KR101067947B1 - Vertical alignment mode liquid crystal display device and method of fabricating thereof - Google Patents

Abstract

A method of manufacturing a liquid crystal display device according to the present invention is to minimize the number of processes, providing a first substrate and a second substrate, forming a driving element on the first substrate, and insulating the entire first substrate. Forming a layer, etching the insulating layer by a photoresist pattern to form projections for making the protective layer and the electric field formed around the symmetrical, forming a pixel electrode on the first substrate; Forming a common electrode on the second substrate.

Vertical alignment, electric field, protrusion, protective layer, lift off, diffraction mask

Description

Vertical alignment mode liquid crystal display device and manufacturing method therefor {VERTICAL ALIGNMENT MODE LIQUID CRYSTAL DISPLAY DEVICE AND METHOD OF FABRICATING THEREOF}

1 is a plan view of a conventional vertical alignment mode liquid crystal display device.

(A) is sectional drawing along the II 'line | wire of FIG.

(B) is sectional drawing along the II-II 'line | wire of FIG.

3 (a) to 3 (d) show a manufacturing method of a conventional vertical alignment mode liquid crystal display device.

4 (a) to 4 (g) illustrate a method of manufacturing a vertical alignment mode liquid crystal display device according to an embodiment of the present invention.

5 is a cross-sectional view showing another structure of the vertical alignment mode liquid crystal display device according to the present invention;

6A to 6G illustrate a method of manufacturing a vertical alignment mode liquid crystal display device according to another exemplary embodiment of the present invention.

7 is a cross-sectional view showing still another structure of a vertical alignment mode liquid crystal display device according to the present invention;

Explanation of symbols on main parts of drawing

104: gate electrode 105: semiconductor layer                 

106: source electrode 107: drain electrode

110: common electrode 120, 130: substrate

122: gate insulating layer 124: protective layer

132: black matrix 134: color filter layer

138: common electrode 139: projection

140: liquid crystal layer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical alignment mode liquid crystal display device and a method of manufacturing the same. In particular, a vertical alignment mode liquid crystal display device and a method for manufacturing the same may be manufactured by reducing protrusions by forming protrusions formed of a protective layer on a thin film transistor substrate. It is about.

Recently, with the development of various portable electronic devices such as mobile phones, PDAs, and notebook computers, there is a growing demand for flat panel display devices for light and thin applications. Such flat panel displays are being actively researched, such as LCD (Liquid Crystal Display), PDP (Plasma Display Panel), FED (Field Emission Display), VFD (Vacuum Fluorescent Display), but mass production technology, ease of driving means, Liquid crystal display devices (LCDs) are in the spotlight for reasons of implementation.

The liquid crystal display device is manufactured by bonding a thin film transistor array substrate and a color filter substrate to each other, and forming a liquid crystal layer between the thin film transistor array substrate and the color filter substrate.

In the thin film transistor array substrate, pixels are arranged in a matrix form, and a thin film transistor, a pixel electrode, and a capacitor are formed in the unit pixel, and the color filter substrate is a common electrode and an actual color for applying an electric field to the liquid crystal layer together with the pixel electrode. An RGB color filter and a black matrix are implemented to implement the.

On the other hand, an alignment layer having an alignment control force is formed on the opposite surface of the thin film transistor array substrate and the color filter substrate so that the liquid crystal molecules of the liquid crystal layer are aligned in a predetermined direction. The liquid crystal molecules oriented as described above are rotated by dielectric anisotropy when the electric field is formed between the pixel electrode formed for each unit pixel of the thin film transistor array substrate and the common electrode formed on the front surface of the color filter substrate, thereby passing light for each unit pixel. They can be turned on or off to display text or images. Such a method of displaying an image by driving liquid crystal molecules is called TN mode (Twisted Nematic mode). However, such a TN mode liquid crystal display device has a disadvantage that the viewing angle is narrowed. This viewing angle problem is caused by the refractive anisotropy of the liquid crystal molecules. In the TN mode, light transmittance is symmetrically distributed in the left and right viewing angles, but light transmittance is asymmetrically distributed in the vertical direction. At the viewing angle in the vertical direction, a range in which the image is reversed is generated and the viewing angle is narrowed.

