JPH10275801A - Manufacture of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method by which a semiconductor device provided with wiring having a desired narrow wiring width is manufactured. SOLUTION: After a tungsten film 1 is formed on an aluminum alloy film 53, the tungsten film 1 is patterned by an anisotropic etching using an etching gas, composed mainly of a fluorine gas by using a resist pattern 54 as an etching mask. Then, the aluminum alloy film 53 is patterned by anisotropic etching using an etching gas, composed mainly of a chlorine gas by using the patterned tungsten film 1 as an etching mask.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a semiconductor device, and more particularly, to a method for manufacturing a wiring.

[0002]

2. Description of the Related Art FIG. 4 is a schematic sectional view showing a conventional method of forming an aluminum alloy wiring used in a semiconductor device.

Step 1 (see FIG. 4A); CVD (Chem
Physical Vapor Deposition method or PVD (Physical V)
An insulating film 52 is formed on a semiconductor substrate 51 by using an apor deposition method. As the insulating film 52, any insulating film such as a silicon oxide film, a silicate glass film, a silicon nitride film, a silicon oxynitride film, and an organic insulating film may be used. Next, the insulating film 52 is formed using the PVD method.
An aluminum alloy film 53 is formed thereon. Subsequently, a resist pattern 54 made of a photoresist film is formed on the aluminum alloy film 53.

Step 2 (see FIG. 4B): The aluminum alloy film 53 is patterned by using an anisotropic etching method using the resist pattern 54 as an etching mask, so that the aluminum An alloy wiring 55 is formed. Here, in the anisotropic etching method, an etching gas mainly containing a chlorine-based gas is used.

At this time, although the resist pattern 54 is not affected by the chlorine-based gas, it is etched by a physical reaction by plasma, causing a large decrease in the film thickness and a decrease in the film thickness and width. According to the anisotropic etching method,
The width of the aluminum alloy wiring 55 is
Therefore, when the width of the resist pattern 54 decreases, the width of the aluminum alloy wiring 55 also decreases.

That is, as shown in FIG. 4A, even if the width of the resist pattern 54 is set to a desired value W1, as shown in FIG. The value W2 is smaller than W1 (W1> W2).
Therefore, the width of the aluminum alloy wiring 55 also becomes a small value W2 corresponding to the width of the resist pattern 54.

As described above, the conventional method for forming an aluminum alloy wiring has a problem that the wiring width is smaller than a desired value. This problem is caused by the ratio of the etching rate between the aluminum alloy film 53 and the resist pattern 54 (that is, the selection ratio of the aluminum alloy to the resist).
Can be solved if is sufficiently high. However, in recent years, further miniaturization of the wiring width has been demanded as semiconductor devices become more highly integrated. Therefore, improvement of the material of the photoresist film and examination of the composition of the etching gas alone
It is difficult to make the ratio of the etching rates sufficiently high.

In recent years, in order to highly integrate a semiconductor device, it has become essential to employ a multilayer wiring structure.
5 and 6 are schematic cross-sectional views showing a method for forming a conventional multilayer wiring structure used in a semiconductor device.

Step 1 (see FIG. 5A); semiconductor substrate 5
An insulating film 52 is formed on 1. Next, an aluminum alloy film 53 and a titanium nitride film 61 are sequentially formed on the insulating film 52 by using the PVD method.

Step 2 (see FIG. 5B): The aluminum alloy film 53 and the titanium nitride film 61 are patterned by using a normal photolithography technique and an anisotropic etching method. Here, the titanium nitride film 61 functions as an antireflection film in photolithography. as a result,
A first layer wiring 71 having a laminated structure of an aluminum alloy film 53 and a titanium nitride film 61 is formed. Next, CVD
The interlayer insulating film 62 is formed on the entire surface of the device formed in the above steps by using the PVD method or the PVD method. As the interlayer insulating film 62, a silicon oxide film, a silicate glass film,
Silicon nitride film, silicon oxynitride film, organic insulating film, etc.
Any insulating film may be used. Subsequently, a contact hole 63 is formed in the interlayer insulating film 62 by using a usual photolithography technique and an anisotropic etching method. In forming the contact hole 63, the titanium nitride film 61 functions as an etching stopper for the interlayer insulating film 62.

