KR20070071648A - Photo mask and method for fabricating liquid crystal display panel using thereof - Google Patents

Abstract

A photomask and a method for manufacturing an LCD(Liquid Crystal Display) panel using the same are provided to enhance uniformity of thickness of a photoresist pattern regardless of the existence of a stepped portion and to improve efficiency of fabrication. A light shielding layer(220) is formed on a transparent substrate(210). A first light transmitting layer(230) is formed on the transparent substrate. A second light transmitting layer(240) is formed along an upper surface of the resultant structure. The transmissivity of the second light transmitting layer is greater than that of the first light transmitting layer. The light shielding layer contains Cr. The first light transmitting layer contains an organic material. The organic material of the first light transmitting layer contains photo acryl. The second light transmitting layer contains CrOx.

Description

Photo mask and method for fabricating liquid crystal display panel using same

1A to 1G are cross-sectional views of respective steps of a manufacturing process of a conventional method for manufacturing a liquid crystal display panel.

2 is a view for explaining a photo mask according to an embodiment of the present invention.

3 is a view for explaining a photoresist pattern according to an embodiment of the present invention.

4A to 4H are cross-sectional views of respective manufacturing process steps of a method of manufacturing a liquid crystal display panel according to an exemplary embodiment of the present invention.

(Explanation of symbols for the main parts of the drawing)

200: photo mask 210: transparent substrate

220: light blocking layer 230: first light transmitting layer

240: second light transmitting layer 310: photoresist pattern

The present invention relates to a photomask and a method of manufacturing a liquid crystal display panel using the same, and more particularly, to a photomask and a method of manufacturing a liquid crystal display panel using the same, which can uniformly form a thickness of a photoresist pattern regardless of a step difference. It is about.

In recent years, due to the rapid progress of semiconductor technology, the demand for flat panel display devices as an electronic display device suitable for a new environment is rapidly increasing according to the trend of miniaturization, thinning, and lightening of electronic devices along with low voltage and low power of various electronic devices. It is increasing. Accordingly, flat panel display devices such as a liquid crystal display, a plasma display panel, an organic EL display, and the like are being developed. In particular, among flat panel display devices, a liquid crystal display device having a small size, a light weight, and a thin film is easy, and has a low power consumption and a low driving voltage.

The liquid crystal display device includes a liquid crystal display panel displaying an image and a driver for applying a driving signal to the liquid crystal display panel. Here, the liquid crystal display panel is composed of a front substrate and a rear substrate and a liquid crystal layer formed between the front substrate and the rear substrate to be bonded at predetermined intervals.

The front substrate is a color filter array substrate. The front substrate is a black matrix layer for blocking light except for the pixel region, and a red, green, and blue color filter layer for displaying color colors and images. A common electrode for implementation is formed. The back substrate is a thin film transistor array substrate, and includes a plurality of data lines arranged in a direction crossing the plurality of gate lines and the gate lines, and a plurality of pixel electrodes and data formed at each pixel defined by crossing the gate lines and the data lines. A plurality of thin film transistors for transmitting a line signal to each pixel electrode is formed. By applying different potentials to the pixel electrode and the common electrode included in the liquid crystal display panel, the molecular arrangement of the liquid crystal material of the liquid crystal layer is changed. The desired image may be realized by adjusting the amount of light transmitted through the transparent liquid crystal display panel according to the changed molecular arrangement.

As described above, the manufacturing method of the liquid crystal display panel having such a structure is required in the photolithography process method, which is a general semiconductor manufacturing method, to form each component in a micronized pattern on a transparent substrate as miniaturization and thinning are required. Follow.

1A to 1G are cross-sectional views of respective steps of a manufacturing process of a conventional method for manufacturing a liquid crystal display panel.

1A to 1G, which illustrate a process of manufacturing a back substrate of a liquid crystal display panel, the back substrate is formed according to the following steps.

First, as shown in FIG. 1A, an ITO (Indium-Tin-Oxide) is deposited on the transparent insulating substrate 101 to form a pixel electrode layer 102. Thereafter, a gate material such as copper (Cu) is deposited on the pixel electrode layer 102 to form the gate electrode layer 103. Thereafter, a first photoresist pattern 104 having a different thickness is formed by using a half tone mask.

Next, as shown in FIG. 1B, the gate electrode layer 103 is etched by a wet etching method, and the pixel electrode layer 102 is wet etched. Thereafter, after partially removing the first photoresist pattern 104 through an ashing process, the gate electrode layer 103 is wet-etched. Thereafter, the first photoresist pattern 104 is removed through a stripping process.