In order to solve the viewing angle problem, a multi-domain that compensates the viewing angle by dividing the pixel into at least two domains such as two domain TN (TDTN) or domain divided TN (DDTN) and changing the field of view angle of each domain domain) Liquid crystal display devices have been proposed.

However, in the case of the multi-domain liquid crystal display device, since the alignment of liquid crystal molecules in each domain must be different, a rubbing process must be performed in each domain. For example, in the case of 2-domain, photoresist is laminated on the second domain of the alignment layer to rub the second domain in the set direction in a state in which the second domain is blocked, thereby rubbing in the setting direction in the first direction. To form. Thereafter, the photoresist of the second domain is removed, the photoresist is formed in the first domain, and then the second domain is rubbed to provide the alignment control force in the set direction. After rubbing of the second domain, the photoresist of the first domain is removed by a developing process.

As described above, in the multi-domain, two photo processes using a photoresist are required to rub one pixel (ie, one substrate), thereby increasing the manufacturing process and increasing the manufacturing cost. In addition, since a photo process such as a photoresist phenomenon affects the alignment film, there is a problem in that the quality of the manufactured liquid crystal display device is degraded.

A liquid crystal display device having a wide viewing angle structure proposed to solve the problem of the multi-domain as described above is a vertical alignment mode liquid crystal display device. In the VA mode, when the voltage is not applied, the long axes of the liquid crystal molecules are arranged perpendicular to the alignment layer, and when voltage is applied, the liquid crystal molecules having negative dielectric anisotropy are oriented obliquely with respect to the electric field. The long axis moves in a horizontal direction from a direction perpendicular to the vertical alignment layer to transmit light.                         

The VA mode liquid crystal display device is superior to the TN mode liquid crystal display device in terms of contrast ratio, response speed, and the like, and divides the alignment direction of the liquid crystal molecules into a plurality of directions, and is highly effective when using a compensation film. It has the advantage of realizing the viewing angle.

1 is a view showing the structure of a conventional VA mode liquid crystal display device. Although the liquid crystal display is substantially composed of a plurality of pixels, only one pixel is illustrated in the drawings for convenience of description.

As shown in the figure, the pixel defined by the gate line 1 and the data line 2 is divided into two regions A and B. As shown in FIG. The regions A and B are domain regions in which liquid crystal molecules are oriented in different directions, and the viewing angles in each domain region are compensated for each other, thereby improving viewing angle characteristics.

On the other hand, the pixel includes a thin film transistor 3 formed at an intersection of a gate line 1 to which a scan signal is applied from an external driving circuit and a data line 2 to which an image signal is applied. The thin film transistor 3 is connected to the gate line 1 to form a gate electrode 4 to which a scan signal is applied, and is formed on the gate electrode 4 to be activated as a scan signal is applied to the gate electrode 2. The semiconductor layer 5 includes a source electrode 6 and a drain electrode 7 formed on the semiconductor layer 5.

The pixel electrode 10 is formed in the pixel to be connected to the drain electrode 7 to activate the liquid crystal (not shown) by applying an image signal as the semiconductor layer 5 is activated. At this time, reference numeral 32 shown in the drawing is a black matrix, which is formed in the region of the thin film transistor 3, the gate line 1 and the data line 2 to prevent light from passing through the region. .

The VA mode liquid crystal display device configured as described above will be described in more detail with reference to FIGS. 2 (a) and 2 (b).

FIG. 2A is a cross-sectional view taken along the line II ′ of FIG. 1 to show the structure of the thin film transistor, and FIG. 2B is a cross-sectional view taken along the line II-II ′ of FIG. 2 to show the structure of the pixel.

As shown in FIG. 2A, the thin film transistor 3 includes a gate electrode 4 formed on a first substrate 20 made of a transparent insulating material such as glass, and a portion of the first substrate 20. And a gate insulating layer 22 formed over, the semiconductor layer 5 formed on the gate insulating layer 22, and a source electrode 6 and a drain electrode 7 formed on the semiconductor layer 5. A passivation layer 24 is formed over the entire first substrate 20 on which the transistor 3 is formed. The pixel electrode 10 is formed on the passivation layer 24, and a contact hole is formed in the first passivation layer 24 so that the pixel electrode 10 is formed through the contact hole. Is electrically connected to the drain electrode 7.

