JPH10177991A - Semiconductor device and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device which has highly reliable wiring by preventing the corrosion of the wiring and a method for manufacturing the device. SOLUTION: After a titanium nitride film 13 is formed on an insulating film 12 as a barrier metal, an aluminum film 14 (14a) and a reflection preventing film composed of a titanium nitride film 15 are successively formed on the film 13. Then a photoresist film 16 is formed on the titanium nitride film 15 and patterned and the titanium nitride films 13 and 15 and aluminum film 14 are etched by using the photoresist film 16 as a mask. After etching, recesses 17 are formed by performing ion sputtering on the film 12 so that the sputtered material 18 from the recesses 17 can adhere to the side wall of aluminum wiring 14a. The ion sputtering conduction is set so that the flow rate of an Ar gas, temperature, microwave output, high-frequency bias output, and pressure can respectively become 500scmm, 25 deg.C, 800W, 2kW, and 1Pa.

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 semiconductor device having a highly reliable wiring in which corrosion is prevented and a method of manufacturing the same.

[0002]

2. Description of the Related Art In a conventional wiring forming process in the manufacture of a semiconductor device, a titanium (Ti) film as a contact metal and a titanium nitride (TiN) film as a barrier metal are formed above a substrate by sputtering. A wiring layer made of aluminum or an aluminum-based alloy.

On the other hand, in recent years, with the increase in the degree of integration of semiconductor integrated circuits, the integration of contact holes and via holes connecting a wiring layer and a diffusion layer or a wiring layer has progressed to, for example, the 0.18 μm rule. In such a semiconductor device, the aspect ratio (for example, when the hole diameter is 0.2
(a hole depth of 1.0 μm with respect to μm) increases to about 5. It is theoretically difficult to apply a sputtering method to form a titanium nitride film or a titanium film on the inner wall of a contact hole having an aspect ratio of 5 or more. (Specifically, a sufficient film is formed on the inner wall of the contact hole. Or the film thickness at the bottom of the contact hole becomes smaller).

Therefore, a titanium nitride film or a titanium film is
It is necessary to form a film by VD (Chemical Vapor Deposition), and a film is formed by a CVD method using a titanium halide or an organic titanium source. Titanium (TiC
ECR (Electron Cyclotron Resonanc) using l ₄ )
e) The plasma CVD method is used. The ECR plasma CVD method has attracted attention because it enables film formation at a lower temperature than the thermal CVD method. In addition, aiming at filling such high aspect ratio holes, the CV
A film formation of aluminum or copper (Cu) by the D method is also being studied.

Although the main purpose of these CVD techniques is to apply them to holes, they can of course also be applied to line wiring for reasons such as unification of manufacturing equipment.

[0006]

In the above-mentioned conventional method for manufacturing a semiconductor device, titanium tetrachloride, which is a reaction gas containing chlorine (Cl), is used for forming titanium or titanium nitride. Chlorine easily remains in the formed titanium nitride film. Therefore, when an aluminum wiring is formed on the titanium nitride film, the aluminum wiring may be corroded by chlorine. In other words, aluminum is stable because it is passively covered, but when ionic substances such as chlorine remaining in the titanium nitride film and moisture entering from the outside of the aluminum wiring coexist, an electrolytic solution is generated and aluminum is corroded. I do.

Further, when forming an aluminum wiring, etching is usually performed using a chlorine-based gas, so that chlorine remains on the aluminum wiring, which may cause corrosion of the aluminum wiring due to chlorine.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above circumstances, and has as its object to provide a semiconductor device having highly reliable wiring by preventing corrosion of wiring and a method of manufacturing the same. It is in.

[0009]

According to a first aspect of the present invention, there is provided a method of manufacturing a semiconductor device.
Forming a wiring layer on the insulating film, and forming a wiring by etching the wiring layer,
Performing ion sputtering on the insulating film exposed by the etching process to attach a sputter to the side wall of the wiring.
Further, it is preferable to use argon ions for the ion sputtering.

In a method of manufacturing a semiconductor device according to a second aspect of the present invention, a step of forming a barrier metal on an insulating film and forming an aluminum film or an aluminum-based alloy film on the barrier metal are provided. A step of forming an anti-reflection film on the aluminum film or the aluminum-based alloy film; and etching the anti-reflection film, the aluminum film or the aluminum-based alloy film, and the barrier metal to form an aluminum film or Forming a wiring made of an aluminum-based alloy film, and performing a step of performing ion sputtering on the insulating film exposed by the etching process, thereby attaching a sputter to a side wall of the wiring. I do. Preferably, the barrier metal and the antireflection film are made of titanium nitride.

