JPH09199593A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to, form an excellent oxide preventive film in a connecting hole. SOLUTION: When the semiconductor device is formed by covering a connecting hole 6 formed at an interlayer insulating layer 1 with a titanium layer 8 for satisfactorily embedding aluminum material with wettability of upper layer interconnection 2 to electrically connect the interconnection 2 and lower layer interconnection 3 disposed at both sides of the layer 1, a titanium nitride film 5 is formed on the upper surface of the interconnection 2. The film 5 disposed under the hole 6 is adhered to the sidewall of the hole 6 to form an oxide preventive film 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum-based connecting hole formed in an interlayer insulating layer for electrically connecting an upper layer wiring and a lower layer wiring which are located with an interlayer insulating layer interposed therebetween. The present invention relates to a semiconductor device in which a material is embedded and a manufacturing method thereof.

[0002]

2. Description of the Related Art A semiconductor device typified by an LSI or the like generally has a multilayer wiring structure in which a lower layer wiring and an upper layer wiring are electrically connected by a connection hole formed in an interlayer insulating layer. Then, with the recent miniaturization and high integration of semiconductor devices, it is necessary to miniaturize the connection holes,
A technique of embedding a metal, which is a wiring material, in the miniaturized connection hole becomes important. Examples of the metal embedding method include high temperature aluminum sputtering, high temperature aluminum reflow, tungsten CVD, aluminum CVD, and copper CVD. Among these methods, aluminum CVD, copper CVD, and the like have not been established as technologies capable of mass production, and tungsten CVD has a drawback of high production cost. Therefore, high-temperature aluminum sputter is expected.

In the high temperature aluminum sputtering described above, a substrate having a connection hole in the interlayer insulating layer is heated to 450 to 500 ° C., and an aluminum material is sputter-deposited in this heated state to form the connection hole of the aluminum material. Is the technology of filling.

Further, as a method improved on this method, as shown in FIG. 4, a connection hole 101 for electrically connecting an upper layer wiring 110 and a lower layer wiring 111, which are located with the interlayer insulating layer 100 interposed therebetween, is formed. In addition, titanium (Ti) having good wettability with respect to an aluminum-based material is formed as a base layer (hereinafter referred to as a base titanium layer) 102 to improve the filling property of the aluminum-based material and form a void in the connection hole 101. A method is known in which the aluminum-based material is filled without the need. The reason why the embedding property of the aluminum-based material becomes good is that the aluminum-based material and titanium undergo an alloying reaction at about 400 ° C. (therefore, the underlying titanium layer 102 becomes an aluminum-titanium alloy layer), and aluminum It is believed to be due to the function of making the system material easier to move.

However, most of titanium-based high melting point metal materials formed by sputtering have a crystal structure,
Since there is a grain boundary in the structure, diffusion of oxygen (oxidation of the titanium-based refractory metal material) easily occurs through the grain boundary, and the interface of the underlying titanium layer 102 with the aluminum-based material is easily oxidized. When such oxidation occurs, the wettability of the aluminum-based material deteriorates, causing defective filling of the connection hole 101. In particular, as the interlayer insulating layer 100, SiO _{2 is used.}
However, when the underlying titanium layer 102 on the side wall of the connection hole 101 is thin, the oxygen of SiO ₂ diffuses into the interface between the titanium film and the aluminum-based material, which causes a defect in filling.

Therefore, in order to prevent the diffusion of the oxygen, the underlying titanium layer 102 and the Si as the interlayer insulating layer 100 are formed.
A method has been proposed in which an antioxidant film is formed as an underlayer of the underlying titanium layer 102 between the layer and O ₂ .

For example, in Japanese Unexamined Patent Publication (Kokai) No. 5-152244, when a wiring is formed by embedding an aluminum-based material through a titanium-based high melting point metal-based material, a polysilicon film or an amorphous film is used as an antioxidant film in a connection hole. A method is disclosed in which a silicon film is formed to improve the filling property of an aluminum-based material.

