KR100744397B1 - Manufacturing method of array substrate of transflective liquid crystal display - Google Patents

Abstract

The present invention discloses a method of manufacturing an array substrate of a transflective liquid crystal display device capable of reducing the number of mask processes. The disclosed method comprises the steps of providing a glass substrate partitioned into a thin film transistor region, a reflective region and a transmissive region, forming a gate metal film on the glass substrate, and forming a first metal film for the gate metal film. Forming a gate line including a gate electrode disposed in the thin film transistor region by performing a mask process and an etching process, and sequentially forming a gate insulating film and an amorphous silicon film on the entire surface of the glass substrate on which the gate line including the gate electrode is formed. And forming an active pattern disposed in a thin film transistor region and an amorphous silicon pattern disposed in a reflective region by performing a second mask process and an etching process on the amorphous silicon film, and a front surface of the substrate including the active pattern. Thin film transistor region using shadow mask process on top Selectively forming an Mo film, forming an Al film on the entire surface of the substrate including the Mo, and performing a third mask process and an etching process on the Al film and the Mo film, wherein the Mo film is disposed in the thin film transistor region; Forming a data line including a source / drain electrode formed of a laminated film of an Al film, and simultaneously forming a reflective electrode of an Al film disposed on an amorphous silicon pattern of a reflective region, and forming a reflective electrode of the data line and the Al film. Forming a protective film on the substrate resultant, and causing a spike to occur on the reflective electrode surface of the Al film by the thermal diffusion during the formation of the protective film, and the fourth mask process and the etching process for the protective film Forming a via hole exposing the source / drain electrodes, and forming the pixel electrode IT on the passivation layer including the via hole. And forming a pixel electrode in contact with the source / drain electrodes through a via hole by forming an O film and performing a fifth mask process and an etching process on the pixel electrode ITO film.

Description

Method for fabricating array substrate of transflective type liquid crystal display

1 is a cross-sectional view showing an array substrate of a conventional transflective liquid crystal display device.

2A to 2G are cross-sectional views illustrating processes for manufacturing an array substrate of a transflective liquid crystal display according to an exemplary embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

100: glass substrate 101: the first photosensitive film pattern

102: gate electrode 103: gate insulating film

104: second photoresist pattern 105a: active pattern

105b: amorphous silicon pattern 106: shadow mask pattern

107: Mo film 108: Al film

109: third photoresist pattern 110: source / drain electrodes

111: reflective electrode 112: protective film

113: spiking 114: fourth photosensitive film pattern

115: via hole 116: pixel electrode

The present invention relates to a transflective liquid crystal display device, and more particularly, to a transflective liquid crystal display device which reduces the number of mask processes.

Thin Film Transitors have been developed in place of CRT (Cathode Ray Tube) based on the advantages of low weight, low voltage driving and low power consumption. In particular, thin film transistor liquid crystal displays (hereinafter referred to as TFT-LCDs) realize high quality, large size, and color that are comparable to CRTs, and thus have recently been used in various fields as well as in the notebook PC and monitor market.

The liquid crystal display may be classified into two types, a transmissive liquid crystal display using a backlight as a light source and a reflective liquid crystal display using natural light as a light source.

Since the transmissive liquid crystal display uses a backlight as a light source, it can implement a bright image even in a dark environment, but has a disadvantage in that power consumption is high by using a backlight. On the other hand, the reflective liquid crystal display device consumes a small amount of power because it uses natural light in the surrounding environment without using a backlight, but has a disadvantage in that it is impossible to use it in a dark environment.

Therefore, in order to solve the above problems, by dividing the pixel portion into a transmission region and a reflection region, it operates in a transmissive type to display an image using its own built-in light source where no indoor or external light source exists, In the environment, a transflective liquid crystal display device which operates as a reflection type for displaying an image by reflecting external incident light has been proposed.

In general, a liquid crystal display device includes two substrates (an array substrate and a color filter substrate) on which electrodes are formed and a liquid crystal layer interposed therebetween, and rearranges the liquid crystal molecules of the liquid crystal layer by applying a voltage to the electrode. By controlling the amount of light transmitted by making a predetermined image.

Hereinafter, a method of manufacturing an array substrate of a conventional transflective liquid crystal display will be briefly described with reference to FIG. 1.