Further, a semiconductor device according to the present invention includes a wiring layer formed on an insulating film, and a corrosion protection film formed on a side wall of the wiring layer. Further, a barrier metal formed between the insulating film and the wiring layer, an anti-reflection film formed on the wiring layer,
It is preferable to further include

In the above semiconductor device and the method of manufacturing the same, the sputtered material (corrosion protection film) from the insulating film is attached to the side wall of the wiring by performing ion sputtering on the insulating film. Therefore, the sputtered material acts as a corrosion protection film for the wiring. That is, by covering the side wall of the wiring with the sputter, it is possible to prevent moisture from entering the wiring from the outside. Therefore, corrosion of the wiring can be prevented, and a highly reliable wiring can be formed.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 are sectional views showing a method for manufacturing a semiconductor device having a highly reliable wiring layer according to the first embodiment of the present invention.

First, as shown in FIG.
An insulating film 12, such as silicon dioxide, is formed on the surface of the substrate 1.

Thereafter, as shown in FIG. 2, a titanium nitride film 13 as a barrier metal is formed on the insulating film 12 by using a chamber for ECR plasma CVD. The film forming conditions at this time were TiCl ₄ ;
₂ ; 8 sccm, H ₂ ; 26 sccm, Ar: 170 sccm, the temperature is 450 ° C., and the microwave output is 2.8 k.
W, pressure is 0.4 Pa.

Next, as shown in FIG.
An aluminum film 14 is formed on 3 using a chamber for thermal CVD. At this time, the film forming conditions are Al
(CH ₃ ) ₂ H (DMAH); 1 sccm, H ₂ ; 400 sc
At a gas flow rate of cm, the temperature is 270 ° C. and the pressure is 160 Pa.

Thereafter, as shown in FIG. 4, a titanium nitride film 15 as an antireflection film is formed on the aluminum film 14 by using a chamber for ECR plasma CVD. The film formation conditions at this time are the same as those for the titanium nitride film 13, that is, TiCl ₄ ; 20 sccm, N ₂ ;
At a gas flow rate of sccm, H ₂ ; 26 sccm, Ar; 170 sccm, the temperature is 450 ° C., the microwave output is 2.8 kW, and the pressure is 0.4 Pa.

Next, as shown in FIG. 5, a photoresist film 16 is patterned on the titanium nitride film 15 as an anti-reflection film by photolithography, and the titanium nitride film ( The antireflection film) 15, the aluminum film 14, and the titanium nitride film (barrier metal) 13 are dry-etched. The etching conditions at this time are as follows: BCl ₃ ; 80 sccm, Cl ₂ ;
At a gas flow rate of 120 sccm, the temperature is 25 ° C., the microwave output is 800 W, the high frequency bias output is 120 W, and the pressure is 667 mPa. By this etching, an aluminum wiring 14a is formed on the insulating film 12 via the titanium nitride film 13.

Thereafter, as shown in FIG. 6, a recess 17 is formed in the underlying insulating film 12 exposed between the aluminum wirings 14a by ion sputtering. At the same time, the spatter 18 from the recess 17 adheres to the side wall of the aluminum wiring 14a. The ion sputtering conditions are as follows: Ar; a gas flow rate of 500 sccm; a temperature of 25 ° C .; a microwave output of 800 W; a high frequency bias output of 2 kW; and a pressure of 1 Pa. The sputtered material 18 contains the insulating film 12 as a main component, but includes a small amount due to the photoresist film 16.

Next, as shown in FIG. 7, the photoresist film 16 is removed at a temperature of 65 ° C. using an organic stripper (trade name: EKC265).

According to the first embodiment, the aluminum wiring 14a is formed on the insulating film 12 through the titanium nitride film 13.
Then, as shown in FIG. 6, the sputtered material 18 from the insulating film 12 is attached to the side wall of the aluminum wiring 14a by performing ion sputtering. Therefore, the sputtered material 18 functions as a corrosion protection film for the aluminum wiring 14a. That is, the aluminum wiring 1
By covering the side wall of 4a with a sputtered object 18 and covering the upper and lower surfaces of the wiring 14a with titanium nitride films 13 and 15,
The entry of moisture from the outside into the aluminum wiring 14a can be suppressed. Therefore, even if chlorine remains in the titanium nitride films 13 and 15 or the aluminum wiring 14a,
This chlorine and water do not coexist. Therefore,
Corrosion of the aluminum wiring 14a due to chlorine can be prevented, and a highly reliable aluminum wiring 14a can be formed.

In the first embodiment, the aluminum film 14 is formed on the titanium nitride film 13 to form the aluminum wiring 14a. It is also possible to form a film and thereby form a wiring made of an aluminum-based alloy.

Hereinafter, a method of manufacturing a semiconductor device having a highly reliable wiring layer according to a second embodiment of the present invention will be described with reference to the drawings. The description of the same parts as in the first embodiment will be omitted, and only different parts will be described.

