JPH10326780A - Semiconductor device and manufacturing method thereof - Google Patents

Abstract

An object of the present invention is to provide a semiconductor device for improving the reliability of electromigration resistance in a contact hole connecting a wiring layer and a method of manufacturing the same. SOLUTION: A first metal wiring layer 2A includes a first metal film 2a arranged on a base interlayer insulating film 1 side, and a first metal film 2a.
a on the second metal film 2b, and a third metal film 2c formed on the second metal film 2b and made of the same metal material as the first metal film 2a. The third metal film 2c is a metal material having higher electromigration resistance than the second metal film 2b.
8 is provided so as to be in contact with the surface of the first metal film 2a.

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 for manufacturing the same, and more particularly, to a semiconductor device for improving electromigration resistance between wiring layers and a method for manufacturing the same.

[0002]

2. Description of the Related Art In semiconductor devices, miniaturization of device dimensions and multi-layer wiring have been promoted for each generation in order to achieve high integration and multi-function of devices. As a result, the density of the current flowing through the wiring and the connection wiring layer connecting the wirings increases, and electromigration caused by the current becomes severe for each generation.

Here, a wiring structure of a conventional semiconductor device will be described with reference to FIGS. FIG.
FIG. 4 is a cross-sectional view for explaining a wiring structure of a conventional semiconductor device, and FIGS. 15 to 18 are cross-sectional views showing manufacturing steps of the semiconductor device according to the cross-sectional structure of FIG.

First, a wiring structure of a conventional semiconductor device will be described with reference to FIG. On the underlying interlayer insulating film 1 made of SiO ₂ or the like,
Å, the first metal wiring layer 2 made of a metal film such as an Al-based alloy
Are formed. On the first metal wiring layer 2, an interlayer insulating film 5 made of SiO ₂ or the like having a thickness of 1.0 to 2.0 μm
A second metal wiring layer 10 made of a metal film such as an l-based alloy is formed.

The first metal wiring layer 2 and the second metal wiring layer 10 have a hole diameter of 0.2 to 1.0 μm provided in the interlayer insulating film 5.
Thickness of 500 to 1 provided in the contact hole 6 of FIG.
It is electrically connected by an underlying metal film 7 of 500 mm and a buried metal film 8 made of a metal material such as W.

Next, referring to FIGS. 15 to 18, FIG.
The manufacturing process of the semiconductor device shown in FIG.

First, referring to FIG. 15, a metal film such as an Al-based alloy having a thickness of 2000 to 150 is formed on underlying interlayer insulating film 1 made of SiO ₂ or the like by a sputtering method or the like.
00 ° is formed. Then, using the photoresist film patterned into a predetermined shape by photolithography as a mask, the metal film is subjected to reactive ion etching to form a first metal wiring layer 2 having a predetermined shape.

Referring to FIG. 16, an interlayer insulating film 5 made of SiO ₂ or the like and having a thickness of 1.0 to 2.0 μm is formed so as to cover underlying interlayer insulating film 1 and first metal wiring layer 2. To form

Next, referring to FIG. 17, a photoresist film patterned into a predetermined shape by photolithography is formed on interlayer insulating film 5. Thereafter, the interlayer insulating film 5 is subjected to reactive ion etching using the photoresist film as a mask, and a contact hole 6 having a hole diameter of 0.2 to 1.0 μm is opened. At this time, the etching shape of the contact hole 6 is either a shape in which the lower end of the contact hole 6 is in contact with the surface of the first metal wiring layer 2 or a shape in which the upper portion of the first metal wiring layer 2 is slightly dug.

Next, referring to FIG. 18, an underlying metal film 7 having a thickness of 500 to 500 nm is formed on the surface of interlayer insulating film 5 by sputtering so as to cover the inner surface of contact hole 6.
1500 ° formed. Then, a buried metal film 8 such as W
Is formed on the entire surface of the underlying metal film 7 by the CVD method, and then the entire surface is etched back to leave the metal film 8 only in the contact hole 6.

Next, a metal film such as an Al-based alloy is formed by a sputtering method or the like, and reactive ion etching of the metal film is performed using a photoresist film patterned by photolithography as a mask, to a thickness of 2000 to 15 nm.
A second metal wiring layer 10 of 000 ° is formed. Thereby, a semiconductor device having the structure shown in FIG. 14 is formed.

[0012]

However, in the semiconductor device having the above structure, the contact hole 6
Inside, disconnection due to electromigration occurs. The disconnection due to the electromigration is likely to occur as a result of the formation of the void 20 at the interface between the contact hole 6 and the first metal wiring layer 2 as shown in FIG.

