KR100731026B1 - Method For Fabricating Liquid Crystal Display Panel - Google Patents

Abstract

The present invention relates to a method of manufacturing a liquid crystal panel in which a sacrificial layer is formed to form a metal pattern by using a CMP technique. Patterning a sacrificial layer, filling a metal into the sacrificial layer recess, removing a surplus metal to form a gate electrode and a gate wiring by a chemical mechanical polish technique, and Forming a gate insulating film; forming a stacked layer of a semiconductor layer and a source / drain electrode on the gate electrode; and laminating a passivation film and a transparent conductive film on the resultant to be connected to the drain electrode. It is characterized by forming.

CMP, profile, plastic

Description

Manufacturing method of liquid crystal panel {Method For Fabricating Liquid Crystal Display Panel}

1 is a plan view showing a general liquid crystal panel.

2A to 2E are cross-sectional views taken along line A-A 'of FIG. 1 for explaining a method of manufacturing a liquid crystal panel according to the prior art.

3A to 3E are cross-sectional views illustrating a method of manufacturing a liquid crystal panel according to the present invention.

* Explanation of symbols on the main parts of the drawings

31 substrate 32 sacrificial layer

33: gate electrode 34: gate wiring

35 gate insulating film 36 semiconductor layer

37 source electrode 38 drain electrode

39: protective film 40: pixel electrode

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device (LCD), and more particularly to a method of manufacturing a liquid crystal panel.

Among flat panel displays, the liquid crystal display device is gradually increasing its weight due to features such as thin, low cost, low power consumption, and easy full color.

Recently, research and development for increasing the size of the screen, high precision, and high definition, increasing productivity, and simplifying the manufacturing process continue.

The liquid crystal display device having such characteristics has a structure in which a color filter substrate as an upper substrate and a thin film transistor (TFT) substrate as a lower substrate are disposed to face each other, and a liquid crystal having dielectric anisotropy is formed therebetween. A thin film transistor added to hundreds of thousands of pixels is switched through a pixel selection address line to drive a voltage to a corresponding pixel.

The liquid crystal panel manufacturing of the liquid crystal display device is classified into a thin film transistor substrate manufacturing process, a color filter substrate manufacturing process, and a liquid crystal cell process. The thin film transistor substrate manufacturing process is repeated by deposition, photography, and etching processes. Forming switching elements for applying a pixel unit signal on the glass substrate, the color filter substrate manufacturing process is to produce a color filter layer of R, G, B using a dye or pigment on the glass substrate on which the black matrix is formed It is a process of forming a transparent conductive film.

In the liquid crystal cell process, the thin film transistor substrate on which the thin film transistor process is completed is bonded to the color filter substrate on which the color filter process is completed, and then a liquid crystal is injected to form a liquid crystal layer therebetween.                         

Hereinafter, a liquid crystal panel manufacturing method according to the related art will be described with reference to the accompanying drawings.

1 is a plan view illustrating a general liquid crystal panel, and FIGS. 2A to 2E are cross-sectional views taken along line AA ′ of FIG. 1 for explaining a method of manufacturing a liquid crystal panel according to the prior art.

A general liquid crystal panel includes a thin film transistor substrate, a color filter substrate composed of a color filter layer and a laminated film of a common electrode, and a liquid crystal layer formed between the two substrates.

Here, the thin film transistor substrate may include a gate wiring 5 and a data wiring 11 arranged in a matrix to distinguish unit pixels as shown in FIG. 1, a thin film transistor 14 formed at an intersection of the two wirings; The pixel electrode 10 is connected to the thin film transistor 14.

Referring to FIGS. 2A through 2E, a method of manufacturing a thin film transistor substrate of the liquid crystal panel is first formed by depositing a metal on the entire surface of the substrate and forming a gate electrode and a gate wiring through photolithography.

That is, after forming a photoresist (2) on the metal 100 deposited on the substrate 1, as shown in Figures 2a and 2b, the patterned mask 12 on the photoresist (2) By positioning and selectively irradiating light, a pattern identical to that of a mask is formed on the photoresist 2. Next, the photoresist of the lighted portion is removed and patterned using a developer.

After completing the photo process, the metal of the portion without the photoresist is etched as shown in FIG. 2C to obtain the desired gate electrode 3 and the gate wiring 4. For reference, the etching process includes dry etching using gas and wet etching using chemical solution.

Next, as shown in FIG. 2D, a gate insulating film 5 is formed on the entire surface including the gate wiring 4 and the gate electrode 3, and a semiconductor layer 6 is formed on the gate electrode 3. The source electrode 7 and the drain electrode 8 are formed on the layer. A data line ('11' in FIG. 1) is formed to cross the gate line 5 at the same time as the source / drain electrode 7/8.

In this case, the laminated film of the gate electrode 3, the semiconductor layer 6, and the source / drain electrodes 7/8 forms a thin film transistor.

Finally, as shown in FIG. 2E, the passivation layer 9 is formed on the entire surface including the thin film transistor, and a portion of the passivation layer 9 is removed to form the pixel electrode 10 connected to the drain electrode 8. .

However, the conventional manufacturing method of the liquid crystal panel as described above has the following problems.

First, when plastic is used as the substrate, the process is complicated because a protective film for protecting the substrate must be further formed from a high temperature process for forming various device patterns.

Second, when the metal is directly patterned by the conventional photolithography process technology, the reliability of the device is deteriorated such that a profile of the patterned metal surface is poor and a step is generated.

