KR101390767B1 - Method for fabricating display device - Google Patents

Abstract

A method of manufacturing a display device includes forming a first conductive layer on a substrate having a plurality of defects on a surface thereof, Selectively patterning the first conductive layer to form an alignment mark with the gate electrode; Forming a gate insulating film and a semiconductor layer on the substrate including the gate electrode and the alignment mark; Forming a second conductive layer on the substrate including the semiconductor layer; And patterning the second conductive layer selectively through a photomask alignment process to simultaneously form a source / drain electrode and a dummy pattern overlapping the alignment mark.

Substrate, alignment mark, alignment mark, photomask, dummy pattern

Description

METHOD FOR FABRICATING DISPLAY DEVICE [0002]

The present invention relates to a method of manufacturing a display device, and more particularly, to a method of manufacturing a display device in which a key portion is blocked by a metal shield pattern to thereby prevent scratching defects of a stainless steel substrate And more particularly, to a display device manufacturing method capable of accurately laminating a succeeding layer without an alignment error to easily perform a manufacturing process of the device.

In general, a process for manufacturing a display device is a process for forming a plurality of patterns as a layer on a substrate. In order to form such a pattern, an etching mask for patterning the film is required.

The etching mask used in the manufacturing process of the display device is usually formed by applying a photoresist film, that is, a photoresist film, and exposing it in a characteristic manner.

Since the pattern of the film to be formed is determined in this exposure step, exposure is a very important process.

Therefore, in order to form an accurate pattern, the mask pattern must be accurately aligned in the exposure apparatus first.

For this purpose, an alignment key is formed in the non-pattern forming region of the substrate.

Alignment of the mask pattern is performed based on the alignment key, and exposure is performed on the photosensitive film to form a photoresist pattern, that is, an etching mask that defines a pattern of the material film.

If the alignment of the etched mask thus formed is deviated, the underlying film pattern formed in advance in the etching process can be damaged.

In the exposure process, the alignment key can recognize various information in the substrate as well as the alignment of the mask pattern, which may vary slightly depending on the exposure method.

A general display device manufacturing method using such an alignment key will now be described with reference to the accompanying drawings.

1A is a plan view showing an alignment mark formed on the outermost portion of a substrate, and FIG. 1B is an enlarged plan view of an "A" portion of FIG. 1A, Axis direction and an alignment mark in the Y-axis direction.

FIG. 2 is a graph showing a plan view of a plurality of alignment marks and a change in intensity at the positions of the respective alignment marks when the laser is irradiated on these alignment marks in a general display device manufacturing method.

Although not shown in the drawing, a metal layer (not shown) for forming a gate electrode is first deposited on the substrate 11 to form a gate electrode constituting a thin film transistor constituting a display element, and then a photoresist film ).

Then, the photoresist film is selectively patterned to form a photoresist film pattern (not shown) after an exposure and development process using a mask is performed.

Subsequently, the metal layer is selectively patterned using the photoresist film pattern (not shown) as a mask to form a gate line (not shown) including a gate electrode (not shown) on the substrate.

Referring to FIG. 1A, when forming the gate electrode, a reference align key 17 is simultaneously formed to precisely align a layer pattern to be formed in a subsequent process. The alignment mark 17 is formed at four points of the outermost portion of the substrate 11. [

1B, the alignment mark 17 is composed of a plurality of alignment marks 17a formed in the X-axis direction and the Y-axis direction.

Next, an insulating film (not shown) for use as a gate insulating film and a semiconductor layer (not shown) for use as an active layer are sequentially deposited on the substrate 11 including the gate electrode, and then patterned. The alignment mark 17 formed in the formation of the mask is used to perform regular alignment with the mask located in the exposure area, and then the exposure process is performed. At this time, it is necessary to previously align the alignment mark (17).

2 (a) and 2 (b), the intensity of light by the irradiation of the laser 21 reflected on the alignment mark 17, that is, a plurality of alignment marks 17a, .

