface of the photosensitive organic film. When the reflective electrode is formed on the unevenly treated photosensitive organic film, a liquid crystal display device having uniform reflection characteristics in the reflective mode may be obtained. .

Next, a second exposure and development process is performed on the photosensitive organic film 308 which is unevenly processed by the first exposure and development process. As a result of the second exposure and development process, a portion of the pixel electrode material is exposed. The exposed pixel electrode material region may be a source, a drain region, and a gate line and a data line.

FIG. 4D illustrates an example in which the pixel electrode material on the source and drain regions is exposed and etched, and as illustrated in ii of FIG. 4D, the pixel on the gate line including the isolation region when the pixel electrode material is etched. The electrode material is also removed together.

Next, as shown in FIG. 4E, a portion of the pixel electrode 307 is exposed by ashing the photosensitive organic layer 308. In particular, the pixel electrode of the region adjacent to the contact hole 310b formed on the drain region 330 is exposed.

Exposing a part of the pixel electrode is to electrically connect the drain region and the pixel electrode in the reflective electrode forming process, which is performed after the contact hole forming process because the upper portion of the pixel electrode is insulated by the photosensitive organic film. .

Next, the first contact layer 310a is removed by applying the ashed photosensitive organic layer 308 as a mask to remove the first insulating layer 303a and the second insulating layer 303b on the source and drain regions 320 and 330. ) And the second contact hole 310b. A third contact hole 310c and a fourth contact hole 310d are also formed on the gate line 304a including the isolation region while the first and second contact holes are formed. Although not shown in the drawing, the third and fourth contact holes are formed and the contact holes are also formed on the storage line including the isolation region.

In particular, the contact hole on the source region 320 is preferably formed so that the source electrode 306 and the source region can be simultaneously exposed. That is, since the source electrode 306 and the source region are insulated by the first insulating layer 303a, the source electrode 306 and the source region are exposed to be electrically connected by a reflective electrode material to be formed later when forming the first contact hole.

Next, as shown in FIG. 4F, the contact hole forming process forms a reflective electrode 309 on the contact hole and the pixel electrode.

The reflective electrode may use molybdenum (M0) or AlNd having good reflection characteristics. The molybdenum and AlNd have excellent ohmic characteristics with respect to the conductive and active layers.

Therefore, a reflective electrode material made of molybdenum or AlNd is deposited on the entire surface of the substrate on which the pixel electrode and the contact hole are formed, and then the reflective electrode material is patterned by performing a photolithography process. As a result of the patterning, as shown in FIG. 4F, a reflective electrode is patterned in the first contact hole 310a on the source region to electrically connect the source electrode 306 and the source region 320 to the drain region. The reflective electrode 309 is also formed on the second contact hole 310b on the 330, the pixel electrode 307, and the photosensitive organic layer 308 on the pixel electrode. The drain region 330 and the pixel electrode 307 are electrically connected by the reflective electrode.

In particular, the reflective electrode 309 is formed in a part of the pixel area to secure the transmission area.

Meanwhile, as shown in ii of FIG. 4F, the gate lines 304a including the isolation regions are connected to each other by the contact holes 310c and 310d and the reflective electrodes.

Through the above process, a semi-transmissive liquid crystal display device using polysilicon as the channel layer of the thin film transistor is completed.

Next, a manufacturing process of a transflective liquid crystal display device using 5 masks as a second embodiment of the present invention will be described with reference to FIGS. 5A to 5F.

As shown in FIG. 5A, an active layer 302 is formed on a transparent substrate 301 such as glass.

Prior to forming the active layer, a buffer layer of a silicon oxide film (Si0 ₂ ) or a silicon nitride film (SiNx) is formed to prevent diffusion of impurities in the substrate 301 into the silicon layer, which may occur during crystallization of amorphous silicon. can do.

The forming of the active layer may include forming an amorphous silicon layer on the substrate 301, heating the amorphous silicon layer to dehydrogenating it, crystallizing the amorphous silicon layer, and patterning the crystallized silicon layer. Ning consists of steps.

In more detail, the amorphous silicon layer is formed to a predetermined thickness on the substrate 301 on which the buffer layer (not shown) is formed by a plasma enhanced chemical vapor deposition (PECVD) method.