On the other hand, the second substrate 30 has a black matrix 32 for preventing light from being transmitted to the image non-display area in which the thin film transistor 3 is formed, and R (Red) formed in the pixel to implement color; A color filter layer 34 of G (Green) and B (Blue) and a common electrode 38 forming an electric field with the pixel electrode 10 when an image signal is applied on the color filter layer 34. In addition, a liquid crystal layer 40 is formed between the first substrate 20 and the second substrate 30. Although not shown in the drawing, an alignment layer for orienting liquid crystal molecules is formed on the pixel electrode 10 and the common electrode 38.

As shown in FIG. 2B, protrusions 39 made of an insulating material are formed at the boundary between the first region A and the second region B on the common electrode 38. As such, the reason why the protrusion 39 is formed on the common electrode 38 between the first and second regions A and B is because of the electric field E between the pixel electrode 10 and the common electrode 38. ) To distort As shown in the figure, an electric field between the pixel electrode 10 and the common electrode 38 is formed symmetrically about the protrusion 39 by the protrusion 39. Accordingly, the liquid crystal molecules arranged along the electric field are also arranged symmetrically along the slit, so that the first region A and the second region B are two domains having different alignment directions from each other.

However, in the aforementioned multi-domain liquid crystal display device, a rubbing process is required twice (or more), whereas in the VA mode liquid crystal display device, a rubbing process is not necessary and a separate photo process is not necessary. Therefore, the manufacturing process can be simplified and the breakage of the alignment film caused by the photo process can be prevented.

The manufacturing method of the liquid crystal display device having the above structure will be described with reference to 3 (a) to FIG. 3 (d). In this case, the thin film transistor and the pixel region are simultaneously shown for convenience of description.

First, as shown in FIG. 3A, a metal is stacked on the first substrate 20 and then etched to form a gate electrode 4. Subsequently, as shown in FIG. 3B, a gate insulating layer 22 is formed over the entire first substrate 20, and then semiconductors are stacked and etched on the gate electrode 4. ), The metal is laminated and etched to form a source electrode 6 and a drain electrode 7 on the semiconductor layer 5.

Thereafter, as shown in FIG. 3C, the protective layer 24 is formed over the entire first substrate 20, and then the pixel electrode 10 is formed on the protective layer 24 of the pixel region.

Meanwhile, as shown in FIG. 3D, the black matrix 32 and the color filter layer 34 are formed on the second substrate 30. Subsequently, after forming the common electrode 38 on the color filter layer 34, a photosensitive resin or the like is laminated in the pixel region (that is, a boundary region of two domains), and then the protrusion 39 is formed.

Thereafter, the first substrate 20 and the second substrate 30 are bonded to each other by a sealing material, and then a liquid crystal is injected between the first substrate 20 and the second substrate 30 to form a liquid crystal layer 40. To form.

The thin film transistor or pixel electrode formed on the first substrate 20 is formed by a photolithography process using a photoresist and a mask. In general, the complexity of a manufacturing process of a liquid crystal display device or a thin film transistor is determined by the number of photo processes, that is, the number of masks used.

In general, in a TN mode liquid crystal display device, a photo process using a mask is mainly used to form a thin film transistor and a pixel electrode on a first substrate and a black matrix on a second substrate. More masks are needed to form

Accordingly, in the above-described method for manufacturing a VA mode liquid crystal display device, a mask for a gate electrode, a mask for a semiconductor layer, a mask for a source electrode and a drain electrode, a mask for a contact hole of a protective layer, a mask for a pixel electrode, a mask for a black matrix, and an RGB color layer It is a 10-mask process that uses a total of 10 masks such as a mask and a protrusion forming mask (a well-known 5-mask thin film transistor array process and a 4-mask color filter process + 1-mask protrusion process). By the way, in order to simplify the manufacturing method of the VA mode liquid crystal display, a low mask method is currently being studied in which the number of masks is reduced to less than five (except a four-mask color filter process), but substantially less than five. The process of using the mask is not realized.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and an object of the present invention is to provide a vertically aligned liquid crystal display device and a method for manufacturing the same, which can simplify the manufacturing process and reduce the manufacturing cost by reducing the number of processes.