However, when such scanning is performed, the pattern of the alignment mark portion is erroneously formed or does not have a desired peak value, so that it is impossible to regularly expose the mask to the normal exposure.

In the case of a conventional glass substrate, defective alignment due to foreign substances may occur, but since there is no pattern on the substrate itself, alignment defects caused by the substrate hardly occur during the alignment process.

However, as shown in FIG. 3, in the case of a substrate made of stainless steel (SUS) or other metal rather than a glass substrate, scratches or scratch defects D), it is impossible to perform alignment normally.

A method of manufacturing a display device according to a related art using a substrate having such a problem will now be described with reference to FIGS. 3 to 5. FIG.

3 is a plan view showing a plurality of alignment marks formed in an alignment mark formed in an outermost portion of a substrate (not shown) made of stainless steel (SUS) in a conventional method of manufacturing a display device.

4 is a photograph showing scratch defects (D) such as scratches or foreign substances existing on the surface of the substrate itself in the conventional method of manufacturing a display device.

FIG. 5 is a graph showing the relationship between the defects D present on the surface of the substrate itself and the intensity variations at the positions of the defects and the respective alignment marks when the laser is irradiated on the plurality of alignment marks It is a graph.

Referring to FIGS. 3 and 4, on a susceptive substrate (not shown in FIG. 1) (see FIG. 1), a susceptor (not shown) is formed to form a gate line (not shown) including a gate electrode, A metal layer for forming a gate line is deposited on the substrate 11, and a photoresist film is coated thereon.

Then, the metal layer is selectively patterned after an exposure and development process using an exposure mask to form a gate electrode on the substrate 11 to form a gate electrode constituting a thin film transistor constituting a display element And a photoresist film (not shown) is coated on the metal layer (not shown).

Then, the photoresist film is selectively patterned to form a photoresist film pattern (not shown) after an exposure and development process using a mask is performed.

Subsequently, the metal layer is selectively patterned using the photoresist film pattern (not shown) as a mask to form a gate line (not shown) including a gate electrode (not shown) on the substrate.

3 and 4, in order to precisely align the pattern of the layer to be formed in the subsequent process, the align key, that is, a plurality of alignment marks (17a) are simultaneously formed.

In addition, the align key 17 is generally formed at four points of the outermost portion of the substrate. At this time, a scratch defect (D) such as a scratch or a foreign object is present on the surface of the sus substrate (not shown in FIG.

Next, when an insulating film and a semiconductor layer are sequentially deposited on the substrate including the gate electrode and then patterned, the mask is placed in alignment with the mask located in the exposure unit using the alignment mark formed at the time of forming the gate electrode, and then the exposure process is performed do. At this time, it is necessary to align the layers 17 formed in the first layer.

Referring to FIG. 5, when the laser beam is scanned in order to perform parallel-to-serial scanning, the laser beam is irradiated at the alignment mark 17 to sense the position for the regularization using the intensity of the light.

However, when scanning is performed in order to perform the orthogonal array, the intensity of light reflected from the alignment mark 17 as well as the intensity of light in a scratch defect (D) such as a scratch or foreign matter existing on the surface of the substrate And strength.

That is, when a key of a photo mask is aligned in an exposure process due to a scratch-resistant defect (D) existing in a substrate made of stainless steel, an interference phenomenon occurs and a normal alignment process can not be performed .

Therefore, since the position of the pattern of the alignment mark is erroneously detected due to the fact that the intensity of the light in the defect (D) such as scratches or foreign substances existing on the surface of the substrate is detected, the alignment can not be properly aligned with the mask, do.

Therefore, in the case of a substrate made of SUS or other metal, it can not be aligned normally due to scratches or foreign substances existing in the substrate itself.