As shown in FIG. 2, on the insulating film 12,
The titanium nitride film 13 as a barrier metal is formed using a chamber for sputtering (for example, DC magnetron sputtering). At this time, the film forming conditions are Ar;
cm, N ₂ ; 70 sccm gas flow, temperature 200 ° C., D
The C output is 12 kW and the pressure is 0.4 Pa.

Next, as shown in FIG.
An aluminum film 14 is formed on 3 using a sputtering chamber (for example, DC magnetron sputtering). At this time, the film forming conditions are as follows: Ar: gas flow rate of 100 sccm, temperature: 200 ° C., DC output: 15 kW, pressure: 0.4 Pa.

Thereafter, as shown in FIG. 4, a sputtering chamber (for example, D
A titanium nitride film 15 as an anti-reflection film is formed using C magnetron sputtering). The film forming conditions at this time are the same as those for the titanium nitride film 13, that is, A
r; 20 sccm, N ₂ ;
00 ° C., DC output 12 kW, pressure 0.4 Pa.

In the second embodiment, the same effects as those in the first embodiment can be obtained.

As described above, the present invention has been described based on the two embodiments. However, these embodiments show preferred embodiments of the present invention, and the technical scope of the present invention is limited to the above embodiments. It goes without saying that it is not a thing.

[0029]

As described above, according to the present invention,
By performing ion sputtering on the insulating film, a sputter is attached to the side wall of the wiring. Therefore, corrosion of the wiring can be prevented, and a semiconductor device having highly reliable wiring and a method for manufacturing the same can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a method for manufacturing a semiconductor device having a highly reliable wiring layer according to a first or second embodiment of the present invention.

FIG. 2 illustrates a method for manufacturing a semiconductor device having a highly reliable wiring layer according to the first or second embodiment of the present invention, and is a cross-sectional view illustrating a step subsequent to FIG.

FIG. 3 is a cross-sectional view showing a method for manufacturing a semiconductor device having a highly reliable wiring layer according to the first or second embodiment of the present invention, and showing a step subsequent to FIG. 2;

FIG. 4 is a cross-sectional view showing a method for manufacturing a semiconductor device having a highly reliable wiring layer according to the first or second embodiment of the present invention, and showing a step subsequent to FIG. 3;

FIG. 5 is a cross-sectional view illustrating a method of manufacturing a semiconductor device having a highly reliable wiring layer according to the first or second embodiment of the present invention, and illustrating a step subsequent to FIG. 4;

FIG. 6 is a cross-sectional view showing a method for manufacturing a semiconductor device having a highly reliable wiring layer according to the first or second embodiment of the present invention, and showing a step subsequent to FIG. 5;

FIG. 7 is a cross-sectional view showing a method for manufacturing a semiconductor device having a highly reliable wiring layer according to the first or second embodiment of the present invention, and showing a step subsequent to FIG. 6;

[Explanation of symbols]

11: silicon substrate, 12: insulating film, 13: titanium nitride film (barrier metal), 14: aluminum film, 14a ...
Aluminum wiring, 15: titanium nitride film (antireflection film), 16: photoresist film, 17: recess by ion sputtering, 18: sputtered material.

Claims (9)

[Claims] A step of forming a wiring layer on the insulating film; a step of forming a wiring by etching the wiring layer; and performing ion sputtering on the insulating film exposed by the etching processing. Attaching a sputter to the side wall of the wiring. 2. The method according to claim 1, wherein the wiring layer is made of aluminum or an aluminum-based alloy. 3. The method according to claim 1, wherein argon ions are used for said ion sputtering. 4. The method according to claim 1, wherein said insulating film is a silicon oxide film. 5. A step of forming a barrier metal on the insulating film, a step of forming an aluminum film or an aluminum-based alloy film on the barrier metal, and a step of reflecting light on the aluminum film or the aluminum-based alloy film. Forming a wiring made of an aluminum film or an aluminum-based alloy film by etching the anti-reflection film, the aluminum film or the aluminum-based alloy film, and the barrier metal; Performing ion sputtering on the insulating film exposed by processing, thereby attaching a sputter to a side wall of the wiring. A method for manufacturing a semiconductor device, comprising: 6. The method according to claim 5, wherein the barrier metal and the antireflection film are made of titanium nitride. 7. A semiconductor device having a wiring, comprising: a wiring layer formed on an insulating film; and a corrosion protection film formed on a side wall of the wiring layer. 8. The semiconductor device according to claim 7, wherein said wiring layer is made of aluminum or an aluminum-based alloy. 9. The semiconductor device according to claim 7, further comprising a barrier metal formed between said insulating film and said wiring layer, and an antireflection film formed on said wiring layer. Semiconductor device.