In order to achieve the above object, the liquid crystal display device according to the present invention includes a first substrate and a second substrate divided into a first region and a second region, a driving element formed in the first region of the first substrate, A first protective layer formed on the driving element, at least one second protective layer formed in the second region and distorting an electric field, a first electrode formed in the second region, and formed on the second substrate; It consists of a 2nd electrode which forms an electric field between 1 electrode, and the liquid crystal layer formed between the said 1st board | substrate and a 2nd board | substrate.

The electric field is distorted by the second protective layer so that the electric field between the first electrode and the second electrode is symmetric about the second protective layer. The first protective layer and the second protective layer are made of the same material, and may be formed of an organic layer or a double layer of an inorganic layer / organic layer.

At least one slit is formed in the common electrode of the second substrate to form a plurality of domains having different alignment directions together with the second protective layer.

In addition, the liquid crystal display device manufacturing method according to the present invention comprises the steps of providing a first substrate consisting of a first region and a second region, forming a driving element in the first region, and the entire first substrate Forming a protective layer, stacking and developing a photoresist on the protective layer to form a first photoresist pattern and a second photoresist pattern in a first region and a second region, respectively; Etching the protective layer using the second photoresist pattern, laminating a transparent conductive material over the entire first substrate, removing the first photoresist pattern and the second photoresist pattern, and Forming projections and pixel electrodes.

The driving device is a thin film transistor, comprising: forming a gate electrode on a first substrate, forming a gate insulating layer on the first substrate, forming a semiconductor layer on the gate insulating layer, and forming the semiconductor layer. Forming a source electrode and a drain electrode thereon.

In addition, the thin film transistor may be formed using a diffraction mask. In this case, the forming of the thin film transistor may include forming a gate electrode on a first substrate and forming a gate insulating layer on the first substrate. Stacking a semiconductor and a metal layer on the gate insulating layer, laminating a first photoresist on the metal layer, and then forming a first photoresist pattern using a diffraction mask, and forming the first photoresist pattern. Etching the semiconductor and the metal layer by using the metal layer; acing the first photoresist pattern to remove photoresist in a partial region; and etching the metal layer by using the aced first photoresist pattern. And forming a source electrode and a drain electrode.

The gate insulating layer is etched simultaneously with the passivation layer, and the first photoresist pattern is positioned only on a part of the drain electrode, and a part of the drain electrode is exposed to the outside by etching the passivation layer so that the pixel electrode is connected to the drain electrode. do. The transparent conductive material is stacked on the first photoresist pattern and the second photoresist pattern so as to retoff the first photoresist pattern and the second photoresist pattern.

In the present invention, a VA mode liquid crystal display device using four masks is manufactured. In the present invention, the VA mode liquid crystal display device is fabricated using three masks. In this case, the 4-mask process or the 3-mask process excludes a color filter process using four masks. In the present invention, the field distortion protrusion is formed on the first substrate on which the thin film transistor is formed. The protrusion is formed of a protective layer or a gate insulating layer / protective layer, and is formed when etching the protective layer or the gate insulating layer / protective layer. Since the patterning of the pixel electrode is lifted up when etching the protective layer, the etching of the protective layer and the patterning of the pixel electrode can be performed by one photo process (that is, by one mask). Can be reduced.

Hereinafter, the VA mode liquid crystal display device according to the present invention will be described in detail with reference to the accompanying drawings.

4 (a) to 4 (g) illustrate a manufacturing method of a VA mode liquid crystal display device according to an exemplary embodiment of the present invention. The manufacturing method of the figure is a conventional 5-mask thin film transistor array process. .

First, as shown in FIG. 4A, a gate electrode 104 is formed on a first substrate 120 made of a transparent insulating material such as glass and including a TFT region and a pixel region. The gate insulating layer 122 is formed over the entire substrate 120. The gate electrode 104 is formed by depositing a metal such as Al, Al alloy, or Cu over the entire first substrate 120 by sputtering or evaporation, and then using a photoresist and a mask. The gate insulating layer 122 is formed by stacking an insulating material such as SiNx or SiO ₂ by a chemical vapor deposition (CVD) method.

In this case, the gate electrode 104 may be formed of a single metal layer as described above, but may be formed of a double layer such as Al / Cr. In this case, the gate electrode 104 can be formed by sequentially stacking Al and Cr and then performing a photo process. Although not shown in the drawing, gate lines are simultaneously formed when the gate electrode 104 is formed.

