JP2001023990A - Semiconductor device and method of manufacturing the same - Google Patents

Abstract

(57) [Problem] To form a multilayer metal wiring with an Al or Al alloy film as a main wiring, even if an antireflection film on the Al or Al alloy film may crack. Al
Alternatively, there is provided a good semiconductor device which does not generate voids 7 in the Al alloy film 3 and a method for manufacturing the same. SOLUTION: An Al or Al alloy film 3 as a main wiring film is formed to a thickness of about 1 μm and
Annealing is performed at 0 ° C. for about 1 to 5 minutes, or plasma processing is performed in an oxygen atmosphere for about 5 to 10 minutes. As a result, the surface of the Al or Al alloy film 3 is oxidized by about several tens to 200 angstroms to form an Al oxide film 10. Antireflection film 4 made of TiN on Al oxide film 10
Is formed on the order of 300 angstroms.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and a method of manufacturing the same, and more particularly, to a metal wiring such as aluminum or an aluminum alloy.

[0002]

2. Description of the Related Art Generally, in LSI metal wiring,
Multi-layer wiring is used because the wiring length increases with higher integration of elements. Further, the metal wiring itself is also formed of a multilayer film in order to improve the connection with the lower layer, the electromigration resistance, and the resist patterning characteristics.

FIGS. 4 to 9 are sectional views showing a conventional method for forming a metal wiring. The description will be made sequentially according to the drawings. First, as shown in FIG. 4, 1 is an insulating film on an element (not shown) formed on a semiconductor substrate, 2 is a barrier metal made of TiN / Ti, and 3 is Al or A which is a main wiring film.
The 1 alloy film and 4 are antireflection films made of TiN, and the metal wiring film is a multilayer film made up of barrier metal 2, Al or Al alloy film 3 and antireflection film 4.

Next, as shown in FIG. 5, plasma processing is performed in an oxygen atmosphere. This is performed to enhance the adhesion between the antireflection film 4 and a photoresist pattern to be formed later and to remove impurities, such as fluorine, which deteriorate the photoresist characteristics. In addition, when there is a defect in the pattern shape or dimensions after the formation of the resist pattern, plasma processing is also performed to remove the resist pattern.

At this time, the metal wiring films 2, 3, and 4 have a thickness of 50 to
It undergoes a thermal cycle of rising to 400 ° C. and then falling to room temperature. Since there is a difference in the thermal expansion coefficient between the Al or Al alloy film 3 and the antireflection film 4, the antireflection film 4 receives stress in this process. As a result, cracks 5 are formed in the portions of the anti-reflection film 4 damaged by the plasma and in the portions where the film quality is weak such as grain boundaries.

Next, as shown in FIG. 6, a photolithography process is performed to form a resist pattern 6. At this time, a developing solution for developing the resist pattern 6 penetrates into the Al or Al alloy film 3 from the cracks 5 of the antireflection film 4 and A
The l or Al alloy film 3 begins to melt and voids 7 are formed in the Al or Al alloy film 3.

Next, as shown in FIG. 7, dry etching for forming a metal wiring pattern is performed using the resist pattern 6 as a mask. At this time, at the same time as the antireflection film 4 is etched, unreacted substances at the time of etching adhere to the side walls of the voids 7 as a deposition film 8. Thereafter, as shown in FIG. 8, when the metal wiring films 2 and 3 are further etched, the deposition film 8 functions as a mask, and the metal wiring films 2 and 3 below the deposition film 8 are not etched and the etching residue 9 is not etched. Will remain as.

FIG. 9 is a plan view of FIG. 8. After etching, a metal wiring pattern is formed and an etching residue 9 remains, which causes a short circuit between wirings.

[0009]

The conventional method for forming a metal wiring is as described above. As shown in FIG. 6, cracks 5 enter the antireflection film 4 on the Al or Al alloy film 3,
When the resist pattern 6 is formed, the developer penetrates from the cracks 5 to form voids 7 in the Al or Al alloy film 3. As a result, there is a problem that an etching residue 9 is generated when the metal wiring pattern is formed by etching, thereby causing a short circuit between the wirings. In addition, there is a problem that the electromigration resistance is deteriorated by the voids 7 generated in the Al or Al alloy film 3.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems. Even if a crack occurs in the antireflection film on the Al or Al alloy film, the Al or A
It is an object of the present invention to provide a good semiconductor device that does not generate voids in an l-alloy film and a method for manufacturing the same.

[0011]

According to a first aspect of the present invention, there is provided a semiconductor device wherein an insulating film containing aluminum is provided above an aluminum film or an aluminum alloy film and below the antireflection film. It is.

A semiconductor device according to a second aspect of the present invention comprises:
The insulating film containing aluminum is an oxide film of aluminum.

According to a third aspect of the present invention, there is provided a semiconductor device comprising:
The insulating film containing aluminum is an aluminum nitride film.