As shown in FIG. 1, the first metal wiring layer 2, the contact hole 6, and the second metal wiring layer 10 have a current flow and an electron flow in the directions indicated by arrows (a, b, c) in the figure. It is thought that there is movement. At this time, the total current I is divided and the currents I ₁ , I ₂ ,.
_{When n} is considered, the current flowing from the first metal wiring layer 2 to the contact hole 6 and further to the second metal wiring layer 10 (moving from the second metal wiring layer 10 to the contact hole 6 and further to the first metal wiring layer 2) The first metal wiring layer 2
The size of the interface between the contact hole 6 and the contact hole 6 is not uniform but different depending on the length of the current path.

The second metal wiring layer 10 to the first metal wiring layer 2
In the circle A (electron path indicated by arrow a), which is the shortest path to, a larger electron movement occurs than in the circle B (electron path indicated by arrow c). The generation of the voids 20 due to electromigration is caused by substances having different metal mobilities (the likelihood of the movement of the wiring material being pushed by the electron flow when a certain current flows in the wiring, and the likelihood of electromigration). At the interface where the transfer of electrons (current value) is large.

Therefore, as a technique for preventing the generation of voids due to such electromigration, there is a structure of a semiconductor device disclosed in Japanese Patent Application Laid-Open No. 7-183378. Here, an outline of the technology disclosed in the above publication will be described with reference to FIG.

According to the structure of the semiconductor device, the first metal wiring layer 2X having a predetermined shape is formed on the underlying interlayer insulating film 1, and the interlayer insulating film 5 is formed on the first metal wiring layer 2X. I have. On the interlayer insulating film 5, a second metal wiring layer 10 having a predetermined shape is formed. The first metal wiring layer 2 </ b> X and the second metal wiring layer 10 are connected by an underlying metal film 7 and an embedded metal film 8 using a metal material such as W by using a contact hole 6 formed in the interlayer insulating film 5. It is electrically connected.

Here, the first metal wiring layer 2X has a two-layer structure of a first metal film 3 and a second metal film 4, and the first metal film 3 has a high melting point such as Ti, TiN and W. A metal material is used, and an Al-based alloy material is used for the second metal film 4.

The contact hole 6 is formed up to the surface of the first metal film 3. In the wiring structure of the semiconductor device having the above structure, the contact hole 6 is formed in the second
It extends through the metal film 4 to the surface of the first metal film 3. Thereby, the contact area between the connection wiring layer including the underlying metal film 7 and the buried metal film 8 and the first metal wiring layer 2X can be increased. As a result, since the current value can be dispersed, the contact hole 6 and the first
It is possible to suppress generation of voids at the interface with the metal wiring layer 2X.

However, in the structure shown in FIG. 20, as shown in FIG. 21, the local concentration of current (electrons) occurs more in the region indicated by the circle C than in the region indicated by the circle D. easy. As a result, voids may occur in the area indicated by the circle C, and the wiring layer may be disconnected due to electromigration.

Accordingly, the present invention has been made in order to solve the above-mentioned problems, and has improved the electromigration resistance by improving the nonuniformity of current (electrons) at the interface between dissimilar metals in the contact hole of a semiconductor device. It is an object of the present invention to provide a semiconductor device for improving the reliability of the semiconductor device by the improvement and a manufacturing method thereof.

[0021]

According to one aspect of a semiconductor device according to the present invention, an interlayer insulating film is interposed on a base interlayer insulating film and electrically connected by a connection wiring layer. A first metal wiring layer; and a second metal wiring layer formed above the first metal wiring layer. The first metal wiring layer includes a first metal film disposed on the base interlayer insulating film side. A second metal film formed on the first metal film, and a third metal film made of the same metal material as the first metal film formed on the second metal film, The first metal film and the third metal film are formed on the second metal film.
It is a metal material having better electromigration resistance than a metal film, and the lower end of the connection wiring layer is
It is provided so as to be in contact with the surface of the metal film.

Preferably, in the semiconductor device according to the above aspect, the first metal wiring layer comprises a fourth metal film made of the same metal material as the second metal film on the third metal film; A fifth metal film made of the same metal material as the first metal film is further formed on the film.

Preferably, in the semiconductor device according to the above aspect, the first metal film is made of at least one metal material selected from the group consisting of Cu, W, Ti, and TiN. Has Al
A series alloy material is used.

In another aspect of the semiconductor device according to the present invention, an interlayer insulating film is interposed on the underlying interlayer insulating film and electrically connected by a connection wiring layer.
A first metal wiring layer and a second metal wiring layer formed above the first metal wiring layer, wherein the first metal wiring layer has a first metal film formed on the base interlayer insulating film side; ,
A second metal film formed on the first metal film and having a specific resistance gradually increasing as the distance from the underlying interlayer insulating film increases, wherein a lower end of the connection wiring layer is formed of the first metal film; It is provided so as to be in contact with the surface of the.