Step 3 (see FIG. 6A): The inside of the contact hole 63 and the interlayer insulating film 6 are formed by using the PVD method.
2, a titanium film 64 and a titanium nitride film 65 are sequentially formed. Step 4 (see FIG. 6B): A tungsten film is formed on the titanium nitride film 65 including the inside of the contact hole 63 by using a blanket tungsten CVD method. Next, the contact holes 6 are formed by using the entire surface etch-back method.
By leaving only the tungsten film embedded in 3, a tungsten plug 66 made of the remaining tungsten film is formed.

Here, the titanium nitride film 65 is indispensable for forming a tungsten film by a blanket tungsten CVD method. If the titanium nitride film 65 is not provided, a tungsten film cannot be formed on the inner side wall of the contact hole 63, and the contact hole 63 cannot be filled with the tungsten film.

The titanium film 64 is provided to reduce the contact resistance between the tungsten plug 66 and the first layer wiring 71. Subsequently, an aluminum alloy film 67 and a titanium nitride film 68 are sequentially formed on the tungsten plug 66 and the titanium nitride film 65 by using the PVD method. Next, the aluminum alloy film 67 and the titanium nitride film 68 are patterned using a normal photolithography technique and an anisotropic etching method. As a result, a second layer wiring 72 having a laminated structure of the aluminum alloy film 67 and the titanium nitride film 68 is formed.

In this manner, the tungsten plug 66
As a result, a multilayer wiring structure including the first layer wiring 71 and the second layer wiring 72 electrically connected to each other is formed. But,
In recent years, the ratio of the depth to the opening diameter of the contact hole 63 has increased due to the miniaturization of the wiring width accompanying the high integration of the semiconductor device. Therefore, the step coverage of the titanium film 64 and the titanium nitride film 65 deteriorates,
Each film 64, on the inner side wall and the bottom of the contact hole 63,
65 is difficult to form. As a result, the contact hole 63 cannot be completely filled with the tungsten plug 66, and there is a problem that the electrical connection between the first layer wiring 71 and the second layer wiring 72 is hindered.

When a silicon oxide film is used as the interlayer insulating film 62, if the contact hole 63 becomes deeper,
Since the ratio of the etching rates of titanium nitride and silicon oxide is small, the titanium nitride film 61 does not sufficiently function as an etching stopper for the interlayer insulating film 62. As a result, the aluminum alloy film 53 is etched unnecessarily,
There has been a problem that the first layer wiring 71 is disconnected or the electric resistance increases. This problem becomes conspicuous when a plurality of contact holes 63 are simultaneously formed and the depth of each contact hole 63 varies.

[0016]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has the following objects.

1) A method of manufacturing a semiconductor device provided with fine wiring having a desired wiring width is provided. 2] To provide a method for manufacturing a semiconductor device having a multilayer wiring structure in which the electrical resistance of each wiring layer is low and the electrical connection between the wiring layers is good.

[0018]

According to the first aspect of the present invention, first and second conductive films having different etching gases are stacked and formed, and the first conductive film is formed using the second conductive film as an etching mask. The point is to perform patterning.

According to a second aspect of the present invention, there is provided the step of forming the first conductive film, the step of etching the first conductive film only with a chlorine-based gas, and the step of forming the second conductive film on the first conductive film. A step of forming a conductive film, the step of etching the second conductive film only with a fluorine-based gas, a step of forming a resist pattern formed of a photoresist film on the second conductive film, and a step of mainly using a fluorine-based gas. Using an etching gas as a component, using a resist pattern as an etching mask,
Patterning a second conductive film; and patterning the first conductive film using an etching gas containing a chlorine-based gas as a main component and using the patterned second conductive film as an etching mask. That is the gist.