Referring to FIG. 1, after depositing a metal film for a gate electrode on a glass substrate 1 partitioned into a thin film transistor TFT region, a reflective region R, and a transmission region T, the gate electrode 2 is patterned. To form a gate line (not shown). Then, after the gate insulating film 3 is deposited to cover the gate line, an undoped amorphous silicon (hereinafter, a-Si) film 4a and a doped amorphous silicon (n + a-Si) film 4b are deposited. Are deposited sequentially, and then the n + a-Si film 4b and the a-Si film 4a are patterned to form an active layer over the gate electrode.

Next, a metal line for source / drain electrodes is deposited on the gate insulating layer 3 including the active layer, and then patterned to form a data line including the source / drain electrodes 5 constituting the thin film transistor. Form. At this time, a portion of the n + a-Si film 4b between the source electrode 5 and the drain electrode is etched together to form a channel.

Next, after the protective film 6 is deposited on the entire surface of the substrate, the via film 7 is etched to form a via hole 7 exposing the source / drain electrodes 5, and then the entire surface of the substrate including the via hole 7. After the ITO film for the pixel electrode is deposited on the substrate, the pixel electrode 8 is contacted with the source / drain electrodes 5 on the transmission region T by patterning it.

Subsequently, after the resin film 9 is deposited on the resultant of the substrate, embossing 10 is formed through exposure and development. Subsequently, after depositing a reflective electrode metal film having excellent reflectivity on the substrate resultant, the reflective electrode metal film portion on the transmission region T is removed by patterning the reflective electrode metal film on the reflective region R. 11) form. This completes the array substrate of the transflective liquid crystal display device.

However, the above-described conventional transflective liquid crystal display device uses a 5-mask process, that is, a gate forming mask process, an active forming mask process, a source / drain forming mask process, a via hole forming mask process, and an ITO pixel to form a transmissive portion. In order to proceed with the formation mask process, and in addition, a two-mask process for the resin film patterning process and the reflective electrode forming process must be further performed to form the reflective part, so that approximately seven mask processes should be performed, and at this time, the mask process Since the photoresist itself includes a photoresist coating, exposure and development process and an etching process, the overall process is not only complicated, but also compared with the manufacturing method of the transmissive and reflective liquid crystal display device in which 5 or 6 mask processes are usually performed. Since the mask process is performed more, there is a problem in that it takes a lot of manufacturing cost and time.

 In particular, in the semi-transmissive TFT-LCD, it is very important to reduce the number of manufacturing steps thereof, especially the number of manufacturing steps of the array substrate. This is because as the number of manufacturing processes is reduced, the manufacturing cost of the TFT-LCD can be reduced, because a larger amount of TFT-LCD can be supplied at a lower price.

Accordingly, an object of the present invention is to provide a method of manufacturing an array substrate of a transflective liquid crystal display device, which is designed to solve the above problems and can reduce the number of mask processes.

Another object of the present invention is to provide a method of manufacturing an array substrate of a transflective liquid crystal display device which can reduce manufacturing cost and time by reducing the number of mask processes.

In order to achieve the above object, the present invention comprises the steps of providing a glass substrate divided into a thin film transistor region, a reflection region and a transmission region; Forming a gate metal film on the glass substrate; Performing a first mask process and an etching process on the gate metal film to form a gate line including a gate electrode disposed in the thin film transistor region; Sequentially forming a gate insulating film and an amorphous silicon film on the entire surface of the glass substrate on which the gate line including the gate electrode is formed; Performing a second mask process and an etching process on the amorphous silicon film to form an active pattern disposed in a thin film transistor region and an amorphous silicon pattern disposed in a reflective region; Selectively forming a Mo film on a thin film transistor region by using a shadow mask process on the entire surface of the substrate including the active pattern; Forming an Al film on the entire surface of the substrate including Mo; A third mask process and an etching process are performed on the Al film and the Mo film to form a data line including a source / drain electrode including a Mo film disposed in a thin film transistor region and a stacked film of an Al film. Forming a reflective electrode of an Al film disposed on the amorphous silicon pattern; Forming a protective film on a substrate resultant on which the reflective electrode of the data line and the Al film is formed, and causing a spike to occur on the surface of the reflective electrode of the Al film by thermal diffusion during formation of the protective film; Performing a fourth mask process and an etching process on the passivation layer to form via holes exposing source / drain electrodes; Forming an ITO film for the pixel electrode on the passivation layer including the via hole; And forming a pixel electrode in contact with a source / drain electrode through a via hole by performing a fifth mask process and an etching process on the pixel electrode ITO film; and providing an array substrate of a transflective liquid crystal display device. do.

Here, the Al film of the source / drain electrode and the reflective electrode is formed in one piece.

