KR101096706B1 - Method For Fabricating Liquid Crystal Display Device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a liquid crystal display device, which is intended to prevent a sensor from not correctly recognizing a process key by covering an opaque layer on a process key due to a process problem. Making; Forming a gate insulating film on an entire surface of the substrate including the gate wiring, the gate electrode, and the process key; Forming a semiconductor layer on the gate insulating layer on the gate electrode; Forming a data line, a source electrode, and a drain electrode on the gate insulating film; Forming a protective film on the entire surface of the gate insulating film including the data line; Removing at least a portion of the passivation layer to form a contact hole corresponding to at least a portion of the drain electrode and an open region corresponding to the process key; Removing the opaque layer formed on the gate insulating film and at least partially overlapping the process key to expose the gate insulating film in the open area; And forming a pixel electrode connected to the drain electrode through the contact hole on the passivation layer and forming a transparent conductive layer covering the exposed gate insulating layer in the open area.

Process key

Description

Method for manufacturing liquid crystal display device {Method For Fabricating Liquid Crystal Display Device}

1 is a plan view showing a process key of a liquid crystal display device.

2 is a diagram when a sensor correctly recognizes a process key.

3 is a diagram when a sensor does not correctly recognize a process key.

4A to 4D are process plan views for explaining a method for manufacturing a liquid crystal display device according to the present invention.

5A to 5E are cross-sectional views illustrating a method of manufacturing a liquid crystal display device according to the present invention.

* Explanation of symbols on the main parts of the drawings

111 substrate 112 gate electrode

113: gate insulating film 114: semiconductor layer

115a: source electrode 115b: drain electrode

116: protective film 117: pixel electrode

118 contact hole 122 process key

125: opaque layer 127: transparent conductive layer

128: open area 130: photoresist

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a liquid crystal display device (LCD), and more particularly, to a method of manufacturing a liquid crystal display device for preventing the sensor from correctly recognizing an opaque layer on a process key.

Recently, the liquid crystal display device, one of the flat panel display devices that are attracting attention, is an element that changes the optical anisotropy by applying an electric field to a liquid crystal that combines the liquidity and the optical properties of the crystal, which is applied to a conventional cathode ray tube. Compared with its low power consumption, small volume, large size, and high definition, it is widely used.

The liquid crystal display device has a structure in which a color filter array substrate as an upper substrate and a thin film transistor (TFT) array substrate as a lower substrate are disposed to face each other, and a liquid crystal having dielectric anisotropy is formed therebetween. A method of applying a voltage to a pixel by switching a TFT added to hundreds of thousands of pixels through a pixel selection address wiring, and maintaining a voltage charged in the pixel until the next address by a capacitor. Is driven.

 As described above, in order to drive the device, various patterns such as a transistor and a capacitor are required, and these patterns must be formed correctly at the correct position.

In order to form the pattern in the correct position, a process key that is a position reference point is required. As the substrate becomes larger and the pattern becomes smaller, more accurate alignment of the pattern is required. There are also various kinds.

Hereinafter, a method of manufacturing a liquid crystal display device according to the prior art will be described with reference to the accompanying drawings.

FIG. 1 is a plan view illustrating a process key of a liquid crystal display, FIG. 2 is a diagram when the sensor recognizes the process key correctly, and FIG. 3 is a diagram when the sensor does not correctly recognize the process key.

One mother substrate 10 may produce several sheets according to the model and size of the liquid crystal display device. In FIG. 1, the scribe line 11 is illustrated as two liquid crystal display devices are produced. The scribe line is a line corresponding to the size of the liquid crystal display device in which the mother substrate is cut, and the liquid crystal display device may be divided into an active area where an image is expressed and a pad area which is an outer portion thereof.

After the various patterns are formed on the mother substrate 10, the substrate is cut along the scribe line 11 to complete the liquid crystal display device. In order to form various patterns on the mother substrate, the scribe line 11 is formed outside the scribe line 11. Are provided with process keys 22a, 22b and 22c for preventing the mask from twisting and checking the degree of alignment between the zones. Such a process key may be formed in the pad portion region of the liquid crystal display device.

The process key varies depending on its role, but when the upper and lower substrates are bonded to each other with a PI printing process key 22a such as a cross mark, which holds a reference point so that an alignment layer can be formed correctly in a desired area. And a bonding process key 22b for positioning the dot to form a silver dot for conducting the upper and lower substrates, and the like.

The process key 22 is formed of an opaque metal layer and its contour is sensed by light projected onto the mother substrate. As shown in FIG. 2, the process key 22, which is a cross mark, returns to normal by light projection. It must be recognized. The right side of the figure is detected by the sensor.