Next, a dehydrogenation process of removing hydrogen contained in the amorphous silicon layer formed first is performed. That is, the amorphous silicon layer is placed in a heating furnace to remove hydrogen by heating at about 400 ℃. The amorphous silicon layer is formed in an amorphous state in which the bonds of molecules are unstable in the formation process, and each molecule has an excess bond group, and hydrogen ions are bonded to the bond group. The hydrogen ions act as a defect in the process of crystallizing amorphous silicon and are removed in advance because they may explode and damage the silicon layer during the process of crystallization.

After the dehydrogenation process, the process of crystallizing the amorphous silicon layer is performed. As the crystallization method, a heating method of heating the amorphous silicon layer in a high temperature furnace and a laser crystallization method of heating and crystallizing the amorphous silicon layer instantaneously using excimer laser energy may be used.

In particular, since the laser crystallization method can greatly increase the grain size during the crystallization process, it is possible to greatly improve the electric mobility compared to the crystallization method by the heating method in terms of electric mobility. effective.

After crystallizing the amorphous silicon layer, the polysilicon layer is patterned as an active layer by applying a first mask. The active layer patterning process may be formed by a photolithography process.

That is, the photosensitive film is coated on the polysilicon layer and the first mask is applied on the photosensitive film to perform an exposure process, a developing process, and a polysilicon layer etching process. The polysilicon layer may be effectively patterned by dry etching.

After the active layer 302 is formed, as shown in FIG. 5B, the first insulating film 303a including the silicon oxide film or the silicon nitride film is formed on the entire surface of the substrate including the active layer 302 layer by PECVD. Form.

In addition, a conductive layer is formed on the first insulating film 303a by a sputtering method. The conductive layer may be formed of aluminum (Al) or molybdenum (Mo) to form a gate line, a data line, and a storage line, and a double layer of aluminum and molybdenum may be used.

After the conductive layer is formed on the first insulating layer 303a, a photosensitive film (not shown) is coated on the conductive layer, a second mask is applied, and a photolithography is performed to etch the gate electrode 304, the storage electrode 305, and The source electrode 306 is formed at the same time.

In this case, the gate line including the gate electrode 304 and the data line including the source electrode 306 vertically intersect each other, and a portion of the gate line is disposed so that the gate line and the data line are not electrically connected to each other at an intersection area. The removed gate line isolation region is formed. Since the storage line including the storage electrode 305 is also formed on the substrate 301 in parallel with the gate line, a connection with a data line may occur, so that a part of the storage line is also removed to form an isolation region. . Ii of FIG. 5B shows a process of forming the gate line 304a and the data line 306a of the isolation region using the K-K 'line of FIG. 3 as a cutting line, and the data line 306a formed in the isolation region of the gate line. You can see a cross section of

After the gate electrode, the source electrode, and the storage electrode are formed, the active layer 302 is formed by applying the gate electrode 304, the source electrode 306, and the storage electrode 305 formed on the active layer 302 as a mask. The source 320 and the drain region 330 are formed. The source 320 and the drain region 330 may be formed by implanting impurity ions on the active layer. In order to form a P-type thin film transistor, group 3 ions may be used as impurities to be implanted. In order to form an N-type thin film transistor, ions of Group 5 may be used as impurities to be implanted.

Forming the source 302 and the drain region 330 in the active layer 302 allows the ohmic contact with the source and drain electrodes by metalizing the active layer by injecting impurities into the active layer. For sake.

After the source and drain regions are formed by ion implantation, as shown in FIG. 5C, a second insulating layer 303b is formed on the gate electrode 304, the source electrode 306, and the storage electrode 305. do. The second insulating layer 303b may be formed of a silicon oxide film or a silicon nitride film as an interlayer insulating layer, or a double layer of a silicon oxide film or a silicon nitride film may be used.

After forming the second insulating layer, hydrogenation is performed to secure the active layer 302 that is damaged during the process. The hydrogenation treatment stabilizes the polysilicon layer by injecting hydrogen ions into the active layer and bonding hydrogen to a bond group in the polysilicon generated during the process.

Next, as shown in FIG. 5D, first and second contact holes 309 and 310 are formed on the source 320 and the drain region 330.

