JPH07263447A - Semiconductor device and its manufacture - Google Patents

Abstract

PURPOSE:To prevent an oxide aluminum film from forming between an aluminum alloy film and a titanium nitride film as an anti-reflection film. CONSTITUTION:An aluminum nitride film 4 is formed between an aluminum film 3 and a titanium nitride film 5 as an anti-reflection film. The aluminum film 3 is composed of aluminum alloy containting silicon (about 1.0%) and copper about 0.1%). When the aluminum film 3 is protected with the aluminum nitride film 4, aluminum oxide is not formed on the surface of the aluminum film 3 at the time of contact with air. Thereby electrons, which have concentrated on the aluminum film 3, are dispersed in the aluminum film 3 and the titanium nitride film 5, or the aluminum nitride film 4, so that electromigration life is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device having a fine-sized aluminum alloy wiring and a method of manufacturing the same.

[0002]

2. Description of the Related Art As the integration of semiconductor devices progresses, and the width of aluminum alloy wiring is gradually miniaturized, it is important to reduce the reflectance of the aluminum film.
Therefore, a wiring structure in which a titanium nitride film is laminated as an antireflection film on an aluminum alloy wiring is most often used.

The conventional semiconductor device described above and a method of manufacturing the same will be described below with reference to the drawings.

FIG. 5 is a sectional view of a conventional semiconductor device.
In FIG. 5, 1 is a silicon substrate, 2 is a boron phosphorus silicate glass film, 3 is an aluminum film, 5 is a titanium nitride film, 6
Is a passivation film.

The titanium nitride film 5 is provided as an antireflection film on the aluminum film 3 to reduce the reflectance of the aluminum film 3 and prevent halation during the formation of a resist pattern for wiring.

FIG. 6 is a flow chart for explaining a conventional method of manufacturing a semiconductor device. The aluminum film 3 and the titanium nitride film 5 are discontinuously formed by the first sputtering apparatus and the second sputtering apparatus, respectively.

[0007]

However, the above-described structure and manufacturing method have a problem that the electromigration life is deteriorated and the reliability of the semiconductor device is lowered.

[0008]

In order to solve the above problems, a semiconductor device of the present invention comprises an aluminum alloy wiring formed in a predetermined pattern on an insulating film of a semiconductor substrate, and aluminum nitride wiring on the aluminum alloy wiring. It has a titanium nitride film formed with the film sandwiched therebetween.

In order to solve the above problems, in the method for manufacturing a semiconductor device of the present invention, after forming an aluminum alloy wiring on a semiconductor substrate, plasma containing nitrogen gas as a main component is irradiated.

After the aluminum alloy wiring is formed on the semiconductor substrate, an aluminum nitride film is formed by reactive sputtering in the same sputtering apparatus used to form the aluminum alloy wiring.

After forming the aluminum alloy wiring on the semiconductor substrate, annealing is performed in an atmosphere containing nitrogen gas as a main component in the same sputtering apparatus used to form the aluminum alloy wiring. Form a film.

Further, after the aluminum alloy wiring is formed on the semiconductor substrate, argon sputter etching is performed, and then a titanium nitride film is continuously formed in the same sputtering apparatus as the argon sputter etching.

[0013]

According to the present invention, the electromigration life can be prevented from being deteriorated by the structure and the manufacturing method thereof, and the reliability of the semiconductor device can be improved.

[0014]

1 is a sectional view of an embodiment of a semiconductor device of the present invention. In FIG. 1, 1 is a silicon substrate, 2 is a boron phosphorus silicate glass film, 3 is an aluminum film, 4 is an aluminum nitride film, 5 is a titanium nitride film, and 6 is a passivation film.

An aluminum nitride film 4 is provided between the aluminum film 3 and the titanium nitride film 5 which is an antireflection film. The aluminum film 3 is made of an aluminum alloy containing about 1.0% silicon and about 0.1% copper.

In the prior art, the aluminum nitride film 4 is not provided, and the sputtering device for the aluminum film 3 and the sputtering device for the titanium nitride film 5 are different, and if discontinuous formation occurs, after the aluminum film 3 is formed, it is exposed to the atmosphere. Since the aluminum film 3 comes into contact with the aluminum film 3, the surface of the aluminum film 3 is oxidized to form an aluminum oxide film. However, if the aluminum film 3 is protected by the aluminum nitride film 4 as in this embodiment,
No aluminum oxide is formed on the surface even when contacted with the atmosphere. Therefore, the movement of electrons concentrated in the aluminum film 3 is dispersed in the aluminum film 3 and the titanium nitride film 5, or the aluminum nitride film 4. Therefore, the electromigration life can be improved.