Preferably, in the semiconductor device according to the above aspect, an Al-based alloy material is used for the first metal film, and a high melting point metal material is used for the second metal film.

Next, in still another aspect of the semiconductor device according to the present invention, a semiconductor device according to the first aspect, in which an interlayer insulating film is interposed on a base interlayer insulating film and electrically connected by a connection wiring layer. A metal wiring layer and a second metal wiring layer formed above the first metal wiring layer, wherein the first metal wiring layer includes a first metal film disposed on the base interlayer insulating film side; The first metal film is formed on the first metal film.
A second metal film having better electromigration resistance than the metal film, and a lower end of the connection wiring layer is provided so as to be in contact with the inside of the second metal film.

Preferably, in the semiconductor device according to the above aspect, an Al-based alloy material is used for the first metal film, and Cu, W, Ti, and T are used for the second metal film.
At least one metal material selected from the group consisting of iN is used.

In one aspect of the method of manufacturing a semiconductor device according to the present invention, a first metal wiring electrically connected to a connection wiring layer on an underlying interlayer insulating film with an interlayer insulating film interposed therebetween. A method for manufacturing a semiconductor device comprising a layer and a second metal wiring layer formed above the first metal wiring layer, comprising the following steps.

First, the first metal wiring layer is formed.
Thereafter, an interlayer insulating film is formed on the first metal wiring layer.

Next, a contact hole communicating with the first metal wiring layer is formed in the interlayer insulating film. afterwards,
The connection wiring layer electrically connected to the surface of the first metal wiring layer is formed in the contact hole.

Next, the second metal wiring layer electrically connected to the connection wiring layer is formed on the interlayer insulating film.

Further, the step of forming the first metal wiring layer includes the following steps. First, a first metal film is formed on the base interlayer insulating film side. Thereafter, a second metal film is formed on the first metal film. Furthermore, this second
A third metal film made of the same metal material as the first metal film is formed on the metal film.

The contact hole is formed in the first contact hole.
It is formed so as to communicate with the metal film. Further, the first metal film and the third metal film are made of a metal material having better electromigration resistance than the second metal film.

Preferably, in the method of manufacturing a semiconductor device according to the above aspect, the step of forming the first metal wiring layer includes forming a fourth metal layer made of the same metal material as the second metal film on the third metal film. The step of forming and the step of forming a fifth metal film made of the same metal material as the first metal film on the fourth metal film are further performed.

Next, in another aspect of the method of manufacturing a semiconductor device according to the present invention, the method comprises the steps of:
A method of manufacturing a semiconductor device having a first metal wiring layer electrically connected by a connection wiring layer and a second metal wiring layer formed above the first metal wiring layer with an interlayer insulating film interposed therebetween. And includes the following steps.

First, a first metal wiring layer is formed. Thereafter, an interlayer insulating film is formed on the first metal wiring layer.

Next, a contact hole leading to the first metal wiring layer is formed in the interlayer insulating film. afterwards,
The connection wiring layer electrically connected to the surface of the first metal wiring layer is formed in the contact hole.

Next, the second metal wiring layer electrically connected to the connection wiring layer is formed on the interlayer insulating film.

The step of forming the first metal wiring layer includes the step of forming the first metal film on the side of the underlying interlayer insulating film and the step of increasing the specific resistance gradually as the distance from the underlying interlayer insulating film increases. Forming a second metal film. Further, the contact hole is formed in the first hole.
It is formed so as to communicate with the metal film.

In the method of manufacturing a semiconductor device, the step of forming the second metal film is preferably performed by diffusing a metal atom into the metal film.

Next, in still another aspect of the method of manufacturing a semiconductor device according to the present invention, an interlayer insulating film is interposed on a base interlayer insulating film and electrically connected by a connection wiring layer. A method for manufacturing a semiconductor device including a first metal wiring layer and a second metal wiring layer formed above the first metal wiring layer, comprising the following steps.

First, the first metal wiring layer is formed.
Thereafter, an interlayer insulating film is formed on the first metal wiring layer.

Next, a contact hole is formed in the interlayer insulating film so that the inside of the first metal wiring layer is exposed. Then, the connection wiring layer electrically connected to the inside of the first metal wiring layer is formed in the contact hole.

Next, the second metal wiring layer electrically connected to the connection wiring layer is formed on the interlayer insulating film.

Further, the step of forming the first metal wiring layer includes the step of forming a first metal film on the side of the underlying interlayer insulating film, and the step of forming a first metal film on the first metal film rather than the first metal film. Forming a second metal film having excellent electromigration resistance.

[0046]

Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same reference numerals indicate the same or corresponding parts.

[First Embodiment] The structure of a semiconductor device according to the first embodiment will be described below with reference to FIG. FIG. 1 is a sectional view showing the structure of the semiconductor device 100 according to the present embodiment.