Subsequently, as illustrated in FIG. 4B, a semiconductor, such as Si, is stacked and etched on the gate insulating layer 122 to form a semiconductor layer 105, and then a source electrode 106 and a drain electrode (above it). 107). When forming the source electrode 106 and the drain electrode 107, the data electrode 102 is also formed at the same time. The semiconductor layer 105 is formed by laminating Si or the like by CVD and then etching the source electrode 106 and the drain electrode 107 by sputtering a metal such as Al, Al alloy, Cu, Mo, Cr, or the like. It is formed by laminating and etching into a single layer or a plurality of layers by a vapor deposition method.

Subsequently, as shown in FIG. 4C, the protective layer 124 is formed by stacking an organic material such as BCB (Benzo Cyclo Butene) or photoacryl over the entire first substrate 120. Subsequently, as shown in FIG. 4 (d), a photoresist is applied on the protective layer 124 and ultraviolet rays are developed after blocking a portion of the area with a mask to develop the protective layer 124. A photoresist pattern 150 is formed thereon. In this case, the photoresist pattern 150 is formed on the TFT region, the pixel region, and the data line 102. On the other hand, although not shown in the figure, the protective layer 124 may be composed of a double layer of an inorganic layer and an organic layer made of SiNx or SiO ₂ .

Thereafter, as shown in FIG. 4E, the protective layer 124 is etched while the protective layer 124 is blocked by the photoresist pattern 150, so that a partial region (ie, the photoresist pattern ( Protective layer 124 of the non-blocking region). The gate insulating layer 122 of the pixel region is exposed to the outside by removing the protective layer 124. In addition, part of the drain electrode 107 of the TFT region is also exposed to the outside. Subsequently, when a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO) is laminated by a sputtering method or a deposition method, the upper portion of the photoresist pattern 150, the upper portion and the outer portion of the gate insulating layer 122 may be formed. The pixel electrode 110 is formed on the exposed drain electrode 107.

Subsequently, as shown in FIG. 4F, when the photoresist pattern 150 having the electrode 110 formed thereon is lifted off, a protective layer may be formed on the TFT region and the data line 102. Although 124 is formed, all other protective layers 124 are removed in the pixel area except the protective layer 139 having a predetermined width. The protective layer 139 formed in the pixel region distorts the electric field of the VA mode liquid crystal display, thereby forming an symmetrical electric field in an area adjacent to the protective layer 139. That is, in the present invention, the protrusion 139 is made of an organic material such as BCB or photoacryl, and the protrusion 139 is preferably formed to have a height of about 1 to 4 μm from the pixel electrode 110. At this time, when the protective layer 224 is composed of an inorganic layer and an organic layer, the protrusion 139 will also be composed of a double layer consisting of an inorganic layer and an organic layer.

On the other hand, as shown in Figure 4 (g), the second substrate 130 is formed with a black matrix 132 made of Cr / CrOx, and the color filter layer 134 of R, G, B. Subsequently, a transparent conductive material such as ITO or IZO is stacked on the color filter layer 134 to form a common electrode 138. Although not shown in the figure, the color filter layer may be reported on the color filter layer 134 and an overcoat layer or a protective layer for planarization may be formed.

After the second substrate 130 manufactured as described above is bonded to the first substrate 120 by a sealing material, a liquid crystal having negative dielectric anisotropy is formed between the first substrate 120 and the second substrate 130. Injecting to form the liquid crystal layer 140. In this case, the liquid crystal layer may be formed by dropping liquid crystal onto the first substrate 120 or the second substrate 130 and then bonding the first substrate 120 and the second substrate 130 together.

As described above, in the VA-mode liquid crystal display device manufacturing method of the present invention, the protective layer 124 is etched to expose the drain electrode to the outside, and then the pixel formed on the gate insulating layer 122 and a part of the drain electrode 107. Since the remaining electrodes except for the electrode 110 are removed when the photoresist pattern is lifted off, the mask for the pixel electrode is not necessary. In addition, since the protrusion 139 is formed at the same time as the protective layer 124, a mask for forming the protrusion 139 is not required. Therefore, the VA mode liquid crystal display device manufacturing method of the present invention requires a total of four masks, a mask for a gate electrode, a mask for a semiconductor layer, a mask for a source electrode and a drain electrode, and a mask for etching a protective layer. Therefore, two masks to be used are reduced compared to the conventional manufacturing method, which required six masks. As a result, the manufacturing process can be greatly simplified and the manufacturing cost can be greatly reduced.

