JPH06151430A - Wiring for semiconductor device and formation thereof - Google Patents

Abstract

PURPOSE:To provide a wiring for semiconductor device of a structure, wherein the embedding property of an aluminum alloy layer is never reduced by oxidation of the surface of a base layer, and a method of forming the wiring. CONSTITUTION:A wiring for semiconductor device is formed of a base layer 22 consisting of a first metal layer and an aluminum alloy layer 24, which is formed on the layer 22 and contains a second metal layer, and in the case where heats of formation at the time of oxidation of the first and second metal layers are assumed DELTAH1 and DELTAH2, the DELTAH1 and the DELTAH2 are set on the condition of ¦DELTAH2¦>¦DELTAH1¦. A method of forming the wiring consists of a process (a) for forming the layer 22 consisting of the first metal layer and a process (b) for forming the layer 24 containing the second metal layer on the layer 22 at a temperature, at which the first and second metal layers react to each other, and in the case where heats of formation at the time of oxidation of the first and second metal layers are assumed DELTAH1 and DELTAH2, the DELTAH1 and the DELTAH2 are set on the condition of ¦DELTAH2¦>¦DELTAH1¦.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring for a semiconductor device and a method for forming the same, more specifically, a wiring for a semiconductor device containing aluminum as a main component, and a semiconductor device containing aluminum as a main component by a so-called high temperature sputtering method. The present invention relates to a method for forming a wiring for use.

[0002]

2. Description of the Related Art With the miniaturization of semiconductor elements in a semiconductor device, a technique for forming fine contact holes, via holes and through holes (hereinafter also collectively referred to as connection holes) has become an important subject. In order to form a connection hole, an interlayer insulating layer is usually formed on a semiconductor substrate or a lower wiring layer on which a diffusion layer is formed, then an opening is formed in the interlayer insulating layer, and then a metal is added to the opening. Embed the wiring material.

As one of the techniques for forming fine connection holes, a high temperature sputtering method of aluminum or aluminum alloy (hereinafter, also simply referred to as Al) has been studied. This high-temperature sputtering method is a technique in which Al or the like is reflowed by forming a film of Al or the like on the substrate by a sputtering method while the substrate is heated to several hundred degrees, and the opening is filled and flattened with Al or the like. is there.

The embedding characteristics of Al or the like in the high temperature sputtering method are greatly influenced by the underlying layer formed on the substrate. When titanium (Ti) having good wettability with Al or the like is used as the material of the underlayer, an Al-Ti alloy layer is formed at the interface between Al and Ti during the film formation of Al or the like by the sputtering method. To be done. By forming this alloy layer, A
l, etc. are drawn in and good embedding is achieved. This state is shown in FIG. 3A, which is a schematic partial cross-sectional view of the semiconductor element, and in FIG. 3B, which is an enlarged view of a region surrounded by a circle in FIG. 3A. Show. In FIG. 3, 10 is a semiconductor substrate, 14 is an interlayer insulating layer, 16 is an opening, and 100 is an opening.
Is a base layer made of Ti, 110 is a metal material wiring layer made of Al or the like, and 102 is an Al—Ti alloy layer.

On the other hand, when the high temperature sputtering method such as Al is applied to the formation of the contact hole,
A barrier metal layer made of TiON or the like is required as an underlayer of Al or the like in order to prevent the penetration of 1 or the like.
Since Al or the like and TiON have poor wettability, if Al or the like is directly formed on the barrier metal layer made of TiON or the like, it becomes difficult to sufficiently fill Al with the opening. In order to cope with this, it is necessary to further form a base layer made of Ti on the barrier metal layer made of TiON or the like to improve the wettability between Al and the base layer.

