KR19990016464A - LCD and its manufacturing method - Google Patents

Abstract

A liquid crystal display device and a method of manufacturing the same are provided. A semiconductor layer is formed on a predetermined region on a substrate, a gate insulating film is formed on the entire surface of the substrate including the semiconductor layer, and a gate line is formed on the gate insulating film so as to pass through the predetermined region of the semiconductor layer. Form. Impurity ions are implanted into the semiconductor layer using the gate line as a mask to form a source region and a drain region, and a first interlayer insulating film is formed on the entire surface including the gate line, and then contacted to the source region and the drain region of the semiconductor layer, respectively. Source and drain electrodes used as data lines are formed on the first interlayer insulating film as much as possible. Next, a second interlayer insulating film is formed on the entire surface including the source electrode and the drain electrode, and a black matrix layer is formed on the second interlayer insulating film to cover the source electrode. A common electrode line made of a transparent conductive material is formed in a predetermined region of the substrate. The aperture ratio is greatly improved by forming a third interlayer insulating film on the entire surface including the common electrode line and forming a pixel electrode in contact with the drain electrode in the pixel region on the third interlayer insulating film.

Description

LCD and its manufacturing method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display element, and more particularly to a liquid crystal display device and a manufacturing method thereof.

In general, a color thin film transistor liquid crystal display is a flat panel display based on a basic principle of forming pixels by changing the light transmittance by changing the direction of liquid crystals according to the magnitude of voltage applied between a pair of transparent electrodes facing in parallel. A device that acts as a module.

FIG. 1 is a plan view illustrating a liquid crystal display according to the related art. As shown in FIG. 1, a liquid crystal display includes a gate electrode 4 formed in one direction with a matrix pixel electrode 10 interposed therebetween. Lines, a line of data electrode 6 formed in a direction perpendicular to the gate electrode 4 line and contacting the semiconductor layer 2 to serve as a source electrode of the thin film transistor, and a semiconductor layer 2 formed in the pixel region. ) And the data electrode 6 'contacted with the pixel electrode 10 and used as the drain electrode of the thin film transistor, and the common electrode 4' formed in the same direction as the gate electrode 4 line and formed over the pixel region. It consists of a line and the black matrix 8 which overlaps with the data electrode 6 line.

Referring to the conventional manufacturing method of the liquid crystal display device configured as described above is as follows.

2A to 2H are cross-sectional views illustrating a manufacturing process of a liquid crystal display device along the line AA ′ of FIG. 1. First, as shown in FIG. 2A, a polycrystal is formed on a transparent insulating substrate 1 such as glass or quartz. An island-like semiconductor layer 2 is formed by patterning and patterning a semiconductor layer 2 such as silicon.

In this case, the semiconductor layer 2 is used as an active region of the thin film transistor and is also used as a lower electrode of the storage capacitor.

After the gate insulating film 3 is formed on the semiconductor layer 2, the photoresist film 11 is coated and patterned on the entire surface as shown in FIG. 2B to pattern the semiconductor layer 2 in the region to be the lower electrode of the storage capacitor. The gate insulating film 3 formed on the top surface is exposed.

An impurity (P or B) is ion implanted into the semiconductor layer 2 under the gate insulating film 3 where the photosensitive film 11 is exposed as a mask.

Subsequently, as shown in FIG. 2C, the photoresist layer 11 is removed, and polycrystalline silicon and silicide materials are sequentially deposited and patterned on the entire surface of the substrate 1 including the gate insulating layer 3 to form the gate electrode 4 and the common layer. The electrode 4 'is formed.

The common electrode 4 'is used as an upper electrode of the storage capacitor.

An impurity (P or B) is ion-implanted into the semiconductor layer 2 using the gate electrode 4 as a mask and heat-treated to form a source region and a drain region.

Subsequently, as illustrated in FIG. 2D, the first interlayer insulating film 5 is deposited on the entire surface of the substrate 1 including the gate electrode 4, and the gate insulating film 3 and the first interlayer insulating film 5 are selectively removed. The source region and the drain region of the semiconductor layer 2 are exposed.

As illustrated in FIG. 2E, a metal electrode is deposited and patterned on the entire surface of the substrate 1 including the first interlayer insulating layer 5 so as to be connected to a source region and a drain region of the exposed semiconductor layer 2. 6,6 ').