Further, in this embodiment, since the aluminum film 3 and the titanium nitride film 5 are continuously formed in the same sputtering apparatus, the aluminum film 3 does not come into contact with the atmosphere. Therefore, the aluminum oxide film is not formed even if the aluminum nitride film 4 is not formed, and the electromigration life is not deteriorated.

In this embodiment, the structure in which the barrier metal is not used as the lower layer of the aluminum alloy wiring has been described, but the same effect can be obtained when the barrier metal is used.

As described above, according to this embodiment, by providing the aluminum nitride film 4 between the aluminum alloy wiring and the titanium nitride film 5, the sputtering apparatus for the aluminum film and the titanium nitride film 5 as the antireflection film are formed. Even when the sputtering apparatus is different and the formation is discontinuous, the deterioration of the electromigration life can be prevented.

FIG. 2 is a process drawing of the first embodiment of the method for manufacturing a semiconductor device of the present invention. First, the aluminum film 3 is formed by the first sputtering apparatus. Next, the aluminum film 3 is irradiated with nitrogen plasma. Finally, the titanium nitride film 5 is formed by the second sputtering device.

In the prior art, the titanium film 5 was formed by the second sputtering apparatus after forming the aluminum film 3 by the first sputtering apparatus. Therefore, the formation of the aluminum film 3 and the titanium nitride film 5 becomes discontinuous, the aluminum film 3 comes into contact with the atmosphere, an aluminum oxide film is formed on the surface of the aluminum film 3, and the electromigration life is deteriorated.

However, when the aluminum film 3 is irradiated with nitrogen plasma after the aluminum film 3 is formed by the first sputtering apparatus as in this embodiment, the aluminum oxide film can be changed to the aluminum nitride film 4. Since the aluminum nitride film 4 thus formed is not oxidized even if it is contacted with the atmosphere, aluminum oxide is not formed even if the irradiation device of nitrogen plasma and the sputtering device of the titanium nitride film 5 are different. Therefore, when the aluminum oxide film is present, the movement of electrons concentrated in the aluminum film 3 can be dispersed in the aluminum film 3 and the titanium nitride film 5 or the aluminum nitride film 4, so that the electromigration life can be improved.

In this embodiment, nitrogen gas is used for plasma irradiation, but the same effect can be obtained when ammonia gas or the like is used.

Further, in this embodiment, the method in which the barrier metal is not used as the lower layer of the aluminum alloy wiring has been described, but the same effect can be obtained when the barrier metal is used.

As described above, according to the present embodiment, aluminum oxide can be converted into the aluminum nitride film 4 by irradiating the plasma containing nitrogen gas as the main component after the aluminum alloy wiring is formed. For this reason,
Even if the sputtering apparatus for the aluminum film 3 and the sputtering apparatus for the titanium nitride film 5 as the antireflection film are different and discontinuous formation occurs, deterioration of the electromigration life can be prevented.

FIG. 3 is a process drawing of the second embodiment of the method of manufacturing a semiconductor device of the present invention. First, the aluminum film 3 is formed by the first sputtering apparatus. Next, the aluminum nitride film 4 is formed by the reactive sputtering method using the same sputtering apparatus used for forming the aluminum film 3. Finally, the titanium nitride film 5 is formed by the second sputtering device.

When the aluminum film 3 is formed by the first sputtering apparatus and then the aluminum nitride film 4 is formed by the same sputtering apparatus, the surface of the aluminum film 3 is protected by the aluminum nitride film 4. Therefore, aluminum oxide is not formed on the surface of the aluminum film 3. Further, since the aluminum nitride film 4 is not oxidized even if it contacts the atmosphere,
Aluminum nitride film 4 sputtering apparatus and titanium nitride film 5
No aluminum oxide is formed even if the sputtering apparatus is different. Therefore, when the aluminum oxide film is present, the movement of electrons concentrated in the aluminum film 3 can be dispersed in the aluminum film 3 and the titanium nitride film 5, or the aluminum nitride film 4, so that the electromigration life can be improved.

Further, in the first embodiment of the method of the present invention, there was a problem that new plasma irradiation equipment was required, and the equipment investment increased. However, according to this embodiment, new equipment is required. There is no problem that capital investment will increase.