However, if the opaque layer 25 overlaps with the process key 22 undesirably, as shown in FIG. 3, the contour of the process key 22 is not correctly recognized by the opaque layer 25 to proceed with the subsequent process. Unavoidable problems arise. In this case, the opaque layer refers to a material layer through which light does not transmit, such as a data wiring material or an active layer material used in the process.

Thus, the manufacturing method of the liquid crystal display device according to the prior art as described above has the following problems.

That is, when the opaque layer overlaps with the process key, the process key is sensed differently from normal by the transmission of light. In this case, it is difficult to accurately check the alignment of the mask and the distortion of the pattern in the array. There will be no.

The present invention has been made to solve the above problems, the liquid crystal to completely remove the opaque layer formed on the process key during the process to prevent the sensor does not recognize the process key is covered with the opaque layer on the process key It is an object of the present invention to provide a method for manufacturing a display device.

Method of manufacturing a liquid crystal display device according to the present invention for achieving the above object comprises the steps of forming a gate wiring, a gate electrode and a process key on a substrate; Forming a gate insulating film on an entire surface of the substrate including the gate wiring, the gate electrode, and the process key; Forming a semiconductor layer on the gate insulating layer on the gate electrode; Forming a data line, a source electrode, and a drain electrode on the gate insulating film; Forming a protective film on the entire surface of the gate insulating film including the data line; Removing at least a portion of the passivation layer to form a contact hole corresponding to at least a portion of the drain electrode and an open region corresponding to the process key; Removing the opaque layer formed on the gate insulating film and at least partially overlapping the process key to expose the gate insulating film in the open area; And forming a pixel electrode connected to the drain electrode through the contact hole on the passivation layer and forming a transparent conductive layer covering the exposed gate insulating layer in the open area.

That is, the present invention is characterized by removing the protective layer on the upper part of the process key to form an open area, thereby simultaneously removing the opaque layer on the upper part of the process key as well as forming the open area.

At this time, irrespective of whether or not the opaque layer is formed, all processes of removing the opaque layer by forming an open area in the portion where the process key is formed are performed so as to prevent incorrect recognition of the process key in advance.

Hereinafter, a method of manufacturing a liquid crystal display device according to the present invention will be described in detail with reference to the accompanying drawings.                     

4A to 4D are process plan views for explaining a method of manufacturing a liquid crystal display device according to the present invention, and FIGS. 5A to 5E are process cross-sectional views showing a method for manufacturing a liquid crystal display device according to the present invention.

4A to 4D illustrate a case in which an opaque layer 125 is formed on the process key 122 (A) and a non-opaque layer (B) are simultaneously formed on one substrate. The invention is to perform the same process on the electric plate without asking whether the opaque layer is formed.

First, as shown in FIG. 4A, a process key 122 is formed on a substrate. The process key 122 is different in form depending on the type and role thereof, but is illustrated in the form of a cross mark in the drawing.

At this time, the process key 122 is formed in the pad portion region, which is the outer portion of the active region, or is formed outside the scribe line so as not to be formed in the active region where the image is displayed.

Thereafter, an insulating film is formed on the entire surface including the process key and the following process is performed. However, in this case, all of the opaque layer 125 is not removed on the process key 122 and a defect occurs.

Since the process key is not correctly recognized by the sensor by the opaque layer, the opaque layer should be removed. As shown in FIG. 4B, the insulating layer covering the opaque layer 125 is removed to open the region 128. To form. The open area 128 is performed for both the case in which the opaque layer remains (A) and the case in which the opaque layer does not remain (B).                     

Next, as shown in FIG. 4C, the opaque layer 125 exposed to the outside through the open region 128 is completely removed. At this time, the process of removing the insulating film and the process of removing the opaque layer are performed at the same time to form the open region. Although the process may be performed separately, it may be preferable to simultaneously perform the process.

Finally, as shown in FIG. 4D, the transparent conductive film 127 is formed to cover the open area 128 in order to prevent the process key 122 from being eroded in a subsequent process.

By completely removing the opaque layer in this order, the process key can be correctly recognized.

The above-described process is described by applying to the manufacturing method of the liquid crystal display device as follows. Here, the region II ′ of FIG. 5A to FIG. 5E represents the cut surface of the II ′ of FIG. 4A.

First, as shown in FIG. 5A, a metal material is deposited and patterned on the substrate 111 to form gate lines (not shown) arranged in a line and a gate electrode 112 branched from the gate lines. . At the same time, a process key 122 having a predetermined shape is formed in the outer portion of the active region or the outer scribe line.

The process key 122 includes an alignment film printing process key, a substrate bonding process key, a silver dot forming process key, and the like.

As illustrated in FIG. 5B, an inorganic insulating material is deposited on the entire surface including the gate electrode 112 to form a gate insulating layer 113, and an amorphous silicon (a) is formed on the gate insulating layer 113. -Si: H) is deposited and patterned to form a semiconductor layer 114 on the gate insulating layer 113 on the gate electrode 112.

