KR20060128078A - Substrate for display panel and method of fabricating the same - Google Patents

Abstract

A substrate for a display device and a method for fabricating the same are provided to form color filter films without any difference in height, thereby preventing various reject such as longitudinal lines. A substrate for a display device includes a protecting film(190) formed with openings(300) at areas overlapping data lines(120) on a substrate(100), and color filter films(150r,150g) of different colors alternately disposed at areas defined by intersection between the data lines and gate lines. The color filter films are overlapped each other at the openings to prevent generation of stepped differences in boundary portions between the color filter films.

Description

Substrate for Display Panel and Method of Fabricating the Same}

1 is a plan view showing a substrate on which a pixel region of a typical liquid crystal display device is formed;

2 is a cross-sectional view of the substrate taken along the line AA ′ of FIG. 1;

3 is a cross-sectional view of the substrate taken along line AA ′ of FIG. 1 in accordance with an embodiment of the present invention;

4A to 4G are cross-sectional views illustrating a method of manufacturing a substrate according to an embodiment of the present invention.

♧ explanation of symbols for main parts of drawing

100-Substrate 110a-Gate Electrode

120-data line 120a-source electrode

120b-Drain electrode 140-Pixel electrode

150-Color filter layer 160-Gate insulation layer

170-Semiconductor Layer 180-Ohmic Contact Layer

190-Shield 200-Contact Holes

300-opening groove

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device substrate and a method for manufacturing the same, and more particularly, to a display device substrate and a method for manufacturing the same, in which a step is reduced at a boundary portion of a color film constituting the color filter film.

In general, a flat panel display (FPD) is a display device that provides a thin and flat screen, and is typically used as a liquid crystal display device (LCD) or a large digital TV that is widely used as a notebook computer monitor. Such as organic light emitting displays (OELDs) used in plasma displays (PDPs) or mobile phones.

The liquid crystal display transmits an image by converting an input electrical signal into visual information by using a property in which light transmittance of a liquid crystal, which is an intermediate state material between a liquid and a crystal, changes according to an applied voltage. A typical liquid crystal display device is composed of two substrates provided with electrodes and a liquid crystal injected between the substrates. Different voltages are applied to the two substrates to apply an electric field to the liquid crystal. At this time, the arrangement of the liquid crystal molecules is changed to change the light transmittance. Such liquid crystal displays have been widely used in recent years because they are lighter in weight, smaller in volume, and operate with smaller power than other display apparatuses having the same screen size.

1 is a plan view showing a substrate on which a pixel region of a typical liquid crystal display device is formed. Referring to FIG. 1, a plurality of gate lines 11 and data lines 12 are formed to intersect horizontally and vertically on a substrate 10. An area in which the gate line 11 and the data line 12 cross each other corresponds to a pixel area, and each of the pixel areas includes a thin film transistor 13 and a pixel electrode 14.

A schematic operation of the liquid crystal display device configured as described above is as follows. First, when the gate-on signal is applied to the gate line 11 and the thin film transistor 13 is turned on, the data voltage of the data line 12 is applied to the pixel electrode 14 through the thin film transistor 13. At this time, a separate substrate (not shown) on which the common electrode is formed is provided on the upper side of the pixel electrode 14. A reference voltage is applied to the common electrode, and a liquid crystal is generated by an electric field corresponding to a voltage difference applied to both electrodes. The arrangement of the molecules is altered.

FIG. 2 is a cross-sectional view taken along the line AA ′ of FIG. 1.

Referring to FIG. 2, a gate insulating layer 16 is formed on the transparent insulating substrate 10. The data line 12 is formed in a predetermined region on the gate insulating layer 16, and the passivation layer 19 is formed on the gate insulating layer 16 and the data line 12. On the other hand, a thin film transistor is formed in a predetermined region on the substrate 10. The thin film transistor includes a gate electrode 11a insulated by the gate insulating film 16, a source electrode 12a, and a drain electrode 12b. . The gate electrode 11a is formed to be connected to the gate line in FIG. 1, the source electrode 12a is connected to the data line 12, and the drain electrode 12b is opposite to the source electrode 12a. Is formed. At this time, the gate electrode 11a is insulated from the gate insulating film 16, and an ohmic contact layer in which impurity ions are implanted and a semiconductor layer 17 in which a channel is formed between the gate insulating film 16 and the passivation film 19. 18 is further formed, and the protective film 19 covers the thin film transistors and the like to protect them.

