KR100249222B1 - Liquid crystal display device and fabricating method of the same - Google Patents

Abstract

A liquid crystal display device and a manufacturing method thereof, comprising: forming a plurality of active layers in a predetermined region on a substrate, forming a first insulating layer on the entire surface of the substrate including the active layer, and transparent to the entire surface of the substrate including the first insulating layer Forming and patterning a conductive material ITO to form a gate line and a storage electrode line, forming a source region and a drain region of each active layer using the gate line as a mask, and forming a second insulating layer on the entire surface of the substrate; Forming a data line on the second insulating layer so as to be connected to the source region of each active layer, and forming a third insulating layer on the entire surface of the substrate including the data line and forming a third insulating layer on the third insulating layer so as to be connected to the drain region of each active layer. By forming a pixel electrode in the pixel region of the liquid crystal display, a liquid crystal display device having greatly improved aperture ratio can be manufactured. .

Description

Liquid crystal display device and fabrication method of the same

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device and a manufacturing method thereof.

Referring to the accompanying drawings, a liquid crystal display and a manufacturing method according to the prior art will be described.

FIG. 1 is a layout view showing a liquid crystal display according to the related art, and FIGS. 2A to 2H are cross-sectional views illustrating a manufacturing process of a liquid crystal display according to line I-I of FIG. 1, as shown in FIG. 2A. Polycrystalline silicon is deposited and patterned on the transparent insulating substrate 1 to form an island-like active layer 2.

Subsequently, as shown in FIG. 2B, the gate insulating film 3 is formed on the entire surface of the substrate 1 including the active layer 2, and the photoresist film 4 is formed on the entire surface of the substrate 1 to form a storage electrode line. The photosensitive film 4 is patterned so that (3) is exposed.

After impurity (P or B) is implanted into the active layer 2 in the region where the storage electrode line is to be formed using the photoresist film 4 as a mask, the photoresist film 4 is removed as shown in FIG. 2C. After depositing polycrystalline silicon and silicide-based materials in sequence on the gate insulating film 3, heat treatment is performed at a temperature of 900 ° C. or higher to reduce the resistance of the silicide-based materials.

The polycrystalline silicon and silicide based materials are patterned to form gate lines 5 and 5 'and storage electrode lines 5a and 5a'.

Subsequently, as shown in FIG. 2D, impurities (P or B) are ion-implanted into the active layer 2 using the gate lines 5 and 5 ′ as masks to form source and drain regions in the active layer 2. Next, as shown in FIG. 2E, a first interlayer insulating film 6 is formed on the entire surface of the substrate 1 including the gate lines 5, 5 ′ and the storage electrode lines 5 a, 5 a ′, and an active layer. Predetermined regions of the first interlayer insulating film 6 and the gate insulating film 3 are etched to expose the source region of (2) to form a metal electrode contact hole 7.

As illustrated in FIG. 2F, a metal line is deposited and patterned on the first interlayer insulating layer 6 to form a data line 8 so as to be connected to the active layer 2 through the metal electrode contact hole 7.

Next, as shown in FIG. 2G, a second interlayer insulating film 9 is formed on the entire surface of the substrate 1 including the data lines 8, and the gate insulating film 3 and the drain region of the active layer 2 are exposed. Predetermined regions of the first and second interlayer insulating films 6 and 9 are etched to form pixel electrode contact holes 10.

As shown in FIG. 2H, a transparent conductive material such as indium tin oxide (ITO) is formed and patterned on the second interlayer insulating layer 9 to be connected to the active layer 2 through the pixel electrode contact hole 10. By forming the pixel electrode 11 as much as possible, the lower plate of the liquid crystal display device is completed.

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

First, since the storage electrode line is formed of an opaque material (polysilicon and silicide-based materials), light does not pass through the pixel area occupied by the storage electrode, and thus the aperture ratio is lowered.

Second, the high cost of heat treatment process is expensive.

Third, the silicide-based material should be heat-treated at high temperature to reduce the resistance after deposition, and if the film is thickened to obtain a low resistance, cracking may occur.

In order to solve such a problem, an object of the present invention is to provide a liquid crystal display device and a method for manufacturing the same, which can improve an aperture ratio.

Another object of the present invention is to provide a liquid crystal display device and a method of manufacturing the same, which can reduce the unit cost by simplifying the manufacturing process.

1 is a layout showing a liquid crystal display according to the prior art

2A through 2H are cross-sectional views illustrating a manufacturing process of a liquid crystal display device according to line I-I of FIG.