Further, in Japanese Patent Laid-Open No. 6-85084,
Disclosed is a method of forming wiring by embedding an aluminum-based material in a connection hole by high-temperature sputtering, and forming polysilicon or impurity-introduced polysilicon as an antioxidant film in the connection hole and performing high-temperature sputtering of the aluminum-based material. There is.

Further, in Japanese Unexamined Patent Publication No. 6-232273, in a wiring method in which a connection hole for connecting to a lower layer wiring provided with an antireflection film made of a titanium-based material is filled with an aluminum-based material, the connection hole is opened. There is disclosed a method of forming a film of a base material in the connection hole without contacting the titanium compound adhering to the side wall of the connection hole with the base material of the aluminum material for filling the connection hole.

[0010]

However, the above-mentioned conventional method requires a step of forming polysilicon or silicon nitride which will be an antioxidant film after forming the connection hole. Further, since polysilicon and silicon nitride are high resistance materials, a step of removing a portion other than the oxidation prevention film on the side wall portion of the connection hole by etching back is required.
Therefore, there is a drawback that the number of processes increases and the production cost becomes expensive.

By the way, a method of using a conductive material as the anti-oxidation film instead of high-resistance polysilicon or amorphous silicon is conceivable. FIG. 5 shows a semiconductor device in which an antioxidant film 103 made of titanium nitride (TiN), which is a conductive material, is deposited and formed. When the anti-oxidation film 103 made of titanium nitride, which is a conductive material, is formed, the connection hole 10
It is not necessary to remove the anti-oxidation film 103 in a portion other than the side wall of 1, that is, in the bottom portion of the connection hole 101 and in the flat portion of the upper layer wiring 110 outside the formation region of the connection hole 101.
The number of steps can be reduced.

Further, the connection hole 101 of the upper wiring 110
In the semiconductor device in which the anti-oxidation film 103 in the flat portion outside the formation region is not removed, the anti-oxidation film 10 in the flat portion outside the formation region of the connection hole 101 of the upper wiring 110 is formed.
3 remains, but if the film thickness is large, there is a drawback that a filling failure caused by so-called overhang is likely to occur.

In view of the above circumstances, it is an object of the present invention to provide a semiconductor device in which an antioxidant film is well formed in the connection hole in a small number of steps and a manufacturing method for manufacturing the semiconductor device. .

[0014]

In order to solve the above-mentioned problems, the semiconductor device of the present invention has the above-mentioned structure for electrically connecting an upper layer wiring and a lower layer wiring which are located with an interlayer insulating layer interposed therebetween. A semiconductor device in which the connection hole formed in the interlayer insulating layer is covered with a titanium-based high-melting-point material that has wettability with respect to the aluminum-based material that is the upper-layer wiring and allows the aluminum-based material to be embedded well. At
As an underlying layer of the titanium-based high melting point material, an antioxidant film made of a conductive material is provided only on the bottom surface portion and the side wall portion of the connection hole.

Since the antioxidant film is a conductive material, even if the antioxidant film is formed on the bottom surface of the connection hole,
There is no problem in electrical connection between the upper layer wiring and the lower layer wiring.
Further, since it has a structure in which the antioxidant film on the bottom surface is not removed, it can be manufactured in a small number of steps. Note that the semiconductor device having this structure does not have a defect such as a filling failure due to a so-called overhang shape unlike the conventional structure in which the oxidation prevention film remains in the flat portion of the upper layer wiring outside the region where the connection hole is formed.

Further, in the semiconductor device of the present invention, in order to electrically connect the upper layer wiring and the lower layer wiring located with the interlayer insulating layer sandwiched therebetween, the connection hole formed in the interlayer insulating layer is provided with In a semiconductor device formed by coating a titanium-based high-melting-point material that has a wettability with respect to an aluminum-based material that is an upper-layer wiring and allows the aluminum-based material to be embedded well, a conductive material is formed on the upper surface of the lower-layer wiring. The conductive material located below the connection hole is attached to the side wall of the connection hole to form an antioxidant film.

