JPS6386550A - Formation of multilayer interconnection layer - Google Patents

Abstract

PURPOSE:To facilitate an etching process as well as to obtain a multilayer interconnection layer, whose insulation is favorable, with high accuracy by a method wherein a polyimide cunadrone layer is partially cured, a photosensitive polyimide cunadrone layer is formed on the upper surface thereof, a first wiring layer 2 is exposed by etching and the polyimide cunadrone layer is completely cured. CONSTITUTION:A polyimide cunadrone layer 3 is formed on the upper surface of a first wiring layer 2 and thereafter, this polyimide cunadrone layer 3 is partially cured. Then, a photosensitive polyimide cunadrone layer 4 is formed on the upper surface of the cunadrone layer 3 and is exposed by UV irradiation 8 using a photo mask 7. A part just over 5 the first wiring layer 2 is selectively etched by developing. The polyimide cunadrone layer 3 is etched using the photosensitive polyimide cunadrone layer 4 as a mask to expose the first wiring layer 2. Subsequently, the polyimide cunadrone layer 3 and the photosensitive polyimide cunadrone layer 4 are completely cured and a second wiring layer 6 is formed in contact with the exposed part.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method of forming a multilayer wiring layer.

[Conventional technology]

Generally, when forming multilayer wiring layers on a substrate using a polyimide giconadron layer, the following method is adopted.

First, the first method is to form a first wiring layer on the substrate-1-, form a polyimide quiconadron layer on it, completely cure the polyimide quiconadron layer, and then Mask alignment, exposure, and development are performed using a resist (resist), followed by etching with human cydine.

Subsequently, after removing the resist, a second wiring layer is formed in contact with the first wiring layer exposed as described above.

The second method involves partially curing the polyimide xiconate layer, masking it using an ordinary lenost, exposing it to light, and continuously developing and etching it with an alkaline developer.

Further, after removing the resist, the polyimide cunatron layer is completely cured, and a second wiring layer is formed in the same manner as in the first method.

In the third method, as shown in FIG.
A wiring layer 21 is formed (FIG. 7(A)), and then a photosensitive polyimide cunatron layer 22 is formed (FIG. 7(A)).
B)). Subsequently, UV irradiation 25 is performed using a photomask 24.
The photosensitive polyimide cunatron layer is exposed to light (FIG. 7(C)).

Next, a developer 23 is applied onto the photosensitive polyimide cunatron layer 22 (FIG. 7(D)), and the unexposed portion 26 of the photosensitive polyimide cunatron layer 22 in the second wiring layer 21 is removed. (Figure 7(E)).

After exposing the first wiring layer 21 in this way,
The photosensitive polyimide cunatron layer 22 is completely cured, and the second wiring layer 24 is formed in contact therewith (FIG. 7(F)).

[Problems to be Solved by the Invention] However, the conventional method described above has the following drawbacks.

That is, although the first method allows for highly accurate etching, it involves danger because it uses hydrazine, which is extremely harmful. Moreover, the process becomes complicated.

Although the second method has the advantage of simplifying the manufacturing process, there is a risk that accuracy may be reduced depending on the curing conditions.

Further, a harmful stripping agent is required to remove the lens, and this stripping process is complicated.

Further, in the third method, although the etching process is extremely simplified, there is a problem that the photosensitive agent evaporates in the subsequent process, the thickness of the photosensitive polyimide cunatron layer decreases, and the insulation deteriorates.

The present invention has been made in view of the above-mentioned matters, and it is an object of the present invention to provide a method for forming a multilayer wiring layer that not only simplifies the etching process but also does not require the use of harmful chemicals, has high precision, and has good insulation. is a technical issue.

[Means for solving problems]

In order to solve the above technical problem, the present invention has the following configuration.

That is, after forming the first wiring layer 2 on the substrate 1 and further forming the polyimide cunatron layer 3 on the upper surface thereof, the polyimide cunatron layer 3 is partially cured, and then the upper surface of the polyimide cunatron layer 3 is cured. A photosensitive polyimide cunatron layer 4 is formed on the photosensitive polyimide cunatron layer 4 (J).
A portion 5 corresponding directly above the wiring layer 2 is selectively etched.

Furthermore, the polyimide cunatron layer 3 is etched using the photosensitive polyimide cunatron layer 4 as a mask to expose the first wiring layer 2, and the polyimide cunatron layer 3 and the photosensitive polyimide cunatron layer 4 are etched.
is completely cured, and then a second wiring layer 6 is formed in contact with this exposed portion to produce a multilayer wiring layer.