3 is a layout diagram showing a liquid crystal display device according to the present invention;

4A through 4H are cross-sectional views illustrating a manufacturing process of a liquid crystal display according to a first exemplary embodiment of the present invention.

5A through 5H are cross-sectional views illustrating a manufacturing process of a liquid crystal display according to a second exemplary embodiment of the present invention.

6A to 6H are cross-sectional views illustrating a manufacturing process of a liquid crystal display according to a third exemplary embodiment of the present invention.

7A and 7B are graphs showing transfer characteristics of a thin film transistor of a liquid crystal display according to the related art and the present invention.

Explanation of symbols for the main parts of the drawings

40: storage electrode line 41: substrate

42: active layer 43: gate insulating film

44 photosensitive film 45 gate electrode

45 ': gate line 46: first interlayer insulating film

47 metal electrode contact hole 48 data line

49: second interlayer insulating film 50: pixel electrode contact hole

51: pixel electrode

According to an exemplary embodiment of the present invention, a liquid crystal display device and a method of manufacturing the same include forming a plurality of active layers in a predetermined region on a substrate, forming a first insulating layer on the entire surface of the substrate including the active layer, and a transparent surface of the substrate including the first insulating layer. Forming and patterning a conductive material, ITO, to form a gate line, a gate electrode, and a storage electrode line; forming a source region and a drain region of each active layer using a gate electrode as a mask; and a second insulating layer on the entire surface of the substrate. Forming a data line on the second insulating layer so as to be connected to the source region of each active layer, forming a third insulating layer on the entire surface of the substrate including the data line, and forming a third insulating layer to be connected to the drain region of each active layer. The pixel electrode is formed in the pixel region on the insulating layer.

Another feature of the present invention is to form the gate electrode from polysilicon and form the gate line and the storage electrode line from ITO.

Another feature of the present invention is that the gate electrode and the gate line are formed of polysilicon, and the storage electrode line is formed of ITO.

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 layout view showing a liquid crystal display according to the present invention, and FIGS. 4A to 4H are cross-sectional views illustrating a manufacturing process of the liquid crystal display according to the first embodiment of the present invention.

As shown in FIG. 4A, first, polycrystalline silicon is deposited and patterned on a transparent insulating substrate 41 such as glass or quartz to form an island-like active layer 42. In this case, the active layer 42 is used as an active region of the thin film transistor and is also used as a storage electrode line.

Subsequently, as shown in FIG. 4B, the gate insulating film 43 is formed on the entire surface of the substrate 41 including the active layer 42 and the photoresist film 44 is formed on the entire surface of the substrate 41 to form the storage electrode line. The photosensitive film 44 is patterned to expose 43.

The lower region of the storage electrode line is formed by implanting impurities such as P (Phosphorus) or B (Boron) onto the active layer 42 of the region where the storage electrode line is to be formed using the photoresist film 44 as a mask.

Subsequently, as illustrated in FIG. 4C, the photoresist layer 44 used as a mask is removed, and an indium tin oxide (ITO) material is deposited and patterned on the gate insulating layer 43 to form the gate electrode 45 and the gate line ( 45 ') and storage electrode line 40.

As such, the reason for forming the gate electrode 45, the gate line 45 ′, and the storage electrode line 40 from ITO will be described later.

As shown in FIG. 4D, impurities (P or B) are ion-implanted into the active layer 42 using the gate electrode 45 and the storage electrode line 40 as a mask, so that the source region and the drain region in the active layer 42. To form.

Next, as shown in FIG. 4E, the first interlayer insulating layer 46 is formed on the entire surface of the substrate 41 including the gate electrode 45 and the storage electrode line 40.

In this case, the first interlayer insulating layer 46 uses a low temperature oxide (LTO) material formed at a temperature of 400 ° C., and the ITO film (gate electrode, gate line) of the lower layer during the formation of the first interlayer insulating layer 46. In the storage electrode line, grains grow to improve electrical and optical characteristics.

The metal electrode contact hole 47 is formed by etching predetermined regions of the first interlayer insulating layer 46 and the gate insulating layer 43 so that the source region of the active layer 42 is exposed.

Specific resistance (μΩcm) Permeability (%) Before LTO Deposition 70 84 After LTO Deposition 16 87

Table 1 is a chart showing the characteristics of the ITO film (1000 Å) before and after depositing the LTO film on the ITO film.

As shown in Table 1, by depositing an LTO material on the ITO film, first, grains of the ITO film are grown, so that the resistivity is further reduced, and the electrical characteristics are greatly improved. Second, the transmittance is increased to improve the optical characteristics.