The forming of the contact hole may include applying a photosensitive organic layer 350 to the second insulating layer 303b, applying a mask to the photosensitive organic layer 350, and then exposing the first photosensitive organic layer to the photosensitive organic layer 350. Developing 350, performing a second exposure by applying a mask on the patterned photosensitive organic film 350, developing the second exposed photosensitive organic film 350, masking the photosensitive film And removing the second insulating layer and the first insulating layer on the source and drain regions 320 and 330.

In this case, as illustrated in ii of FIG. 5D, third and fourth contact holes 310d and 310d are formed on the gate line 304a including the isolation region. The third and fourth contact holes 310d and 310d are formed simultaneously with the contact holes formed on the source and drain regions 320 and 330. Although not shown in the drawing, a contact hole is also formed on the storage line of the isolation region.

Meanwhile, two exposure processes are applied to the photosensitive organic layer 350 in the process of forming the contact hole, and the surface of the photosensitive organic layer 350 is embossed through the first exposure and development process. do. The uneven treatment of the photosensitive organic layer 350 is to allow the reflected light of the reflective electrode formed on the photosensitive organic layer 350 to be uniformly reflected.

The surface of the photosensitive organic film is unevenly processed through the first exposure and development process, and then the second insulating layer 303b is exposed by removing the photosensitive organic film on the source and drain regions through the second exposure and development process.

The contact hole is formed by removing the first insulating layer 303a and the second insulating layer 303b formed over the source and drain regions by applying the photosensitive organic layer 350 patterned through the second exposure and development process as a mask. .

In this case, the first contact hole 310a on the source region of the contact hole is formed to expose the source electrode 306 and the source region 320 together. That is, since the source electrode 306 and the source region 320 are insulated from each other by the first insulating layer 303a, a conductive layer is formed on the first contact hole 310a to be connected to each other.

Meanwhile, as illustrated in ii of FIG. 5D, the first contact hole 310a and the second contact hole 310b are simultaneously formed on the gate line 304a and the storage line (not shown) including the isolation region. Third and fourth contact holes 310c and 310d are formed.

After the contact hole is formed, a pixel electrode material is formed on the entire surface of the substrate including the uneven photosensitive organic layer 307 and the contact hole by a sputtering method.

Next, as illustrated in FIG. 5E, the pixel electrode material is patterned by applying a photolithography process to form the pixel electrode 307. As a result of the photo etching, the pixel electrode material is removed from the contact hole, and the pixel electrode is formed only in the pixel region.

The removal of the pixel electrode formed in the contact hole is performed because the pixel electrode material has conductivity, but the active layer and the source electrode have poor contact characteristics. Therefore, the source electrode and the active layer are deposited by depositing another material having excellent ohmic contact characteristics. Connect.

As described above, the pixel electrode 307 is formed, and then the reflective electrode 309 is formed.

The reflective electrode may use molybdenum (M0) or AlNd having good reflection characteristics. The molybdenum and AlNd have excellent ohmic characteristics with respect to the conductive and active layers.

Therefore, a reflective electrode material made of molybdenum or AlNd is deposited on the entire surface of the substrate on which the pixel electrode and the contact hole are formed, and then the reflective electrode material is patterned by performing a photolithography process. As a result of the patterning, as shown in FIG. 4F, a reflective electrode is patterned in the first contact hole 310a on the source region to electrically connect the source electrode and the source region, and to form a second contact on the drain region 330. A reflective electrode 309 is formed over the hole 310b and a part of the pixel electrode. The drain electrode and the pixel electrode are electrically connected by the reflective electrode.

The reflective electrode is formed on a portion of the pixel electrode to secure a transmissive region of the pixel region.

Meanwhile, as illustrated in ii of FIG. 5F, gate lines including isolation regions are connected to each other through contact holes 310c and 310d and by reflective electrodes.

As a result, the transflective liquid crystal display device according to the present invention can effectively produce the transflective liquid crystal display device even when the reduced photolithography process is applied. In particular, in the manufacturing of the liquid crystal display device, the mask process to be used has to go through a series of processes such as exposure, development process and cleaning process, so that the yield can be increased by reducing the mask process, and defects that may occur in the production process Can be reduced. In addition, although the mask used in the liquid crystal display is expensive, the production cost can be reduced by reducing the number of masks.