In reality, in order to obtain ohmic contact with the diffusion layer, a contact layer made of Ti is required under the barrier metal layer made of TiON or the like. Therefore, in the connection hole, as shown in FIG. 3C, from the semiconductor substrate 10 side, Ti (contact layer) 104 / TiON is formed.
(Barrier metal layer) 106 / Ti (base layer) 100 / A
A laminated structure such as 1 (metal wiring material layer) 110 is formed. Usually, these laminated structures are formed by a sputtering method.

[0007]

During high temperature sputtering of Al or the like, oxygen in the interlayer insulating film 14 made of SiO _{2 in the} structure shown in FIG. 3 (A) and the structure shown in FIG. 3 (C). The barrier metal layer 106 made of TiON
Oxygen in the silicon diffuses to a certain extent in the underlayer 100 made of Ti, but in a portion where the underlayer 100 made of Ti is very thin, the oxygen reaches the surface of the underlayer. Therefore, the surface of the underlayer 100 formed on the side wall near the bottom of the opening 16 is oxidized, the wettability with Al or the like is deteriorated, and the embeddability of Al or the like is lowered (see FIG. 4). Therefore, it is indispensable to prevent deterioration of wettability of Al or the like due to oxidation of the surface of the underlayer 100 during high-temperature sputtering of Al or the like, and not lower embeddability of Al or the like.

Therefore, an object of the present invention is to provide a semiconductor device wiring in which the embedding property of the aluminum alloy layer formed on the underlayer is not deteriorated by the oxidation of the surface of the underlayer, and such a semiconductor device wiring. It is to provide a method of forming.

[0009]

A wiring for a semiconductor device according to a first aspect of the present invention is an underlayer made of a first metal,
And an aluminum alloy layer formed on the underlayer and containing a second metal. In order to achieve the above object, the heat of formation when the first metal is oxidized is ΔH ₁ , and the heat of generation when the second metal is oxidized is ΔH ₁ .
When H ₂ is set, | ΔH ₂ |> | ΔH ₁ |

Further, the semiconductor device wiring according to the second aspect of the present invention comprises a first underlayer made of a first metal, and a first underlayer.
A second metal formed on the underlayer of and a second metal
And an aluminum alloy layer formed on the second underlayer. Then, in order to achieve the above object, the heat of formation when the first metal is oxidized is Δ
When the heat generated when H ₁ and the second metal are oxidized is ΔH ₂ , | ΔH ₂ |> | ΔH ₁ |.

In these semiconductor device wirings of the present invention, it is desirable that the first metal be titanium and the second metal be zirconium or hafnium.

The method for forming a wiring for a semiconductor device according to the first aspect of the present invention comprises: (a) a step of forming a base layer made of a first metal; and (b) an aluminum alloy containing a second metal. Forming a layer on the underlayer at a temperature at which the first metal of the underlayer and the second metal of the aluminum alloy layer react. In order to achieve the above object, the heat of formation when the first metal is oxidized is ΔH ₁ ,
When the heat of formation when the second metal is oxidized is ΔH ₂ , | ΔH ₂ |> | ΔH ₁ |.

Further, in the method for forming a semiconductor device wiring according to the second aspect of the present invention, (a) the step of forming the first underlayer made of the first metal, and (b) the second metal. Forming a second underlayer on the first underlayer, and
(C) A step of forming an aluminum alloy layer on the second underlayer at a temperature at which the first metal of the first underlayer and the second metal of the second underlayer react. In order to achieve the above object, when the heat of formation when the first metal is oxidized is ΔH ₁ and the heat of generation when the second metal is oxidized is ΔH ₂ , | ΔH ₂ |> | ΔH ₁ |.

In these semiconductor device wiring forming methods of the present invention, it is desirable that the first metal be titanium and the second metal be zirconium or hafnium.