Next, as shown in FIG. 1C, the gate insulating layer 105 is deposited, and the semiconductor layer 106 is formed on the gate insulating layer 105. Thereafter, a source drain electrode layer 107 is formed on the semiconductor layer 106 to form a source electrode and a drain electrode. Thereafter, the second photoresist pattern 108 is formed using a halftone mask.

Next, as shown in FIG. 1D, the source drain electrode layer 107 is etched by a wet etching method.

Next, as shown in FIG. 1E, the semiconductor layer 106 and the gate insulating layer 105 are continuously etched by a dry etching method.

Next, as shown in FIG. 1F, the second photoresist pattern 108 is partially removed through an ashing process.

Next, as shown in FIG. 1G, after the ashing process of FIG. 1F, the back substrate is further completed through at least one process step using a photolithography method. The completed back substrate 100 includes a gate pad 110, a data pad 120, a data line 130, a pixel electrode 140, a gate line 150, and a thin film transistor 160. do.

Meanwhile, the second photoresist pattern 108 of the X region and the Y region illustrated in FIG. 1E is formed flat in the pattern forming process. That is, the second photoresist pattern 108 has the same height from the transparent insulating substrate 101 in the X region and the Y region, but is formed by the source drain electrode layer 107 having a step in the X region and the Y region. The resist pattern 108 has a thickness of the X region thicker than that of the Y region. For this reason, the problem that the ashing time of FIG. 1F becomes long arises.

Accordingly, an object of the present invention is to provide a photomask capable of uniformly forming a thickness of a photoresist pattern regardless of a step.

Another object of the present invention is to provide a method of manufacturing a liquid crystal display panel using the photo mask described above.

Technical problems to be achieved by the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned above may be clearly understood by those skilled in the art from the following description. There will be.

A photo mask according to an embodiment of the present invention for achieving the technical problem is formed on a transparent substrate, a light blocking layer formed on the transparent substrate, a first light transmitting layer formed on the transparent substrate and the transparent substrate And a second light transmitting layer having a higher transmittance than the first light transmitting layer.

In the photomask according to the embodiment of the present invention, the light blocking layer preferably includes chromium (Cr).

In addition, in the photomask according to the embodiment of the present invention, the first light transmitting layer preferably includes an organic material.

In addition, in the photo mask according to the embodiment of the present invention, the organic material preferably includes photo acryl.

In addition, in the photomask according to the embodiment of the present invention, the second light transmitting layer preferably includes chromium oxide (CrOx).

In addition, in the photomask according to the embodiment of the present invention, the second light transmitting layer is preferably formed on at least one layer of the light blocking layer or the first light transmitting layer.

According to another aspect of the present invention, there is provided a method of manufacturing a liquid crystal display panel, wherein forming at least one layer of a metal layer, an insulating layer, a protective layer, or a semiconductor layer on a substrate is different from each other. Applying a flat photoresist on the uppermost layer of the substrate including at least two other regions, and a photoresist pattern using a photo mask corresponding to each of the regions and including at least two light transmission layers having different light transmittances. Forming a step.

A method of manufacturing a liquid crystal display panel according to an embodiment of the present invention includes a first region having a first height of the substrate and a second region having a second height lower than the first height, The mask includes a first light transmitting layer corresponding to the first region and having a first light transmittance, and a second light transmitting layer corresponding to the second region and having a second light transmittance higher than the first light transmittance. It is preferable.

In the method of manufacturing a liquid crystal display panel according to an exemplary embodiment of the present invention, it is preferable that the first light transmitting layer includes an organic material.

In addition, in the method of manufacturing a liquid crystal display panel according to an embodiment of the present invention, it is preferable that the organic material includes photoacryl.

In addition, in the method of manufacturing a liquid crystal display panel according to an embodiment of the present invention, the second light transmitting layer preferably includes chromium oxide (CrOx).

In addition, in the method of manufacturing a liquid crystal display panel according to an exemplary embodiment of the present invention, it is preferable that the second transmission layer is formed on at least one layer of the first light transmitting layer or the light blocking layer that blocks the light.

Specific details of other embodiments are included in the detailed description and the drawings. Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. Like reference numerals refer to like elements throughout.

Hereinafter, with reference to the accompanying drawings, a specific embodiment according to the present invention will be described.

2 is a view for explaining a photo mask according to an embodiment of the present invention.

As shown in FIG. 2, the photomask 200 according to the exemplary embodiment of the present invention may include the transparent substrate 210, the light blocking layer 220, the first light transmitting layer 230, and the second light transmitting layer 240. ).