1 is a plan view showing a part of an array substrate of a general transflective liquid crystal display device;

2A to 2F are flowcharts showing a manufacturing process along line II ′ of the liquid crystal display shown in FIG. 1.

3 is a plan view showing a part of an array substrate of a transflective liquid crystal display of the present invention;

4A to 4F are flowcharts illustrating a process of manufacturing a liquid crystal display device according to a first embodiment of the present invention.

5A to 5F are flowcharts illustrating a process of manufacturing a liquid crystal display device according to a second embodiment of the present invention.

********** Explanation of symbols for the main parts of the drawings **********

301: substrate 302: active layer

303a and 303b Insulation layer 304 Gate electrode

305: storage electrode 306: source electrode

310a, 310b, 310c, 310d: contact hole

350: photosensitive organic film 307: pixel electrode

309: reflecting electrode 320: source region

Claims (20)

Forming an active layer on the substrate; Forming a gate line, a data line and a storage line on the active layer; Forming a source and a drain region in the active layer; Continuously forming an insulating layer and a pixel electrode material on the gate line, the data line and the storage line; Forming a pixel electrode and a contact hole by applying a mask on the pixel electrode material; And forming a reflective electrode on the pixel electrode. Forming an active layer on the substrate; Forming a gate line, a data line and a storage line on the active layer; Forming a source region and a drain region on the active layer; Forming an insulating layer on the gate electrode, the source electrode, and the storage electrode; Forming a photosensitive organic film on the insulating layer; Forming contact holes on the source and drain regions; Forming a pixel electrode on the photosensitive organic film; And forming a reflective electrode on the contact hole and the pixel electrode. The method of claim 1, wherein the forming of the active layer is performed. Forming an amorphous silicon layer on the substrate; Dehydrogenating the amorphous silicon layer; Crystallizing the amorphous silicon layer; Patterning the crystallized silicon layer comprising a semi-transmissive liquid crystal display device. The method of claim 3, wherein the crystallization step is performed by irradiating a laser onto the amorphous silicon layer. The method of claim 1 or 2, wherein the gate line, the data line, and the storage line are simultaneously formed on the same layer. The method of claim 1, wherein the gate line and the storage line comprise a separation region in which portions of the gate line and the storage line are separated. 3. The method of claim 1 or 2, further comprising forming a buffer layer on the substrate. 7. The method of claim 6, wherein the gate line and the storage line including the isolation region include contact holes. 10. The method of claim 8, wherein the contact holes formed on the gate line and the storage line are formed simultaneously with the contact holes formed on the source and drain regions. 7. The method of claim 6, wherein the gate line and the storage line including the isolation region are connected by the pixel electrode. The method of claim 1, wherein the forming of the source and drain regions is performed. A method of manufacturing a transflective liquid crystal display device comprising the step of implanting impurity ions on the active layer. The method of claim 1, wherein the forming of the pixel electrode and the contact hole is performed. Forming a photosensitive organic layer on the pixel electrode material; Etching the pixel electrode material to form a pixel electrode; Ashing the photosensitive organic film; And removing the insulating film on the source and drain regions. The method of claim 12, wherein forming the pixel electrode First exposing and developing the photosensitive organic film; Second exposure and development of the photosensitive organic film; A method of manufacturing a transflective liquid crystal display device comprising etching the pixel electrode material. The method of claim 12, wherein a part of the pixel electrode is exposed by the ashing process. The method of claim 1, wherein a photosensitive organic film is further formed between the pixel electrode and the reflective electrode. The method of claim 2, wherein the forming of the contact hole is performed. And a first exposure and a second exposure to the photosensitive organic film. The method of manufacturing a transflective liquid crystal display device according to claim 16, wherein the photosensitive film is uneven by the first exposure. The method of claim 2, wherein the contact hole is formed on a source electrode formed by branching from a data line and on the source region. The method of claim 2, wherein the reflecting plate is formed in a part of a unit pixel area. The method of manufacturing a transflective liquid crystal display device according to claim 1 or 2, wherein the active layer is hydrogenated next to the insulating layer forming step.