The color filter film 15 is formed on the passivation film 19. The color filter film 15 is for realizing color, and is composed of red, green, and blue color films 15r and 15g, which are three primary colors of light, among which a red film 15r and a green color are shown in FIG. Membrane 15g is shown. The color layers 15r and 15g are formed for each pixel area where the data line and the gate line cross each other in FIG. 1. Therefore, as shown in FIG. 2, different color films 15r and 15g are formed on the left and right sides of the data line 12. A pixel electrode 14 for each pixel is formed on the color filter layer 15, and although not shown in FIG. 2, the pixel electrode 14 includes a liquid crystal together with a common electrode formed on a substrate provided separately. Works to change the array of. On the other hand, in the region where the thin film transistor is formed, the pixel electrode 14 and the drain electrode 12b are formed on the upper layer and the lower layer of the passivation layer 19, and these are electrically formed by the contact hole 20 formed in the passivation layer 19. Is connected.

The color filter film 15 is usually formed in the order of red / green / blue using a photoresist containing a color indicating pigment. That is, after forming the green photoresist film in a state where the red film 15r is formed, the green film 15g is formed by patterning according to a photolithography process. However, it is difficult to form the red film 15r and the green film 15g so as to be clearly distinguished from each other in the process technology, and as shown in FIG. The overlapping area is increased in thickness than other parts and protrudes to the upper part, which causes various defects such as vertical streaks and a decrease in contrast ratio (CR).

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a substrate for a display device in which a step of a portion where a color film overlaps is reduced. In addition, another technical problem of the present invention is to provide a method of manufacturing the substrate for a display device.

In order to achieve the above technical problem, the present invention provides a substrate for a display device. According to the display substrate, the protective film of the portion where the color filter film protrudes from the color filter film formed on the protective film is removed. That is, the surface of the color filter film can be formed flat by removing the height of the stepped portion of the color filter film from the protective film in advance.

Specifically, the display device substrate of the present invention includes a substrate and a plurality of gate lines formed in a predetermined region on the substrate, a gate insulating film covering the substrate and the gate line, and a plurality of gate lines formed on the gate insulating film so as to intersect the gate line. And a color filter layer formed on the passivation layer and the passivation layer covering the data line, wherein the passivation layer is formed with an opening groove in an area overlapping the data line. The color filter layer is formed by alternately arranging color layers representing different colors in each of the regions where the gate lines and the data lines cross each other, so that a step does not occur at a boundary between the color layers representing the different colors. Color films showing different colors are formed to overlap each other in the opening groove.

The opening groove may have a width greater than that of the data line. That is, although the data lines serve as boundary between color films showing different colors, the opening grooves may be formed in a somewhat wider range than actual overlapping portions in consideration of process margins and the like. In addition, it is preferable to remove the entire protective film in an area overlapping the data line so that the depth of the opening groove is formed to be equal to the thickness of the protective film. This is because when only a part of the protective film in the region overlapping with the data line is removed, it is not easy to form the opening groove having a uniform thickness.

As described above, the substrate on which the step of the color filter film is removed and the opening groove is formed may be manufactured as follows. That is, the manufacturing method of the present invention comprises the steps of forming a plurality of gate lines in a predetermined region on a substrate, forming a gate insulating film covering the substrate and the gate line, a plurality of intersecting the gate lines on the gate insulating film Forming a data line, forming a passivation layer covering the gate insulating layer and the data line, forming an opening groove by removing an area overlapping the data line in the passivation layer, and forming a color on the passivation layer on which the opening groove is formed. Forming a filter film.

