KR100228429B1 - Lcd device and its manufacturing method - Google Patents

Abstract

The present invention discloses a liquid crystal display and a method of manufacturing the same for preventing electric field distortion and signal distortion.

The present invention discloses a method of forming a counter electrode on a semiconductor substrate; Forming a gate insulating film on the counter electrode; Etching a portion of the gate insulating layer to form a hole to expose a region predetermined by a data electrode wiring and a region predetermined by a pixel electrode; And embedding a metal film in the hole to form a data electrode wiring and a pixel electrode.

Description

Liquid Crystal Display and Manufacturing Method Thereof

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device and a manufacturing method thereof, and more particularly, to a liquid crystal display device capable of stably driving a liquid crystal and a manufacturing method thereof.

In general, liquid crystal displays constitute display elements such as televisions and graphic displays, and especially active matrix type liquid crystal displays have high-speed response characteristics and are suitable for high pixel counts, thereby increasing the quality of display screens, increasing the size, and displaying color screens. It greatly contributes to the realization of money.

The liquid crystal display includes a pair of transparent glass substrates, thin film transistors and pixel electrodes formed on at least one substrate, a color filter and a counter electrode formed on the other substrate, and a liquid crystal material between the pair of glass substrates. This is done by encapsulation.

Here, as the liquid crystals used in recent years, a twist nematic mode (hereinafter referred to as TN) liquid crystal having excellent optical characteristics is used, and the twisted nematic mode has a twist angle of 90 °, and the liquid crystal molecules are upper and lower glass. Since they are arranged parallel to the substrate plane, or the arrangement direction is 90 ° difference between both substrates, the entire molecular array is arranged so that there is a continuous 90 ° change between the two substrates, and when the liquid crystal voltage is applied, the electric field is opposed It is formed perpendicular to the two substrate surfaces.

However, the liquid crystal display of the TN structure has a chronic problem of narrowing the viewing angle.

Therefore, the liquid crystal display of the IPS mode, which can form a wide field of view by forming a counter electrode formed on the upper glass substrate in the lower glass substrate and applying a horizontal electric field when a voltage is applied to the electrode, Proposed. As shown in FIG. 1, the liquid crystal display of the IPS (In Plane Swiching) mode includes a gate line 2A and a gate line 2A in a row direction for scanning an image on the lower glass substrate 1. The counter electrode 2B is formed on the same plane as and spaced apart by a predetermined distance. The counter electrode 2B also serves as a storage capacitor for maintaining the liquid crystal for a predetermined time, and its shape has a " □ " shape to define a unit cell. Although not shown in the drawing, a gate insulating film (not shown) is formed to provide electrical insulation between the lower gate line 2A and the materials to be formed later, and includes a gate including the gate line 2A. In a predetermined portion of the insulating film, a semiconductor layer 4 serving as a channel of the thin film transistor is formed. The data line 5A and the pixel electrode 5B are formed on the same plane, and the data line 5A intersects the gate line 2A perpendicularly and the semiconductor layer 4 on the gate line 2A. ) Overlaps a predetermined portion to form a source electrode 5A-1, and the pixel electrode 5B is formed in an “I” shape so as to divide the surface surrounded by the counter electrode 2B, and the gate of the pixel electrode 5B is formed. Portions parallel to the line 2A each overlap with a portion parallel to the gate line of the counter electrode 2B, and one end of the pixel electrode 5B extends to overlap the semiconductor layer 4. Here, reference numeral 5A-1 denotes a source electrode of the thin film transistor, and 5B-1 denotes a drain electrode of the thin film transistor.

In order to show the cross section of the liquid crystal display element of FIG. 1, the figure cut out by the II-II 'line is shown in FIG. FIG. 2 schematically shows the relationship between the data line, the counter electrode and the pixel electrode. The semiconductor layer 4 of FIG. 1 is not shown.

First, metals, such as aluminum, titanium, tantalum, and chromium, are deposited on the transparent lower glass substrate 1 and patterned in a predetermined form to form a gate line (not shown) and a counter electrode 2B. The gate insulating film 3 is formed so as to be insulated from the metal line to be formed in the. The gate insulating film 3 is formed in double or a metal oxide film. Subsequently, although not shown in the figure, a first semiconductor layer serving as a channel and a doped second semiconductor layer serving as an ohmic contact are formed on the gate insulating film 3 as is known. Thereafter, a metal film is deposited on the resultant, and then partially etched to form the data electrode wiring 5A and the pixel electrode 5B.

However, the liquid crystal display of the conventional IPS mode has the advantage that the counter electrode 2B and the pixel electrode 5B are formed on the same substrate, so that the viewing angle is excellent using a parallel electric field. Since the counter electrode 2B and the pixel electrode 5B are not formed on the same line, as shown in FIG. 2, a complete planar electric field is not applied. As a result, the electric field is distorted, and the liquid crystal is unstable.

In addition, since the data electrode wiring is formed at a position higher than the counter electrode, the signal of the data electrode wiring acts as noise to the pixel electrode, resulting in deterioration of the pixel electrode.

In order to prevent such a phenomenon, the area of the counter electrode should be formed wide or the distance between the counter electrode and the data electrode wiring should be kept wide.