A first metal wiring layer 2A of 2000-15000 ° is formed on a base interlayer insulating film 1 made of SiO ₂ or the like. Above the first metal wiring layer 2A, Si
An interlayer insulating film 5 made of O ₂ or the like and having a thickness of 1.0 to 2.0 μm is formed. On this interlayer insulating film 5, A
Film thickness of 2000-15000 made of l-type alloy material etc.
The second metal wiring layer 10 is formed.

Here, as shown in FIG. 1, the first metal wiring layer 2A has a first metal film 2a, a second metal film 2b, a third metal film 2c, It has a multi-layer structure of a metal film 2d and a fifth metal film 2e.

For the second metal film 2b and the fourth metal film 2d, an Al-based alloy material is used.
The second metal film 2b is formed on the metal film 2c and the fifth metal film 2e.
And Cu, W, Ti, Ti as metal materials having better electromigration resistance than the fourth metal film 2d.
N is used.

Further, in the present embodiment, in order to electrically connect first metal wiring layer 2A and second metal wiring layer 10, contact hole having a hole diameter of 0.2 to 1.0 μm is formed in interlayer insulating film 5. In the contact hole 6, an underlying metal film 7 having a thickness of 500 to 1500 膜厚 and an embedded metal film 8 made of a high melting point metal material such as tungsten are provided. Here, the lower end of the contact hole 6 is provided up to a position reaching the surface of the first metal film 2a.

Next, the semiconductor device 100 having the above structure
Will be described with reference to FIGS.
2 to 4 are cross-sectional process diagrams showing a manufacturing process according to the cross-sectional structure of the semiconductor device 100 shown in FIG.

First, referring to FIG. 2, underlying interlayer insulating film 1
A first metal film 2a, a second metal film 2b, a third metal film 2c, a fourth metal film 2d, and a fifth metal film 2e each having a thickness of 500 to 1000 ° are formed thereon. Here, as described above, the second metal film 2b and the fourth metal film 2d include
An Al-based alloy material is used, and the first metal film 2a, the third metal film 2c, and the fifth metal film 2e are metal materials having higher electromigration resistance than the second metal film 2b and the fourth metal film 2d. Cu, W, Ti, NiN are used. Thereafter, the first metal wiring layer 2A including the first metal film 2a to the fifth metal film 2e is patterned using a known photolithography technique.

Next, referring to FIG. 3, first metal wiring layer 2
The interlayer insulating film 5 made of SiO or the like and having a thickness of 1.0 to 2.0 μm is deposited using a CVD method or the like so as to cover “a”. Then, the first metal film 2a is formed by reactive ion etching using a known photolithography technique.
The contact hole 6 reaching the surface is formed.

Next, referring to FIG. 4, an underlaying metal film 7 having a thickness of 500-1500.degree. Is deposited by a sputtering method so as to cover the inner peripheral surface of contact hole 6 and the surface of interlayer insulating film 5. Referring to FIG. Then, a buried metal film 8 such as W
Is deposited on the entire surface by the CVD method, and then the entire surface is etched back, so that W is left only in the contact hole 6 to form the buried metal film 8.

Next, the underlying metal film 7 and the buried metal film 8
A metal film made of an Al-based alloy or the like is deposited using a sputtering method so as to cover the metal film, and the metal film is patterned by a known photolithography technique to form a second metal wiring layer 10. As a result, FIG.
The semiconductor device 100 according to the present embodiment shown in FIG.

As described above, according to the semiconductor device and the method of manufacturing the same according to the present embodiment, the first metal wiring layer 2A is formed of Al
Metal film 2b and fourth metal film 2 made of a base alloy material
d is sandwiched between the first metal film 2a, the third metal film 2c, and the fifth metal film 2e having excellent electromigration resistance. Further, the first metal wiring layer 2A and the second metal wiring layer 10 The lower end of the wiring layer for electrical connection is the surface of the first metal film 2a.

As a result, as shown in FIG. 5, even when voids 20 are formed in the fourth metal film 2d, the fourth metal film 2d is made of a metal material having excellent electromigration resistance, that is, the fourth metal film 2d. Since the third metal film 2c and the fifth metal film 2e formed of a metal material having lower mobility than the Al-based alloy layer of 2d are sandwiched, the void 20 is formed between the third metal film 2c and the fourth metal film 2e. Does not grow.

Therefore, it is possible to prevent a fatal disconnection of the first metal wiring layer 2A. As a result, at the contact hole and the wiring interface between the first metal wiring layer 2A and the second metal wiring layer 10, a critical disconnection does not occur, and the electrical reliability in the contact hole portion can be improved. Becomes

Here, in the above-described embodiment,
Although the first metal wiring layer 2A has a five-layer structure, the first metal film
The same operation and effect can be obtained even with a three-layer structure of a, the second metal film 2b and the third metal film 2c. The same applies to a structure having five or more layers.