The color filter layer may be formed by alternately arranging color layers representing different colors for each of the regions where the gate line and the data line cross each other, and the color layers of different colors overlap each other in the opening grooves. . In addition, a contact hole for electrically connecting an upper layer and a lower layer of the protective film, which is an insulating film, is formed in a predetermined region of the protective film, and the contact hole is formed simultaneously with the opening groove, thereby increasing process efficiency.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be applied and modified in various forms. Rather, the following embodiments are provided to clarify the technical spirit disclosed by the present invention, and furthermore, to fully convey the technical spirit of the present invention to those skilled in the art having an average knowledge in the field to which the present invention belongs. Therefore, the scope of the present invention should not be construed as limited by the embodiments described below. In addition, in the drawings presented in conjunction with the following examples, the size of layers and regions are simplified or somewhat exaggerated to emphasize clarity, and like reference numerals in the drawings indicate like elements.

The present invention is characterized on the vertical structure of the substrate and is not different from the conventional structure of FIG. 3 is a cross-sectional view illustrating a structure of a substrate according to an exemplary embodiment of the present invention, taken along the line AA ′ of FIG. 1.

Referring to FIG. 3, a gate electrode 110a is formed in a predetermined region on the transparent insulating substrate 100, and a gate insulating layer 160 is formed on the substrate 100 and the gate electrode 110a. The semiconductor layer 170 and the ohmic contact layer 180 are formed on the gate insulating layer 160 in the region where the gate electrode 110a is formed, and the source electrode 120a and the drain electrode 120b are formed on the ohmic contact layer 180. Is formed. Impurity ions are implanted into the ohmic contact layer 180 and a channel region is formed in the semiconductor layer 170, and the gate electrode 110a / source electrode 120a / drain electrode 120b form a thin film transistor. do. The gate electrode 110a and the source electrode 120a are connected to a plurality of gate lines (not shown) and data lines 120 that are formed on the substrate 100 while crossing each other. Therefore, the data line 120 is formed on the gate insulating layer 160 when the source electrode 120a is formed. Each region that is divided while the gate line and the data line 120 cross each other corresponds to a pixel region. In FIG. 3, separate pixel areas are formed on the left and right sides of the data line 120, and each pixel electrode 140 is provided in each of the pixel areas. The pixel electrodes 140 on the right are separate for different pixel regions. A passivation layer 190 is formed on the thin film transistor, and the passivation layer 190 covers the upper portion of the gate insulating layer 160 in the region where the data line 120 is formed.

The color filter layer 150 for realizing color is formed on the passivation layer 190. In the color filter film 150, color films 150r and 150g representing different colors are alternately arranged for each pixel area, and they are bounded by the data line 120. Therefore, in the color filter film 150 formed of the red, green, and blue films, which are three primary colors of normal light, the red film 150r and the green film 150g are partially overlapped with the data line as a boundary. It is formed in a state. The pixel electrode 140 is formed on each of the color films 150r and 150g of different colors on the color filter film 150.

The pixel electrode 140 is formed on the passivation layer 190 on the region where the thin film transistor is formed, and a drain electrode 120b is formed under the passivation layer 190. The pixel electrode 140 and the drain electrode 120b are electrically connected to each other by the contact hole 200 formed in the passivation layer 190.

An opening groove 300 is formed in the passivation layer 190. The opening groove 300 is formed on an area overlapping the data line 120, and as shown in FIG. 3, edges of the red layer 150r and the green layer 150g are formed in the opening groove 300. Overlapping. The opening groove 300 is formed such that regions in which different color films 150r and 150g overlap, such as the red film 150r and the green film 150g, do not protrude upward. In general, when the color filter film 150 is formed, a red, green, and blue color is formed in a predetermined order. For example, when the red film 150r is formed and then the green film 150g is formed, the red film 150r and the green film are formed. The boundary of 150g is not clear and some may overlap. When the red layer 150r and the green layer 150g overlap in this manner, the thicknesses of the edge portions of the overlapped red layer 150r and the green layer 150g are added to increase the thickness and to the top, compared to the single color layer. It may protrude. However, if the height of the base is lowered by forming the opening groove 300 on the passivation layer 190, which is a base where the red layer 150r and the green layer 150g are formed in advance, the depth of the opening groove 300 protrudes. The height of the part can be lowered. As a result, as shown in FIG. 3, even when the red film 150r and the green film 150g overlap, the top surface may be formed flat and uniformly.