As a result, when the insulating layer or the metal layer formed thereafter is aligned on the alignment mark formed on the susceptor substrate together with the gate electrode, if the transmittance of the layer is low, the alignment can be normally performed. However, , Scratch defects (D) such as scratches and foreign matter on the susce substrate are directly detected by the laser, and normal alignment is impossible.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide a metal shield pattern, The scratch-resistant defects of the substrate made of stainless steel or other metal materials are obscured, so that the succeeding layers can be accurately laminated without aligning errors to easily perform the manufacturing process of the device And a display device manufacturing method.

According to an aspect of the present invention, there is provided a method of manufacturing a display device, including: forming a first conductive layer on a substrate having a plurality of defects on a surface thereof; Selectively patterning the first conductive layer to form an alignment mark with the gate electrode; Forming a gate insulating film and a semiconductor layer on the substrate including the gate electrode and the alignment mark; Forming a second conductive layer on the substrate including the semiconductor layer; And patterning the second conductive layer selectively through a photomask alignment process to simultaneously form a source / drain electrode and a dummy pattern overlapping the alignment mark.

Here, the alignment mark is formed at an edge of the outermost portion of the substrate.

The alignment mark is composed of a plurality of alignment marks in the X-axis direction and a plurality of alignment marks in the Y-axis direction.

Wherein the photomask alignment process comprises: forming a photoresist film on a second conductive layer formed on a substrate including the semiconductor layer; Performing an exposure process and a development process by laser irradiation while the photomask is positioned on the basis of the alignment mark; Forming a photoresist film pattern by selectively patterning the photoresist film after performing the exposure and development processes; And forming a dummy pattern together with the source / drain electrodes by selectively patterning the second conductive layer using the photoresist film pattern as a mask.

The substrate comprises a substrate of stainless steel or other metallic material, or a substrate on which a plurality of scratchable defects are present.

The scratch-resistant defect is not detected by the dummy pattern overlapping with the alignment mark during laser irradiation performed through the photomask alignment process.

The display device manufacturing method includes: forming a protective film on a substrate on which a source / drain electrode and a dummy pattern are formed; Selectively removing the protective film to form a contact hole; And forming a pixel electrode connected to the drain electrode through the contact hole on the protective film.

As described above, the method of manufacturing a display device according to the present invention has the following effects.

A method of manufacturing a display device according to the present invention is a method of manufacturing a display device in which a key portion is blocked with a metal shield pattern so that a plurality of scratch resistant defects are present on the surface, Since scratch defects of a substrate made of a material are masked, the subsequent layers can be accurately stacked without aligning errors, thereby facilitating the manufacturing process of the device.

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

6A is a plan view showing a gate line formed on a stainless steel (SUS) substrate (not shown) and an alignment mark formed on the outermost portion of the substrate in the method of manufacturing the display device according to the present invention.

6B is an enlarged plan view of the "B" portion of the alignment mark shown in FIG. 6A, and is a plan view showing a plurality of alignment marks and scratch-resistant defects D formed in the X-axis direction and the Y-

7A is a cross-sectional view illustrating a data line and source / drain electrodes formed on a stainless steel (SUS) substrate (not shown) and an alignment mark formed on the outermost portion of the substrate, according to an embodiment of the present invention. FIG.

Fig. 7B is an enlarged plan view of the "C" portion of the alignment mark shown in Fig. 7A, and is a plan view showing a dummy pattern formed on a plurality of alignment marks formed in the X-axis direction and the Y-

8 is a cross-sectional view of an alignment mark formed together with a data line and a source / drain electrode in a method of manufacturing a display device according to the present invention.

6A and 6B, a display device is formed on a stainless steel substrate, that is, a flexible sus (SUS) substrate 101 in which scratch defects (D) such as a large number of scratches or foreign substances are present on the surface Al, Ti, Ta, or alloys thereof or other metal materials are deposited on the susce substrate 101 by sputtering or other deposition method to form the gate lines 105 of the thin film transistors, A first photoresist film (not shown) is coated on the first metal layer (not shown). At this time, scratch defects (D) such as scratches or foreign substances are present on the surface of the susce substrate 101 itself.