Further, although only the first metal wiring layer 2A has a multi-layered structure, the structure is not necessarily limited to this structure. For example, as shown in FIG. Interlayer insulating film 1 on top
00, a second metal wiring layer AL2 formed above the first metal wiring layer AL1 with an interlayer insulating film 200 therebetween, and a second metal wiring layer AL2
By adopting the multi-layer structure of the present embodiment for the third metal wiring layer AL3 formed above the generation layer AL2 with the interlayer insulating film 300 interposed therebetween, the electrical reliability between the wiring layers can be improved. It is possible to achieve.

[Second Embodiment] The structure of a semiconductor device according to a second embodiment will be described below with reference to FIG. FIG. 7 is a cross-sectional view showing the structure of the semiconductor device 200 in this embodiment.

A first metal wiring layer 2 having a thickness of 2000 to 15000 ° is formed on a base interlayer insulating film 1 made of SiO ₂ or the like.
B is formed. Above the first metal wiring layer 2B,
A second metal wiring layer 10 made of Al-based alloy material or the like having a thickness of 2000-15000 ° is formed with an interlayer insulating film 5 made of SiO ₂ or the like having a thickness of 1.0-2.0 μm interposed. .

Here, as shown in FIG. 7, the first metal wiring layer 2 B is gradually formed as the distance from the first metal film 3 made of an Al-based alloy material or the like having a thickness of 500 to 1000 ° and the underlying interlayer insulating film 1 increases. And a second metal film 4 having a large specific resistance. Here, the change in the specific resistance of the second metal film 4 is set so as to gradually change between ρ = 3.0 to several tens μΩcm.

The first metal wiring layer 2 B and the second metal wiring layer 10 are connected to the underlying metal film 7 and the buried metal film 7 by using the contact holes 6 formed in the interlayer insulating film 5 in the same manner as in the first embodiment. They are electrically connected using the metal layer 8. The lower end of the contact hole 6 is provided so as to reach the surface of the first metal film 3.

Next, the semiconductor device 200 having the above structure
Will be described with reference to FIGS. 8 and 9. 8 and 9 show the semiconductor device 2 shown in FIG.
It is sectional process drawing which shows the manufacturing process according to the cross-sectional structure of No. 00.

First, referring to FIG. 8, underlying interlayer insulating film 1
A first metal film 3 having a thickness of 500 to 1000 ° is formed thereon using a high melting point metal material such as Ti, TiN, or W. Thereafter, a second metal film 4 made of an Al-based alloy material is formed on the first metal film 3 to a thickness of 2000-15000. Here, as described above, in order to set the specific resistance value of the second metal film 4 so as to increase as the distance from the interlayer insulating film 1 increases, first, the second main metal layer 4 is formed, and then the second main metal layer 4 is formed. A metal film such as Ti serving as a diffusion source is formed on the surface of the second metal film 4 by a sputtering method or a CVD method.

Thereafter, a heat treatment is performed to
The Ti atoms on the surface are diffused into the Al film. As a result, A
The Ti concentration in the l film decreases from the outermost surface of the second metal film 4 toward the underlying interlayer insulating film 1, and has a high resistance on the outermost surface with a high Ti concentration and a lower resistance on the side of the underlying interlayer insulating film 1 with a low Ti concentration. Can obtain a low-resistance layer. In particular,
As described above, the value ρ of the specific resistance of the second metal film 4 is 3.0 to 3.0.
It will gradually change between tens of μΩcm.

Under the condition shown in FIG. 7, for example, when the opening diameter of the contact hole 6 is 0.5 μm and the depth is 1.0 μm, there is a difference in length between the shortest path and the longest path by about twice. The specific resistance of the second metal film 4 is 6.0 μm on the outermost surface side.
Ωcm, which is about twice as high as 3.0 μΩcm on the base interlayer insulating film 1 side. For this purpose, the desired value of the specific resistance can be obtained by diffusing about 1.5 wt% of Ti into the Al film.

Next, referring to FIG. 9, an interlayer insulating film 5 is formed on second metal film 4. Thereafter, in the same manner as in the first embodiment, a contact hole 6 is opened in the interlayer insulating film 5 using a known photolithography technique using reactive ion etching. At this time, the lower end of the contact hole 6 is etched until it reaches the surface of the first metal film 3.

Thereafter, through an operation similar to that shown in FIG. 4 in the first embodiment, an underlying metal film 7 and an embedded metal layer 8 are formed in contact hole 6 and a second metal interconnection of a predetermined shape is formed. The layer 10 is formed. This allows
The semiconductor device 200 according to Embodiment 2 shown in FIG. 7 can be formed.