As shown in FIG. 4G, in the VA mode liquid crystal display according to the present invention, the protrusion 139 is formed in the pixel region of the first substrate 120 with the same material as that of the protective layer 124. The protrusion 139 distorts the electric field E formed between the pixel electrode 110 and the common electrode 138 so that the electric field E is symmetric about the protrusion 139. Accordingly, the liquid crystal molecules arranged along the electric field are also symmetrically arranged along the protrusion 139, so that two domains having different alignment directions of the liquid crystal molecules are formed around the protrusion 139.

In the drawing, although one protrusion 139 is formed to form two domains, a plurality of protrusions 139 may be formed on the first substrate 120 to form three or more domains.

Meanwhile, the pixel electrode 110 may be formed on the first substrate 120 instead of the gate insulating layer 122 as shown in FIG. 5. In this case, the protective layer 124 and the gate insulating layer 122 are etched by the photoresist pattern 150 to form the pixel electrode 110 on the first substrate 120. In this case, the pixel electrode 110 is formed on a portion of the drain electrode 107 so that a signal input through the thin film transistor is applied to the pixel electrode 110. In addition, the protrusion 139 is formed by etching the gate insulating layer 122 and the protective layer 124. That is, the protrusion 139 is made of the same material as the gate insulating layer 122 and the protective layer 124.

6A to 6G illustrate a method of manufacturing a VA mode liquid crystal display device according to another exemplary embodiment of the present invention.

First, as shown in FIG. 6A, a gate electrode made of a single layer or a plurality of layers of Al, Al alloy, Cu, Cr, or the like is formed on a first substrate 220 including a TFT region and a pixel region. After forming 204, the gate insulating layer 222, the semiconductor 205a, and the metal layer 206a are sequentially stacked on the entire first substrate 120.

Subsequently, as illustrated in FIG. 6B, when the photoresist layer 250a is laminated on the metal layer 106a and then irradiated with ultraviolet rays using a diffraction mask, the photoresist is removed from the pixel region and the TFT is removed. The photoresist pattern 250 is formed in the region. At this time, since the intensity of the light irradiated to the TFT region is changed by the slit formed in the diffraction mask, the photoresist on the upper portion of the gate electrode 204 is removed while a portion of the photoresist on the upper side of the gate electrode 204 is removed. The photoresist is left as it is, a photoresist pattern 250 having a different thickness is formed.

When the metal layer 205a and the semiconductor 206a are continuously etched while the metal layer 205a is blocked by the photoresist pattern 250 as described above, as shown in FIG. 205 and metal pattern 206b are formed. In this case, a data line 202b is also formed, and the semiconductor layer 202a remains under the data line 202b. Then, when the photoresist pattern 250 is ashed, the thin photoresist on the gate electrode 204 is removed while only a part of the photoresist on both sides is removed.

Subsequently, as shown in FIG. 6 (d), the metal pattern 206b is etched using the photoresist pattern 250 with a portion removed, and the photoresist pattern 250 is removed to form the semiconductor layer 205. The source electrode 206 and the drain electrode 207 are formed. Thereafter, an organic material or an inorganic material / organic material such as BCB or photoacryl is laminated on the first substrate 220 to form a protective layer 224, and a photoresist is laminated and developed on the photoresist pattern 252. ). In this case, the photoresist pattern 253 is formed on the TFT region, the pixel region, and the data line 202b.

Thereafter, as shown in FIG. 6E, the gate insulating layer 222 and the protective layer 224 are etched in a partial region while the protective layer 224 is blocked by the photoresist pattern 252. The gate insulating layer 222 and the protective layer 224 are removed. By removing the gate insulating layer 222 and the protective layer 224, a portion of the first substrate 220 and the drain electrode 207 of the TFT region of the pixel region is exposed to the outside. Subsequently, a transparent conductive material such as ITO or IZO is laminated by a sputtering method or a deposition method to form an upper portion of the photoresist pattern 252, a pixel region of the first substrate 220, and an upper portion of the drain electrode 207 exposed to the outside. The pixel electrode 210 is formed on the substrate.