Then, a second interlayer insulating film 7 is deposited on the entire surface of the substrate 1 including the data electrodes 6 and 6 ', and light is deposited on the second interlayer insulating film 7 as shown in FIG. 2F. A film that can be blocked is deposited and then patterned to form a black matrix 8 to overlap the data electrode 6.

Subsequently, as shown in FIG. 2G, a flattening film 9 such as spin on glass (SOG) is formed on the front surface including the black matrix 8 to remove the step, and as shown in FIG. 2H, the flattening film (9) and the predetermined region of the second interlayer insulating film 7 are removed to expose the data electrode 6 'contacted to the drain region of the semiconductor layer 2.

Substrate fabrication is completed by depositing and patterning a transparent conductive material such as ITO on the planarization film 9 to form the pixel electrode 10 in the pixel region so as to be connected to the data electrode 6 '.

The liquid crystal display and the manufacturing method according to the prior art had the following problems.

Since the common electrode line formed in the pixel area and used as the upper electrode of the storage capacitor is formed of a double layer of a polycrystalline silicon film and a silicide film, light does not pass and the aperture ratio is reduced by the area occupied by the common electrode line.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal display device and a method of manufacturing the same, which can improve aperture ratio by allowing light to pass through a common electrode line of a pixel region.

1-a plan view showing a liquid crystal display according to the prior art

2A to 2H-Process cross-sectional view showing a manufacturing process of a liquid crystal display device along the line AA ′ of FIG. 1

3-a plan view showing a liquid crystal display according to a first embodiment of the present invention

4A to 4G-Process cross-sectional view showing a manufacturing process of a liquid crystal display device along the line B-B 'of FIG.

5-a plan view showing a liquid crystal display according to a second embodiment of the present invention

6A through 6G-Process cross-sectional view showing the manufacturing process of the liquid crystal display device along the line C-C 'of FIG.

Explanation of symbols for main parts of the drawings

21 substrate 22 semiconductor layer

23 gate insulating film 24 gate electrode

25: first interlayer insulating film 26, 26 ': data electrode

27: second interlayer insulating film 28: black matrix layer

29; Planarization film 30: common electrode

31: third interlayer insulating film 32: pixel electrode

A liquid crystal display device according to the present invention is a liquid crystal display device having a plurality of gate lines and data lines formed in a direction perpendicular to each other between a pixel area in a matrix form and the pixel area, wherein a source region and a drain are formed in each pixel region on a substrate. A source electrode to cover a plurality of semiconductor layers formed with regions, source and drain electrodes used as data lines formed in contact with source and drain regions of each semiconductor layer, and source electrodes used as data lines, respectively A black matrix layer formed on the top to block light, a common electrode line formed over the pixel area in the same direction as the gate line, and made of a transparent conductive material to serve as a lower electrode of the storage capacitor, and connected to the drain electrode Formed in the area and transferred to the upper electrode of the capacitor. It is composed of the pixel electrode which is used.

In the liquid crystal display device manufacturing method according to the present invention is a liquid crystal display device having a plurality of gate lines and data lines formed in a direction perpendicular to each other between the pixel region of the matrix form and the pixel region, the semiconductor layer in a predetermined region on the substrate Forming a gate insulating film on the entire surface of the substrate including the semiconductor layer; forming a gate line on the gate insulating film so as to pass through a predetermined region of the semiconductor layer, and implanting impurity ions into the semiconductor layer using the gate line as a mask; Forming a drain region, and forming a first interlayer insulating film on the entire surface including the gate line and source and drain electrodes used as data lines on the first interlayer insulating film so as to contact the source and drain regions of the semiconductor layer, respectively. Forming a front surface including a source electrode and a drain electrode Forming a second interlayer insulating film and forming a black matrix layer covering the source electrode on the second interlayer insulating film, forming a planarization film on the entire surface including the black matrix layer, and forming a common conductive material in a predetermined region on the planarization film. Forming an electrode line, and forming a third interlayer insulating film on the entire surface including the common electrode line and forming a pixel electrode to contact the drain electrode in the pixel region on the third interlayer insulating film.

The LCD according to the present invention having the features as described above and a method of manufacturing the same will be described with reference to embodiments with reference to the accompanying drawings.