As described above, according to the semiconductor device and the method of manufacturing the same of this embodiment, in the conventional structure shown in FIG.
However, as in the present embodiment, the resistivity of the second metal film 4 is gradually increased in the direction away from the underlying interlayer insulating film 1 to increase the specific resistance value ratio. As shown in FIG. 10, the current (electrons) at the interface between the contact hole 6 and the first metal wiring layer 2B is changed to the first current.
It becomes possible to disperse in the thickness direction of the metal wiring layer 2B. As a result, it is possible to make the current (electron) density uniform in the thickness direction of the first metal wiring layer 2B. This makes it possible to improve the electrical reliability.

Third Embodiment The structure of a semiconductor device according to a third embodiment will be described below with reference to FIG. FIG. 11 is a sectional view showing the structure of the semiconductor device 300 according to the present embodiment.

A first metal wiring layer 2C having a thickness of 2100-17000 ° is formed on a base interlayer insulating film 1 made of SiO ₂ or the like. Above the first metal wiring layer 2C, an interlayer insulating film 5 made of SiO ₂ having a thickness of 1.0 to 2.0 μm is interposed with a thickness of 2000 to 15000.
A second metal wiring layer 10 made of an Al-based alloy material or the like is formed.

As shown in FIG. 11, the first metal wiring layer 2C has a thickness of 2000-15000 °, a first metal film 2g made of an Al-based alloy material, and a thickness of 100-100 mm.
It has a two-layer structure with a second metal film 2h using a metal material of Ti, TiN, W, and Cu that has better electromigration resistance than the first metal film 2g.

Further, according to the structure of this embodiment, since the first metal wiring layer 2c and the second metal wiring layer 10 are electrically connected, the interlayer insulating film 5 has a hole diameter of 0.2 to 1.0 μm. A contact hole 6 is provided. In the contact hole 6, an underlying metal film 7 having a thickness of 500 to 1500 Å and a buried metal film 8 made of a refractory metal material such as tungsten are provided. Here, the lower end of the contact hole 6 is provided so as to be in contact with the inside of the second metal film 2h.

Next, the semiconductor device 300 having the above structure
Will be described with reference to FIGS. FIGS. 12 and 13 are cross-sectional process diagrams showing manufacturing steps according to the cross-sectional structure of the semiconductor device 300 shown in FIG.

First, referring to FIG. 12, a first metal film 2g made of an Al-based alloy material and having a thickness of 2000-15000 ° is deposited on underlying interlayer insulating film 1 by using a CVD method or the like. Then, a film having a thickness of 1 is formed on the first metal film 2g.
A second metal film 2h made of a metal material such as Ti, TiN, W, and Cu is deposited at 00 to 2000 °.

Next, reactive ion etching is performed on the first metal film 2g and the second metal film 2h using a known photolithography technique to perform predetermined patterning, thereby completing the first metal wiring layer 2C. Let it.

Next, referring to FIG. 13, an interlayer insulating film 5 is deposited to cover the first metal wiring layer 2C. Thereafter, the contact holes 6 are formed in the interlayer insulating film 5 by using a known technique.
The hole is opened. At this time, the lower end of the contact hole 6 has a structure in which the etching is stopped inside the second metal film 2h.

Next, through a process similar to that shown in FIG. 4 in the first embodiment, semiconductor device 300 in the present embodiment shown in FIG. 11 can be completed.

As described above, according to the semiconductor device and the method of manufacturing the same in the present embodiment, the contact between the first metal wiring layer 2C and the second metal wiring layer 10 in the second metal film 2h having high electromigration resistance is provided. Is provided. As a result, since the metal layer that was in contact with the conventional contact hole was an Al-based alloy material, a hole was likely to be formed in the contact portion. However, in the present embodiment, a metal film excellent in electromigration was used. Therefore, it is possible to improve the reliability of the contact portion.

It is to be noted that, even if the structure described in FIG. 6 of the first embodiment is applied to the structure of the second or third embodiment, the function and effect of each embodiment can be obtained.

The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0085]

According to one aspect of the semiconductor device and the method of manufacturing the same according to the present invention, the first metal wiring layer is
A second metal film and a fourth metal film made of an Al-based alloy material, a first metal film having excellent electromigration resistance;
A structure sandwiched between the third metal film and the fifth metal film is employed. Further, the lower end of the wiring layer for electrical connection between the first metal wiring layer and the second metal wiring layer is used as the surface of the first metal film.

Thus, for example, even when voids occur in the fourth metal film, the fourth metal film is made to have a higher mobility than a metal material having excellent electromigration resistance, that is, an Al-based alloy layer of the fourth metal film. Since the third metal film and the fifth metal film formed of a metal material having a small size are sandwiched, voids do not grow in the third metal film and the fourth metal film.