According to a third aspect of the present invention, there is provided a process for forming a first conductive film, the first conductive film being etched only with a fluorine-based gas, and a second conductive film being formed on the first conductive film. A step of forming a conductive film, the step of etching the second conductive film only with a chlorine-based gas, a step of forming a resist pattern formed of a photoresist film on the second conductive film, and a step of mainly using a chlorine-based gas. Patterning the second conductive film using an etching gas as a component and using a resist pattern as an etching mask; and etching the patterned second conductive film using an etching gas containing a fluorine-based gas as a main component. And a step of patterning the first conductive film as a mask for use.

According to a fourth aspect of the present invention, the step of forming the first conductive film, the step of etching the first conductive film only with a chlorine-based gas, and the step of forming the first conductive film using a CVD method. Forming a tungsten film on the film, forming a resist pattern of a photoresist film on the tungsten film, using an etching gas containing a fluorine-based gas as a main component, using the resist pattern as an etching mask, Patterning a film;
And a step of patterning the first conductive film using an etching gas containing a chlorine-based gas as a main component and using the patterned tungsten film as an etching mask.

According to a fifth aspect of the present invention, a step of forming a tungsten film on a conductive film using a CVD method, a step of forming a resist pattern made of a photoresist film on the tungsten film, The point is that a step of patterning a tungsten film and a conductive film is provided as an etching mask.

According to a sixth aspect of the present invention, in the method of manufacturing a semiconductor device according to the fourth or fifth aspect, a step of forming an interlayer insulating film on the device formed in the above step, A step of using a tungsten film as an etching stopper when forming a contact hole in the film.

According to a seventh aspect of the present invention, there is provided a method of forming a tungsten film using a CVD method, forming an interlayer insulating film on the tungsten film, and forming a contact hole in the interlayer insulating film. And a step of using a tungsten film as an etching stopper.

According to an eighth aspect of the present invention, in the method of manufacturing a semiconductor device according to the seventh aspect, the selective tungsten C
The gist of the present invention is that a step of selectively growing tungsten on a tungsten film exposed from the bottom of the contact hole by using a VD method to form a tungsten plug is provided.

The “first conductive film” described in the claims and the means for solving the problems corresponds to the “aluminum alloy film 53” described in the embodiment of the present invention, and the “first conductive film” also The “conductive film 2” corresponds to the “tungsten film 1”, and the “conductive film” also corresponds to the “titanium film 11”.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) A manufacturing method according to a first embodiment of the present invention will be described below with reference to the drawings. In the present embodiment, the same components as those of the conventional embodiment shown in FIG.

FIG. 1 is a schematic sectional view showing the method for forming the aluminum alloy wiring according to the present embodiment. Step 1 (see FIG. 1A): An insulating film 52 is formed on a semiconductor substrate 51. Next, the insulating film 52 is formed using the PVD method.
An aluminum alloy film 53 (thickness: 5500 °, composition; silicon: 1%, copper: 0.5%) is formed thereon. Subsequently, a tungsten film 1 (thickness: 1000 °) is formed on the aluminum alloy film 53 by using the PVD method. Then, a resist pattern 54 made of a photoresist film is formed on the tungsten film 1.

Step 2 (see FIG. 1B): The tungsten film 1 is patterned using an anisotropic etching method using the resist pattern 54 as an etching mask.

Here, RIE is used for the anisotropic etching method.
(Reactive Ion Etching) method
The subject is etching gas; SF₆, N_Two, Gas flow rate; SF
₆/ N _Two= 80/40 sccm, radio frequency (RF) power; 40
0 W, chamber pressure; 150 mT, cathode temperature; 7
0 ° C.

Step 3 (see FIG. 1C): The aluminum alloy film 53 is etched by using an anisotropic etching method using the patterned tungsten film 1 as an etching mask. Is formed.

Here, the RIE method is used for the anisotropic etching method, and the etching condition is an etching gas;
l ₃ , Cl ₂ , N ₂ , gas flow rate; BCl ₃ / Cl ₂ / N
₂ = 40/60/20 sccm, radio frequency (RF) power; 40
0 W, chamber pressure; 30 mT, cathode temperature; 70
° C.

As described above, according to the present embodiment, the following operations and effects can be obtained. (1) The tungsten film 1 is formed on the aluminum alloy film 53. Next, the tungsten film 1 is patterned by an anisotropic etching method using an etching gas containing a fluorine-based gas as a main component and using the resist pattern 54 as an etching mask. Subsequently, the aluminum alloy film 53 is patterned by an anisotropic etching method using the patterned tungsten film 1 as an etching mask using an etching gas mainly containing a chlorine-based gas.