Since the antioxidant film is a conductive material, even if the antioxidant film is formed on the bottom surface of the connection hole,
There is no problem in electrical connection between the upper layer wiring and the lower layer wiring.
Further, since it has a structure in which the antioxidant film on the bottom surface is not removed, it can be manufactured in a small number of steps. Further, since the conductive material located below the connection hole is attached to the side wall of the connection hole to form an antioxidant film, there is no need to deposit the conductive material on the interlayer insulating layer. .

The thickness of the side wall of the antioxidant film made of the conductive material may be gradually reduced from the lower side to the upper side of the connection hole.

Here, in order to embed the aluminum-based material to the bottom of the connection hole, it is necessary to secure high wettability on the lower side of the connection hole. If the thickness of the antioxidant film on the lower side of the connection hole is thick, the oxidation of the titanium underlayer is surely prevented on the lower side of the connection hole, so the lower side of the connection hole has higher wettability. Is ensured and the filling characteristics of the aluminum-based material are improved.

The antioxidant film made of the conductive material may be a titanium nitride film. Particularly, when a titanium nitride film is formed as a conductive material on the upper surface of the lower layer wiring and the titanium nitride film located below the connection hole is attached to the side wall of the connection hole to form an antioxidant film. In addition, the titanium nitride film functions as an antireflection film when patterning the lower layer wiring by the photolithography process and when forming a connection hole in the interlayer insulating layer, and thus halation during resist exposure in the photolithography process is prevented. Can be prevented.

An aluminum-titanium alloy layer may be formed between the conductive material and the lower wiring. According to this, when the conductive material located below the connection hole is attached to the sidewall of the connection hole by sputter etching to form an antioxidant film, all the conductive material under the connection hole is oxidized. Even if the aluminum-titanium alloy is completely used as a protective film and is completely lost, the aluminum-titanium alloy functions as a stopper for the sputter etching, so that the lower layer wiring can be prevented from being scraped by the sputter etching. As a result, it is possible to prevent the effective aspect ratio of the connection hole from increasing, and it is possible to bury the material of the upper layer wiring in the connection hole with good yield.

When the overall thickness of the conductive material is d1 and the thickness of the portion of the conductive material located below the connection hole is d2, d1 ≧ 60 nm, d1−d2 ≧ 60.
It may be nm. According to this, when the conductive material located below the connection hole is attached to the side wall portion of the connection hole to form the antioxidant film, the thickness of the antioxidant film is not The thickness of the anti-oxidation film is well controlled because it is determined by the mutual relationship between the thickness of the anti-oxidation film and the thickness of the portion located below the connection hole, and it is possible to prevent a situation in which the film thickness is insufficient. The production yield of semiconductor devices can be improved.

Further, the method of manufacturing a semiconductor device according to the present invention
The method for manufacturing a semiconductor device according to any one of the above, characterized in that the conductive material located below the connection hole is attached to a sidewall portion of the connection hole by a sputter etching process.

With this method, the step of forming the conductive material on the interlayer insulating layer and the step of removing the excess conductive material are not required, and the manufacturing cost of the semiconductor device can be reduced. Furthermore,
Since the anti-oxidation film is formed on the side wall of the connection hole by using sputter etching, the series of steps up to the filling of the aluminum-based material can be performed while the substrate is kept in vacuum, and the effect of oxygen due to atmospheric exposure can be reduced. It can be reduced as much as possible. Further, sputter etching is a method used in a general semiconductor device manufacturing process and has high controllability and reliability, so that a semiconductor device having a good filling property of an aluminum-based material can be manufactured with high yield.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a vertical sectional side view of the semiconductor device of this embodiment. An aluminum-based material (for example, AlSiC) is sandwiched between the interlayer insulating layers 1 made of SiO _2.
The upper layer wiring 2 and the lower layer wiring 3 made of u) are formed. An aluminum-titanium (Al-Ti) alloy layer 4 is formed on the lower wiring 3, and a titanium nitride (TiN) layer 5 as a conductive material is further formed on the aluminum-titanium alloy layer 4. Has been formed. The aluminum-titanium alloy layer 4 is a titanium layer (4 ': see FIG. 3A) at the time of film formation, and the titanium layer (4') is the upper wiring 2 and is made of an aluminum-based material at a high temperature. It is formed by alloying with the heat of the Degas process during sputtering.