The present invention is limited to the case of a substrate made of a stainless steel material. However, it is also possible to use a substrate made of other metal other than the stainless steel material. In particular, a substrate having scratches, scratches, (For example, a glass substrate or a transparent insulating substrate), any substrate is applicable.

Although not shown in the drawings, a bulk layer (not shown in FIG. 8, not shown) using an insulating material may be formed before a first metal layer (not shown) is formed on the suscepter 101.

Then, a laser is irradiated to the first photoresist film (not shown) through a first mask, and the first photoresist film (not shown) is developed, and then the first photoresist film Thereby forming a first photoresist film pattern (not shown).

At this time, a first photoresist film pattern (not shown) for forming an alignment mark is also formed at four points of the outermost portion of the susceptor substrate 101.

Then, the first metal material layer is selectively patterned using the first photoresist film pattern (not shown) for forming the gate lines and the alignment marks to form the gate lines 105 and the alignment marks 107 .

At this time, at the time of forming the gate line 105, a gate electrode 105a extending vertically in the gate line 105 is also formed.

The alignment mark 107 is formed at four outermost portions of the susceptor substrate 101 and includes a plurality of alignment marks 107a in the X axis direction and a plurality of alignment marks 107a in the Y axis direction .

After the first photoresist film pattern is removed, a gate insulating film (not shown) and a semiconductor layer (not shown) are sequentially deposited on the entire surface of the susceptor substrate 101 including the gate line 105 and the alignment mark 107 .

Subsequently, a second photoresist film (not shown) is coated on the semiconductor layer (not shown), and then an exposure process and a developing process using a second mask are performed. Then, the second photoresist film (not shown) To form a second photoresist film pattern (not shown).

Then, the semiconductor layer is selectively patterned using the second photoresist film pattern as a mask to form a semiconductor layer pattern (not shown) overlapping the gate electrode 105a.

At this time, the process of forming the semiconductor layer pattern (not shown) may be patterned independently using a separate mask as described above, or may be patterned using a single mask together with the second metal layer to be formed in a subsequent process.

After removing the second photoresist film pattern (not shown), a data line (not shown in FIG. 7A) 111a and a source / drain electrode (not shown) are formed on the entire surface of the susceptor 101 including the semiconductor layer pattern. A second metal layer (not shown) is deposited by depositing Mo, AlNd, Al, Ti, Ta, or alloys thereof or other metal materials by a sputtering method or other vapor deposition method to form the first metal layer .

At this time, the second metal layer (not shown) is formed on the entire surface of the susceptor substrate (not shown) including the alignment mark 107 formed at the outermost portion of the susceptor substrate 101.

Next, a third photoresist film (not shown) is coated on the second metal layer (not shown), and then an exposure process and a development process using a third mask (not shown) are performed. Then, To form a third photoresist film pattern (not shown).

In this case, the third photoresist film pattern (not shown) may include the alignment mark (not shown in FIG. 7A) including an area to be formed by the data line 111a and the source / drain electrodes 111b and 111c (Not shown) that overlaps the first metal layer.

Referring to FIG. 7A, the second metal layer is selectively patterned using the third photoresist film pattern (not shown) as a mask to form a data line 111a and source / drain electrodes 111b and 111c.

At this time, at the time of patterning the second metal layer, as shown in FIG. 7B, a part of the second metal layer above the alignment key 107 is also selectively patterned to form a dummy pattern 111d.

An upper portion of the alignment mark 107 formed together with the gate line 105 at the time of forming the source / drain electrodes 111b and 111c to cover the scratchy defect D such as scratches or foreign substances on the susce substrate 101 The second metal layer for forming the source / drain electrodes covers the gate electrode 105a, thereby covering the scratch-resistant defect D on the susceptor substrate 101 under the gate electrode 105a.
That is, when forming the source / drain electrodes 111b and 111c, a dummy pattern 111d is further formed on the alignment mark 107 as described above, so that alignment can be normally performed in a subsequent photo process.