In the fine opening, since the thickness of the underlayer (or the first underlayer, which is also generically referred to as the underlayer hereinafter) deposited on the sidewall of the opening is thin, the underlayer is high in temperature. During sputtering by the sputtering method, it can be easily oxidized by oxygen from the oxygen-containing layer. However, the first
When the heat of formation when the metal of the above is oxidized is ΔH ₁ and the heat of formation when the second metal is oxidized is ΔH ₂ , | ΔH ₂ |>
| ΔH ₁ |. Further, the aluminum alloy layer is formed at a temperature at which the first metal and the second metal react with each other. As a result, the oxide containing the first metal formed on the surface of the underlayer or the like is reduced by the second metal.

Thus, the reaction between the first metal and the second metal at the interface between the underlayer and the aluminum alloy layer is promoted, and aluminum, the first metal, While the alloy composed of the oxide of the second metal and the second metal is formed, the aluminum alloy is drawn into the opening, and the embeddability of the aluminum alloy in the opening is improved.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings based on embodiments.

Example 1 Example 1 relates to a semiconductor device wiring and a method for forming the same according to the first aspect of the present invention.

That is, the wiring for a semiconductor device in Example-1 is composed of an underlayer made of a first metal and an aluminum alloy layer formed on the underlayer and containing a second metal. When the heat of formation when the first metal is oxidized is ΔH ₁ and the heat of generation when the second metal is oxidized is ΔH ₂ , | ΔH ₂ |> | ΔH ₁ | And

In addition, in the method of forming the wiring for the semiconductor device in Example-1, (a) an underlayer made of a first metal is formed, and then (b) an aluminum alloy layer containing a second metal is formed. , Is formed on the underlayer at a temperature at which the first metal of the underlayer reacts with the second metal of the aluminum alloy layer. Then, the heat generated when the first metal is oxidized is ΔH
_1. When the heat of formation when the second metal is oxidized is ΔH ₂ , | ΔH ₂ |> | ΔH ₁ |

In Example 1, the first metal is titanium (Ti) and the second metal is zirconium (Zr).

[Step-100] First, the diffusion layer 12 is formed on the semiconductor substrate 10 by a conventional method, and then the interlayer insulating layer 14 made of SiO ₂ is formed on the semiconductor substrate 10 by a usual method. After that, the opening 16 is formed in the interlayer insulating layer 14 by photolithography and etching.
To form. Thus, the structure shown in the schematic partial cross-sectional view of FIG.

[Step-110] Next, a contact layer 18 made of Ti and having a thickness of 30 nm is formed on the interlayer insulating layer 14 and inside the opening 16 by a sputtering method. The conditions for forming the contact layer 18 can be set as follows, for example. DC power: 4 kW Substrate temperature: 150 ° C Process gas: Ar = 100 sccm Pressure: 0.5 Pa

[Step-120] After that, the contact layer 1
A barrier metal layer 20 made of TiON and having a thickness of 70 nm is formed on the substrate 8 by sputtering (see FIG. 1B).
The conditions for forming the barrier metal layer 20 can be set as follows, for example. DC power: 5 kW Substrate temperature: 150 ° C. Process gas: Ar / N ₂ -6% O ₂ = 40/70 sccm Pressure: 0.5 Pa

[Step-130] Next, the underlying layer 22 made of the first metal, which is a feature of the present invention, is formed on the entire surface (see FIG. 1C). The first metal is titanium (Ti). Underlayer 22 made of the first metal and having a thickness of 30 nm
The forming conditions of can be set as follows, for example. DC power: 4 kW Substrate temperature: 150 ° C Process gas: Ar = 100 sccm Pressure: 0.5 Pa

[Step-140] Thereafter, the aluminum alloy layer 24 containing the second metal, which is a feature of the present invention.
Is formed on the underlayer 22 by a so-called high temperature stamper method (see FIG. 1D). The second metal is zirconium (Z
r). Al-1 containing a second metal (Zr)
The formation of the aluminum alloy layer 24 composed of
Metal (Ti) and the second metal of the aluminum alloy layer (Z
It is carried out at a temperature (480 to 500 ° C) at which r) reacts.