Next, a data line (not shown) defining a sub-pixel crossing the gate line by depositing and patterning a metal material on the entire surface including the semiconductor layer 114, and branching from the data line, the semiconductor layer 114. ) Overlapping source / drain electrodes 115a and 115b, respectively. The stacked film of the gate electrode 512a, the semiconductor layer 514, and the source / drain electrodes 515a and 515b in the active region constitutes a thin film transistor TFT.

However, when the semiconductor layer or the data wiring layer is patterned, the opaque layer 125 remains on the gate insulating layer 113 on the process key 122. The opaque layer 125 must be removed to remove the process key ( The outline of 122) is correctly recognized so that subsequent processing can proceed smoothly. Removal of the opaque layer 125 will be performed later.

Subsequently, as shown in FIG. 5C, an organic insulating material such as BCB is coated on the entire surface including the source / drain electrodes 115a and 115b or an inorganic insulating material such as silicon oxide or silicon nitride is deposited to form a protective film ( 116).

Subsequently, the photoresist 130 is coated on the passivation layer 116 and then patterned into a desired shape by applying photo etching technology.

Next, as illustrated in FIG. 5D, the protective layer 116 exposed between the photoresist 130 may be dry-etched to expose the contact hole 118 and the upper portion of the process key 122 where the drain electrode 115b is exposed. At the same time, an open region 128 through which the gate insulating layer 113 is exposed is formed. In this case, when the protective layer 116 is dry-etched to form the open region 128, the opaque layer 125 is also removed at the same time. As such, the process of forming the open region 128 and the process of removing the opaque layer 125 are performed at all portions where the process key 122 is formed.

At this time, the dry etching can remove not only the data wiring layer material but also the active layer material, so that the opaque layer can be removed in the protective film dry etching process. In particular, when the data line layer material is molybdenum (Mo), it is easily removed by dry etching. The gate insulating layer 113 may also be etched by dry etching, but since the dry etching is performed within a given process time, it may be difficult to etch the gate insulating layer 113.

Finally, the photoresist 130 is stripped and a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO) is deposited on the entire surface including the passivation layer 116 as shown in FIG. 5E. Then, the pixel electrode 117 is formed by patterning. At this time, the transparent conductive film 127 is simultaneously formed to cover the open area 128 in order to prevent erosion of the process key 122 in a subsequent process.

The substrate formed in this way can correctly prevent process defects in subsequent processes since the process key is correctly recognized in the process of alignment film printing, upper and lower substrate counter-adhesion, and silver dot formation processes.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be apparent to those of ordinary skill.

That is, the above embodiment is illustrated and described with reference to the process key in the form of a cross mark, but the form of the process key is not limited thereto.

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

First, by completely removing the opaque layer overlapping the process key, the process key is correctly recognized during processes such as alignment film printing, upper and lower substrate opposing bonding, and silver dot forming processes, so that subsequent processes can be performed smoothly without defects.

Second, since the opaque layer can be removed at the same time the protective film is etched, no additional process is required.

Claims (9)

Forming a gate wiring, a gate electrode, and a process key on the substrate; Forming a gate insulating film on an entire surface of the substrate including the gate wiring, the gate electrode, and the process key; Forming a semiconductor layer on the gate insulating layer on the gate electrode; Forming a data line, a source electrode, and a drain electrode on the gate insulating film; Forming a protective film on the entire surface of the gate insulating film including the data line; Removing at least a portion of the passivation layer to form a contact hole corresponding to at least a portion of the drain electrode and an open region corresponding to the process key; Removing the opaque layer formed on the gate insulating film and at least partially overlapping the process key to expose the gate insulating film in the open area; And And forming a transparent conductive film on the passivation layer, the pixel electrode being connected to the drain electrode through the contact hole, and at the same time forming a transparent conductive film covering the exposed gate insulating film of the open area. Manufacturing method. delete The method of claim 1, Forming the contact hole and the open area and removing the opaque layer are performed simultaneously, And a portion of the passivation layer corresponding to the open area and the opaque layer are removed together. The method of claim 3, wherein And forming the contact hole and the open area and removing the opaque layer are performed simultaneously by dry etching. The method of claim 1, The opaque layer is formed in the step of forming the semiconductor layer, or the method of manufacturing a liquid crystal display device, characterized in that formed in the step of forming a data line, a source electrode and a drain electrode. The method of claim 1, And the data line is formed of molybdenum (Mo). The method of claim 1, And the process key is formed outside the active area of the liquid crystal display device. The method of claim 1, And the open area is formed so as to correspond to all the portions where the process key is formed. The method of claim 1, And said process key comprises an alignment film printing process key, a substrate bonding process key, and a silver dot forming process key.

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