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In particular, as shown in FIG. 8, when the alignment process using the photomask is performed to form the source / drain electrodes 111b and 111c, the alignment proceeds normally.

This is because the alignment process proceeds in a state where the second metal layer for forming the source / drain electrode having a low transmittance is deposited on the alignment mark 107 formed along with the gate line 105 in the first metal layer, This is because scratch defects (D) such as scratches and foreign substances existing on the surface of the susce substrate 101 itself are not detected at the time of laser irradiation.

In this way, the manufacturing process of the thin film transistor constituting the display element is completed. Hereinafter, the processes to be performed are applied to the liquid crystal display device (LCD), the organic light emitting diode (OLED) device, electrophoretic display device (EPD), and the like.

Here, the manufacturing process of a display device using a metal substrate will be described.

Next, a protective film (not shown) is deposited on the entire surface of the susce substrate 101 after removing the third photoresist film pattern.

Subsequently, a fourth photoresist film (not shown) is coated on the protective film, and then an exposure and development process using a fourth mask is performed. Then, the fourth photoresist film is selectively patterned to form a fourth photoresist film pattern ).

6A and 6B, when the source / drain electrodes (see 111b and 111c in FIG. 6A) are formed to cover the scratch defects D such as scratches or foreign substances on the susce substrate 101, When the upper portion of the alignment mark 107 formed with the gate line 105 is covered with the second metal layer having low transmittance for forming the source / drain electrode, Since the scratch-resistant defect (D) of the susceptor substrate is not recognized, the second metal layer serves to cover the scratchy defect (D), and the second metal layer is covered on the gate electrode and the aliquot A normal alignment can be performed because the gate electrode and the alignment key 107 can be distinguished during a laser irradiation for an alignment process.

8, a dummy pattern 107a is formed on a plurality of alignment marks 107a constituting the alignment mark 107 at the time of forming the source / drain electrodes (refer to 111b and 111c in FIG. 7B) 111d are additionally formed, so that the alignment process can be normally performed even in the photolithography process using the fourth mask.

Then, the protective film (not shown) is selectively removed using the fourth photoresist film pattern (not shown) as a mask to form a contact hole (not shown) exposing a part of the drain electrode 111c.

After the fourth photoresist film pattern is removed, a transparent conductive layer (not shown) is formed on the entirety of the susceptor 101 by using indium-tin-oxide (ITO), indium-zinc- Lt; / RTI >

Then, a fifth photoresist film (not shown) is coated on the transparent conductive layer, and then an exposure and development process using a fifth mask is performed. Then, the fifth photoresist film is selectively patterned to form a fifth photoresist film pattern (Not shown).

At this time, in order to cover the scratch defects (D) such as scratches or foreign substances existing on the surface of the susce substrate itself, the upper portion of the alignment marks formed together with the gate lines at the time of forming the source / The second metal layer covers the scratch-resistant defect (D) by covering the first metal layer with a second metal material layer for forming a drain electrode.

That is, as shown in FIG. 8, a dummy pattern 111d is additionally formed in the alignment mark 107 at the time of forming the source / drain electrodes, and alignment can be normally performed even in the photolithography process using the fifth mask have.

Next, although not shown in the drawing, the transparent conductive layer is selectively patterned using the fifth photoresist film pattern as a mask to form a pixel electrode (not shown) electrically contacting the drain electrode (not shown) through the contact hole (Not shown).

This completes the process of manufacturing the thin film transistor on the suscep substrate.

However, the present invention is not limited to a display device such as an electrophoretic display device, a liquid crystal display device, and an organic electroluminescent device, The present invention can be applied to all devices using thin film transistors, that is, other devices including semiconductor devices, which are formed on a substrate having scratch defects such as a large number of scratches or foreign substances.