However, such a method lowers the aperture ratio of the pixel electrode and causes a problem that is difficult to be applied to a highly integrated liquid crystal display device.

Accordingly, the present invention has been made to solve the above-mentioned conventional problems, and the gate electrode wirings, the counter electrodes, the data electrode wirings, and the pixel electrodes constituting the liquid crystal display are all formed on the same line in the same plane, thereby preventing electric field distortion and An object of the present invention is to provide a liquid crystal display device which reduces pixel electrode deterioration.

In addition, another object of the present invention is to provide a method for manufacturing the above liquid crystal display device.

1 is a plan view of a liquid crystal display of a general IPS mode.

FIG. 2 is a cross-sectional view of FIG. 1 taken along the line II-II '.

3 (a) to 3 (c) are cross-sectional views for explaining a liquid crystal display device and a manufacturing method thereof according to the present invention.

* Explanation of symbols for main parts of the drawings

11 semiconductor substrate 12 counter electrode

13 gate insulating layer 14A data electrode wiring

14B: pixel electrode

In order to achieve the above object of the present invention, the liquid crystal display device of the present invention, the pixel electrode for driving the liquid crystal and the counter is formed spaced apart from the same substrate at a predetermined distance to form an electric field parallel to the pixel electrode A liquid crystal display comprising an electrode, wherein the pixel electrode and the counter electrode are formed on the same line of the same substrate.

The liquid crystal display device of the present invention further includes a data electrode wiring and a counter electrode formed on the same substrate as the data electrode wiring and spaced apart from the data electrode wiring by a predetermined distance to form a parallel electric field. The data electrode wirings and the counter electrodes are formed on the same line of the same substrate.

Further, the liquid crystal display device of the present invention is located between the data electrode wiring, the pixel electrode positioned at a predetermined distance apart from the data electrode wiring, the data electrode wiring and the pixel electrode, and the data electrode wiring and the pixel electrode respectively. A liquid crystal display device comprising a counter for forming a parallel electric field, wherein the data electrode wiring, the pixel electrode, and the counter are each formed on the same substrate and are positioned on the same line.

In addition, the manufacturing method of the liquid crystal display device according to the present invention comprises the steps of forming a counter electrode on the semiconductor substrate; Forming a gate insulating film on the counter electrode; Etching a portion of the gate insulating layer to form a hole to expose a region predetermined by a data electrode wiring and a region predetermined by a pixel electrode; And embedding a metal film in the hole to form a data electrode wiring and a pixel electrode.

According to the present invention, the counter electrode, the data electrode wiring, and the pixel electrode are formed on the same line, thereby achieving a perfect planar electric field, thereby preventing electric field distortion and signal distortion of the data electrode wiring.

EXAMPLE

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 (a) and 3 (c) are cross-sectional views for explaining a liquid crystal display and a method of manufacturing the same according to the present invention, wherein 11 denotes an insulating substrate, 12 denotes a counter electrode, and 13 Represents an insulating film. In addition, 14A represents data electrode wiring, 14B represents a pixel electrode, and 15 represents a protective film.

The planar configuration of the liquid crystal display of the present invention is the same as that of the conventional IPS mode, and a description thereof will be omitted.

First, FIG. 2 (a) is a cross section in which the counter electrode 12 is formed on the insulating substrate 11, and a film having excellent conductive properties such as a metal film, for example, aluminum and tantalum, has a predetermined thickness on the insulating substrate. Is deposited. Subsequently, the metal film is partially patterned to form a counter electrode 12 and a gate electrode wiring (not shown). In this case, before the counter electrode 12 is formed, a buffer oxide film, for example, a silicon nitride film, a silicon nitride oxide film, or a tantalum oxide film may be formed on the insulating substrate 11. Thereafter, a gate insulating film 13 is formed on the insulating substrate 11 on which the counter electrode wiring 12 is formed. In this case, a silicon oxide film, a silicon nitride film, a silicon oxide film, a laminated film of a silicon nitride film, or a silicon nitride oxide film may be used as the gate insulating film.

Subsequently, in FIG. 2B, the data electrode wiring region H1 and the pixel electrode region H2 of the liquid crystal display are exposed, and the data electrode wiring predetermined region and the pixel electrode predetermined region are disposed on the gate insulating layer 13. A mask pattern (not shown) is formed so that it can be exposed. Since the mask pattern is a mask required in the pad opening process for applying a predetermined driving voltage to the liquid crystal display, a separate mask pattern forming process is excluded.

Subsequently, the gate insulating film 13 is exposed in the form of this mask pattern to expose the data electrode wiring region H1 and the pixel electrode region H2. Although not shown in the drawing, the semiconductor layer forming process, the etch stopper forming process, and the ohmic contact layer forming process of the thin film transistor are performed before the mask pattern forming process.