In the interlayer insulating layer 1, a connection hole 6 for electrically connecting the upper layer wiring 2 and the lower layer wiring 3 is formed. A base titanium layer (Al—Ti) 8 is formed on the bottom surface and sidewalls of the connection hole 6 and on the interlayer insulating layer 1. The underlying titanium layer 8 has wettability with respect to the aluminum-based material of the upper wiring 2 and has a titanium (Ti) layer (8 ′: formed in the connection hole 6 in order to satisfactorily embed the aluminum-based material. FIG. 3D shows that the aluminum-based material for the upper layer wiring 2 is formed into an Al—Ti alloy when it is sputtered at high temperature.

An antioxidant film 7 made of titanium nitride (TiN), which is a conductive material, is formed as a base layer of the base titanium layer 8 on the bottom surface and the side wall of the connection hole 6. The antioxidant film 7 is specifically the titanium nitride layer 5 which is the conductive material and is located below the connection hole 6.
Are redeposited on the side wall of the connection hole 6 by the sputter etching process. The thickness of the antioxidant film 7 is formed so as to gradually decrease from the lower side to the upper side of the connection hole 6.

In the semiconductor device configured as described above, since the antioxidant film 7 is a conductive material, even if the antioxidant film 7 is formed on the bottom surface of the connection hole 6,
There is no problem in electrical connection between the upper layer wiring and the lower layer wiring.
Further, since the structure is such that the antioxidant film 7 on the bottom surface is not removed, it can be manufactured in a small number of steps.

Further, since the anti-oxidation film 7 is formed by redepositing the titanium nitride layer 5 located below the connection hole on the side wall of the connection hole 6, a conductive material is formed on the interlayer insulating layer 1. No deposition step is required. Therefore, unlike the conventional structure in which the oxidation prevention film remains in the flat portion of the upper layer wiring 2 outside the region where the connection hole 6 is formed, a defect such as a filling failure due to a so-called overhang shape does not occur.

Further, since the thickness of the anti-oxidation film 7 is gradually reduced from the lower side to the upper side of the connection hole 6, the filling property of the aluminum-based material for the upper layer wiring 2 is improved. That is, in order to fill the bottom of the connection hole 6 with the aluminum-based material, it is necessary to secure high wettability on the lower side of the connection hole 6. If the thickness of the antioxidant film 7 below the connection hole 6 is large, the oxidation of the underlying titanium layer (Al—Ti) 8 is surely prevented below the connection hole 6, and the lower side of the connection hole 6 is prevented. On the other hand, since high wettability is secured, the filling property of the aluminum-based material is improved.

Further, a titanium nitride film 5 is formed as a conductive material on the upper surface of the lower layer wiring 3, and the titanium nitride film 5 located below the connection hole 6 is attached to the side wall portion of the connection hole 6 to be oxidized. Since the anti-reflection film 7 is formed, the titanium nitride film 5 serves as an anti-reflection film when the lower wiring is patterned by the photolithography process and the connection hole 6 is formed in the interlayer insulating layer 1 in the manufacturing method described later. It will function, and halation during resist exposure in the photolithography process can be prevented.