First embodiment

3 is a plan view illustrating a liquid crystal display according to a first exemplary embodiment of the present invention, and FIGS. 4A to 4G are cross-sectional views illustrating a manufacturing process of the liquid crystal display according to the line BB ′ of FIG. 3.

First, as shown in FIG. 4A, a semiconductor layer 22 such as polycrystalline silicon is formed and patterned on a transparent insulating substrate 21 such as glass or quartz to form an island-like semiconductor layer 22.

In this case, the semiconductor layer 22 is used as an active region of the thin film transistor.

After the gate insulating film 23 is formed on the semiconductor layer 22, a gate electrode material is deposited and patterned on the entire surface of the substrate 21 including the gate insulating film 23, as shown in FIG. 4B. 22) The gate electrode 24 is formed on the top.

An impurity (P or B) is ion-implanted into the semiconductor layer 22 using the gate electrode 24 as a mask and heat-treated to form a source region and a drain region.

Subsequently, as illustrated in FIG. 4C, the first interlayer insulating layer 25 is deposited on the entire surface of the substrate 21 including the gate electrode 24, and the gate insulating layer 23 and the first interlayer insulating layer 25 are selectively removed. The source region and the drain region of the semiconductor layer 22 are exposed.

As illustrated in FIG. 4D, the metal electrode is deposited and patterned on the entire surface of the substrate 21 including the first interlayer insulating layer 25 so as to be connected to the source and drain regions of the exposed semiconductor layer 22. 26,26 ').

Here, the data electrode 26 is a source electrode of the thin film transistor, and the data electrode 26 'is a drain electrode of the thin film transistor.

Then, a second interlayer insulating film 27 is deposited on the entire surface of the substrate 21 including the data electrodes 26 and 26 ', and as shown in FIG. 4E, light is lighted like a metal on the second interlayer insulating film 27. A black matrix layer 28 is formed to cover the data electrode 26 by depositing and patterning a film that can be blocked.

Subsequently, a planarization film 29 such as spin on glass (SOG) is formed on the entire surface including the black matrix layer 28 to remove a step, and as shown in FIG. 4F, ITO and ITO are formed on the planarization film 29. The same transparent conductive material is deposited and patterned to form the common electrode 30.

Here, the common electrode 30 is used as the lower electrode of the storage capacitor.

After the third interlayer insulating film 31 is formed on the entire surface including the common electrode 30, as shown in FIG. 4G, the third interlayer insulating film 31, the planarizing film 29, and the second interlayer insulating film 27 are formed. ), A predetermined region is removed to expose the data electrode 26 'contacted to the drain region of the semiconductor layer 22.

Substrate fabrication is completed by depositing and patterning a transparent conductive material such as ITO on the third interlayer insulating layer 31 to form the pixel electrode 32 in the pixel region so as to be connected to the data electrode 26 '.

Here, the pixel electrode 32 is used as an upper electrode of the storage capacitor.

As shown in FIGS. 3 and 4G, the structural features of the liquid crystal display device formed as described above are formed directly under the pixel electrode without forming a common electrode on the semiconductor layer as in the related art, thereby forming a storage capacitor together with the pixel electrode. Is the point.

That is, since the pixel electrode and the common electrode constituting the storage capacitor are made of a transparent conductive material such as ITO, light is also transmitted through the storage capacitor region, thereby improving the aperture ratio.

Second embodiment

5 is a plan view illustrating a liquid crystal display according to a second exemplary embodiment of the present invention, and FIGS. 6A to 6G are cross-sectional views illustrating a manufacturing process of the liquid crystal display according to the line C-C ′ of FIG. 5.

6a to 6c are the same as the manufacturing process of Figs. 4a to 4c of the first embodiment of the present invention, detailed description thereof will be omitted.

As illustrated in FIG. 6D, a metal is deposited and patterned on the entire surface of the substrate 21 including the first interlayer insulating layer 25 to be connected to the source and drain regions of the exposed semiconductor layer 22. 26 ').

Here, the data electrode 26 is a source electrode of the thin film transistor, and the data electrode 26 'is a drain electrode of the thin film transistor.

The planarization film 29 is formed on the entire surface of the substrate 21 including the data electrodes 26 and 26 'to eliminate the step difference.

Next, as shown in FIG. 6E, the black matrix layer 28 is deposited on the planarization layer 29 so as to cover the data electrode 26 by depositing and patterning a film capable of blocking light such as metal. Form.