Forming the protective film and causing spikes on the surface of the reflective electrode of the Al film may include: depositing a protective film on the entire surface of the glass substrate formed with the data line and the reflective electrode of the Al film; And annealing the protective film at a temperature of 250 to 350 ° C. for 25 to 35 seconds to cause spikes on a surface of the reflective electrode of the Al film.

The spiking is characterized in that it is formed to have a size of 1900 ~ 2100Å.

Forming the passivation layer and spiking the reflective electrode surface of the Al film may include: depositing a passivation film on the entire surface of the glass substrate formed with the reflective electrode of the data line and the Al film; And annealing the protective film at a temperature of 250 to 350 ° C. for 140 to 160 seconds so that spikes occur on the reflective electrode surface of the Al film.

The spiking is characterized in that it is formed to have a size of 2900 ~ 3100Å.

Forming the protective film and causing spikes on the surface of the reflective electrode of the Al film may include: depositing a protective film on the entire surface of the glass substrate formed with the data line and the reflective electrode of the Al film; And annealing the protective film at a temperature of 250 to 350 ° C. for 290 to 310 seconds so that spikes occur on the surface of the reflective electrode of the Al film.

The spiking is characterized in that it is formed to have a size of 6900 ~ 7100Å.

(Example)

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, the technical principle of the present invention will be described. In the present invention, the source / drain electrodes are formed of the metal film for the source / drain electrodes, and the reflective electrodes are integrally formed with the source / drain electrodes.

In addition, an active pattern made of an amorphous silicon film is formed in the thin film transistor region, and an amorphous silicon pattern is formed in the reflective region, and the silicon surface is spiked on the surface of the aluminum by using the thermal diffusion effect of the amorphous silicon pattern and the reflective electrode. ).

In this case, the conventional transflective liquid crystal display device generally requires seven masks in the manufacture of the array substrate thereof. In the present invention, the reflective electrode is used as the source / drain electrode forming process using the source / drain metal film of the thin film transistor. By simultaneously forming and removing the resin process for forming the embossing, the array substrate of the transflective liquid crystal display device can be manufactured by five mask processes.

Accordingly, the present invention can reduce the manufacturing cost by the number of reduced mask process as well as the process simplification.

In detail, FIGS. 2A to 2G are cross-sectional views illustrating a method of manufacturing an array substrate of a transflective liquid crystal display according to an exemplary embodiment of the present invention.

Referring to FIG. 2A, a gate metal film is deposited on a glass substrate 100 partitioned into a thin film transistor region TFT, a reflective region R, and a transmission region T. Referring to FIG. Thereafter, a first photoresist layer pattern 101 covering a gate line formation region including a gate electrode is formed on the gate metal layer using a first mask with respect to the gate metal layer, and then, a first mask is formed. The gate metal film portion not covered by the first photoresist pattern 101 is etched to form a gate line including a gate electrode 102 disposed in the thin film transistor region TFT.

Referring to FIG. 2B, after the first photoresist layer pattern is removed, a gate insulating layer 103 and an amorphous silicon layer are sequentially deposited on the entire surface of the glass substrate on which the gate line including the gate electrode 102 is formed. Here, the amorphous silicon film is flowed at 500sccm and 2800sccm SiH ₃ and H ₂ gas respectively according to the Plasma Enhanced Chemical Vapor Deposition (PECVD) process, the interval is 2cm, the pressure and voltage under the conditions of 300mtorr and 450Ｗ, respectively Perform.

Thereafter, a second photoresist layer pattern 104 is formed on the amorphous silicon layer using the second mask on the amorphous silicon layer to cover the active pattern formation region and the reflection region R. A portion of the amorphous silicon film that is not covered by the second photoresist pattern 104 is etched to form an active pattern 105a and a gate insulating film 103 of the reflective region on the gate insulating film 103 of the TFT. An amorphous silicon pattern 105b is formed on the substrate. Here, the amorphous silicon pattern 105b formed in the reflective region R causes a thermal diffusion effect with the subsequent reflective electrode.

Referring to FIG. 2C, after removing the second photoresist layer pattern, the reflective region R and the transmission region T are covered on the entire surface of the glass substrate including the active pattern 105a and the amorphous silicon pattern 105b. After the shadow mask pattern 106 is formed, a molybdenum (Mo) film 107 is selectively deposited on the thin film transistor region TFT that is not covered by the shadow mask pattern using the shadow mask pattern 106.