Next, as shown in FIG. 4F, a metal is formed and patterned on the first interlayer insulating layer 46 to form the data line 48 so as to be connected to the active layer 42 through the metal electrode contact hole 47.

As shown in FIG. 4G, a second interlayer insulating film 49 is formed on the entire surface of the substrate 41 including the data line 48, and the gate insulating film 43 and the first and the second interlayer insulating film 49 are exposed to expose the drain region of the active layer 42. Predetermined regions of the second interlayer insulating layers 46 and 49 are etched to form pixel electrode contact holes 50.

Next, as illustrated in FIG. 4H, a transparent conductive material such as ITO is formed and patterned on the second interlayer insulating layer 49 to form the pixel electrode 51 to be connected to the active layer 42 through the pixel electrode contact hole 50. This completes the lower plate production of the liquid crystal display device.

Second embodiment

5A through 5H are cross-sectional views illustrating a manufacturing process of a liquid crystal display according to a second exemplary embodiment of the present invention.

5A and 5B are the same as those of FIGS. 4A and 4B of the first embodiment of the present invention, and thus description thereof will be omitted.

As shown in FIG. 5C, the photosensitive film 44 used as a mask is removed, and a gate electrode material (polycrystalline silicon or silicide-based material containing impurities) is deposited and patterned on the gate insulating film 43. The electrode 45 is formed.

Subsequently, as illustrated in FIG. 5D, impurities (P or B) are ion-implanted into the active layer 42 using the gate electrode 45 as a mask to form a source region and a drain region in the active layer 42.

As shown in FIG. 5E, an indium tin oxide (ITO) material is deposited and patterned on the gate insulating layer 43 to be connected to the gate electrode 45 and the gate line 45 ′ and the storage electrode line 40. The first interlayer insulating film 46 is formed on the entire surface of the substrate 41 including the gate line 45 'and the storage electrode line 40, and the first interlayer is exposed so that the source region of the active layer 42 is exposed. Predetermined regions of the insulating film 46 and the gate insulating film 43 are etched to form a metal electrode contact hole 47.

5F to 5H, which are subsequent processes, are the same as those of FIGS. 4F to 4H of the first embodiment of the present invention, and thus description thereof will be omitted.

Third embodiment

6A through 6H are cross-sectional views illustrating a manufacturing process of a liquid crystal display according to a third exemplary embodiment of the present invention.

6A and 6B are the same as FIGS. 4A and 4B of the first embodiment of the present invention, and thus description thereof will be omitted.

As shown in FIG. 6C, the photoresist film 44 used as a mask is removed, and a gate electrode material (polycrystalline silicon or silicide-based material containing impurities) is deposited and patterned on the gate insulating film 43. The electrode 45 and the gate line 45 'are formed.

Subsequently, as illustrated in FIG. 6D, impurities (P or B) are ion-implanted into the active layer 42 using the gate electrode 45 as a mask to form a source region and a drain region in the active layer 42.

6E, after forming and patterning an indium tin oxide (ITO) material on the gate insulating layer 43 to form the storage electrode line 40, a substrate including the storage electrode line 40 ( 41. The first interlayer insulating layer 46 is formed on the entire surface, and predetermined regions of the first interlayer insulating layer 46 and the gate insulating layer 43 are etched to expose the source region of the active layer 42, thereby contacting the metal electrode contact hole 47. ).

6f to 6h, which are subsequent steps, are the same as those of FIGS. 4f to 4h of the first embodiment of the present invention, and thus description thereof will be omitted.

As described above, the present invention can improve the aperture ratio by forming the gate electrode, the gate line, and the storage electrode line by ITO, or by forming only the gate line, the storage electrode by ITO, or by forming only the storage electrode by ITO.

7A is a graph illustrating transfer characteristics of a thin film transistor of a liquid crystal display according to the related art, and FIG. 7B is a graph illustrating transfer characteristics of a thin film transistor of a liquid crystal display according to the present invention.

As shown in FIGS. 7A and 7B, the transfer characteristics of the present invention in which the gate line is formed of ITO and the prior art transistor in which the gate line is formed of the silicide-based material are the same except for the threshold voltage.

That is, the threshold voltage of the transistor according to the prior art is 7.5 V, and the threshold voltage of the transistor according to the present invention is measured differently to 4.5 V, but there is no difference between the conventional and the present invention in other transfer characteristics.

The manufacturing method of the liquid crystal display according to the present invention has the following effects.

First, since the storage electrode line is formed of ITO, which is a transparent conductive material, light is transmitted to an area occupied by the storage capacitor and the aperture ratio is improved, thereby making it possible to manufacture a liquid crystal display device having high quality.

