JPH0555211A - Forming method of wiring - Google Patents

Abstract

PURPOSE:To manufacture an excellent large-area thin-film device at low cost through a simple process by conducting the formation of a recessed trench and the formation of a first layer wiring in a glass substrate through the same mask. CONSTITUTION:A photo-resist film 20 is exposed and developed, and a glass substrate 1 is exposed in the forming section of a first layer wiring. The edge of a resist pattern 21 obtained by patterning the photo-resist film 20 is sharpened as much as possible at that time. The glass substrate 1 in an exposed section is removed through a wet etching method, etc., while using the resist pattern 21 as a mask. Consequently, a slightly side-etched recessed trench 3 is formed. A metallic film 30 such as aluminum is deposited on the whole surface. It is desirable that the thickness of the metallic film 30 is formed in approximately the same depth as the depth of the recessed trench 3. The edge of the resist pattern 21 is sharpened, and the recessed trench 3 is slightly side-etched, thus completely cutting the metallic film 30 at a stepped section. The resist pattern 21 is removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring forming method, and more particularly, to a method for forming a multi-layer wiring on a glass substrate.

[0002]

2. Description of the Related Art Conventionally, as a technique in such a field, for example, JP-A-59-124123 and JP-A-61-94366.
There is something shown in the issue. In these, a recess is provided in a part of a glass substrate, and elements of thin film transistors (TFTs) (for example, a source electrode and a drain electrode) are embedded therein. However, the multilayer wiring on the glass substrate has not been devised in the past, and various problems have occurred.

[0003]

That is, when a large-area thin film electronic device is manufactured on a glass substrate, many intersections are formed in the wiring. Therefore, the parasitic capacitance is increased, the S / N ratio is deteriorated, or leak current, short circuit, or disconnection due to a step is likely to occur. If the technique of the above-mentioned publication is applied to overcome this problem, the process becomes complicated and it is not suitable for a large area and low cost thin film device.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. The first step is to coat a glass substrate with a mask material and selectively expose the glass substrate by patterning. And a second step of forming a groove on the glass substrate exposed by etching, and a first step by depositing a wiring material and removing the mask material.
It is characterized by comprising a third step of forming a layer wiring, a fourth step of forming an insulating film on the entire surface, and a fifth step of forming a second layer wiring of a predetermined pattern on the insulating film. ..

[0005]

According to the present invention, it is possible to form the concave groove and the first layer wiring in the glass substrate through the same mask, and it is possible to flatten the surface.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 and FIG. 2 are cross-sectional views of the element for each step for explaining the process of the embodiment.

First, a glass substrate 1 such as Pyrex or quartz is prepared, and a photoresist film 20 is formed on the entire surface by spin coating. A photosensitive polyimide film may be used instead of the photoresist film 20 (see FIG. 1A).

Next, the photoresist film 20 is exposed and developed by the photolithography technique to expose the glass substrate 1 at the first layer wiring forming portion. At this time, the resist pattern 2 formed by patterning the photoresist film 20
Edge 1 should be as sharp as possible (see FIG. 1 (b)).

Next, using the resist pattern 21 as a mask, the exposed portion of the glass substrate 1 is wet-etched or the like.
To remove. The etching depth is the resist pattern 2
It is desirable that the thickness d ₁ of 1 is about 1/10 of the thickness d ₁ = 2.0 μm (about 2000 Å), whereby the slightly side-etched concave groove 3 is formed. (See FIG. 1 (c)).

Next, a metal film 3 of aluminum or the like is formed on the entire surface.
0 is deposited. It is desirable that this thickness be approximately the same as the depth of the concave groove 3 (2000 angstrom). At this time, the edge of the resist pattern 21 is sharp and the groove 3 is slightly side-etched, so that the metal film 30 is completely cut at the step (see FIG. 2A). After that, when the resist pattern 21 is removed by an organic solvent or ashing, the concave groove 3 is formed by the lift-off method.
The metal film 30 is left as the first layer wiring 31.

Next, the insulating film 4 is formed on the entire surface (FIG. 2).
(See (b)). The insulating film 4 is made of SiO having a small dielectric constant.
₂ and Si ₃ N ₄ are preferred. The thickness may be 4000 angstroms or less. Next, the second layer wiring 5 is formed on the insulating film 4. Its thickness is about 4000 angstroms. The second layer wiring 5 can be formed by, for example, a lift-off method (see FIG. 2C).

FIG. 3 is a perspective view showing a part of the device manufactured by the above process in cross section. As shown,
The surface of the interlayer insulating film 4 is flattened, so that the step at the intersection can be almost eliminated. Therefore, it is possible to prevent a short circuit and a leak current between the first layer wiring 31 and the second layer wiring 5, and it is also possible to prevent disconnection of the second layer wiring 5.
Also, the parasitic capacitance between the first layer wiring 31 and the second layer wiring 5 can be reduced.

[0014]

As described above in detail, according to the wiring forming method of the present invention, it is possible to form the concave groove and the first layer wiring in the glass substrate through the same mask. Can be flattened. Therefore, there is an effect that a large area thin film device having excellent characteristics can be provided at low cost by a simple process.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the first half of the process of an example.

FIG. 2 is a cross-sectional view showing the latter half of the process of the example.

FIG. 3 is a perspective view of a device manufactured in an example.

[Explanation of Codes] 1 ... Glass substrate 20 ... Photoresist film 21 ... Resist pattern 3 ... Recessed groove 30 ... Metal film 31 ... First layer wiring 4 ... Insulating film 5 ... Second layer wiring

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location H01L 29/784 9056-4M H01L 29/78 311 A

Claims (2)

[Claims] 1. A first step of coating a glass substrate with a mask material to selectively expose the glass substrate by patterning, and a second step of forming a concave groove in the exposed glass substrate by etching. A third step of forming a first layer wiring by depositing a wiring material and removing the mask material; a fourth step of forming an insulating film on the entire surface; and a second layer wiring having a predetermined pattern. A fifth step of forming on the insulating film, the wiring forming method. 2. The wiring forming method according to claim 1, wherein the depth of the groove and the thickness of the first layer wiring are substantially the same.