JPH0634438B2 - Wiring electrode formation method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for forming a wiring electrode, and more particularly to a method for forming a wiring electrode used in an active matrix array or the like, in which disconnection does not easily occur.

[Conventional technology]

With the progress of office automation in recent years, development of a flat panel display device as a man-machine interface has been actively promoted. Also in liquid crystal display devices, active matrix substrates are being actively developed in order to obtain a large amount of display information equivalent to that of CRTs. Since one active element is used for one pixel in the active matrix substrate, it is necessary to form thin wiring electrodes over a large area.

2A to 2C are schematic cross-sectional views showing an example of a conventional method of forming a wiring electrode in the order of steps. Fig. 2 (a)
As shown in FIG. 2B, a step of sequentially forming the first conductive film 2 and the second conductive film 4 on the insulating substrate 1, and a photoresist on the second conductive film 4 as shown in FIG. 2B. A step of forming a resist pattern 3 for a wiring electrode by a method, and second and first conductive films 4 and 2 as shown in FIG.
And the resist was removed in order. In the case of this forming method, the first conductive film 2 often has good adhesiveness to the insulating substrate 1, and the second conductive film 4 often has good electric characteristics. When there is a film, naturally only one conductive film is used.

[Problems to be solved by the invention]

When an active matrix substrate is manufactured using such a wiring electrode forming method, the resist pattern 3
If there is a defect in the second conductive films 2 and 4, there is a drawback that the yield is very poor because the wire breaks.

An object of the present invention is to eliminate such a conventional defect and provide a method for forming a wiring electrode in which disconnection does not easily occur.

[Means for solving problems]

A method of forming a wiring electrode according to the present invention comprises a step of forming a first conductive layer on an insulating substrate, a step of forming a first wiring electrode resist pattern on the first conductive layer by a photoresist method, The step of removing the resist after patterning the first conductive layer by etching, the step of forming the second conductive layer, and the step of forming the first wiring electrode and shape on the second conductive layer by the photoresist method are performed. Forming a second wiring electrode resist pattern having the same width but slightly different width; and etching the second conductive layer using an etchant that hardly etches the first conductive layer, and then removing the resist It has a process to do.

[Action]

If the method for forming a wiring electrode of the present invention is used, the first conductive layer and the second conductive layer are patterned in two steps, and the first conductive layer is etched when the second conductive layer is pattern-etched. Not done. Therefore, even if there is a defect in the first resist pattern or the first conductive layer, the disconnection does not occur unless the defect in the second resist pattern or the second conductive layer is in the same place as the former. The probability that defects will occur at the same location in the former and the latter is extremely low, and therefore, the wiring electrodes are hardly broken. Although the conductive layer may partially remain as a defect, since the pitch of one pixel is about 10 times the wiring electrode width in the active matrix array used for a liquid crystal display, the rest of the conductive layer is a defect as a display. Is rarely.

EXAMPLES Next, the present invention will be described in detail with examples.

Comparison between the case where the method of forming the wiring electrode of the present invention is applied to the gate electrode wiring of the thin film transistor array for a liquid crystal display device having the number of elements of 400 × 640 and the display area of 180 mm × 240 mm, and the case where the conventional method of forming the wiring electrode is performed. And explain.

1 (a) to 1 (f) are schematic cross-sectional views showing an embodiment of a method of forming a wiring electrode according to the present invention in the order of steps.

In this embodiment, as shown in FIG. 1A, soda glass is used as the insulating substrate 1, and chromium is formed as the first conductive layer 2 on the insulating substrate 1 to a thickness of 400 Å by the direct current argon sputtering method. As shown in FIG. 1B, the resist pattern 3 of the wiring electrode having a width of 15 μm is formed by the positive photoresist method.
Was formed. Next, as shown in FIG. 1 (c), chromium was pattern-etched with an etching solution containing cerium ammonium nitrate as a main component, and then the resist was removed. Then, as shown in FIG. 1 (d), aluminum is formed as the second conductive layer 4 to a thickness of 600 Å by vapor deposition, and as shown in FIG. 1 (e), aluminum is formed by a positive photoresist method.
A resist pattern 3 of a wiring electrode having a width of 5 μm was formed.
Finally, as shown in FIG. 1F, aluminum was pattern-etched with an etching solution containing phosphoric acid as a main component, and then the resist was removed to form a gate wiring electrode. At this time, no disconnection of the gate wiring electrode was observed. The rest of the conductive layers are 5 to 25 μmφ, 25 μmφ
There were two of the above, but there was almost no problem because the pitch of the gate wiring electrodes was 375 μm.

On the other hand, when the conventional method of forming a wiring electrode shown in FIGS. 2A to 2C is used, there are two disconnections of the gate wiring electrode, and a thin film transistor array is formed using this substrate to form a liquid crystal display. In that case, a disconnection defect has occurred.

〔The invention's effect〕

As described above, the method of forming a wiring electrode according to the present invention can be performed in any of the steps of forming the first and second conductive layers and the step of forming the resist patterns for the first and second wiring electrodes. Since the probability of occurrence at the same place is extremely low, disconnection does not occur, and it is possible to form a wiring electrode in which disconnection does not occur easily.

[Brief description of drawings]

1 (a) to 1 (f) are schematic cross-sectional views showing one embodiment of the method for forming a wiring electrode of the present invention in the order of steps, and FIG. 2 (a).
8A to 8C are schematic cross-sectional views showing an example of a conventional method of forming a wiring electrode in the order of steps. 1 ... Insulating substrate, 2 ... First conductive layer, 3 ... Resist pattern, 4 ... Second conductive layer.

Claims (1)

[Claims] 1. A step of forming a first conductive layer on an insulating substrate, a step of forming a resist pattern for a first wiring electrode on the first conductive layer by a photoresist method, and the first conductive layer. A step of patterning the layer by etching and then removing the resist; a step of forming a second conductive layer; and a step of forming a second conductive layer on the second conductive layer by a photoresist method, which has the same shape as the first wiring electrode and is slightly wide. Forming a resist pattern for a second wiring electrode having a different pattern;
The method of forming a wiring electrode according to claim 1, further comprising the step of removing the resist after patterning the second conductive layer by etching using an etchant that hardly etches.