1A is a plan view showing an alignment mark formed on the outermost portion of a substrate, and FIG. 1B is an enlarged plan view of an "A" portion of FIG. 1A, Fig. 6 is a plan view showing alignment marks in the Y-axis direction. Fig.

FIG. 2 is a graph showing a plan view of a plurality of alignment marks and a change in intensity at the positions of the respective alignment marks when the laser is irradiated on the alignment marks in a general display device manufacturing method.

3 is a plan view showing a plurality of alignment marks formed in an alignment mark formed in the outermost portion of a stainless steel (SUS) substrate (not shown) in a conventional method of manufacturing a display device.

4 is a photograph showing scratch defects (D) such as scratches or foreign substances existing on the surface of the sus substrate itself in the conventional method of manufacturing a display device.

FIG. 5 is a graph showing the relationship between a defect (D) existing on the surface of the sus substrate itself and a plurality of alignment marks, FIG.

6A is a plan view showing a gate line formed on a stainless steel substrate (not shown) and an alignment mark formed on the outermost portion of the substrate in the method of manufacturing a display device according to the present invention.

FIG. 6B is an enlarged plan view of the "B" portion of the alignment mark shown in FIG. 6A, and is a plan view showing a plurality of alignment marks and scratchable defects D formed in the X-axis and Y-axis directions.

7A is a cross-sectional view illustrating a data line and source / drain electrodes formed on a stainless steel (SUS) substrate (not shown) and an alignment mark formed on the outermost portion of the substrate, according to an embodiment of the present invention. Floor plan.

Fig. 7B is an enlarged plan view of the "C" portion of the alignment mark shown in Fig. 7A, and is a plan view showing a dummy pattern formed on a plurality of alignment marks formed in the X-axis direction and the Y-

8 is a cross-sectional view of an alignment mark formed together with a data line and a source / drain electrode in a method of manufacturing a display device according to the present invention.

[0001] Description of the Prior Art [0002]

101: SUS substrate 105: gate line

105a: gate electrode 107:

107a: alignment mark 111a: data line

111b: source electrode 111c: drain electrode

111d: dummy pattern

Claims (8)

Forming a first conductive layer on a substrate on which a plurality of scratches or foreign objects are present in a scratchable defect (D); Selectively patterning the first conductive layer to form an alignment mark with the gate electrode; Forming a gate insulating film and a semiconductor layer on the substrate including the gate electrode and the alignment mark; The second conductive layer having a low transmittance is formed on the substrate including the semiconductor layer to cover the plurality of scratch-resistant defects (D) which are not recognized during the laser irradiation for the alignment process, Covering the identifiable gate electrode and the aliquot; And Selectively patterning the second conductive layer having a low transmittance through a photomask alignment process using the laser to simultaneously form a dummy pattern overlapping with the alignment mark capable of being distinguished by the laser with the source / And a second electrode formed on the first electrode. The method according to claim 1, wherein the alignment mark is formed at a corner of an outermost portion of the substrate. The display device manufacturing method according to claim 1, wherein the alignment mark comprises a plurality of alignment marks in the X-axis direction and a plurality of alignment marks in the Y-axis direction. The method according to claim 1, wherein the step of aligning the photomask using the laser comprises: Forming a photoresist film on a second conductive layer formed on a substrate including the semiconductor layer; Performing an exposure process and a development process by laser irradiation while the photomask is positioned on the basis of the alignment mark; Forming a photoresist film pattern by selectively patterning the photoresist film after performing the exposure and development processes; And forming a dummy pattern together with the source / drain electrodes by selectively patterning the second conductive layer using the photoresist film pattern as a mask. The method of claim 1, wherein the substrate comprises stainless steel, another metal material, or a transparent substrate. delete delete The method according to claim 1, Forming a protective film on the substrate on which the source / drain electrode and the dummy pattern are formed; Selectively removing the protective film to form a contact hole; And forming a pixel electrode connected to the drain electrode through the contact hole on the protective film.

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