(2) In the step 2, the resist pattern 54 is not affected by the fluorine-based gas. Further, since the thickness of the tungsten film 1 is small, the resist pattern 54 is etched by a physical reaction due to plasma, but the film thickness is small and the film thickness and width are hardly reduced. In other words, the thickness of the tungsten film 1 is set to be small in step 1 so that the width of the resist pattern 54 does not decrease in step 2. In step 3, the etching rate ratio between the tungsten film 1 and the aluminum alloy film 53 is 50 or more. Therefore, the thickness of the tungsten film 1 can be reduced.

According to the anisotropic etching method, the width of the patterned tungsten film 1 is determined by the resist pattern 54.
Is equal to the width of That is, as shown in FIG.
If the width of the resist pattern 54 is set to a desired value W1, as shown in FIG. 1B, the width of the patterned tungsten film 1 also becomes the value W1.

(3) In step 2, since the aluminum alloy film 53 is hardly etched by a fluorine-based gas, the aluminum alloy film 53 is not patterned or its surface is not roughened.

(4) In step 3, the resist pattern 54 is not attacked by the chlorine-based gas, but is etched by a physical reaction due to plasma, causing a large decrease in film thickness and a decrease in film thickness and width. On the other hand, since the tungsten film 1 is hardly etched by the chlorine-based gas, its thickness and width hardly decrease.

According to the anisotropic etching method, the width of the aluminum alloy wiring 55 is equal to the width of the patterned tungsten film 1. That is, as shown in FIG. 1B, the width of the patterned tungsten film 1 has a value W1.
Then, as shown in FIG. 1C, the width of the aluminum alloy wiring 55 also becomes the value W1.

(5) From the above (2) and (4), if the width of the resist pattern 54 is set to a desired value W1, the width of the aluminum alloy wiring 55 can be set to the same value W1. Therefore, according to the method for forming an aluminum alloy wiring of the present embodiment, even if the wiring width is reduced, the width can be set to a desired value.

The thickness of the tungsten film 1 is 3
It is appropriate to set the angle in the range of 00 to 2000 °, preferably, in the range of 500 to 1000 °.
If the thickness is larger than this range, the wiring layer becomes thick, the flatness of the interlayer insulating film is deteriorated, and the processing of the tungsten film 1 itself tends to be difficult. Conversely, if the thickness is smaller than this range, the crystallinity of the tungsten film 1 tends to deteriorate.

The ratio of the thickness of the aluminum alloy film 53 to the thickness of the tungsten film 1 (aluminum alloy film 53 / tungsten film 1) is suitably set in the range of 4 to 20, preferably 6 to 10. What is necessary is just to set to a range. If it is larger than this range, it tends to be difficult to process the aluminum alloy film 53 itself. Conversely, when the distance is smaller than this range, the wiring resistance tends to increase.

Note that the first embodiment may be modified as follows, and the same operation and effect can be obtained in such a case. [1] A barrier metal film is formed below the aluminum alloy film 53 (between the aluminum alloy film 53 and the insulating film 52). Further, a cap metal film is formed on the aluminum alloy film 53 (between the aluminum alloy film 53 and the tungsten film 1). As the barrier metal film or the cap metal film, titanium, a titanium alloy, titanium nitride, or the like is used.

[2] The etching gas used in step 2 is replaced with a gas mainly composed of a suitable fluorine-based gas other than SF ₆ . That is, as the fluorine-based gas, F
₂ , SF ₆ , CF ₄ , NF ₃ , CHF ₃ , CH ₂ F ₂ ,
It shall include at least one gas selected from the group consisting of C ₂ F ₆ and C ₃ F ₈ .

[3] Etching gas used in step 3
To Cl_Two, BCl_ThreeOther suitable chlorine-based gases
Replace with the gas to be replaced. In other words, as chlorine-based gas
Is Cl_Two, BCl_Three, CCl_Four, CCl_Two, SiCl
_Four, SiH_TwoCl_Two, PCl _ThreeSelected from the group consisting of
It shall contain at least one selected gas.