According to a fourth aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising the steps of forming an aluminum film or an aluminum alloy film, and then forming an insulating film containing aluminum on the aluminum film or the aluminum alloy film. Forming the antireflection film on the insulating film containing aluminum.

According to a fifth aspect of the present invention, in the method for manufacturing a semiconductor device according to the fourth aspect, the step of forming an insulating film containing aluminum on the aluminum film or the aluminum alloy film comprises forming the aluminum film or the aluminum alloy film on the aluminum film or the aluminum alloy film. This is a step of forming an aluminum oxide film on the surface of the aluminum film or aluminum alloy film by annealing or plasma treatment in an oxygen atmosphere.

According to a sixth aspect of the present invention, in the method of manufacturing a semiconductor device according to the fourth aspect, the step of forming an insulating film containing aluminum on the aluminum film or the aluminum alloy film includes the step of forming the aluminum film or the aluminum alloy film. This is a step of forming an aluminum nitride film on the surface of the aluminum film or aluminum alloy film by annealing or plasma treatment in a nitrogen atmosphere.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 (a)-
(C) and FIG. 2 are sectional views showing a method for forming a metal wiring according to the first embodiment of the present invention. The description will be made sequentially according to the drawings. First, as shown in FIG. 1A, after an insulating film 1 is formed on an element (not shown) formed on a semiconductor substrate, a barrier metal 2 made of TiN / Ti is formed to about 1000 angstroms. Further, an Al or Al alloy film 3 as a main wiring film is formed to a thickness of about 1 μm.

Thereafter, in an oxygen atmosphere at 100 to 400 ° C.
For about 1 to 5 minutes, or plasma processing for about 5 to 10 minutes in an oxygen atmosphere. As a result, the surface of the Al or Al alloy film 3 is oxidized by about several tens to 200 angstroms to form an Al oxide film 10.
At this time, in order to suppress an increase in wiring resistance, the thickness of the Al oxide film 10 must be suppressed to within 10% of the thickness of the Al or Al alloy film 3.

Next, as shown in FIG. 1B, an antireflection film 4 made of TiN is formed on the Al oxide film 10 to a thickness of about 300 Å. At this time, the metal wiring film becomes a multilayer film including the barrier metal 2, the Al or Al alloy film 3, the Al oxide film 10 and the antireflection film 4.

Next, as shown in FIG. 1C, a photolithography process is performed to form a resist pattern 6. At this time, due to the difference in the thermal expansion coefficient between the Al or Al alloy film 3 and the anti-reflection film 4, the anti-reflection film 4 is subjected to stress by plasma treatment or the like after the formation of the anti-reflection film 4, and cracks 5 Is generated, and in the photomechanical process, even if the developer penetrates from the cracks 5, the Al oxide film 10 is 1 to 2 angstroms / min. Since the dissolution rate is about the same, the penetration of the developer can be stopped by the Al oxide film 10. Therefore, the void 7 is not generated in the Al or Al alloy film 3.

In this way, even if a crack 5 is formed in the antireflection film 4 during the wiring forming process and the developing solution is used, the surface of the Al or Al alloy film 3 remains on the Al oxide film 10.
And the void 7 is not formed.

Thereafter, as shown in FIG. 2, dry etching is performed using the resist pattern 6 as a mask to form a metal wiring pattern. At this time, since no voids are formed in the Al or Al alloy film 3, no deposition film adheres to the sidewalls of the voids, and no etching residue is formed. In addition, deterioration of electromigration resistance can be suppressed.

Embodiment 2 FIG. In the first embodiment, Al
Alternatively, the case where the Al oxide film 10 is formed on the surface of the Al alloy film 3 has been described. Here, the case where an Al nitride film is formed instead of the Al oxide film 10 will be described. FIG. 3 is a sectional view showing the structure of the metal wiring film according to the second embodiment of the present invention.

As shown in FIG. 3, FIG.
In the same manner as (a), after forming an insulating film 1 on an element (not shown) formed on a semiconductor substrate, TiN / Ti
A barrier metal 2 of about 1000 angstroms is formed. Further, the main wiring film Al or Al
The alloy film 3 is formed with a thickness of about 1 μm.

Thereafter, in a nitrogen atmosphere at 100 to 400 ° C.
For about 1 to 5 minutes, or plasma processing for about 5 to 10 minutes in a nitrogen atmosphere. As a result, the surface of the Al or Al alloy film 3 is nitrided by about several tens to 200 angstroms to form the Al nitride film 11.
At this time, in order to suppress an increase in wiring resistance, the thickness of the Al nitride film 11 must be suppressed to within 10% of the thickness of the Al or Al alloy film 3.

Next, an antireflection film 4 made of TiN is formed on the Al nitride film 11 in the same manner as in FIG. 1B of the first embodiment. At this time, the metal wiring film becomes a multilayer film including the barrier metal 2, the Al or Al alloy film 3, the Al nitride film 11 and the antireflection film 4. If you do this,
The Al nitride film 11 has the same function as the Al oxide film of the first embodiment, and provides the same effect as that of the first embodiment.