Further, since the aluminum-titanium alloy 4 is formed between the titanium nitride film 5 which is the conductive material and the lower layer wiring 3, the conductive material which is located below the connection hole 6 is formed. When a certain titanium nitride film 5 is attached to the side wall of the connection hole by sputter etching to form the oxidation prevention film 7, all of the titanium nitride film 5 under the connection hole 6 is used as the oxidation prevention film 7 and is completely removed. Even when it is lost, the aluminum-titanium alloy 4 functions as a stopper for the sputter etching, so that it is possible to prevent the lower layer wiring 3 from being scraped by the sputter etching. Thereby, the effective aspect ratio of the connection hole 6 can be prevented from increasing, and the material of the upper layer wiring 2 can be embedded in the connection hole 6 with a good yield.

Next, a method of manufacturing a semiconductor device will be described.
In the description of this manufacturing method, a manufacturing method for the semiconductor device having the structure shown in FIG. 2 will be described. In the semiconductor device shown in FIG. 2, in addition to the structure of FIG. 1, an aluminum-titanium (Al—Ti) alloy film 9 is formed on the lower surface side of the lower layer wiring 3, and titanium nitride (TiN) is formed on the upper surface side of the upper layer wiring 2. Membrane 1
1 and aluminum-titanium (Al-Ti) alloy film 10
Is formed.

3A to 3F are process diagrams showing a method of manufacturing the semiconductor device of FIG. 2 in the order of processes. First, FIG.
As shown in (a), a lower layer wiring structure is formed. To form this lower layer wiring structure, a titanium film 9 is formed to a thickness of 20 nm on a substrate (not shown), and the lower layer wiring 3 is formed to a thickness of 500 nm on this titanium film 9. Further, a titanium layer 4'is formed to a thickness of 20 nm on the lower layer wiring 3,
A titanium nitride (TiN) layer 5 is formed on this titanium layer 4 '. Then, the lower layer wiring structure is patterned. A known lithography method and dry etching method can be used for patterning each of these layers. The thickness of the titanium nitride (TiN) layer 5 is determined based on the results shown in the examples described later.

Next, as shown in FIG. 3B, SiO ₂ to be the interlayer insulating layer 1 is formed on the titanium nitride layer 5. The interlayer insulating layer 1, which is the SiO ₂ layer, is first
P-TEOS (Tetra-Ethyl-Ortho)
-Silicate) to form a first SiO ₂ layer of 500 n
m, and then SOG (Spin on G
and etch back, and then the second P-TE
It is obtained by forming a second SiO ₂ layer with a thickness of 500 nm by OS. After that, a connection hole 6 is formed in the interlayer insulating layer 1 by using a known lithography method and dry etching method, and the titanium nitride layer 5 is exposed at the bottom of the connection hole 6. The diameter of the connection hole 6 is 0.5μ.
m, and the taper angle (side wall inclination angle) was 85 °.

Next, as shown in FIG. 3C, Ar ^{+ is applied} to the titanium nitride layer 5 located at the bottom of the connection hole 6 by an argon (Ar) sputter etching method,
Titanium nitride is ejected and adhered to the side wall of the connection hole 6. Titanium nitride and connection hole 6 formed by this attachment
The titanium nitride left on the bottom of the film becomes the antioxidant film 7. In the above-mentioned argon (Ar) sputter etching method, as described above, the titanium nitride layer 5 is hit with Ar ⁺ to eject titanium nitride and attach it to the side wall of the connection hole 6. Since the amount of adhesion to the side wall portion is small, the thickness of the titanium nitride (antioxidation film 7) adhered to the side wall portion of the connection hole 6 is formed so as to gradually decrease from the lower side to the upper side of the connection hole 6. It

Next, as shown in FIG. 3D, the underlying titanium film 8 is formed by sputtering so that the flat portion (the upper surface of the interlayer insulating layer 1) has a thickness of about 100 nm.