Therefore, it is possible to prevent a fatal disconnection of the first metal wiring layer. As a result, at the contact hole and the wiring interface between the first metal wiring layer and the second metal wiring layer, a critical disconnection does not occur, and it is possible to improve the electrical reliability in the contact hole portion. . As a result, a highly reliable semiconductor device and a method for manufacturing the same can be provided.

Next, according to another aspect of the semiconductor device and the method of manufacturing the same according to the present invention, the value ratio of the specific resistance is gradually increased in the direction in which the second metal film moves away from the underlying interlayer insulating film. The contact hole and the first
The current (electrons) at the interface with the metal wiring layer can be dispersed in the thickness direction of the first metal wiring layer.

As a result, it is possible to make the current (electron) density uniform in the thickness direction of the first metal wiring layer. This makes it possible to improve the electrical reliability. As a result, a highly reliable semiconductor device and a method for manufacturing the same can be provided.

Next, in still another aspect of the semiconductor device and the method of manufacturing the same according to the present invention, in a second metal film having strong electromigration resistance,
A contact with the second metal wiring layer is provided.

As a result, since the metal layer which had been in contact with the contact hole in the past was made of an Al-based alloy material, a hole was easily formed in the contact portion. However, in the present invention, a metal film excellent in electromigration was used. Therefore, it is possible to improve the reliability of the contact portion. As a result, a highly reliable semiconductor device and a method for manufacturing the same can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a structure of a semiconductor device 100 according to a first embodiment.

FIG. 2 is a first sectional process view showing a manufacturing process of the semiconductor device 100 according to the first embodiment.

FIG. 3 is a second sectional process view showing a manufacturing step of the semiconductor device 100 in the first embodiment.

FIG. 4 is a third sectional process view showing a manufacturing process of semiconductor device 100 in First Embodiment;

FIG. 5 is a schematic diagram for explaining an operation and effect of the semiconductor device 100 according to the first embodiment;

FIG. 6 is a cross-sectional view showing a structure when the semiconductor device in Embodiment 1 is applied to another semiconductor device;

FIG. 7 is a cross-sectional view illustrating a structure of a semiconductor device 200 according to a second embodiment.

FIG. 8 is a first sectional process view showing a manufacturing process of the semiconductor device in the second embodiment.

FIG. 9 is a second sectional process view showing the manufacturing process of the semiconductor device in the second embodiment.

FIG. 10 is a schematic diagram illustrating the operation principle of a semiconductor device in Embodiment 2.

FIG. 11 is a cross-sectional view showing a structure of a semiconductor device 300 according to a third embodiment.

FIG. 12 is a first cross-sectional process view showing a manufacturing step of the semiconductor device in the third embodiment;

FIG. 13 is a second sectional process view showing the manufacturing process of the semiconductor device in the third embodiment.

FIG. 14 is a cross-sectional view illustrating a structure of a semiconductor device according to a conventional technique.

FIG. 15 is a first cross-sectional process view showing a manufacturing step of a semiconductor device in a conventional technique.

FIG. 16 is a second sectional process view showing the manufacturing process of the semiconductor device in the conventional technique.

FIG. 17 is a third sectional process view showing the manufacturing process of the semiconductor device in the conventional technique.

FIG. 18 is a fourth sectional process view showing the manufacturing process of the semiconductor device in the conventional technique.

19 is a schematic diagram for explaining a problem of the semiconductor device shown in FIG.

FIG. 20 is a cross-sectional view showing a structure of a semiconductor device according to another embodiment of the prior art.

21 is a schematic diagram for explaining a problem of the conventional semiconductor device shown in FIG.

[Explanation of symbols]

1 base interlayer insulating film, 2A, 2B, 2C first metal wiring layer, 2a first metal film, 2b second metal film, 2c third
Metal film, 2d fourth metal film, 2e fifth metal film, 5 interlayer insulating film, 7 underlying metal film, 8 embedded metal film, 10
2nd metal wiring layer, 6 contact holes, 3rd metal film, 4th metal film.

Claims (12)

