JPH01152644A - Semiconductor device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a semiconductor device, and particularly to a semiconductor device using multilayer wiring.

(Prior Art) Multilayer wiring is sometimes used in semiconductor devices, particularly semiconductor integrated circuits. FIG. 3 shows a partial cross-sectional view of an example of a semiconductor device with multilayer wiring.

In the semiconductor device 31 shown in FIG. 3, two layers of wiring are provided. A first layer wiring pattern 34 is formed using AI or the like on an insulating film 33 such as an oxide film such as Sing formed on a Si substrate 32. An insulating film 35 is formed on the −th layer wiring pattern 34 to cover the pattern, and a second layer wiring pattern 36 is further formed thereon. The - layer wiring pattern 34 and the second layer wiring pattern 36 are connected to each other via a through hole 37. A protective film 3 is provided on the second layer wiring pattern 36.
9 is provided.

As the material for the insulating film 35 between the wiring patterns 34 and 36, polymer resins such as polyimide are widely used. The reason for this is that the polymer resin film has a desirable characteristic of excellent film surface flatness.

(Problems to be Solved by the Invention) However, since the polymer resin film is an organic substance, it has the property of absorbing moisture, and this property causes several problems.

One such problem is variation in device characteristics due to moisture infiltration. However, this variation is almost recovered by drying again.

The second problem is that the moisture absorbed by the polymer resin film gets around to the bottom of the wiring pattern formed on the film, and when the moisture evaporates during subsequent heat treatment, the wiring pattern is pushed up. .

It means that it swells.

The biggest problem caused by swollen wiring patterns is disconnection. In FIG. 3, when the wiring pattern 36 swells, the wiring pattern 34 and the wiring pattern 3
Since the adhesion between the wiring pattern 34 and the wiring pattern 36 is good, the wiring pattern 36 will not be separated from the wiring pattern 34 at the connection between the wiring pattern 34 and the wiring pattern 36 via the through hole 37. There is a risk of it breaking. Even if there is no disconnection in the wafer state.

Wires may break due to heating during die bonding after being divided into chips by dicing, and abnormalities may be discovered during post-packaging inspections.

Furthermore, even if normal operation is confirmed at the time of product shipment, wires may break after being used for a long time.

Problems other than disconnections include the appearance of the wiring pattern worsening due to the swell, and during inspection by observing the wafer surface, the swollen area may be mistaken for foreign matter, and the chip with the swell may be judged as a defective product. Sometimes I put it away.

As described above, when the wiring pattern swells, the yield of products decreases and efficient production is hindered.

The occurrence rate of problematic wiring pattern swelling depends on the width of the wiring pattern, and increases as the width increases. Therefore, by narrowing the width of the wiring pattern, the problem of swelling can be avoided. However, the width of the wiring pattern cannot be reduced when the wiring resistance is required to be kept low from the viewpoint of the characteristics of the circuit to be formed, or when the wiring pattern is used as a light-shielding metal.

In order to prevent wiring from swelling, the first step is to prevent moisture absorption. One of the techniques to prevent moisture absorption is to make the insulating film between wiring layers a two-layer structure in which an inorganic material such as a CVD SiO□ film is layered on a polymer resin film. There are problems with increased cost and compatibility between the polymer resin film and the inorganic film.

A known technique for preventing wiring swelling without interfering with moisture absorption will be described with reference to FIGS. 4 and 5. In this technique, as shown in FIG. 4, a hole 42 for venting gas is provided in a wide portion of a wiring pattern 41. However, if the wiring pattern is to have a function as a light-shielding metal, as shown in FIG. It goes under 51. As described above, there is a problem in that the light shielding ability of the wiring pattern is reduced.

The present invention has been made in view of the above problems, and its purpose is to prevent the wiring pattern on the insulating film from swelling even during heat treatment after the insulating film between the wiring layers of multilayer wiring has absorbed moisture. Another object of the present invention is to provide a semiconductor device whose light-shielding ability does not deteriorate even when a wiring pattern is used as a light-shielding metal.

(Means for Solving the Problems) A semiconductor device of the present invention includes a first insulating film and a first wiring pattern formed on the first insulating film.

a second insulating film formed on the first wiring pattern;
and a second wiring pattern formed on the second insulating film and connected to the first wiring pattern via a through hole provided in the second insulating film. The second insulating film has at least one hole reaching from the upper surface of the second insulating film to the first insulating film, and the second wiring pattern extends through the hole. and is coupled to the first insulating film, thereby achieving the above object.