Subsequently, as shown in FIG. 6F, when the photoresist pattern 150 is lifted off, a protective layer 224 is formed on the TFT region and the data line 202 and protrusions having a predetermined width in the pixel region. 239 is formed. At this time, the protrusion 239 is formed of a double layer formed by etching the gate insulating layer 222 and the protective layer 224.

As illustrated in FIG. 6G, the black matrix 232 and the color filter layers 234 of R, G, and B are formed on the second substrate 230. Subsequently, a transparent conductive material such as ITO or IZO is stacked on the color filter layer 234 to form a common electrode 238, and then the first and second substrates 220 and 230 are bonded to each other by a sealing material. The liquid crystal layer 140 is formed between the first substrate 220 and the second substrate 230 to complete the VA mode liquid crystal display device.

As described above, in the VA mode liquid crystal display device of this embodiment, a total of three masks are used, a mask for the gate electrode, a mask for the semiconductor layer 205 and the source / drain electrodes 206 and 207, and a mask for the organic protective layer 224 pattern. do. That is, it is a 3-mask process. Therefore, it is possible to reduce the three masks compared to the conventional manufacturing method of the VA mode liquid crystal display device in which six masks are used. Therefore, the manufacturing method is greatly simplified as compared with the prior art.

On the other hand, the VA mode liquid crystal display device of FIG. 6 (g) produced by this embodiment has the same structure as the VA mode liquid crystal display device of the structure shown in FIG. Therefore, the pixel region is divided into a plurality of domains having symmetric electric fields by at least one protrusion 239 formed in the pixel region, thereby improving viewing angle characteristics. In addition, the VA mode liquid crystal display device of this embodiment may be formed in the structure shown in Fig. 4G. That is, the pixel electrode 210 of the pixel region may be formed on the gate insulating layer 222. In this case, the same process as in FIGS. 6A to 6G is performed except that only the protective layer 224 is etched by the photoresist pattern 252 of FIG.

7 is a view showing another structure of the VA mode liquid crystal display device according to the present invention. In the VA mode liquid crystal display device shown in Figs. 4 (g) and 5 (g) (or Fig. 6 (g)), protrusions formed of a protective layer or a gate insulating layer / protective layer are formed on the first substrate to form a liquid crystal layer. Distort the applied electric field. On the other hand, in the VA mode liquid crystal display device having the structure shown in FIG. 7, not only the protrusion 239 formed of the protective layer 224 or the gate insulating layer / protective layers 222 and 224 is formed on the first substrate 220. Slits 272a and 272b from which a part of the common electrode 238 is removed are formed on the second substrate 230.

Like the projections 239, the slits 272a and 272b are used to distort the electric field in the pixel region to improve viewing angle characteristics. The slits 272a and 272b are formed by etching the photoelectrode after forming the common electrode 238. Therefore, in the VA mode liquid crystal display device having this structure, one more slit forming mask is required, which results in a 5-mask or 4-mask process.

The projections 239 and the slits 272a and 272b divide the pixel regions into a plurality of domains, respectively, and are not formed at positions facing each other. In FIG. 7, four domains are formed by one protrusion 239 and two slits 272a and 272b. The number of the protrusions 239 and the slits 272a and 272b is not limited, but at least one of the protrusions 239 and the slits 272a and 272b may be formed in each pixel area to form the required number of domains in the pixel.

As described above, in the VA mode liquid crystal display device according to the present invention, since the protective layer and the pixel electrode are formed by one mask, the manufacturing process can be simplified and the manufacturing cost can be greatly reduced as compared with the conventional manufacturing method. In addition, since the projections for improving the viewing angle characteristics by distorting the electric field applied to the liquid crystal layer are also formed when the protective layer is formed on the first substrate, the manufacturing process can be further simplified.