[4] An aluminum alloy film 53 is formed on the tungsten film 1. Next, the aluminum alloy film 53 is patterned by an anisotropic etching method using an etching gas containing a fluorine-based gas as a main component and using the resist pattern 54 as an etching mask. Subsequently, the tungsten film 1 is patterned by an anisotropic etching method using the patterned aluminum alloy film 53 as an etching mask, using an etching gas mainly containing a chlorine-based gas.

[5] The aluminum alloy film 53 is replaced with a film of another metal (aluminum alone, chromium, copper, iron, etc.) which is etched only by chlorine-based gas. [6] The tungsten film 1 is replaced with a film of another metal (such as tantalum) etched only by a fluorine-based gas.

[7] When the tungsten film 1 is formed,
Blanket tungsten CVD, not PVD
Method. (Second Embodiment) A manufacturing method according to a second embodiment of the present invention will be described below with reference to the drawings. In the present embodiment, the same components as those of the conventional embodiment shown in FIGS. 5 and 6 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 2 and FIG. 3 are schematic sectional views showing the method for forming the multilayer wiring structure according to the present embodiment. Step 1 (see FIG. 2A); an insulating film 52 is formed on the semiconductor substrate 51. Next, the insulating film 52 is formed using the PVD method.
An aluminum alloy film 53 and a titanium film 11 (thickness: 3
00Å) are sequentially formed.

Then, blanket tungsten CV
Using a method D, a tungsten film 12 (thickness: 800 °) is formed on the entire surface of the flat titanium film 11. Here, the tungsten film 12 is formed at a film forming temperature of 450 ° C., a pressure of 2 Torr, and tungsten hexafluoride (WF ₆ , flow rate: 1).
A reduction method using silane (SiH ₄ , flow rate: ₃ sccm) of 2 sccm) is used.

Step 2 (see FIG. 2B): The aluminum alloy film 53, the titanium film 11, and the tungsten film 12 are patterned by using ordinary photolithography and anisotropic etching. As a result, the first layer wiring 13 having a laminated structure of the aluminum alloy film 53, the titanium film 11, and the tungsten film 12 is formed. Next, an interlayer insulating film 62 (thickness: 6000 °) is formed on the entire surface of the device formed in the above steps. Subsequently, a contact hole 63 is formed in the interlayer insulating film 62 by using a usual photolithography technique and an anisotropic etching method. When forming the contact hole 63, the tungsten film 1
2 functions as an etching stopper for the interlayer insulating film 62.

Step 3 (see FIG. 3A): Tungsten is selectively formed on the tungsten film 12 exposed from the bottom of the contact hole 63 by using a selective tungsten CVD method. As a result, the inside of the contact hole 63 is filled with tungsten, and the tungsten plug 14 made of the tungsten is formed.

Here, the tungsten plug 14 is formed by forming silane (flow rate: 6 sccm) of tungsten hexafluoride (flow rate: 10 sccm) at a film forming temperature: 300 ° C., pressure: 10 mTorr.
cm).

Step 3 (see FIG. 3B): An aluminum alloy film 67 and a titanium nitride film 68 are sequentially formed on the tungsten plug 14 and the interlayer insulating film 62 by using the PVD method. Next, the aluminum alloy film 67 is formed using ordinary photolithography and anisotropic etching.
Then, the titanium nitride film 68 is patterned. As a result, a second layer wiring 72 having a laminated structure of the aluminum alloy film 67 and the titanium nitride film 68 is formed.

Thus, the tungsten plug 14
Thus, a multilayer wiring structure including the first layer wiring 13 and the second layer wiring 72 electrically connected to each other is formed. As described above, according to the present embodiment, the following operations and effects can be obtained.