The heat of formation when the first metal (Ti) is oxidized is ΔH ₁ , and the heat of formation when the second metal is oxidized is ΔH _2.
, Then | ΔH ₂ |> | ΔH ₁ |. Specifically, ΔH ₂ = −125 kcal ΔH ₁ = −110 kcal.

The conditions for forming the aluminum alloy layer 24 by the high temperature sputtering method can be set as follows, for example. During sputtering, Al-1% Si / 0.
A target of 5-2.0% Zr was used. Moreover, in Example-1, in order to further improve the embeddability of the aluminum alloy layer into the opening 16, sputtering was performed in two steps. [First-stage sputtering] DC power: 22.5 kW Substrate temperature: Unheated process gas: Ar = 100 sccm Pressure: 0.5 Pa [Second-stage sputtering] DC power: 10.5 kW Substrate temperature: 480-500 ° C Process gas: Ar = 100 sccm Pressure: 0.5 Pa

Since the thickness of the underlayer 22 deposited on the side wall of the opening is thin in the fine opening, the underlayer 22 made of Ti is deposited at a temperature of T during sputtering by the high temperature sputtering method.
It can be easily oxidized by the barrier metal layer 20 made of iON or the interlayer insulating layer 14 made of SiO ₂ . However, the absolute value of the heat of formation (ΔH ₂ ) -125 kcal of ZrO ₂ is larger than the absolute value of the heat of formation (ΔH ₁ ) -110 kcal of TiO ₂ . In addition, the formation of the aluminum alloy layer 24 is performed by using the first metal (Ti) and the second aluminum alloy layer.
Temperature (480-500 ° C) at which the other metal (Zr) reacts
Done in. As a result, the oxide (TiO ₂ ) formed on the surface of the underlayer 22 is reduced by Zr. Zr + TiO _x → ZrO _x + Ti Thus, the reaction between Ti and Al-Si-Zr at the interface between the underlayer 22 and the aluminum alloy layer 24 is promoted,
Near the interface of the aluminum alloy layer 24 and the underlying layer 22, Al-Si-Ti- ZrO X alloy while being formed, Al-Si-Zr alloy is drawn into the opening.
As a result, the embeddability of the aluminum alloy in the opening is improved.

(Example-2) Example-2 is the same as Example-1.
The present invention relates to a modification of the wiring for a semiconductor device and the method for forming the same according to the first aspect of the present invention. In Example-2, the aluminum alloy layer 24 in [Step-140] was formed by a so-called co-sputtering method. The conditions for forming the aluminum alloy layer 24 can be set as follows, for example. Targets used: Al-1% Si and Zr DC power: 1,0 kW Substrate temperature: 480-500 ° C Process gas: Ar = 100 sccm Pressure: 0.5 Pa

(Example-3) Example-3 and Example-1
The present invention relates to a modification of the wiring for a semiconductor device and the method for forming the same according to the first aspect of the present invention. In Example-3, hafnium (H) is used as the second metal in the aluminum alloy layer 24 formed in [Step-140].
f) is contained.

In Example-3, the opening 16 provided in the interlayer insulating layer 14 on the semiconductor substrate 10 was formed by the same method as in [Step-100] to [Step-120] of Example-1.
A contact layer 18, a barrier metal layer 20, and a base layer 22 made of Ti are formed on the inner and interlayer insulating layers 14.

Thereafter, the aluminum alloy layer 24 containing the second metal (Hf) is formed by the high temperature sputtering method. The conditions for forming the aluminum alloy layer 24 can be set as follows, for example. In the high temperature sputtering method,
An Al-1% Si / 0.5-2.0% Hf target was used. [First-stage sputtering] DC power: 22.5 kW Substrate temperature: Unheated process gas: Ar = 100 sccm Pressure: 0.5 Pa [Second-stage sputtering] DC power: 10.5 kW Substrate temperature: 480-500 ° C Process gas: Ar = 100 sccm Pressure: 0.5 Pa