Referring to FIG. 2D, after removing the shadow mask pattern, an aluminum (Al) film 108 is deposited on the entire surface of the glass substrate including the Mo film 107. Here, the Al film is flowed at 50 sccm Ar gas at a temperature of 230 ℃ according to the sputtering process, the pressure and voltage are carried out under the conditions of 0.5pascal and 13K 13 respectively.

Next, a data line formation region and a reflection region including a source / drain electrode are formed on the Al layer 108 by using a third mask process on the Al layer 108 and the Mo layer 107. After forming the third photoresist pattern 108 covering R), the Al film 108 and the Mo film 107 that are not covered by the third photoresist pattern 109 are etched to form a thin film transistor region ( While forming a data line (not shown) including a source / drain electrode 110 composed of a laminated film of an Mo film 107 and an Al film 108 disposed on a TFT, an amorphous silicon pattern 105b of a reflection region is formed. The reflective electrode 111 of the Al film disposed thereon is formed. At this time, the Al film of the source / drain electrode 110 and the reflective electrode 111 is formed in one piece.

Here, the present invention forms the source / drain electrode 110 with the Mo film 107 and the Al film 108, and simultaneously forms the reflective electrode 111, thereby manufacturing an array substrate of a conventional transflective liquid crystal display device. In this case, the mask process for forming the source / drain electrodes and the reflective electrode, that is, one mask process, can be reduced as compared with the two mask processes.

Referring to FIG. 2E, after removing the third photoresist layer pattern, a protective layer 112 is deposited on the resultant glass substrate on which the reflective electrode 111 of the data line and the Al layer is formed. Then, annealing is performed on the passivation layer 112. At this time, spikes (113), that is, irregularities occur on the surface of the reflective electrode 111 of the Al film.

As such, the spiking 113 may increase the diffuse reflection efficiency of the reflective electrode 111 formed in the reflective region R, while reducing the specular reflection of the incident light.

In detail, when the annealing is performed on the passivation layer 112, an Al silicon pattern 105b and a reflective electrode 111 of the Al layer are thermally diffused, so that Si of the amorphous silicon pattern 105b is agglomerated toward the Al layer. As the ductility is relatively weak, the surface rises, which is called spike phenomenon. On the other hand, the size of the spiking depends on the conditions of the annealing.

For example, when the protective film 112 is annealed at a temperature of 250 to 350 ° C. for 25 to 35 seconds, the spiking has a size of 1900 to 2100 μs and the protective film 112 is at a temperature of 250 to 350 ° C. When the annealing is performed at 140 to 160 seconds at, the spiking has a size of 2900 to 3100 μs, and when the protective film 112 is annealed at a temperature of 250 to 350 ° C. for 290 to 310 seconds, the spiking is performed. It has a size of 6900-71007.

 In the present invention, when the annealing is performed on the passivation layer 112, a thermal diffusion operation occurs between the amorphous silicon pattern 105b formed in the reflective region R and the reflecting electrode 111 made of an Al film, thereby reflecting the reflective electrode 111. Spikes 113, that is, irregularities occur on the surface of the. Therefore, the method of manufacturing an array substrate of a conventional transflective liquid crystal display device by eliminating the resin embossing forming process of depositing a resin under the reflective film and patterning the resin using a mask in order to generate irregularities in the conventional reflective region R. Compared to this, one mask process can be reduced.

Accordingly, the manufacturing cost can be reduced as well as the number of mask processes saved, and the process can be simplified.

Referring to FIG. 2F, after forming the fourth photoresist layer pattern 114 exposing a portion of the source / drain electrode 110 on the passivation layer 112 by using a fourth mask process with respect to the passivation layer 112, By using this, the exposed portion of the passivation layer 112 is etched to form a via hole 115.

Referring to FIG. 2G, after removing the fourth photoresist pattern, an ITO film for pixel electrode is deposited on the passivation layer 112 including the via hole 115. Thereafter, a fifth photoresist pattern (not shown) covering each pixel region is formed on the ITO film for the pixel electrode by using a fifth mask process on the ITO film for the pixel electrode, and then the fifth photoresist pattern is used. A portion of the ITO film for the pixel electrode not covered by the photoresist pattern is etched to form the pixel electrode 116 contacting the source / drain electrode 110 through the via hole 115, and then the fifth photoresist pattern is removed. An array substrate of a transflective liquid crystal display device according to an embodiment of the present invention is manufactured.