The transparent substrate 210 completely passes light in an area where an opaque material is not formed during exposure. Thereby, light is irradiated to the photoresist.

The light blocking layer 220 is formed in a predetermined region on the transparent substrate 210 according to the pattern of the photoresist to be formed. During exposure, light is completely blocked in the region where the light blocking layer 220 is formed. As a result, light is not irradiated to the photoresist. The light blocking layer 220 includes a metal material, and preferably, the light blocking layer 220 is formed of a light blocking material including chromium (Cr).

The first light transmitting layer 230 is formed in a predetermined region on the transparent substrate 210 according to the pattern of the photoresist to be formed. At the time of exposure, only part of the light is transmitted in the region where the first light transmitting layer 230 is formed. As the first light transmitting layer 230 has a predetermined transmittance, only part of light is irradiated to the photoresist. The first light transmitting layer 230 according to an embodiment of the present invention includes an organic material to adjust the transmittance. It is preferred that the organic material include photo acryl.

The second light transmitting layer 240 is formed in a predetermined region on the transparent substrate 210 according to the pattern of the photoresist to be formed. The second light transmitting layer 240 has a higher transmittance than the first light transmitting layer 230. Therefore, only part of the light is transmitted in the region where the second light transmitting layer 240 is formed during exposure, and a larger amount of light is transmitted than the first light transmitting layer 230. As the second light transmitting layer 240 has a predetermined second transmittance, only part of light is irradiated to the photoresist. The second transmission layer 240 includes chromium oxide (CrOx) to control the transmittance. In addition, since the second light transmitting layer 240 has a higher light transmittance than the light blocking layer 220 and the first light transmitting layer 230, at least one of the light blocking layer 220 and the first light transmitting layer 230. It can be formed on the layer of. That is, in order to facilitate the manufacturing process of the photomask, it is possible to form the second light transmitting layer 240 on the remaining region except for the region through which light is to be completely passed.

3 is a view for explaining a photoresist pattern according to an embodiment of the present invention.

As shown in FIG. 3, a photoresist pattern 310 having a plurality of monolayers is formed according to the patterns of the layers 220, 230, and 240 formed on the transparent substrate 210. That is, in the region where the light blocking layer 220 of the photo mask is formed, the photoresist is not removed at all during the photoresist development, and thus has the first height h1 from the reference plane. In addition, in the region where the first light transmitting layer 230 of the photomask 200 is formed, the photoresist is partially removed to have a second height h2 as the photoresist is removed. In addition, in the region where the second light transmitting layer 240 of the photo mask is formed, when the photoresist is partially developed, the photoresist is partially removed to have a third height h3 lower than the second height h2 from the reference plane. Also, in the region where only the transparent substrate 210 of the photomask is formed, the photoresist is completely removed during the photoresist development.

As described above, the photoresist pattern 310 formed by using the photomask according to the exemplary embodiment of the present invention has three single layers h1, h2, and h3 having different heights from the reference plane. As mentioned earlier in FIG. 1, when using a conventional halftone mask, the problem caused by the photoresist pattern having a double monolayer is improved by using a photomask according to an embodiment of the present invention. can do.

In another embodiment of the present invention, the patterns of the layers 220, 230, and 240 formed on the photomask may be changed according to necessity and use. In addition, the photomask of this invention can be used in the various process which requires the photoresist pattern which has a some single layer.

4A to 4H are cross-sectional views of respective manufacturing process steps of a method of manufacturing a liquid crystal display panel according to an exemplary embodiment of the present invention.

4A to 4H, which illustrate a process of manufacturing a back substrate of a liquid crystal display panel according to an exemplary embodiment of the present invention, the back substrate is formed according to the following steps.

First, as shown in FIG. 4A, an indium-tin-oxide (ITO) is deposited on the transparent insulating substrate 401 to form a pixel electrode layer 402. Thereafter, a gate material such as copper (Cu) is deposited on the pixel electrode layer 402 to form the gate electrode layer 403. Thereafter, a first photoresist pattern 404 having a different thickness is formed by using a half tone mask.

Next, as shown in FIG. 4B, the gate electrode layer 403 is etched by a wet etching method, and the pixel electrode layer 402 is wet etched. Thereafter, the first photoresist 404 is partially removed through an ashing process, and then the gate electrode layer 403 is wet etched. Thereafter, the first photoresist 404 is removed through a stripping process.