In the fine openings, the thickness of the underlayer 22 deposited on the sidewalls of the opening is thin, so that the underlayer 22 made of Ti is not affected by the T
It can be easily oxidized by the barrier metal layer 20 made of iON or the interlayer insulating layer 14 made of SiO ₂ . However, the absolute value of the heat of formation (ΔH ₂ ) −130 kcal of HfO ₂ is larger than the absolute value of the heat of formation (ΔH ₁ ) −110 kcal of TiO ₂ . In addition, the formation of the aluminum alloy layer 24 is performed by using the first metal (Ti) and the second aluminum alloy layer.
Temperature (480-500 ° C) at which the metal (Hf) reacts
Done in. As a result, the oxide (TiO ₂ ) formed on the surface of the underlayer 22 is reduced by Hf. Hf + TiO _x → HfO _x + Ti Thus, the reaction of Al-Si-Hf and Ti at the interface between the underlayer 22 and the aluminum alloy layer 24 is promoted, and Al- near the interface between the aluminum alloy layer 24 and the underlayer 22 while Si-Ti-HfO _X alloy is formed, Al-Si-Hf alloy is drawn into the opening.
As a result, the embeddability of the aluminum alloy in the opening is improved.

(Embodiment 4) The embodiment 4 is the same as the embodiment 3
The present invention relates to a modification of the wiring for a semiconductor device and the method for forming the same according to the first aspect of the present invention. In Example-4, the aluminum alloy layer 24 was formed by a so-called co-sputtering method. The conditions for forming the aluminum alloy layer 24 can be set as follows, for example. Target to be used: Al-1% Si and Hf DC power: 1.0 kW Substrate temperature: 480 to 500 ° C. Process gas: Ar = 100 sccm Pressure: 0.5 Pa

(Embodiment 5) Embodiment 5 relates to a semiconductor device wiring and a method for forming the same according to the second aspect of the present invention.

That is, the semiconductor device wiring according to the embodiment-5 is the first underlayer made of the first metal, and the second underlayer made of the second metal and formed on the first underlayer. It comprises a formation and an aluminum alloy layer formed on the second underlayer. When the heat of formation when the first metal is oxidized is ΔH ₁ and the heat of formation when the second metal is oxidized is ΔH ₂ , | ΔH ₂ |> | ΔH ₁ | To do.

In addition, in the method of forming the wiring for the semiconductor device in Example-5, (a) the first underlayer made of the first metal is formed, and then (b) the second underlayer made of the second metal. Forming a base layer on the first base layer, and then (C)
The step of forming an aluminum alloy layer on the second underlayer at a temperature at which the first metal of the first underlayer and the second metal of the second underlayer react. When the heat of formation when the first metal is oxidized is ΔH ₁ and the heat of formation when the second metal is oxidized is ΔH ₂ , | ΔH ₂ |> | ΔH ₁
It is characterized by |.

In Example 5, the first metal is titanium (Ti) and the second metal is zirconium (Zr).

[Step-200] First, the diffusion layer 12 is formed on the semiconductor substrate 10 by a conventional method, and then the interlayer insulating layer 14 made of SiO ₂ is formed on the semiconductor substrate 10 by a normal method. After that, the opening 16 is formed in the interlayer insulating layer 14 by photolithography and etching.
To form.

[Step-210] Next, a contact layer 18 made of Ti and having a thickness of 30 nm is formed on the interlayer insulating layer 14 and inside the opening 16 by a sputtering method. The conditions for forming the contact layer 18 can be the same as those in [Step-110] of Example-1.

[Step-220] After that, the contact layer 1
A barrier metal layer 20 made of TiON and having a thickness of 70 nm is formed on the layer 8 by sputtering (see FIG. 2A).
The conditions for forming the barrier metal layer 20 can be the same as those in [Step-120] of Example-1.