[Claims] A first metal wiring layer electrically connected by a connection wiring layer and formed above the first metal wiring layer with an interlayer insulating film interposed therebetween on the underlying interlayer insulating film; A second metal wiring layer, wherein the first metal wiring layer includes a first metal film disposed on the base interlayer insulating film side, a second metal film formed on the first metal film, The first metal film formed on the second metal film;
A third metal film made of the same metal material as the metal film, wherein the first metal film and the third metal film are metal materials having better electromigration resistance than the second metal film; A semiconductor device, wherein a lower end of the wiring layer is provided so as to be in contact with a surface of the first metal film. 2. The first metal wiring layer includes a fourth metal film made of the same metal material as the second metal film on the third metal film, and the first metal film on the fourth metal film. 2. The semiconductor device according to claim 1, further comprising: a fifth metal film made of the same metal material. 3. The first metal film is made of at least one metal material selected from the group consisting of Cu, W, Ti, and TiN, and the second metal film is made of an Al-based alloy material. The semiconductor device according to claim 1, wherein: 4. A first metal wiring layer and a metal wiring layer formed above the first metal wiring layer and electrically connected to each other by a connection wiring layer with an interlayer insulating film interposed therebetween on the underlying interlayer insulating film. A first metal wiring layer formed on the side of the underlying interlayer insulating film, and a first metal wiring layer formed on the first metal film; A second metal film whose specific resistance gradually increases as the distance increases, wherein a lower end of the connection wiring layer is provided so as to be in contact with a surface of the first metal film. 5. The semiconductor device according to claim 4, wherein an Al-based alloy material is used for said first metal film, and a high melting point metal material is used for said second metal film. 6. A first metal wiring layer and a metal wiring layer formed above the first metal wiring layer and electrically connected by a connection wiring layer with an interlayer insulating film interposed therebetween on the underlying interlayer insulating film. A second metal wiring layer, wherein the first metal wiring layer is formed of a first metal film disposed on the base interlayer insulating film side and the first metal film formed on the first metal film. And a second metal film having excellent electromigration resistance, wherein the lower end of the connection wiring layer is provided so as to be in contact with the inside of the second metal film. 7. An Al-based alloy material is used for the first metal film, and at least one metal material selected from the group consisting of Cu, W, Ti and TiN is used for the second metal film. The semiconductor device according to claim 6. 8. A first metal wiring layer electrically connected by a connection wiring layer and formed above the first metal wiring layer with an interlayer insulating film interposed therebetween on the underlying interlayer insulating film. A method of manufacturing a semiconductor device including a second metal wiring layer, comprising: forming the first metal wiring layer; forming an interlayer insulating film on the first metal wiring layer; Forming a contact hole communicating with the first metal wiring layer in the film; forming the connection wiring layer electrically connected to a surface of the first metal wiring layer in the contact hole; Forming the second metal wiring layer electrically connected to the connection wiring layer on the interlayer insulating film; and forming the first metal wiring layer on the side of the base interlayer insulating film Forming a first metal film on the substrate; Forming a second metal film on the first metal film; and forming a third metal film made of the same metal material as the first metal film on the second metal film; The step of forming a hole is formed so as to communicate with the first metal film, and the first metal film and the third metal film are made of a metal material having higher electromigration resistance than the second metal film. , A method of manufacturing a semiconductor device. 9. The step of forming the first metal wiring layer includes: forming a fourth metal film made of the same metal material as the second metal film on the third metal film; Forming a fifth metal film made of the same metal material as the first metal film on the first metal film.
A method for manufacturing a semiconductor device according to claim 8. 10. A first metal wiring layer electrically connected by a connection wiring layer and formed above the first metal wiring layer with an interlayer insulating film interposed therebetween on the underlying interlayer insulating film. A method of manufacturing a semiconductor device including a second metal wiring layer, comprising: forming the first metal wiring layer; forming an interlayer insulating film on the first metal wiring layer; Forming a contact hole communicating with the first metal wiring layer in the film; forming the connection wiring layer electrically connected to a surface of the first metal wiring layer in the contact hole; Forming the second metal wiring layer electrically connected to the connection wiring layer on the insulating film; and forming the first metal wiring layer on the side of the base interlayer insulating film. Forming a first metal film; Forming a second metal film on the first metal film, the resistivity of which gradually increases as the distance from the underlying interlayer insulating film increases, wherein the step of forming the contact hole comprises: A method for manufacturing a semiconductor device formed so as to communicate with a metal film. 11. The step of forming the second metal film is performed by diffusing metal atoms into the metal film.
A method for manufacturing a semiconductor device according to claim 10. 12. A first metal wiring layer electrically connected by a connection wiring layer and formed above the first metal wiring layer with an interlayer insulating film interposed therebetween on the underlying interlayer insulating film. A method of manufacturing a semiconductor device having a second metal wiring layer, wherein: forming the first metal wiring layer; forming an interlayer insulating film on the first metal wiring layer; Forming a contact hole in the interlayer insulating film so that the inside of the metal wiring layer is exposed; and forming the connection wiring layer electrically connected to the inside of the first metal wiring layer in the contact hole. A step of forming the second metal wiring layer electrically connected to the connection wiring layer on the interlayer insulating film, wherein the step of forming the first metal wiring layer comprises: Forming a first metal film on the insulating film side Process and, on the first metal layer, forming a second metal film having excellent electromigration resistance than the first metal film includes a method of manufacturing a semiconductor device.