Next, as shown in FIG. 4C, the gate insulating layer 405 is deposited, and the semiconductor layer 406 is formed on the gate insulating layer 405. Thereafter, a source drain electrode layer 407 for forming the source electrode and the drain electrode is formed on the semiconductor layer 406. In this case, the source drain electrode layer 407 includes at least two or more regions different in height from the transparent insulating substrate 401. That is, it includes the Y region which is the first region having the first height and the X region which is the second region having the second height lower than the first height.

Thereafter, as shown in FIG. 4D, a second photoresist 408 is formed on the source drain electrode layer 407. In this case, the second photoresist 408 is formed flat so as to have the same height from the transparent insulating substrate 401.

Thereafter, as shown in FIG. 4E, a second photoresist pattern 408 having a triplex monolayer is formed using a photomask according to an exemplary embodiment of the present invention. That is, the photoresist is exposed using a photomask including at least two light transmission layers corresponding to the X region and the Y region and having different light transmittances. Preferably using a photomask comprising a first light transmission layer corresponding to the Y region and having a first light transmittance, and a second light transmission layer corresponding to the X region and having a second light transmission higher than the first light transmission. Do it. The X region and the Y region of the second photoresist have different heights, that is, have different heights from the transparent insulating substrate 401, so that they have the same thickness. Here, a more detailed description of the photo mask will be omitted since it has been fully described with reference to FIGS. 2 and 3. Thereafter, the source drain electrode layer 407 is wet etched.

Thereafter, as shown in FIG. 4F, the semiconductor layer 406 and the gate insulating layer 405 are continuously etched by a dry etching method.

Thereafter, as shown in FIG. 4G, the second photoresist pattern 408 is partially removed through the ashing process. At this time, since the X region and the Y region of the second photoresist 408 have the same thickness, the ashing time can be further reduced compared to the conventional. Thereby, the efficiency of a manufacturing process can be improved.

Thereafter, as shown in FIG. 4H, after the ashing process of FIG. 4G, the back substrate is further completed through at least one process step using a photolithography method. The completed back substrate 400 includes a gate pad 410, a data pad 420, a data line 430, a pixel electrode 440, a gate line 450, and a thin film transistor 460. do.

As such, the technical configuration of the present invention described above can be understood by those skilled in the art that the present invention can be implemented in other specific forms without changing the technical spirit or essential features of the present invention.

Therefore, the exemplary embodiments described above are to be understood as illustrative and not restrictive in all aspects, and the scope of the present invention is indicated by the following claims rather than the detailed description, and the meaning and scope of the claims and All changes or modifications derived from the equivalent concept should be interpreted as being included in the scope of the present invention.

As described above, according to the present invention, the thickness of the photoresist pattern can be uniformly formed regardless of the step by improving the structure of the photomask.

Moreover, this invention has the effect which can improve the efficiency of a manufacturing process by manufacturing a liquid crystal display panel using the photomask mentioned above.

Claims (12)

Transparent substrates; A light blocking layer formed on the transparent substrate; A first light transmitting layer formed on the transparent substrate; And And a second light transmitting layer formed on the transparent substrate and having a higher transmittance than the first light transmitting layer. The method of claim 1, The light blocking layer comprises chromium (Cr). The method of claim 1, And the first light transmitting layer comprises an organic material. The method of claim 3, And the organic material comprises photo acryl. The method of claim 1, The second light transmitting layer is a photo mask, characterized in that containing chromium oxide (CrOx). The method according to claim 1 to 5, And the second light transmitting layer is formed on at least one of the light blocking layer and the first light transmitting layer. Forming at least one of a metal layer, an insulating layer, a protective layer, or a semiconductor layer on the substrate; Applying a flat photoresist on the top layer of the substrate including at least two regions of different heights; And And forming a photoresist pattern using a photo mask including at least two light transmission layers corresponding to the respective areas and having different light transmittances. The method of claim 7, wherein The uppermost layer of the substrate comprises a first region having a first height and a second region having a second height lower than the first height, The photo mask may include a first light transmission layer corresponding to the first region and having a first light transmittance, and a second light transmission layer corresponding to the second region and having a second light transmission higher than the first light transmission. The manufacturing method of the liquid crystal display panel characterized by including. The method of claim 8, The first light transmitting layer comprises an organic material. The method of claim 9, And the organic material comprises photo acryl. The method of claim 8, The second light transmitting layer comprises a chromium oxide (CrOx) manufacturing method of the liquid crystal display panel. The method according to claim 7 to 11, And the second transmission layer is formed on at least one layer of the first light transmission layer or the light blocking layer that blocks the light.

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