Next, as shown in FIG. 3E, the upper wiring 2 is formed by the high temperature aluminum sputtering method. The upper layer wiring 2 is formed by sequentially performing a first film forming process and a second film forming process. In the first film forming process,
The actual temperature of the substrate is set to 150 ° C. to form an aluminum-based material with a thickness of 200 nm. In the second film forming process, the actual temperature of the substrate is set to 480 ° C. to form an aluminum-based material to a thickness of 400 nm. Note that the heat of the second film formation process causes the titanium layer 4 ′ on the lower side of the underlying titanium layer 5 to react with Al of the lower layer wiring 3 to form aluminum-titanium (A
The l-Ti) alloy layer 4 is to be formed. Also, Ar
Degas treatment performed prior to sputter etching, specifically, the actual substrate temperature is 500 ° C. in an atmosphere of 6
By the process of leaving for 0 seconds, the titanium layer 9 ′ on the lower side of the lower layer wiring 3 reacts with Al of the lower layer wiring 3 to form the aluminum-titanium (Al—Ti) alloy layer 9.

Next, as shown in FIG. 1F, after forming an aluminum-titanium (Al-Ti) alloy layer 10 and a titanium nitride layer 11 as an antireflection film on the upper layer wiring 2, a known method is used. The upper wiring 2 is patterned by using the lithography method and the dry etching method.

[0041]

EXAMPLES Next, the film thickness of the titanium nitride (TiN) layer 5 was variously set, and it was verified whether or not the aluminum-based material was buried in the connection hole 6, and the results are shown.

In this verification, the titanium nitride (TiN) layer 5 was used.
The experiment is carried out by changing the film thickness of 30 nm to 100 nm in steps of 10 nm, and changing the amount of the titanium nitride layer 5 cut by the argon (Ar) sputter etching method in steps of 10 nm. Then, the quality of embedding of the aluminum-based material in the connection hole is evaluated by SEM (scanning electron microscope) observation and the resistance value of the connection hole.

The SEM observation was conducted by making 10 connection holes each having a diameter of 0.5 μm under each condition and evaluating them according to the following criteria. ×: One or more holes were not embedded at all in 10 holes. Δ: One or more holes were partially embedded in 10 holes. ○: All 10 holes were completely embedded.

The connection hole resistance value is 0.5 μm when the connection hole is 2
The total resistance value of 000 pieces is divided by 2000 and the resistance value per connection hole is shown.
It is shown as a pen (complete failure). In addition, 2000
If all of them are completely embedded, the resistance value is 0.8
Although it is about Ω, the resistance value shows a value of several Ω or more if all 2000 pieces are not completely embedded even if it is evaluated as ◯ by the SEM observation of the 10 holes.

Table 1 below is a table showing the evaluation results. As can be seen from this table, it is the titanium nitride (T) that satisfies both the SEM observation and the contact hole resistance value.
This is when the shaving amount of the iN) layer 5 is 60 nm or more.
Therefore, the total thickness of the titanium nitride (TiN) layer 5 is d1, and the thickness of the titanium nitride (TiN) layer 5 located below the connection hole 6 after the formation of the antioxidant film 7 is d2. At this time, it is considered desirable to form so that d1 ≧ 60 nm and d1−d2 ≧ 60 nm.

[0046]

[Table 1]

Although the titanium nitride film is used as the anti-oxidation film in the above embodiments, tungsten nitride (WN) and tungsten silicide are used as the material that functions as a conductive and anti-reflection film like the titanium nitride film. (W
Si) and the like, and these can be used as a conductive material that serves as an antioxidant film. In addition to AlSiCu, AlSi, AlCu, AlSi can be used as the aluminum-based material to be embedded in the connection hole by high-temperature aluminum sputtering.
Ti, AlGe, or the like can be used. Further, the method of forming the aluminum-based material is not limited to high-temperature sputtering, and for example, high-pressure sputtering in which a pressure of about 700 atm is applied to fill the connection hole, or where the substrate is heated and buried after the aluminum-based material is formed, that is, so-called Various methods such as aluminum flow can be used.

[0048]

As described above, according to the present invention, a semiconductor device having an anti-oxidation film for preventing the oxidation of a titanium-based high melting point material can be manufactured in a small number of steps.