[Effect]

Since the photosensitive polyimide cunatron layer 4 is patterned by an optical method, sufficient precision can be obtained, and since the polyimide cunatron layer is partially cured, there is no need to use harmful chemicals such as hydranone. Furthermore, since no resist is used, there is no need to use harmful stripping agents.

Furthermore, since the photosensitive polyimide cunatron layer serves as a mask layer in the etching process of the polyimide cunatron layer, the polyimide cunatron layer serving as an insulating layer is not etched to a required amount.

〔Example〕

Embodiments of the present invention will be described based on FIGS. 1 to 6.

First, a first wiring layer 2 made of an aluminum layer is placed on a substrate.
After forming a polyimide cunatron layer 3 on the upper surface of the polyimide cunatron layer 3, as shown in FIG. 1, this polyimide cunatron layer 3 is partially cured.

Next, as shown in FIG. 2, a photosensitive polyimide cunatron layer 4 is formed on the upper surface of the polyimide cunatron layer 3.

Subsequently, as shown in FIG.
The photosensitive polyimide cunatron layer 4 is exposed to V radiation 8.

Furthermore, as shown in FIG. 4, a portion 5 of the photosensitive polyimide cunatron layer 4 corresponding to the bottom of the first wiring layer 2 is selectively etched by development.

Furthermore, as shown in FIG. 5, the polyimide cunatron layer 3 is etched using the photosensitive polyimide cunatron layer 4 as a mask to expose the first wiring layer 2. Subsequently, the polyimide cunatron layer 3 and the photosensitive polyimide cunatron layer 4 are completely cured.

In this case, the thickness of the photosensitive polyimide cunatron layer 4 is reduced by 40%.

Subsequently, as shown in FIG. 6, a second wiring layer 6 is formed in contact with this exposed portion.

As described above, the present invention employs patterning using an optical method, so sufficient accuracy can be obtained.
Furthermore, since the polyimide cunatron layer only needs to be partially cured, there is no need to use harmful chemicals such as hydrazino. Also, since it does not use Lenst, there is no need to use harmful stripping agents.

Furthermore, in the etching process of the polyimide cunatron layer, the photosensitive polyimide cunatron layer serves as a mask layer, so the polyimide cunatron layer as an insulating layer is not etched into the required material and has good insulation properties. becomes.

〔Effect of the invention〕

According to the present invention, after forming a polyimide cunatron layer on the upper surface of the first wiring layer formed on the substrate, a photosensitive polyimide cunatron layer is formed on the upper surface, and in the photosensitive polyimide cunatron layer, selectively etching a portion directly above the first wiring layer;
The etching process is easy because the first wiring layer is exposed by etching the polyimide cunatron layer in the relevant part, and then the second wiring layer is formed in contact with this exposed part. Of course, there is no need to use harmful chemicals, and a multilayer wiring layer with high precision and good insulation can be formed.

[Brief explanation of the drawing]

1 to 6 are cross-sectional views of a multilayer wiring layer showing an embodiment of the present invention, and FIG. 7 is a cross-sectional view of a multilayer wiring layer showing a conventional manufacturing process of a multilayer wiring layer. DESCRIPTION OF SYMBOLS 1... On the substrate, 2... First wiring layer, 3... Polyimide cunatron layer, 4... Photosensitive polyimide cunatron layer, 5... The first wiring layer in the photosensitive polyimide cunatron layer 6. Second wiring layer. 7... Photomask, 8... UV irradiation. Figure 1 Figure 2 Figure 3 Figure 4 Figure 6 Figure 7

Claims (1)

[Claims] (1) After forming a first wiring layer on the substrate and further forming a polyimide cunadrone layer on its upper surface, this polyimide cunadrone layer is partially cured, and a photosensitive polyimide cunadrone layer is formed on the upper surface. Then, selectively etching a portion of the photosensitive polyimide cunadrone layer corresponding to the first wiring layer, and using the photosensitive polyimide cunadrone layer as a mask, remove the polyimide cunadrone layer. After exposing the first wiring layer by etching and completely curing the polyimide cunadron layer and the photosensitive polyimide cunadron layer, contacting this exposed portion to form a second wiring layer. Characteristic multilayer wiring layer formation method.