[Step-230] Next, the first underlayer 22A made of the first metal, which is a feature of the present invention, is formed on the entire surface (see FIG. 2B). The first metal is titanium (Ti). First underlayer 22A having a thickness of 30 nm
The formation conditions of can be the same as the formation conditions of the underlayer 22 in [Step-130] of Example-1.

[Step-240] After that, the second underlayer 22B made of the second metal, which is a feature of the present invention, is formed on the first underlayer 22A (see FIG. 2C). .
The second metal comprises zirconium (Zr). When the heat of formation when the first metal (Ti) is oxidized is ΔH ₁ and the heat of generation when the second metal (Ti) is oxidized is ΔH ₂ , | ΔH ₂
|> | ΔH ₁ |. Specifically, ΔH ₂ = −125 kcal ΔH ₁ = −110 kcal. The second base layer 22B can be formed, for example, under the following conditions. DC power: 1.0 kW Substrate temperature: 200 ° C Process gas: Ar = 40 sccm Pressure: 0.4 Pa

[Step-250] After that, the aluminum alloy layer is formed on the second underlayer at a temperature at which the first metal of the first underlayer 22A and the second metal of the second underlayer 22B react with each other. 22B (see FIG. 2D). Al-1
The formation of the aluminum alloy layer 24 composed of% Si is 48
Perform at 0-500 ° C. The conditions for forming the aluminum alloy layer 24 by the high temperature sputtering method can be set as follows, for example. During sputtering, Al-1%
A Si target was used. In addition, in Example-5, in order to further improve the embeddability of the aluminum alloy layer into the opening 16, sputtering was performed in two steps. [First-stage sputtering] DC power: 22.5 kW Substrate temperature: Unheated process gas: Ar = 100 sccm Pressure: 0.5 Pa [Second-stage sputtering] DC power: 10.5 kW Substrate temperature: 480-500 ° C Process gas: Ar = 100 sccm Pressure: 0.5 Pa

In the fine openings, the thickness of the first underlayer 22A deposited on the side wall of the opening is thin, so that the first underlayer 22A made of Ti is made of TiON during sputtering by the high temperature sputtering method. It can be easily oxidized by the barrier metal layer 20 or the interlayer insulating layer 14 made of SiO ₂ . However, in Example-5, Ti
A second Zr layer on the first underlayer 22A made of
Underlying layer 22B is formed.

The heat of formation of ZrO ₂ (ΔH ₂ ) -125 kcal is more than the absolute value of the heat of formation of TiO ₂ (ΔH ₁ ) -110 kcal.
The absolute value of is larger. In addition, the aluminum alloy layer 24
Is formed at a temperature (480 to 500 ° C.) at which the first metal (Ti) and the second metal (Zr) react with each other. As a result, the oxide formed on the surface of the first underlayer 22A (T
iO ₂ ) is reduced by Zr of the second underlayer 22B. Zr + TiO _x → ZrO _x + Ti Thus, Ti and Z in the vicinity of the interface between the first underlayer 22A, the second underlayer 22B and the aluminum alloy layer 24 are formed.
reaction between r and Al-Si is promoted, in these near the interface, Al-Si-Ti-ZrO _X alloy while being formed, Al-Si alloy is drawn into the opening. As a result, the embeddability of the aluminum alloy in the opening is improved.

(Example-6) Example-6 is the same as Example-5.
The invention relates to the semiconductor device wiring and the modification of the method for forming the same according to the second aspect of the present invention. In Example-6, the second underlayer 22B formed in [Step-240] is made of hafnium (Hf).

The conditions for forming the second underlayer 22B made of Hf can be set as follows, for example. DC power: 1.0 kW Substrate temperature: 200 ° C. Process gas: Ar = 40 sccm Pressure: 0.4 Pa

Although the present invention has been described based on the preferred embodiments, the present invention is not limited to these embodiments. The various numerical values given in each example are merely examples, and can be changed as appropriate. In addition to the sputtering method, the underlayer and the aluminum alloy layer in the first aspect of the present invention, or the first underlayer, the second underlayer and the aluminum alloy layer in the second aspect of the present invention, For example, it can be formed by a vacuum vapor deposition method. The aluminum alloy layer can also be formed by, for example, the CVD method.