Further, when the thickness of the antioxidant film made of the conductive material is gradually reduced from the lower side to the upper side of the connection hole, high wettability is secured in the lower side of the connection hole. The embedding characteristics of the aluminum-based material are improved.

Further, when the anti-oxidation film made of the conductive material is a titanium nitride film, the titanium nitride film functions as an anti-reflection film, so that the resist exposure in the photolithography process in the semiconductor device manufacturing is performed. Halation can be prevented.

When an aluminum-titanium alloy is formed between the conductive material and the lower layer wiring,
Since the aluminum-titanium alloy prevents the lower layer wiring below the conductive material from being scraped when the conductive material is sputtered, the material of the upper layer wiring can be embedded in the connection hole with good yield.

By restricting the overall thickness of the conductive material and the thickness of the portion located below the connection hole, it is possible to prevent a situation in which the thickness of the anti-oxidation film becomes insufficient, thereby preventing a semiconductor device. Can improve the production yield.

The method of manufacturing a semiconductor device according to the present invention eliminates the step of forming a conductive material on the interlayer insulating layer and the step of removing the excess conductive material, and has an effect of reducing the manufacturing cost of the semiconductor device. .

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional side view showing a semiconductor device of the present invention.

FIG. 2 is a vertical cross-sectional side view showing a modified example of the semiconductor device of the present invention.

FIG. 3 is a process drawing showing the manufacturing method of the semiconductor device in FIG.

FIG. 4 is a vertical cross-sectional side view showing a state in which a titanium layer is formed in a conventional connection hole.

FIG. 5 is a vertical cross-sectional side view showing a semiconductor device formed by depositing titanium nitride by sputtering to form an anti-oxidation film.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Interlayer insulation layer 2 Upper layer wiring 3 Lower layer wiring 4 Aluminum-titanium alloy layer 5 Titanium nitride layer (conductive material) 6 Connection hole 7 Antioxidation film 8 Titanium base layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location H01L 21/90 A

Claims (7)

[Claims] 1. An aluminum-based material that is the upper layer wiring in a connection hole formed in the interlayer insulating layer for electrically connecting the upper layer wiring and the lower layer wiring that are located with the interlayer insulating layer sandwiched therebetween. In a semiconductor device which is coated with a titanium-based high-melting-point material having a wettability with respect to which the aluminum-based material can be embedded well, an antioxidant film made of a conductive material is used as a base layer of the titanium-based high-melting-point material. A semiconductor device, which is provided only on a bottom surface portion and a side wall portion of the connection hole. 2. An aluminum-based material, which is the upper layer wiring, in a connection hole formed in the interlayer insulating layer for electrically connecting the upper layer wiring and the lower layer wiring, which are located with the interlayer insulating layer sandwiched therebetween. In a semiconductor device formed by coating a titanium-based high-melting-point material having a wettability with respect to which the aluminum-based material can be embedded well, a conductive material is formed on the upper surface of the lower layer wiring, and a conductive material is formed below the connection hole. A semiconductor device characterized in that the conductive material that has been positioned is attached to a side wall portion of a connection hole to form an antioxidant film. 3. The semiconductor according to claim 1, wherein the thickness of the sidewall of the antioxidant film made of the conductive material is gradually reduced from the lower side to the upper side of the connection hole. apparatus. 4. The anti-oxidation film made of the conductive material is a titanium nitride film.
The semiconductor device according to any one of 1. 5. The semiconductor device according to claim 1, further comprising an aluminum-titanium alloy layer formed between the conductive material and the lower wiring. 6. When the overall thickness of the conductive material formed on the upper surface of the lower layer wiring is d1, and the thickness of the portion of the conductive material located below the connection hole is d2,
6. The semiconductor device according to claim 1, wherein d1 ≧ 60 nm and d1−d2 ≧ 60 nm. 7. The method of manufacturing a semiconductor device according to claim 1, wherein the conductive material located below the contact hole is sputter-etched to form a sidewall portion of the contact hole. A method of manufacturing a semiconductor device, comprising: adhering to a semiconductor device.