The width of the opening groove 300 may be wider than the width of the data line 120. As described above, since the opening groove 300 is formed to eliminate the step at the boundary portion of the color film 150r and 150g, the opening groove 300 is the color film 150r and 150g as shown in FIG. It may be formed to fit the width of the data line 120 corresponding to the boundary. However, since the boundary between the color films 150r and 150g is not easy to be clearly formed, the width of the opening groove 300 may be somewhat relaxed in consideration of the fact that the width of the overlapping portions may be slightly expanded. It is.

The depth of the opening groove 300 may be formed to be the same as the thickness of the protective film 190. That is, in the region overlapping with the data line 120, the entire protective layer 190 is removed, rather than only a part of the protective layer 190. This is because the opening groove 300 having a uniform thickness can be easily formed by etching the upper surface of the data line 120 based on the data line 120 formed under the passivation layer 190. to be.

Hereinafter, a method of manufacturing a substrate having a structure in which an opening groove is formed as described above will be described.

4A to 4G are cross-sectional views illustrating a method of manufacturing the substrate of FIG. 3 according to an embodiment of the present invention.

Referring to FIG. 4A, first, a metal film is deposited on a transparent insulating substrate 100 using a sputtering method, and then a gate electrode 110a is formed through a photolithography process using a mask. As the substrate 100, a glass substrate is usually used, and as the metal film, chromium (Cr) or the like is used. Although not shown in the drawing, the gate electrode 110a is connected to the gate line. In this step, the gate line is formed together.

Referring to FIG. 4B, the gate insulating layer 160, the semiconductor layer 170, and the ohmic contact layer 180 are sequentially deposited, and then the semiconductor layer 170 and the ohmic contact layer are formed through a photolithography process using a mask. Pattern 180. The gate insulating layer 160 may use a silicon oxide film, a silicon nitride film, or the like, and the semiconductor layer 170 and the ohmic contact layer 180 may use amorphous silicon, and the like. In the case of an n-type thin film transistor, the ohmic contact layer may be used. In 180, ions are implanted with n-type impurities.

Referring to FIG. 4C, another metal film using chromium or the like is deposited by using a sputtering method and patterned to form a source electrode 120a / drain electrode 120b. In this case, a portion of the ohmic contact layer 170 and the semiconductor layer 180 exposed between the source electrode 120a and the drain electrode 120b are removed to remove the gate electrode 110a / source electrode 120a / drain. A channel region of the thin film transistor including the electrode 120b is formed. Similar to the gate electrode 110a and the gate line, the source electrode 120a is connected to the data line 120 and the source electrode 120a and the data line 120 are simultaneously patterned.

Referring to FIG. 4D, a protective film 190 using a silicon oxide film or a silicon nitride film is formed on the resultant material. The protective layer 190 is to protect the thin film transistor, etc. can be formed using chemical vapor deposition.

Referring to FIG. 4E, the passivation layer 190 is patterned to form the contact hole 200 and the opening groove 300. The pixel electrode 140 (see FIG. 3) is formed on the passivation layer 190 in a subsequent process, and the contact hole 200 is for electrically connecting the pixel electrode 140 and the drain electrode 120b. That is, the pixel electrode 140 is inserted into the contact hole 200 to be in contact with the drain electrode 120b, and the data voltage of the data line 120 is applied to the pixel electrode 140 through the thin film transistor.

The opening groove 300 is formed by etching the passivation layer 190 in a portion in contact with the data line 120 so that the upper surface of the data line 120 is exposed. The opening groove 300 is a novel component added in the present invention, but instead of adding a separate process for forming the same, it proceeds by merging into the existing forming process of the contact hole 200.

Referring to FIG. 4F, a color filter layer 150 is formed on the passivation layer 190 on which the contact hole 200 and the opening groove 300 are formed. The color filter layer 150 may be formed on a separate upper substrate facing the lower substrate 100 on which the thin film transistor is provided, centered on the liquid crystal. However, since the precision of the assembly between the upper substrate and the lower substrate 100 has a significant effect on the display quality, the color filter film is used for the purpose of reducing the influence caused by the miss assembly. 150 may be formed on the lower substrate 100. This is commonly referred to as a color filter on array (COA) structure, and the present invention is applied to the above described COA structure.