(Example) The present invention will be described below with reference to Examples.

FIG. 1 shows a partial cross-sectional view of a semiconductor device 1 according to an embodiment of the present invention. A first layer wiring pattern 4 is formed using AI or the like on a Si substrate 2 on which elements of MO3 structure or bipolar structure are formed, with an insulating film 3 such as an oxide film such as 5i02 interposed therebetween. The wiring pattern 4 is covered with an insulating film 5 made of a polymer resin film, and a second layer wiring pattern 6 is formed on the insulating film 5 using AI or the like. The second layer wiring pattern is covered with a protective film 9.

A through hole 7 is provided in the insulating film 5.

The second layer wiring pattern 6 is connected to the first layer wiring pattern 4 via a through hole 7. The insulating film 5 is further provided with holes 68 (hereinafter referred to as "dummy through holes") at predetermined intervals that communicate from one top surface of the insulating film 5 to a portion of the insulating film 3 where wiring is not provided. The dummy through hole 8 has no electrical function. The second layer wiring pattern 6 is in close contact with the insulating film 3 via the dummy through hole 8, and its adhesion is strong. Since the second layer wiring pattern 6 is connected to the substrate at locations other than the through holes 7 in this way, swelling of the second layer wiring pattern 6 when the semiconductor device 1 is heat treated is sufficiently suppressed. .

The manufacturing process of the semiconductor device 1 shown in FIG. 1 will be explained. FIG. 2(a) shows a state in which a first layer wiring pattern 4 is formed after an insulating film 3 such as an oxide film is formed on a Si substrate 2. As shown in FIG. As shown in FIG. 2(b).

An insulating film 5 made of a polymer resin film is formed on the entire surface of the substrate in FIG. 2(a).
is formed using a spin cord and a curing process.

Next, as shown in FIG. 2(C), a through hole 7 is formed in the insulating film 5 at a position where the second layer wiring and the first layer wiring are connected to each other, and a through hole 7 is formed in the part of the insulating film 3 where the wiring is not connected. Dummy through holes 8 are formed at corresponding predetermined positions.

Through hole 7 and dummy through hole 8 are formed simultaneously by etching. Therefore, the provision of the dummy through hole 8 hardly complicates the manufacturing process or increases cost. After the through holes 7 and dummy through holes 8 are formed, as shown in FIG. 2(d), a second wiring layer is formed by vapor deposition or sputtering, and is patterned into a predetermined pattern by etching. A wiring pattern 6 is formed.

Finally, a protective film 9 is formed on the entire surface as shown in FIG.

The embodiments in which two-layer wiring has been described above have been described.

The present invention is also applicable to semiconductor devices having multilayer wiring of three or more layers.

(Effects of the Invention) According to the present invention, a semiconductor device in which a wiring pattern on an insulating film does not swell even when heat treatment is performed after the insulating film between wiring layers absorbs moisture can be provided at the same cost as before. Moreover, since the wiring pattern of the semiconductor device of the present invention does not have a gas venting hole, the light-shielding ability does not deteriorate even when the wiring pattern is used as a light-shielding metal.

4. Figure 1 is a partial sectional view of one embodiment of the present invention, Figure 2 (a)
~(Hitoshi is a diagram explaining a part of the manufacturing process of the example, FIG. 3 is a partial cross-sectional view of a conventional semiconductor device with multilayer wiring,
FIG. 4 is a plan view of a conventional wiring pattern provided with gas vent holes, and FIG. 5 is a partial sectional view of a conventional semiconductor device having a wiring pattern provided with gas vent holes.

DESCRIPTION OF SYMBOLS 1... Semiconductor device, 2... St substrate, 3... First
insulating film, 4... first wiring pattern, 5... second
insulation film.

6... Second wiring pattern, 7... Through hole,
8...Dummy through hole (hole).

that's all

Claims (1)

[Claims] 1. a first insulating film, a first wiring pattern formed on the first insulating film, a second insulating film formed on the first wiring pattern, and a second insulating film; The first insulating film is formed on the first insulating film through a through hole provided in the second insulating film.
a second wiring pattern connected to the wiring pattern, wherein the second insulating film is connected to the second wiring pattern.
at least one hole reaching the first insulating film from the upper surface of the insulating film, and the second wiring pattern is coupled to the first insulating film through the hole. Device.