The common electrode 30 is formed on the pixel region and the black matrix layer 28 by depositing and patterning a transparent conductive material such as ITO on the entire surface including the black matrix layer 28.

Here, the material of the common electrode 30 is patterned to cover the black matrix layer 28. The reason is that when the black matrix layer 28 is exposed when the common electrode 30 is etched, the material is black when the selectivity is poor. This is to prevent the matrix layer 28 from being removed.

In addition, the common electrode 30 is used as a lower electrode of the storage capacitor.

6F, the second interlayer insulating layer 27 is formed on the entire surface including the common electrode 30, and then the second interlayer insulating layer 27 and the planarization layer 29 are illustrated in FIG. 6G. ), A predetermined region is removed to expose the data electrode 26 'contacted to the drain region of the semiconductor layer 22.

Substrate fabrication is completed by depositing and patterning a transparent conductive material such as ITO on the second interlayer insulating layer 27 to form the pixel electrode 32 in the pixel region so as to be connected to the data electrode 26 '.

Here again, the pixel electrode 32 is used as the upper electrode of the storage capacitor.

In the second embodiment of the present invention formed as described above, the structural feature is that the common electrode formed of a transparent conductive material such as ITO is formed directly under the pixel electrode as in the first embodiment of the present invention to form a storage capacitor together with the pixel electrode to form an aperture ratio. In addition, the black electrode layer is formed on the planarization film and the common electrode is formed to cover the black matrix layer.

The liquid crystal display device and the manufacturing method thereof according to the present invention have the following effects.

Both the upper electrode and the lower electrode of the storage capacitor are formed using a transparent conductive film through which light such as ITO passes, thereby allowing light to pass through the portion occupied by the storage capacitor, thereby improving the aperture ratio.

In particular, in the HD class LCD, since the size of the pixel is small and the relative portion of the area occupied by the storage capacitor is large, the aperture ratio can be greatly improved when using the technique of the present invention.

Claims (7)

A liquid crystal display device having a plurality of gate lines and data lines formed in a direction perpendicular to each other between a pixel area in a matrix form and a plurality of pixel areas, the plurality of pixel areas having a source area and a drain area formed in each pixel area on a substrate. A semiconductor layer; A source electrode and a drain electrode used as data lines formed in contact with the source region and the drain region of each semiconductor layer, respectively; A black matrix layer formed on the source electrode so as to cover the source electrode used as the data line and blocking light; A common electrode line formed over the pixel area in the same direction as the gate line and made of a transparent conductive material and used as a lower electrode of the storage capacitor; And a pixel electrode connected to the drain electrode and formed in each pixel region and used as an upper electrode of the capacitor. The liquid crystal display of claim 1, wherein the common electrode line is formed on the black matrix layer to cover the black matrix layer. The liquid crystal display of claim 1, wherein the common electrode line is formed of indium tin oxide (ITO). In a liquid crystal display device having a plurality of gate lines and data lines formed in a direction perpendicular to each other between a pixel region having a matrix form and a pixel region, a semiconductor layer is formed on a predetermined region on a substrate, and the front surface of the substrate including the semiconductor layer. Forming a gate insulating film on the substrate; Forming a gate line on the gate insulating layer so as to pass through a predetermined region of the semiconductor layer, and implanting impurity ions into the semiconductor layer using the gate line as a mask to form a source region and a drain region; Forming a first interlayer insulating film on the entire surface including the gate line, and forming a source electrode and a drain electrode on the first interlayer insulating film so as to contact the source and drain regions of the semiconductor layer, respectively; Forming a second interlayer insulating film on the entire surface including the source electrode and the drain electrode, and forming a black matrix layer on the second interlayer insulating film to cover the source electrode; Forming a planarization layer on the entire surface including the black matrix layer, and forming a common electrode line made of a transparent conductive material in a predetermined region on the planarization layer; And forming a third interlayer insulating film on the entire surface including the common electrode line, and forming a pixel electrode in contact with the drain electrode on the pixel region on the third interlayer insulating film. . The method of claim 4, wherein the common electrode line and the pixel electrode are formed of indium tin oxide (ITO). The method of claim 4, wherein the black matrix layer is formed on the planarization layer. 7. The method of claim 6, wherein a common electrode line is formed on the black matrix layer to cover the black matrix layer formed on the planarization layer.