The present invention has been made to solve the above problems, to provide a method for manufacturing a liquid crystal panel to improve the process characteristics by forming a sacrificial layer having a recessed portion and forming a metal pattern in the recessed portion by CMP technology. There is a purpose.

According to an aspect of the present invention, there is provided a method of manufacturing a liquid crystal panel, the method including: applying a sacrificial layer on a first substrate; and patterning the sacrificial layer to have a recessed portion at a depth of half the sacrificial layer; Filling a recess in the sacrificial layer, forming a gate electrode and a gate wiring by removing excess metal using a chemical mechanical polish technique, and forming a gate insulating film on the resultant; And forming a lamination film of a semiconductor layer and a source / drain electrode on the gate electrode, and laminating a transparent conductive film on the resultant to be connected to the protective film and the drain electrode.

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

3A to 3E are cross-sectional views taken along line AA ′ of FIG. 1 for explaining a method of manufacturing a liquid crystal panel according to the present invention.

The liquid crystal panel is manufactured by forming a color filter substrate as an upper substrate and a thin film transistor substrate as a lower substrate and injecting a liquid crystal layer between the two substrates.                     

In this case, the color filter substrate forms a color filter layer to implement color, and forms a common electrode on the color filter layer.

The thin film transistor substrate may include a gate line and a data line arranged in a matrix to separate pixel regions, a thin film transistor formed at an intersection of the gate line and the data line, and electrically connected to the thin film transistor. It consists of a pixel electrode located in a region.

Referring to the thin film transistor substrate manufacturing method in detail, first, as shown in FIG. 3A, a sacrificial layer 32, such as photo BCB (benzocyclobutene), capable of photolithography is formed on the substrate 31.

The sacrificial layer 32 then serves to protect the substrate 31 from the high temperature when the gate metal and the gate wiring are formed. Therefore, the selection range of the wiring material is also widened, so that the optimum low resistance wiring can be selected, and the substrate can be used as well as the glass substrate and the plastic substrate, so that the characteristics of the flexible substrate can be effectively used.

Next, a mask including a slit diffracting light is placed on the sacrificial layer and the sacrificial layer is selectively exposed. At this time, the time is adjusted to half-exposure to half the depth of the sacrificial layer. Next, the sacrificial layer 32 is patterned to have a recessed shape as shown in FIG. 3B by performing a delay dvelope.

Thereafter, the patterned sacrificial layer 32 is filled with metal. The metal is deposited by a sputtering method using copper (Cu), molybdenum (Mo), aluminum (Al), chromium (Cr), etc. as gate electrodes and gate wirings to be formed later.

The excess portion of the filled metal is then removed using a chemical mechanical polish (CMP) method. This allows the metal upper surface to be completely flat as in FIG. 3C to provide a very good profile of the gate electrode 33 and the gate wiring 34 and to eliminate the step resulting from the poor profile.

Next, as shown in FIG. 3D, a gate insulating layer 35 is formed on the entire surface including the gate electrode 33 and the gate wiring 34, and the semiconductor layer 36 and the source / drain electrode are formed on the gate electrode 33. (37/38) is laminated. The source / drain electrodes are formed simultaneously with the data lines.

Here, as the gate insulating layer 35, an inorganic insulating material of a silicon nitride film or a silicon oxide film, an organic BCB or an acrylic resin is used, and the semiconductor layer 36 is made of amorphous silicon (a-Si). ) Is deposited by PECVD (Plasma Enhanced Chemical Vapor Deposition) method.

At this time, the laminated film of the gate electrode 33, the semiconductor layer 36, and the source / drain electrodes 37/38 is a thin film transistor and serves to selectively turn on / off a data signal according to the gate voltage. Do it.

Finally, as shown in FIG. 3E, the passivation layer 39 is formed on the entire surface including the thin film transistor and the data line using BCB or acrylic resin, and the protection layer is partially removed to be electrically connected to the drain electrode 38. The pixel electrode 40 is formed.

Indium tin oxide (ITO) containing about 5% of tin oxide is mainly used as the pixel electrode 40.

The manufacturing method of the liquid crystal panel of the present invention as described above has the following effects.

First, instead of performing the photolithography process directly on the wiring material, the choice of large area wiring material can be expanded by using CMP technology.

Second, smoothing the metal surface by CMP technology solves the step problem caused by the poor profile of the metal surface.

Third, when the substrate is plastic, a protective film must be further formed on the substrate in preparation for the subsequent high temperature process. In the present invention, a sacrificial layer is formed to protect the substrate at the same time as the metal pattern so that a separate protective film is not necessary. This becomes simpler.

Fourth, the problem of low adhesion between the substrate and the metal is solved by forming a sacrificial layer having excellent adhesion between the substrate and the metal.

Claims (4)

Forming a sacrificial layer by applying photo benzocyclobutene (BCB) on the substrate; Half-exposure the light by diffracting the sacrificial layer through a mask; Delay developing the semi-exposed sacrificial layer to form recesses; Filling metal into recesses of the sacrificial layer; Forming a gate electrode and a gate wiring by removing excess metal by a chemical mechanical polish technique; Forming a gate insulating film on an entire surface of the substrate including the gate electrode and the gate wiring; Forming a stacked film of a semiconductor layer and a source / drain electrode on the gate insulating film on the gate electrode; Forming a protective film on the laminated film of the semiconductor layer and the source / drain electrodes; And, And removing the protective film on the drain electrode and stacking the transparent conductive film electrically connected to the drain electrode. delete delete The method of claim 1, wherein the substrate is a glass substrate or a plastic substrate.

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