KR930005561B1 - Making method and display panel of lcd - Google Patents

Abstract

The display panel of a LCD device having a thin film transistor (TFT) is mfd. by (a) forming a metal layer on the substrate, (b) covering a photoresist film on the metal layer to form a gate electrode line (c) forming a pattern for an anode oxidization, and then partially forming an insulating layer on the line, (d) and lifting off the photoresist film covered on the line, and then forming a TFT device.

Description

Display panel of liquid crystal display device and manufacturing method thereof

1 is a cross-sectional view of a conventional TFT.

2 to 5 are process flowcharts showing the process according to the present invention among the process steps for manufacturing the display panel portion of the liquid crystal display device.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film transistor (hereinafter referred to as TFT), and more particularly, to a method of forming a gate electrode of a TFT, an interlayer insulating layer formed thereon, and a display panel portion accordingly.

TFT is an active device having a structure similar to an inverse-staggered MOS transistor, which is formed on the gate electrode formed on the glass and silver insulating substrate, the gate insulating layer formed on the gate electrode, and the gate insulating layer. And a source / drain electrode formed thereon.

TFTs having such a structure are applied to, for example, active matrix LCD devices. In particular, the semiconductor layer referred to as a switching element for an active matrix LCD device is an amorphous layer. The structure now described is as shown in cross section in FIG.

1 is a cross-sectional view of a conventional TFT, where 10 is a substrate, 11 is a gate electrode, 12 is a gate insulating film, 13 is a conductor layer, 14 is a five-layer layer, and 15 is a source / drain electrode.

The display device has many pixels arranged in rows and columns. Each pixel includes a TFT which is a switching element, a liquid crystal cell, an electrode, and a capacitor.

The display apparatus has an address line and a data line, wherein the gates of the TFTs arranged in each row are connected to the same address line, and the source / drain of the TFTs arranged in each column are simultaneously connected to the same data line. That is, the TFTs are arranged in a matrix of rows and columns, and the gates of the TFTs are formed over the address lines.

FIG. 2B, which is an accompanying drawing, shows two address lines as an example, and FIG. 2A, which is a cross section taken along the AA 'line of FIG. 2B, shows an address line patterned on the substrate 1, wherein the TFT is a line It is formed on the basis of. Hereinafter, this address line is called a gate electrode.

As mentioned, a TFT must have a gate electrode and a gate insulating layer formed thereon, and various methods for forming the TFT are provided, but a method of forming an insulating layer having a relatively high dielectric based on anodization is known. Examples of this are disclosed, for example, in US Pat. No. 4,469,568.

In a more general process sequence, a photoresist film is applied to a metal layer coated on the substrate 3 by a sputtering method over the entire surface, and a mask is exposed, developed, and then etched to form a strip like 2b. The gate electrode line is formed. To remove the used photoresist film and to form an interlayer insulating layer on the gate electrode, apply an anodization mask such as a photoresist film to perform anodization, for example here, and then apply an appropriate voltage and current after exposure and development of the display panel area. By supplying, the insulating layer of predetermined thickness is formed.

However, since the gate electrode line is formed of a thin film and the insulating layer is formed by decreasing the thickness of the gate electrode line by anodization according to the formation of a good insulating layer, the bulk resistance of the gate line is increased, so that the signal is applied when the signal is applied. Results in a delay.

In addition, although the above-described rough procedure is described, more specifically, a photolithography process requiring almost 15 steps is required, and it is known that the relationship between the number of stems of photolithography process and the yield of panel for LCD is inversely related to each other. There is a panel manufacturing according to many steps as in the prior art can not expect effective improvement of the production yield.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the insulating layer is formed only partially between the regions where the address line, the data line, and the semiconductor layer intersect each other to reduce signal delay, and also to effectively use the photoresist film during the process. The aim is to provide a series of process steps that reduce the process steps to double the effect of production yield and so on.

It is still another object of the present invention to provide a display panel portion of an LCD display device having a switching thin film transistor manufactured by the aforementioned series of process steps.

In order to achieve the above object, the present invention provides a method for manufacturing a display panel of a liquid crystal display device having a thin film transistor, wherein a metal layer is formed on a substrate to form an address line (gate electrode line), and a photoresist film is covered thereon. Forming a strip-type gate electrode line and applying an anodization mask thereon to expose the metal layer only in the region where the gate electrode line, the data line to be formed, and the semiconductor layer overlap each other; By developing and anodizing, an insulating layer is partially formed on the gate electrode line, and the photoresist film applied on the gate electrode line is removed, and then the display panel portion is fabricated through the TFT element forming step. Consists of steps.