Claims (37)

A first substrate and a second substrate divided into a first region and a second region; A thin film comprising a gate electrode formed in the first region of the first substrate, a gate insulating layer made of an inorganic material, a gate insulating layer formed on the gate electrode, a semiconductor layer formed on the gate insulating layer, and a source electrode and a drain electrode formed on the semiconductor layer. transistor; A protective layer made of an organic material and formed on the thin film transistor; At least one protrusion formed on the first substrate in the second region to distort an electric field, and comprising two layers made of the same material as the gate insulating layer and the protective layer of the thin film transistor; A first electrode formed in the second region; A second electrode formed on the second substrate to form an electric field between the first electrode and the first electrode; At least one slit formed on the second electrode and distorting an electric field together with the protrusion; And And a liquid crystal layer formed between the first substrate and the second substrate. The liquid crystal display device of claim 1, wherein a symmetrical electric field is formed between the first electrode and the second electrode with respect to the protrusion. delete delete The liquid crystal display device according to claim 1, wherein the organic protective layer is made of Benzo Cyclo Butene (BCB) or photoacrylic. delete delete delete delete The liquid crystal display device according to claim 1, wherein the protrusion has a height of 1 to 4 mu m from the first electrode. delete delete delete The liquid crystal display device according to claim 1, wherein a part of the drain electrode is exposed from the protective layer, and a first electrode is disposed thereon. The method of claim 1, A black matrix formed on the second substrate; And And a color filter layer formed on the second substrate. delete The liquid crystal display device according to claim 1, wherein the liquid crystal layer is formed of liquid crystal molecules having negative dielectric anisotropy. Providing a first substrate comprising a first region and a second region; Forming a driving element in the first region; Forming a protective layer over the entire first substrate; The photoresist is laminated and developed on the protective layer to form a first photoresist pattern and a second photoresist pattern in the first region and the second region, respectively, and protect the photoresist using the first photoresist pattern and the second photoresist pattern. Etching the layer; Stacking a transparent conductive material over the entire first substrate; And Forming a pixel electrode by lifting off the first photoresist pattern and the second photoresist pattern to form protrusions in a second region, and removing the transparent conductive material on the first photoresist pattern and the second photoresist pattern. Liquid crystal display device manufacturing method consisting of. 19. The method of claim 18, wherein the forming of the protective layer comprises stacking organic materials. The method of claim 18, wherein forming the protective layer, Stacking inorganic materials; And A method of manufacturing a liquid crystal display device, comprising the steps of laminating an organic material. 19. The method of claim 18, wherein the forming of the driving device comprises forming a thin film transistor. The method of claim 21, wherein forming the thin film transistor comprises: Forming a gate electrode on the first substrate; Forming a gate insulating layer on the first substrate; Forming a semiconductor layer on the gate insulating layer; And And forming a source electrode and a drain electrode on the semiconductor layer. The method of claim 21, wherein forming the thin film transistor comprises: Forming a gate electrode on the first substrate; Forming a gate insulating layer on the first substrate; Stacking a semiconductor and a metal layer on the gate insulating layer; Stacking a first photoresist on the metal layer and forming a first photoresist pattern using a diffraction mask; Etching the semiconductor and the metal layer using the first photoresist pattern; Acing the first photoresist pattern to remove photoresist in a partial region; And Forming a semiconductor layer, a source electrode, and a drain electrode by etching the metal layer using the aced first photoresist pattern. 19. The method of claim 18, further comprising etching the gate insulating layer. 25. The method of claim 24, wherein the gate insulating layer is etched simultaneously with the protective layer. 24. The method of claim 22 or 23, wherein the first photoresist pattern is positioned only above a part of the drain electrode, and a part of the drain electrode is exposed to the outside by etching the protective layer. . 27. The method of claim 26, wherein a pixel electrode is formed on the exposed drain electrode. The method of claim 18, wherein the transparent conductive material is stacked on the first photoresist pattern and the second photoresist pattern. 29. The liquid crystal display device of claim 28, wherein the removing of the first photoresist pattern and the second photoresist pattern comprises retreating the first photoresist pattern and the second photoresist pattern. Manufacturing method. The method of claim 18, Providing a second substrate; Forming a black matrix and a color filter layer on the second substrate; Forming a common electrode on the color filter layer; Bonding the first substrate and the second substrate to each other; And Forming a liquid crystal layer between the first substrate and the second substrate further comprising the step of forming a liquid crystal display device. 31. The method of claim 30, wherein the forming of the liquid crystal layer comprises placing a negative dielectric anisotropic liquid crystal between the first substrate and the second substrate. 31. The method of claim 30, further comprising forming at least one slit in the common electrode. delete delete delete delete delete

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