As described above, in the past, two mask processes were performed to form the source / drain electrodes and the reflective electrode. However, in the present invention, the source / drain electrodes are formed at the same time as the source / drain electrodes are formed of the metal film for the source / drain electrodes. By forming the reflective electrode integrally with the, it is possible to reduce one mask process compared with the conventional process.

In addition, the resin film is conventionally patterned by using a mask after deposition in order to form irregularities in the reflective region. However, in the present invention, the amorphous silicon pattern of the reflective region and the thermal diffusion of the reflective electrode are used to spy on the surface of the Al film. By generating spiking, ie, unevenness, one mask process can be reduced as compared with the conventional process.

As mentioned above, although the present invention has been illustrated and described with reference to specific embodiments, the present invention is not limited thereto, and the scope of the following claims is not limited to the scope of the present invention. It can be easily understood by those skilled in the art that can be modified and modified.

As described above, the present invention simultaneously forms a source / drain electrode and a reflective electrode with a metal film for a source / drain electrode, and utilizes the thermal diffusion effect between the amorphous electrode film pattern formed in the reflective electrode and the reflective region. By generating spiking, ie, embossing, on the surface, the present invention can reduce the number of masks compared to the prior art, which requires seven masks by making an array substrate by using only about five mask processes. As a result, the manufacturing cost can be reduced by the reduced number of masks and the number of processes, and the process can be simplified.

Claims (8)

Providing a glass substrate partitioned into a thin film transistor region, a reflection region and a transmission region; Forming a gate metal film on the glass substrate; Performing a first mask process and an etching process on the gate metal film to form a gate line including a gate electrode disposed in the thin film transistor region; Sequentially forming a gate insulating film and an amorphous silicon film on the entire surface of the glass substrate on which the gate line including the gate electrode is formed; Performing a second mask process and an etching process on the amorphous silicon film to form an active pattern disposed in a thin film transistor region and an amorphous silicon pattern disposed in a reflective region; Selectively forming a Mo film on a thin film transistor region by using a shadow mask process on the entire surface of the substrate including the active pattern; Forming an Al film on the entire surface of the substrate including Mo; A third mask process and an etching process are performed on the Al film and the Mo film to form a data line including a source / drain electrode including a Mo film disposed in a thin film transistor region and a stacked film of an Al film. Forming a reflective electrode of an Al film disposed on the silicon pattern; Forming a protective film on a substrate resultant on which the reflective electrode of the data line and the Al film is formed, and causing a spike to occur on the surface of the reflective electrode of the Al film by thermal diffusion during formation of the protective film; Performing a fourth mask process and an etching process on the passivation layer to form via holes exposing source / drain electrodes; Forming an ITO film for the pixel electrode on the passivation layer including the via hole; And Performing a fifth mask process and an etching process on the pixel electrode ITO layer to form a pixel electrode contacting the source / drain electrode through a via hole; Array substrate manufacturing method of a transflective liquid crystal display device comprising a. The method of claim 1, And the Al film of the source / drain electrode and the reflective electrode is integrally formed. The method of claim 1, Forming the protective film and causing the spike to occur on the surface of the reflective electrode of the Al film, Depositing a protective film on the entire surface of the glass substrate formed with the reflective electrode of the data line and the Al film; And And annealing the protective film at a temperature of 250 to 350 ° C. for 25 to 35 seconds so that spikes occur on a surface of the reflective electrode of the Al film. The method of claim 3, wherein The spiking method of manufacturing an array substrate of a transflective liquid crystal display device, characterized in that formed to have a size of 1900 ~ 2100Å. The method of claim 1, Forming the protective film and causing the spike to occur on the surface of the reflective electrode of the Al film, Depositing a protective film on the entire surface of the glass substrate formed with the reflective electrode of the data line and the Al film; And And annealing the protective film at a temperature of 250 to 350 ° C. for 140 to 160 seconds so that spikes occur on a surface of the reflective electrode of the Al film. The method of claim 5, And wherein the spiking is formed to have a size of 2900-3100 Å. The method of claim 1, Forming the protective film and causing the spike to occur on the surface of the reflective electrode of the Al film, Depositing a protective film on the entire surface of the glass substrate formed with the reflective electrode of the data line and the Al film; And And annealing the protective film at a temperature of 250 to 350 ° C. for 290 to 310 seconds so that spikes occur on a surface of the reflective electrode of the Al film. The method of claim 7, wherein The spiking method of manufacturing an array substrate of a transflective liquid crystal display device, characterized in that formed to have a size of 6900 ~ 7100Å.

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