Process purity provided according to the object of the present invention is as shown in the drawing of FIG. 3 including FIG. 2 is described in the prior art description, but since the present invention proceeds from this step, the present invention will be described below using this figure. 2A and 2B show the steps before the metal layer 2 is patterned on the glass substrate 3 and the photoresist film 4 is removed thereon as described above. In the present invention, the process of FIG. 3 is performed without removing the photoresist film in the process of FIG.

In the following description of the drawings, (a) is a cross-sectional view, and (b) is a plan view thereof.

The step of FIG. 3 shows that the photoresist film 4 is partially removed. In this step, the anodic oxidation mask (not shown) is exposed and the photoresist film (not shown) is removed so that the photoresist film 4 in FIG. 2 is not removed, and the photoresist film 4 is partially removed as in FIG. 4) is developed to partially form the exposed region 5 of the metal layer 2. In this step, the partially etched region, that is, the portion labeled '5' is a region where the gate electrode line 1, the source, the data line, and the semiconductor layer cross each other, and the two conductive layers are electrically connected to each other. Since the insulating layer is required to be interposed therebetween so as not to be connected, the area is to be formed in advance at this stage. Thus, along the opening width in FIG. 3B, the data line will subsequently be formed in a direction orthogonal to the gate busline. Subsequently, a hard bake process, which may be selectively performed by the etching process, may be performed to firmly attach the photoresist film. In a subsequent step, anodization is performed on the exposed region 5 of the metal layer as shown in FIG.

When anodization is performed, an insulating layer 6 is formed on the exposed metal layer as shown in FIG. 4A, and the openings are covered with an insulating layer as shown in FIG. 4B, which is a plan view of the cross sectional view. At this time, since the photoresist film 4 acts as a mask during anodization, a reaction layer does not occur in the underlying metal layer, and an insulating layer is formed only in the opening. Subsequently, the glass is removed from the electrolytic cell for anodization and optionally subjected to shower exposure and ashing operations to facilitate photoresist removal, and to remove residual photoresist film as shown in FIG. do.

The subsequent steps can follow a known procedure, which is important because the insulating layer formed during anodization is formed of two layers by application of the gate insulating film formed on the gate electrode, which is a synergistic effect of preventing pinholes between overlapping bus lines. Produces the effect. Furthermore, in connection with the above-mentioned problem, since the insulation by anodization is partly formed on the gate electrode line, reduction of signal delay is obtained than in the prior art.

In accordance with the present invention, the photolithography process is shortened. Since the process proceeds without performing frequent photo work, at least 4 steps are shortened to increase the manufacturing yield. Specifically, since the photo layer is etched after the anodization mask is applied without removing the photo resist film applied for forming the metal electrode layer pattern, the process may be shortened and the failure rate may be reduced.

Summarizing the process described now, an address metal line is formed on a substrate prepared for forming an LCD display panel portion, and a portion of the address metal line is coated with an insulating layer, and then a gate insulating layer is deposited over the entire surface.

In the present invention, the gate electrode may be formed in an address line, that is, a gate electrode line, or may be formed on a hook to form a gate electrode formed along the gate electrode line. The pixel portion is formed by a known technique, but according to the method of the present invention, a double insulating layer is interposed only in a portion where the gate electrode, the data electrode, and the semiconductor layer overlap in the LCD display panel portion. However, in some cases, when the gate insulating layer has a plurality of layers, the overlapping portion may be a plurality of layers. The present invention includes a display panel portion for an LCD of such a structure.

Claims (3)

In the method of fabricating a panel portion of a liquid crystal display device having a thin film transistor, a metal layer is formed on a substrate to form an address line (gate electrode line), and a gate electrode line is formed by covering a photoresist film thereon, and anodizing thereon. The insulating layer is partially formed on the gate electrode line by exposing, developing, and anodizing the metal layer to be exposed only in a region where the gate electrode line, the data line, and the semiconductor layer to be formed are overlapped by forming a pattern; And forming a display panel through a thin film transistor (TFT) element forming step after removing the photoresist film applied on the gate electrode line. The method of claim 1, wherein the insulating layer is formed by anodization only in a region where the gate electrode line, the data line, and the semiconductor layer overlap. A thin film transistor (TFT) having a gate electrode formed on the substrate, a gate insulating layer, a semiconductor layer, and a source / drain is arranged in a matrix, an address line is connected to the gate electrode, and a data line is connected to the source or drain electrode. In the display panel portion of the liquid crystal display device, an interlayer insulating layer formed by anodization is formed only in an area where the address line, the data line, and the semiconductor layer intersect each other, and are formed of at least two insulating layers together with the gate insulating layer. A display panel portion of a liquid crystal display device.