Second, since the gate line and the storage electrode line are formed of ITO, the deposition process and heat treatment process of the conventional silicide-based material may be reduced, thereby simplifying the overall manufacturing process.

Third, the gate line is formed of ITO, thereby preventing film cracking and improving electrical characteristics.

Claims (8)

In the manufacturing method of the 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, Forming a plurality of active layers in a predetermined region on the substrate, and forming a first insulating layer on the entire surface of the substrate including the active layers; Forming and patterning indium tin oxide (ITO) on the entire surface of the substrate including the first insulating layer to form a plurality of gate lines, gate electrodes, and storage electrode lines; Implanting impurity ions into each of the active layers using the gate electrode as a mask to form a source region and a drain region; Forming a second insulating layer on an entire surface of the substrate including the gate electrode, and forming a plurality of data lines on the second insulating layer so as to be connected to a source region of each active layer; Forming a third insulating layer on the entire surface of the substrate including the data lines, and forming a pixel electrode in a pixel region on the third insulating layer so as to be connected to a drain region of each active layer. Device manufacturing method. The method of claim 1, wherein the gate line, the gate electrode, and the storage electrode line are formed of the same material as the pixel electrode. The method of claim 1, wherein the second insulating layer is formed of low temperature oxide (LTO). In the manufacturing method of the 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, Forming a plurality of active layers in a predetermined region on the substrate, and forming a first insulating layer on the entire surface of the substrate including the active layers; Forming a plurality of gate electrodes by forming and patterning a conductive material over an entire surface of the substrate including the first insulating layer; Implanting impurity ions into each of the active layers using the gate electrode as a mask to form a source region and a drain region; Forming and patterning indium tin oxide (ITO) on the entire surface of the substrate including the gate electrode to form a plurality of gate lines and storage electrode lines to be connected to the gate electrodes; Forming a second insulating layer on an entire surface of the substrate including the gate line, and forming a plurality of data lines on the second insulating layer so as to be connected to a source region of each active layer; Forming a third insulating layer on the entire surface of the substrate including the data lines, and forming a pixel electrode in a pixel region on the third insulating layer so as to be connected to a drain region of each active layer. Device manufacturing method. In the manufacturing method of the 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, Forming a plurality of active layers in a predetermined region on the substrate, and forming a first insulating layer on the entire surface of the substrate including the active layers; Forming and patterning a conductive material on the entire surface of the substrate including the first insulating layer to form a plurality of gate electrodes and gate lines; Implanting impurity ions into each of the active layers using the gate electrode as a mask to form a source region and a drain region; Forming a storage electrode line by forming and patterning indium tin oxide (ITO) on the entire surface of the substrate including the gate electrode; Forming a second insulating layer on an entire surface of the substrate including the storage electrode line, and forming a plurality of data lines on the second insulating layer so as to be connected to the source region of each active layer; Forming a third insulating layer on the entire surface of the substrate including the data lines, and forming a pixel electrode in a pixel region on the third insulating layer so as to be connected to a drain region of each active layer. Device manufacturing method. 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 having a matrix form and the pixel area. Board; A plurality of semiconductor layers formed with a source region and a drain region in each pixel region on the substrate; A plurality of gate electrodes formed between a source region and a drain region of each semiconductor layer and made of indium tin oxide (ITO) material; A plurality of gate lines connected to the gate electrode and made of indium tin oxide (ITO) material; A storage electrode line formed on each of the semiconductor layers and made of indium tin oxide (ITO) material; And And a pixel electrode contacting the drain region of the semiconductor layer and formed in each pixel region. 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 having a matrix form and the pixel area. Board; A plurality of semiconductor layers formed with a source region and a drain region in each pixel region on the substrate; A plurality of gate electrodes formed between the source and drain regions of each semiconductor layer and made of polysilicon; A plurality of gate lines connected to the gate electrode and made of indium tin oxide (ITO) material; A storage electrode line formed on each of the semiconductor layers and made of indium tin oxide (ITO) material; And And a pixel electrode contacting the drain region of the semiconductor layer and formed in each pixel region. 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 having a matrix form and the pixel area. Board; A plurality of semiconductor layers formed with a source region and a drain region in each pixel region on the substrate; A plurality of gate electrodes formed between the source and drain regions of each semiconductor layer and made of polysilicon; A plurality of gate lines connected to the gate electrode and made of polysilicon; A storage electrode line formed on each of the semiconductor layers and made of indium tin oxide (ITO) material; And And a pixel electrode contacting the drain region of the semiconductor layer and formed in each pixel region.

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