[0027]

As described above, according to the present invention, the insulating film containing aluminum is provided above the aluminum film or the aluminum alloy film and below the antireflection film. In the photoengraving process, even if the developer penetrates through cracks, the developer can be stopped by the insulating film containing aluminum, and voids may be generated in the aluminum or aluminum alloy film. Also, no etching residue remains when forming the metal wiring, and deterioration of electromigration resistance can be suppressed.

Further, since the insulating film containing aluminum is made of an aluminum oxide film, the dissolving speed of the aluminum oxide film in the developing solution is low, and the penetration of the developing solution can be stopped by the aluminum oxide film. .

Since the insulating film containing aluminum is made of an aluminum nitride film, the dissolution rate of the aluminum nitride film in the developing solution is low, and the penetration of the developing solution can be stopped by the aluminum nitride film. .

After the step of forming the aluminum film or the aluminum alloy film, a step of forming an insulating film containing aluminum on the aluminum film or the aluminum alloy film, and a step of forming the antireflection film on the insulating film containing aluminum. The surface of the aluminum or aluminum alloy film is protected by the aluminum insulation film even if the antireflection film is cracked during the wiring formation process and then treated with a developing solution. No void is formed, no etching residue remains when forming a metal wiring, and deterioration of electromigration resistance can be suppressed.

Further, the step of forming an insulating film containing aluminum on the aluminum film or the aluminum alloy film according to claim 4 comprises:
Since the aluminum film or aluminum alloy film is annealed or plasma-treated in an oxygen atmosphere to form an aluminum oxide film on the surface of the aluminum film or aluminum alloy film, the aluminum oxide film can be easily formed. Can be formed with good control.

Further, the step of forming an insulating film containing aluminum on the aluminum film or the aluminum alloy film according to claim 4 comprises:
The aluminum film or aluminum alloy film is subjected to annealing or plasma treatment in a nitrogen atmosphere to form an aluminum nitride film on the surface of the aluminum film or aluminum alloy film. Can be formed with good control.

[Brief description of the drawings]

FIG. 1 is a sectional view illustrating a method for forming a metal wiring according to a first embodiment of the present invention;

FIG. 2 is a cross-sectional view showing a method for forming a metal wiring according to the first embodiment of the present invention;

FIG. 3 is a cross-sectional view illustrating a structure of a metal wiring film according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a conventional method for forming a metal wiring.

FIG. 5 is a cross-sectional view showing a conventional method for forming a metal wiring.

FIG. 6 is a cross-sectional view showing a conventional method for forming a metal wiring.

FIG. 7 is a cross-sectional view showing a conventional method for forming a metal wiring.

FIG. 8 is a cross-sectional view showing a conventional method for forming a metal wiring.

FIG. 9 is a plan view of FIG. 8;

[Explanation of symbols]

3 Al or Al alloy film, 4 antireflection film, 6 resist pattern, 10 Al oxide film, 11 Al nitride film.

Continued on the front page F-term (reference) 4M104 BB14 DD65 DD71 DD72 DD78 DD86 DD89 EE05 EE08 EE14 EE16 FF17 FF18 GG13 HH01 HH14 HH20 5F033 HH08 HH09 HH18 HH33 MM05 MM13 QQ03 QQ73 QQ76 QQ89 SSRR XXRR

Claims (6)

[Claims] 1. A semiconductor device having a multi-layered metal wiring composed of an aluminum film or an aluminum alloy film and an anti-reflection film on a semiconductor substrate, the upper part of the aluminum film or the aluminum alloy film and the lower part of the anti-reflection film. A semiconductor device comprising an insulating film containing aluminum. 2. The semiconductor device according to claim 1, wherein the insulating film containing aluminum is an oxide film of aluminum. 3. The semiconductor device according to claim 1, wherein the insulating film containing aluminum is an aluminum nitride film. 4. A step of forming an aluminum film or an aluminum alloy film on a semiconductor substrate, a step of forming an antireflection film on the aluminum film or aluminum alloy film, and a step of forming the aluminum film or aluminum alloy film and the antireflection film Forming a multi-layer metal wiring by patterning the film; and a method of manufacturing a semiconductor device, comprising: after the step of forming the aluminum film or aluminum alloy film,
Manufacturing a semiconductor device, comprising: a step of forming an insulating film containing aluminum on the aluminum film or the aluminum alloy film; and a step of forming the antireflection film on the insulating film containing aluminum. Method. 5. The step of forming an insulating film containing aluminum on an aluminum film or an aluminum alloy film is performed by annealing or plasma-treating the aluminum film or the aluminum alloy film in an oxygen atmosphere. 5. The method according to claim 4, further comprising the step of forming an aluminum oxide film on the film surface. 6. The step of forming an insulating film containing aluminum on an aluminum film or an aluminum alloy film is performed by annealing or plasma-treating the aluminum film or the aluminum alloy film in a nitrogen atmosphere. 5. The method according to claim 4, further comprising the step of forming an aluminum nitride film on the film surface.