Thereafter, FIG. 2 (c) is a cross section in which the data electrode wiring 14A and the pixel electrode 14B are formed on the same line as the counter electrode 12, and the exposed data electrode wiring H1 and the pixel electrode region H2. The metal film is formed on the gate insulating film 13 by the sputtering method so as to be in contact with the metal film. Then, the metal film is etched and removed so as to expose the gate insulating layer 13 by etching, chemical mechanical polishing or anisotropic etching to form the data electrode wiring 14A and the pixel electrode 14B. . At this time, the height of the data electrode wiring 14A and the pixel electrode 14B is preferably equal to or lower than the height of the counter electrode 12.

Thus, the counter electrode 12, the data electrode wiring 14A, and the pixel electrode 14B are positioned on the same line. At this time, although the gate electrode is not shown, the counter electrode 12, the data electrode wiring 14A, and the pixel electrode 14B are positioned on the same line. Thereafter, a passivation film 15 for protecting the thin film transistor (not shown) and the pixel electrode 14B is formed. Preferably, the passivation film 15 is formed of the same film as the gate insulating film 15.

As described in detail above, according to the present invention, by forming the counter electrode, the data electrode wiring and the pixel electrode on the same line, a complete planar electric field is achieved, thereby preventing electric field distortion and signal distortion of the data electrode wiring.

Therefore, the liquid crystal drive of the liquid crystal display device can be stabilized, the pixel electrode characteristics are improved, and the characteristics of the liquid crystal display apparatus are improved.

In addition, this invention can be implemented in various changes within the range which does not deviate from the summary.

Claims (22)

A liquid crystal display comprising a pixel electrode for driving a liquid crystal and a counter electrode spaced apart from each other at a predetermined distance to form an electric field parallel to the pixel electrode, wherein the pixel electrode and the counter electrode are formed on the same substrate. It is formed on the same line of the liquid crystal display device. The liquid crystal display of claim 1, wherein the pixel electrode height is equal to or smaller than the height of the counter electrode. The liquid crystal display device according to claim 1 or 2, wherein the pixel electrode and the counter electrode are spaced apart by a predetermined distance with a gate insulating film interposed therebetween. A liquid crystal display comprising a data electrode wiring and a counter electrode formed on the same substrate as the data electrode wiring and spaced apart from the data electrode wiring by a predetermined distance to form a parallel electric field. The liquid crystal display device formed on the same line of the same board | substrate. The liquid crystal display of claim 4, wherein a height of the data electrode wiring is equal to or smaller than a height of the counter electrode. The liquid crystal display device according to claim 4 or 5, wherein the pixel electrode and the counter electrode are spaced apart by a predetermined distance with the gate insulating film interposed therebetween. A data electrode wiring, a pixel electrode positioned to be spaced apart from the data electrode wiring by a predetermined distance, and a counter electrode positioned between the data electrode wiring and the pixel electrode and forming an electric field parallel to the data electrode wiring and the pixel electrode, respectively. A liquid crystal display device comprising: the data electrode wiring, the pixel electrode, and the counter electrode are formed on the same substrate and are located on the same line. 8. The liquid crystal display device according to claim 7, wherein the height of the pixel electrode and the data electrode wiring is equal to or smaller than the height of the counter electrode. The liquid crystal display device of claim 7 or 8, wherein the pixel electrode, the counter electrode, and the pixel electrode are spaced apart by a predetermined distance with the gate insulating film interposed therebetween. Forming a counter electrode on the semiconductor substrate; Forming a gate insulating film on the counter electrode; Etching a portion of the gate insulating layer to form a hole to expose a region predetermined by a data electrode wiring and a region predetermined by a pixel electrode; And embedding a metal film in the hole to form a data electrode wiring and a pixel electrode. The method of claim 10, wherein the forming of the counter electrode comprises: forming a metal film on the insulating substrate; And partially patterning the metal film. 12. The method of claim 10 or 11, further comprising forming a buffer insulating film prior to forming the counter electrode on the semiconductor substrate. The method of claim 12, wherein the buffer insulating film is one of an insulating film such as a silicon oxide film, a silicon nitride film, a silicon nitride oxide film, and a tantalum oxide film. The method of claim 10, wherein the gate insulating film is one film selected from a silicon oxide film, a silicon nitride film, a silicon oxide film, a laminated film of a silicon nitride film, and a silicon nitride oxide film. The method of claim 10, wherein forming a hole by partially etching the gate insulating layer to expose a predetermined region of the data electrode wiring and a predetermined region of the pixel electrode includes: a pad opening process for applying a predetermined voltage of the liquid crystal display; A method of manufacturing a liquid crystal display device, characterized in that it proceeds simultaneously. The method of claim 10, wherein the embedding of the metal film in the hole to form the data electrode wiring and the pixel electrode comprises: depositing a metal film on the resultant material; And removing the deposition film to expose the gate insulating film. The method of claim 16, wherein the metal film is formed by a sputtering method. The method of claim 16, wherein the removing of the gate insulating layer to be exposed is performed by an etch back process. The method of claim 16, wherein the removing of the gate insulating layer to be exposed is performed by a chemical mechanical polishing process. The method of claim 10, further comprising, after forming the data electrode wiring and the pixel electrode, forming a passivation layer on the resultant. A method according to claim 14 or 20, wherein the protective film is formed of the same film as the gate insulating film. The method of claim 10, wherein the semiconductor substrate is an insulating substrate.