The color filter film 150 is formed by alternately arranging red, green, and blue films, which are three primary colors of light. In FIG. 4F, a red film 150r and a green film 150g formed at a boundary of the data line 120 among red, green, and blue colors are formed. When the color filter film 150 is formed, the color filter film 150 is formed in a predetermined order of red / green / blue. Therefore, first, a red photoresist film is formed by using a spin method or the like, followed by exposure and development. The negative photoresist is generally used as the photoresist, and in this case, a portion not exposed to light is removed when the developing process is performed. At this time, the edge portion of the red film 150r on the data line 120 is slightly inclined. In this state, the green photoresist film is formed, and then exposure and development are performed again to form the green film 150g, and the blue film is similarly formed. The boundary between the red film 150r and the green film 150g is overlapped with the edges of the color films 150r and 150g formed to be inclined, and the thickness thereof is thicker than the other parts. Therefore, although it may protrude upward, the opening groove 300 is formed on the data line 120 at the boundary between the red film 150r and the green film 150g, so that the opening groove 300 is formed as deep as the red film. The boundary portion between the 150r and the green film 150g is formed to have a low height. Therefore, the red film 150r / green film 150g does not protrude upward from the boundary portion, and the same applies to the blue film.

Referring to FIG. 4G, the conductive film 140 ′ for the pixel electrode is deposited using indium tin oxide, indium zinc oxide, or the like on the substrate 100 on which the opening groove 300 is formed. Subsequently, when the conductive film 140 'is patterned to form a pixel electrode, a substrate as shown in FIG. 3 is completed.

Although the substrate manufacturing method of the present invention has been described with reference to exemplary drawings, the substrate having the structure in which the opening groove of the present invention is formed may be manufactured by other methods besides the method shown in FIGS. 4A to 4G. In addition, although a thin film transistor is formed in order to explain a gate insulating film or a protective film, a feature of the present invention relates to an opening groove formed in a region in which a data line is formed. Therefore, a thin film transistor having a structure different from that of FIG. The technology of the present invention is also applied to the substrate provided as it is.

As described above, according to the substrate for a display device of the present invention and a method of manufacturing the same, the color filter film is uniformly formed without any difference in height, thereby preventing various defects such as vertical streaks.

Claims (10)

Board, A plurality of gate lines formed in predetermined regions on the substrate, A gate insulating film covering the substrate and the gate line; A plurality of data lines formed on the gate insulating film to cross the gate lines; A protective film covering the data line and a color filter film formed on the protective film; And the opening is formed in the passivation layer in an area overlapping the data line. The method of claim 1, The color filter layer may be formed by alternately arranging color layers representing different colors for each of the regions where the gate lines and the data lines cross each other, and the color layers representing the different colors overlap each other in the opening grooves. A display device substrate. The method according to claim 1 or 2, And a width of the opening groove is larger than a width of the data line. The method according to claim 1 or 2, And a depth of the opening groove is equal to a thickness of the passivation layer. The method according to claim 1 or 2, And a pixel electrode formed on the color filter film for each region where the gate line and the data line cross each other. Forming a plurality of gate lines in a predetermined region on the substrate; Forming a gate insulating film covering the substrate and the gate line; Forming a plurality of data lines intersecting the gate lines on the gate insulating film; Forming a passivation layer covering the gate insulating layer and the data line; Forming an opening groove by removing an area overlapping the data line in the passivation layer; And forming a color filter film on the passivation film on which the opening groove is formed. The method of claim 6, The color filter layer may be formed by alternately arranging color layers representing different colors for each of the regions where the gate lines and the data lines cross each other, and the color layers of the different colors overlap each other in the opening grooves. The manufacturing method of the board | substrate for display apparatuses made into it. The method according to claim 6 or 7, And wherein the opening groove is formed by etching a protective film in an area overlapping the data line until the data line is exposed. The method of claim 8, And forming a pixel electrode on the color filter film for each region where the gate line and the data line cross each other. The method of claim 9, A thin film transistor connected to the gate line and the data line is formed in each region where the gate line and the data line cross each other, and a contact hole connecting the thin film transistor and the pixel electrode is formed in a predetermined region of the passivation layer. And a tact hole is formed simultaneously with the opening groove.

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