{1} A titanium film 11 is formed on the aluminum alloy film 53. Next, a tungsten film 12 is formed on the entire surface of the titanium film 11 by using a blanket tungsten CVD method. Subsequently, the first layers 13 are formed by patterning the films 53, 11, and 12. Next, the first
An interlayer insulating film 62 is formed on the layer wiring 13 and the interlayer insulating film 6 is formed.
Then, a contact hole 63 is formed in FIG. Subsequently, a tungsten film is selectively grown on the tungsten film 12 exposed from the bottom of the contact hole 63 by using a selective tungsten CVD method to form a tungsten plug 14. Next, the second layer wiring 7 is formed on the tungsten plug 14.
Form 2

{2} In step 1, the tungsten film 1
2 is formed on the entire surface of the flat titanium film 11. Therefore,
Since the step coverage of the tungsten film 12 does not matter, the partial pressure of tungsten hexafluoride at the time of forming the tungsten film 12 can be reduced. In the blanket tungsten CVD method, when the partial pressure of tungsten hexafluoride is low, the tungsten film 12 can be easily formed on the titanium film 11.

Here, the titanium film 11 also has a function of reducing the contact resistance between the aluminum alloy film 53 and the tungsten film 12. In {3} step 2, when patterning the first layer wiring 13, the tungsten film 12 functions as an antireflection film in photolithography. Here, since the tungsten film 12 is formed by using a blanket tungsten CVD method, the reflectance can be easily controlled.
It can be used as an effective anti-reflection film.

Incidentally, when the wavelength of the exposure light in photolithography is 436 nm, the aluminum alloy film 53
Is 200% of the silicon ratio, whereas the reflectance of the tungsten film 12 is about 80% of the silicon ratio. On the other hand, the reflectance of the titanium nitride film 61 shown in FIG. 5 is about 75% of the silicon ratio. Therefore, according to the present embodiment, the first layer wiring 13 can be patterned into a desired wiring width, as in the conventional embodiment.

{4} In the step 2, when a silicon oxide film is used as the interlayer insulating film 62, the etching rate ratio between tungsten and silicon oxide is large.
Functions sufficiently as an etching stopper for the interlayer insulating film 62. As a result, there is no possibility that the aluminum alloy film 53 is unnecessarily etched, and even when the plurality of contact holes 63 are simultaneously formed, even if the depths of the Disconnection and increase in electric resistance can be reliably avoided.

In the step {5}, since the tungsten film 12 is exposed at the bottom of the contact hole 63, the tungsten film is selectively formed on the tungsten film 12 by using the selective tungsten CVD method. The tungsten plug 14 can be formed. for that reason,
Even if the contact hole 63 becomes deep, it is easy to completely fill the inside with the tungsten plug 14, and a good electrical connection between the first layer wiring 71 and the second layer wiring 72 can be obtained.

Incidentally, the thickness of the tungsten film 12 is
For the same reason as for the tungsten film 1, 300 to 200
It is appropriate to set it in the range of 0 °, preferably 50 °.
What is necessary is just to set in the range of 0-1000 degree | times.

The thickness of the titanium film 11 is suitably set in the range of 200 to 1000 ° for the same reason as that of the tungsten film 1, preferably 300 to 500 °.
What is necessary is just to set in the range of Å.

The second embodiment may be modified as described below, and the same operation and effect can be obtained in such a case. [1] The titanium film 11 is replaced with a titanium nitride film or a tungsten titanium alloy film.

[2] The second embodiment and the first embodiment are used together. That is, in patterning the first layer wiring 13 in step 2 of the second embodiment, first, an etching gas containing a fluorine-based gas as a main component is used, and a resist pattern formed on the tungsten film 12 is etched. The tungsten film 12 is patterned by the anisotropic etching method described below. Subsequently, the titanium film 11 and the aluminum alloy film 53 are patterned by an anisotropic etching method using an etching gas containing a chlorine-based gas as a main component and using the patterned tungsten film 12 as an etching mask.

In this case, as described in {3}, the tungsten film 12 functions as an effective anti-reflection film, so that the tungsten film 12 can be accurately patterned to a desired wiring width. As a result, the first layer wiring 13 can also be accurately patterned to a desired wiring width.

Although the embodiments have been described above, technical ideas other than the claims that can be grasped from the embodiments will be described below. (A) In the method of manufacturing a semiconductor device according to claim 7 or 8, the tungsten film is formed on a film selected from the group consisting of a titanium film, a titanium nitride film, and a titanium tungsten alloy film. Of manufacturing a semiconductor device formed in a semiconductor device.