In this embodiment, the aluminum nitride film 4 is formed by reactive sputtering, but aluminum nitride is formed by a method of performing heat treatment containing nitrogen as a main component in the same sputtering apparatus used for forming aluminum alloy wiring. The same effect can be obtained by forming the film 4.

In this embodiment, the method in which the barrier metal is not used as the lower layer of the aluminum alloy wiring has been described, but the same effect can be obtained when the barrier metal is used.

As described above, according to the present embodiment, the aluminum nitride film 4 is formed by performing reactive sputtering or heat treatment in an atmosphere containing nitrogen gas as a main component in the same sputtering apparatus used for forming aluminum alloy wiring. Can be formed. Therefore, even if the sputtering apparatus for the aluminum film 3 and the sputtering apparatus for the titanium nitride film 5 as the antireflection film are different and discontinuous formation occurs, the deterioration of the electromigration life can be prevented.

FIG. 4 is a process drawing of the third embodiment of the method of manufacturing a semiconductor device of the present invention. First, the aluminum film 3 is formed by the first sputtering apparatus. Next, argon sputter etching is performed by the second sputtering device. Finally, the titanium nitride film 5 is formed by the same sputtering device as the argon sputter etching.

After the aluminum film 3 is formed by the first sputtering apparatus, argon sputter etching is performed by the second sputtering apparatus to remove the aluminum oxide film on the surface of the aluminum film 3. Further, since the argon sputter etching and the titanium nitride film 5 are formed by the same sputtering apparatus, aluminum oxide is not formed thereafter.
Therefore, when the aluminum oxide film is present, the electrons concentrated in the aluminum film 3 are dispersed in the aluminum film 3 and the titanium nitride film 5, so that the electromigration life can be improved.

In this embodiment, the method in which the barrier metal is not used as the lower layer of the aluminum alloy wiring has been described, but the same effect can be obtained when the barrier metal is used.

As described above, according to this embodiment, the aluminum oxide film can be removed by performing argon sputter etching and forming the titanium nitride film in the same sputtering apparatus after forming the aluminum alloy wiring. .
Therefore, even when the sputtering apparatus for the aluminum film and the sputtering apparatus for the titanium nitride film which is the antireflection film are different and discontinuous formation occurs, the deterioration of the electromigration life can be prevented.

[0036]

According to the present invention, since the formation of the aluminum oxide film can be prevented, the deterioration of the electromigration life can be prevented and the reliability of the semiconductor device can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of a semiconductor device of the present invention.

FIG. 2 is a process drawing of the first embodiment of the method of manufacturing a semiconductor device of the present invention.

FIG. 3 is a process drawing of the second embodiment of the method of manufacturing a semiconductor device of the present invention.

FIG. 4 is a process chart of a third embodiment of the method for manufacturing a semiconductor device of the present invention.

FIG. 5 is a sectional view of a conventional semiconductor device.

FIG. 6 is a process diagram of a conventional method for manufacturing a semiconductor device.

[Explanation of symbols]

 1 Silicon substrate 2 Boron phosphorus silicate glass film 3 Aluminum film 4 Aluminum nitride film 5 Titanium nitride film 6 Passivation film

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H01L 21/318 M H01L 21/31 C

Claims (5)

[Claims] 1. An aluminum alloy wiring formed in a predetermined pattern on an insulating film of a semiconductor substrate, and a titanium nitride film formed by sandwiching an aluminum nitride film on the aluminum alloy wiring. Semiconductor device. 2. A method of manufacturing a semiconductor device, which comprises irradiating a plasma containing nitrogen gas as a main component after forming an aluminum alloy wiring on a semiconductor substrate. 3. A semiconductor device comprising: forming an aluminum alloy wiring on a semiconductor substrate; and then forming an aluminum nitride film by reactive sputtering in the same sputtering apparatus used to form the aluminum alloy wiring. Manufacturing method. 4. Aluminum nitride wiring is formed on a semiconductor substrate and then annealed in an atmosphere containing nitrogen gas as a main component in the same sputtering apparatus used to form the aluminum alloy wiring. A method for manufacturing a semiconductor device, which comprises forming a film. 5. An aluminum alloy wiring is formed on a semiconductor substrate, then argon sputter etching is performed, and then a titanium nitride film is continuously formed in the same sputtering apparatus as the argon sputter etching. Of manufacturing a semiconductor device.