The contact layer and the barrier metal layer are examples, and various known layers can be formed between the underlayer (first underlayer) and the inside of the opening. In the examples, the opening was formed in the semiconductor substrate on which the diffusion layer was formed, but the opening is formed on various wiring layers such as the underlying wiring layer, and the semiconductor device wiring of the present invention and the method for forming the same are provided. Can be applied.

[0051]

According to the present invention, the reaction between the first metal and the second metal at the interface between the underlayer or the like and the aluminum alloy layer is promoted, and aluminum or the like near the interface between the aluminum alloy layer and the underlayer is promoted. A first metal, and a second
Since the aluminum alloy is drawn into the opening while the alloy composed of the oxide of the metal is formed, the embeddability of the aluminum alloy in the opening is improved.

[Brief description of drawings]

FIG. 1 is a schematic partial cross-sectional view of a semiconductor element for explaining the process of Example-1 relating to the wiring for a semiconductor device and the method for forming the same according to the first aspect of the present invention.

FIG. 2 is a schematic partial cross-sectional view of a semiconductor element for explaining the process of Example-5 relating to the semiconductor device wiring and the method for forming the same according to the second aspect of the present invention.

FIG. 3 is a schematic partial cross-sectional view of a semiconductor device for explaining a conventional high temperature sputtering method.

FIG. 4 is a schematic partial cross-sectional view of a semiconductor element for explaining problems in the conventional high temperature sputtering method.

[Explanation of symbols]

 10 Semiconductor Substrate 12 Diffusion Layer 14 Interlayer Insulation Layer 16 Opening 18 Contact Layer 20 Barrier Metal Layer 22 Underlayer 22A First Underlayer 22B Second Underlayer 24 Aluminum Alloy Layer

Claims (6)

[Claims] 1. A wiring for a semiconductor device, which comprises an underlayer made of a first metal and an aluminum alloy layer formed on the underlayer and containing a second metal, wherein the first metal is [Delta] H ₁ generated heat when oxidized, when the [Delta] H ₂ the heat of formation when oxidizing the second _{metal, | ΔH 2 |> | ΔH} 1 | a semiconductor device wiring, characterized in that. 2. A first underlayer made of a first metal, the first underlayer.
A second metal formed on the underlayer of and a second metal
Of the underlayer and the aluminum alloy layer formed on the second underlayer, wherein the heat generated when the first metal is oxidized is ΔH ₁ , The wiring for a semiconductor device is characterized by: | ΔH ₂ |> | ΔH ₁ |, where ΔH ₂ is the heat generated when the metal is oxidized. 3. The wiring for a semiconductor device according to claim 1, wherein the first metal is titanium and the second metal is zirconium or hafnium. 4. A step of forming a base layer made of a first metal, and an aluminum alloy layer containing a second metal, the first metal of the base layer and the second metal of the aluminum alloy layer. Is formed on the underlayer at a temperature at which is reacted, the heat of formation when oxidizing the first metal is ΔH ₁ , and the heat of formation when oxidizing the second metal is ΔH _2. Is defined as | ΔH ₂ |> | ΔH ₁ |. 5. A step of forming a first underlayer made of a first metal, a step of forming a second underlayer made of a second metal on the first underlayer, and an aluminum alloy layer. Is formed on the second underlayer at a temperature at which the first metal of the first underlayer reacts with the second metal of the second underlayer. When the heat of formation when the metal is oxidized is ΔH ₁ and the heat of generation when the second metal is oxidized is ΔH ₂ , | ΔH ₂ |> | ΔH ₁ | Method for forming wiring. 6. The method for forming a wiring for a semiconductor device according to claim 4, wherein the first metal is titanium and the second metal is zirconium or hafnium.