(B) In the above (A), any one of the films selected from the group consisting of a titanium film, a titanium nitride film, and a titanium tungsten alloy film is formed on an aluminum alloy film. .

[0068]

According to the invention described in any one of the first to sixth aspects, it is possible to provide a method of manufacturing a semiconductor device provided with fine wiring having a desired wiring width.

According to the invention as set forth in any one of claims 7 and 8, a multilayer wiring structure having a low electric resistance of each wiring layer and good electric connection between the wiring layers is provided. A method for manufacturing a semiconductor device can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view for explaining a manufacturing process according to a first embodiment.

FIG. 2 is a schematic cross-sectional view illustrating a manufacturing process according to a second embodiment.

FIG. 3 is a schematic cross-sectional view illustrating a manufacturing process according to a second embodiment.

FIG. 4 is a schematic cross-sectional view for explaining a conventional manufacturing process.

FIG. 5 is a schematic cross-sectional view for explaining a conventional manufacturing process.

FIG. 6 is a schematic cross-sectional view for explaining a conventional manufacturing process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Tungsten film as a 2nd conductive film 11 ... Titanium film as a conductive film 12 ... Tungsten film 13 ... First layer wiring 14 ... Tungsten plug 53 ... Aluminum alloy film as a 1st conductive film 62 ... Interlayer insulating film 63… Contact hole

Claims (8)

[Claims] A first and a second etching gas having different etching gases.
A method of manufacturing a semiconductor device, comprising forming a conductive film in a stacked manner and patterning the first conductive film using the second conductive film as an etching mask. A step of forming a first conductive film, a step of etching the first conductive film only with a chlorine-based gas, and a step of forming a second conductive film on the first conductive film. , Second
Forming a resist pattern formed of a photoresist film on the second conductive film; and forming a resist pattern using an etching gas containing a fluorine-based gas as a main component. Patterning the second conductive film using as a mask for etching; and etching the first conductive film using the patterned second conductive film as an etching mask using an etching gas containing a chlorine-based gas as a main component. Patterning a semiconductor device. Forming a first conductive film, etching the first conductive film only with a fluorine-based gas, and forming a second conductive film on the first conductive film; , Second
The conductive film is etched only by a chlorine-based gas, forming a resist pattern of a photoresist film on the second conductive film, and etching the resist pattern using an etching gas containing a chlorine-based gas as a main component. Patterning the second conductive film by using as a mask for etching, and etching the first conductive film using the patterned second conductive film as an etching mask by using an etching gas containing a fluorine-based gas as a main component. Patterning a semiconductor device. 4. A step of forming a first conductive film, the first conductive film is etched only with a chlorine-based gas, and a tungsten film is formed on the first conductive film by using a CVD method. Forming a resist pattern made of a photoresist film on the tungsten film; patterning the tungsten film using an etching gas containing a fluorine-based gas as a main component and using the resist pattern as an etching mask; Patterning the first conductive film using an etching gas mainly containing a chlorine-based gas and using the patterned tungsten film as an etching mask. 5. A step of forming a tungsten film on a conductive film using a CVD method, a step of forming a resist pattern made of a photoresist film on the tungsten film, and a step of forming a tungsten film using the resist pattern as an etching mask. And a step of patterning a conductive film. 6. The method of manufacturing a semiconductor device according to claim 4, wherein an interlayer insulating film is formed on the device formed in the step, and a contact hole is formed in the interlayer insulating film. Using the tungsten film as an etching stopper. 7. A step of forming a tungsten film using a CVD method, a step of forming an interlayer insulating film on the tungsten film, and using the tungsten film as an etching stopper when forming a contact hole in the interlayer insulating film. And a method of manufacturing a semiconductor device. 8. The method of manufacturing a semiconductor device according to claim 7, wherein tungsten is selectively grown on a tungsten film exposed from a bottom of said contact hole by using a selective tungsten CVD method to form a tungsten plug. A method for manufacturing a semiconductor device, comprising: