JPH09129643A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of hillocks, and also to obtain a semiconductor device having an excellent step coverage even when a contact hole of large aspect ratio is formed and also having almost no connection failure by a method wherein, after formation of a metal amalgam layer, the mercury contained in the amalgam layer is removed by heat treatment. SOLUTION: When a semiconductor device is manufactured, a process with which a metal amalgam layr 6 is formed, and another process, with which the mercury contained in the amalgam layer 6 is removed by heat-treating the amalgam layer 6, are provided. For example, a BPSG film 3 is formed on the lower layer wiring 2 formed on a silicon substrate 1, and a contact hole 4, reaching the lower layr wiring 2, is perforated. Then, aluminum amalgam 5 is applied to the whole surface using a spin coating method, and an aluminum amalgam layer 6 is formed on the inner part of the contact hole and on the BPSG film 3. Then, the mercury in the amalgam layer 6 is evaporated by heating to the prescribed temperature, and an aluminum thin film 6 is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device, and is particularly suitable for use in forming a metal wiring in a contact hole having a high aspect ratio.

[0002]

2. Description of the Related Art With the increase in integration and multi-layer wiring of semiconductor devices, an insulating film is formed to connect source / drain diffusion layers in a semiconductor substrate to metal wiring or to connect upper and lower wiring layers to each other. The aspect ratio of the contact holes formed is increasing. Here, the aspect ratio is defined as the ratio of the height to the diameter of the opening.

Generally, in order to form the metal wiring in the contact hole, the sputtering method is preferable in terms of process cost and stability. However, in the narrow and deep contact hole having a large aspect ratio as described above,
For example, when aluminum wiring is formed by the sputtering method, a so-called shadowing effect occurs before the inside of the contact hole is filled with aluminum, and the inlet portion of the contact hole is blocked with aluminum, so that the inside of the contact hole is blocked. In this case, the aluminum coverage deteriorates, and a disconnection defect due to electromigration or stress migration easily occurs near the bottom of the contact hole.

Therefore, in order to fill the contact hole having such a large aspect ratio with aluminum,
When aluminum is formed in the contact hole portion or after the film is formed, a heat treatment is performed at a high temperature of 500 ° C. to 550 ° C. to fluidize the aluminum and pour it into the contact hole.

According to this method, the inside of the contact hole can be reliably filled with a metal such as aluminum, so that it is possible to form a metal wiring having excellent coverage and hardly causing a disconnection defect.

[0006]

However, according to the method described above, heat treatment at a high temperature close to the melting point of aluminum is required to fluidize the aluminum. When heat treatment is performed at such a high temperature, many small protrusions called hillocks are formed on the surface of aluminum, which causes troubles such as leakage current flowing between wirings, which leads to reliability of wiring. However, there was a problem in that

Further, depending on the surface condition of the aluminum underlayer, the fluidity of aluminum is impaired, the inside of the contact hole is not filled with aluminum, and sufficient coverage cannot be obtained.

On the other hand, Japanese Patent Laid-Open No. 61-119063 discloses that
A step of forming an insulating film on the diffusion layer of the semiconductor device; a step of etching the insulating film to form a contact hole; a step of forming a metal layer on the entire surface of the semiconductor device; and a step of forming a metal layer on the metal layer. And a step of bringing amalgam into contact with mercury to produce a semiconductor device.

However, according to the above-mentioned method, fluid amalgam remains inside the semiconductor device, and there is a problem in terms of reliability and environmental hygiene.

The present invention has been made in order to solve the above-mentioned problems, prevents hillocks causing a leak current between wirings from occurring without deteriorating reliability and environmental hygiene, and has an aspect ratio. It is an object of the present invention to be able to form a metal wiring which has excellent step coverage even when a contact hole having a large diameter is formed and which hardly causes disconnection failure.

[0011]

A method for forming a metal wiring of the present invention is a method for manufacturing a semiconductor device, which comprises a step of forming a metal amalgam layer, and a heat treatment of the metal amalgam layer to obtain the amalgam. And a step of removing mercury contained in the layer.

Another feature of the present invention is that
A method of manufacturing a semiconductor device, comprising: forming an insulating film on a base conductive layer; forming a contact hole in the insulating film, the contact hole reaching the base conductive layer; The method is characterized by including a step of forming a metallic amalgam layer on the film and a step of subjecting the amalgam layer to a heat treatment to remove mercury contained in the amalgam layer.

Another feature of the present invention is a method of manufacturing a semiconductor device, which comprises a step of forming an opening portion penetrating the insulating film in an insulating film above a semiconductor substrate, The method is characterized by including a step of forming a metallic amalgam layer inside the hole and on the insulating film, and a step of subjecting the amalgam layer to a heat treatment to remove mercury contained in the amalgam layer.

Another feature of the present invention is the method for manufacturing a semiconductor device according to any one of claims 1 to 3, wherein the metal is aluminum (Al),
It is characterized by containing at least one selected from copper (Cu), platinum (Pt), and thallium (Tl).

Another feature of the present invention is the method for manufacturing a semiconductor device according to any one of claims 1 to 3, wherein the step of applying the heat treatment is 100
It is characterized in that the amalgam layer is heat-treated in a reduced pressure atmosphere of Torr or less.

Another feature of the present invention is the method for manufacturing a semiconductor device according to any one of claims 1 to 3, wherein the step of performing the heat treatment includes forming the amalgam layer. It is characterized in that the heat treatment is performed at a temperature of 400 ° C to 450 ° C.

Another feature of the present invention is the method for manufacturing a semiconductor device according to any one of claims 1 to 3, wherein the volume ratio of mercury to aluminum in the amalgam layer is 20. It is characterized by being more than double.

Another feature of the present invention is the method for manufacturing a semiconductor device according to any one of claims 1 to 3, wherein after the step of removing the mercury, the amalgam layer is formed. Is included in the wiring pattern.

Another feature of the present invention is the method for manufacturing a semiconductor device according to claim 2.
The step of forming the amalgam layer includes a step of applying an amalgam layer of the metal inside the contact hole and on the insulating film.

Another feature of the present invention is the method of manufacturing a semiconductor device according to claim 2.
The step of forming the amalgam layer includes a step of forming the metal film inside the contact hole and on the insulating film, and a step of applying mercury to the metal film.

Another feature of the present invention is the method for manufacturing a semiconductor device according to claim 2.
After the step of forming the contact hole, a step of forming a conductive film inside the contact hole and on the insulating film is further included.

Another feature of the present invention is the method for manufacturing a semiconductor device according to claim 11, wherein the conductive film is titanium (Ti) or nickel (N).
i), cobalt (Co), tungsten (W), titanium nitride (TiN), and titanium tungsten (TiW).

Another feature of the present invention is the method for manufacturing a semiconductor device according to claim 3,
It is characterized in that the step of forming the amalgam layer includes a step of applying the metal amalgam layer inside the opening and on the insulating film.

Another feature of the present invention is the method for manufacturing a semiconductor device according to claim 3,
It is characterized in that the step of forming the amalgam layer includes a step of forming a metal film inside the opening and on the insulating film, and a step of applying mercury to the metal film.

Another feature of the present invention is the method for manufacturing a semiconductor device according to claim 3,
After the step of forming the opening, a step of forming a conductive film inside the opening and on the insulating film is further included.

Another feature of the present invention is the method for manufacturing a semiconductor device according to claim 15, wherein the conductive film is titanium (Ti) or nickel (N).
i), cobalt (Co), tungsten (W), titanium nitride (TiN), and titanium tungsten (TiW).

[0027]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing a method of forming a metal wiring according to the first embodiment of the present invention in the order of steps. Here, aluminum (Al) wiring is formed. The metal used for wiring is not limited to aluminum, but copper (Cu), platinum (Pt), thallium (T
1) or an alloy containing these elements.

First, as shown in FIG. 1A, as a pre-stage, on the lower layer wiring 2 made of a polycrystalline silicon film or an aluminum alloy formed on the silicon substrate 1, an interlayer insulating film having a thickness of 500 to 500 is formed. BPSG (b of about 1000 nm
oron-phosphosilicate gla
ss) film 3 is formed and the hole diameter reaching the lower layer wiring 2 is 0.2 to
A contact hole 4 of about 0.4 μm is opened in the BPSG film 3. In this case, the aspect ratio reaches up to 5 times.

Next, the amalgam 5 made of aluminum, which is previously formed by synthesizing aluminum and mercury, is spin-coated to form the lower wiring and the BPSG film 3.
And to the entire surface of the substrate on which the contact holes are formed.

Here, the volume ratio of mercury to aluminum in the amalgam 5 is preferably 20 times or more. When the metal used for the wiring is copper, the volume ratio of mercury to copper is preferably 100 times or more,
In the case of platinum, the volume ratio of mercury to platinum is preferably 10 times or more, and in the case of thallium, the volume ratio of mercury to thallium is preferably 2 times or more.
By applying the amalgam 5, an amalgam layer 6 of aluminum is formed inside the contact hole 4 and on the BPSG film 3 as shown in FIG. 1B.

Next, the substrate on which the amalgam layer 6 is formed is heated to a temperature within a predetermined range to evaporate and remove the mercury in the amalgam layer 6. The lower limit of this temperature range is 16.7 atm for mercury vapor at 356.7 ° C.
The temperature must be higher than 356.7 ° C, and is preferably 400 ° C or higher in consideration of the evaporation rate.

On the other hand, the upper limit of this temperature range must be lower than about 650 ° C., which is the melting point of aluminum.
The temperature is preferably 450 ° C. or lower in order to generate alloy spikes caused by the above-mentioned hillocks and aluminum diffusing into cracks in the silicon substrate.

The upper limit of this temperature range can be changed according to the type of metal used for the wiring. In this embodiment, since aluminum is used for the wiring, the heating temperature is about 400 ° C.

As a result of evaporating mercury, as shown in FIG. 1C, only aluminum in the amalgam layer 6 remains inside the contact hole 4 and on the BPSG film 3, so that this portion is left. An aluminum thin film 7 is formed on the. The aluminum thin film 7 has a purity of 99.999% or more and is formed so as to completely fill the contact hole 4. After that, the aluminum thin film 7 is processed into a desired wiring pattern.

As described above, in this embodiment, since the liquid amalgam 5 which is highly fluid at room temperature is applied, the contact hole 4 having a high aspect ratio is not affected by the surface condition of the BPSG film 3, The aluminum thin film 7 having high coverage and high purity can be formed. Therefore, the wiring formed by processing the aluminum thin film 7 is extremely reliable with almost no disconnection failure.

Further, in this embodiment, since heat of about 400 ° C. is only applied to evaporate mercury from the amalgam and heat treatment at a high temperature of 500 ° C. to 550 ° C. is not required, the surface of the aluminum thin film 7 is hillocked. Is not formed, and leakage current does not flow between wirings due to this hillock. Further, the method of the present embodiment has an advantage that it can be easily performed by a relatively small number of steps of applying the amalgam 5 and performing heat treatment. Moreover, since a sputtering process is not required, the equipment therefor can be omitted.

In this embodiment, amalgam 5 and BP
In order to reduce the interfacial tension between the SG film 3 and the wettability between them, the BPSG film 3 may be washed with hydrofluoric acid when the contact holes 4 are opened. In this case, the surface of the BPSG film 3 becomes hydrophilic, and the amalgam 5 smoothly flows into the contact hole 4, so that the contact hole 4 is not filled with the aluminum thin film.

In the present embodiment, it is possible to rapidly evaporate mercury by performing the heat treatment step of evaporating mercury in a reduced pressure atmosphere at a pressure of 100 (Torr) or less. Further, the evaporated mercury may be recovered by a closed recovery device such as a trap attached separately.

In this embodiment, the lower layer wiring 2 is formed on the silicon substrate 1 with a polycrystalline silicon film or the like, and the aluminum wiring and the lower layer wiring 2 are connected through the contact holes. Instead of 2, the impurity diffusion layer formed on the surface of the silicon substrate 1 and the aluminum wiring may be connected via a contact hole.

Next, regarding the second embodiment of the present invention,
A description will be given with reference to FIGS.

First, as shown in FIG. 2A, as a preliminary step, a film having a thickness of 500 to 500 is formed as an interlayer insulating film on the lower wiring 2 made of a polycrystalline silicon film formed on the silicon substrate 1.
The BPSG film 3 of about 1000 nm is formed, and the lower wiring 2
Contact hole 4 with a hole diameter of 0.2 to 0.4 μm
Are opened in the BPSG film 3. After that, contact hole 4
A titanium nitride (TiN) film 8 having a film thickness of about 20 to 50 nm is formed on the inner surface of and the BPSG film 3 by the sputtering method.

The metal formed inside the contact hole and on the BPSG film is not only titanium nitride but also titanium (TiN), nickel (Ni), cobalt (Co), tungsten (W), titanium tungsten (TiW). ), Or an alloy containing these elements.

Next, as shown in FIG. 2B, an amalgam 5 of aluminum, which is produced in advance by synthesizing aluminum and mercury, is applied to the entire surface by spin coating. By applying the amalgam 5, an amalgam layer 6 of aluminum is formed inside the contact hole 4 and on the titanium nitride film 8 as shown in FIG. 2C.

The thickness of the amalgam layer 6 is determined in consideration of the desired wiring thickness and the volume fraction of aluminum in the amalgam. That is, when forming a wiring having a film thickness of 1 μm, an amalgam layer containing mercury about 20 times as much as aluminum needs to have a film thickness of about 20 μm.

Next, a heat treatment at about 400 ° C. is performed to evaporate and remove the mercury in the amalgam layer 6.
As a result, as shown in FIG. 2D, the aluminum thin film 7 which completely fills the contact hole 4 inside the contact hole 4 and on the titanium nitride film 8 with a purity of 99.999% or more.
Is formed. After that, the aluminum thin film 7 is processed into a desired wiring pattern.

In this embodiment as well, as in the first embodiment, since the liquid amalgam 5 which is highly fluid at room temperature is applied, the surface state of the BPSG film 3 is applied to the contact hole 4 having a high aspect ratio. The aluminum thin film 7 having high coverage and high purity can be formed regardless of the above. Also,
Since only heat of about 400 ° C. is applied to evaporate mercury from the amalgam, no hillock is formed on the surface of the aluminum thin film 7.

Further, in the present embodiment, the titanium nitride film 8 is interposed between the aluminum thin film 7 and the lower layer wiring 2 and functions as a barrier film, so that the electromigration resistance life of the aluminum thin film 7 is greatly improved. Can be made.
Further, as described above, when the impurity diffusion layer formed on the surface of the silicon substrate 1 and the aluminum thin film 7 are connected, the titanium nitride film 8 plays a role of preventing alloy spike due to aluminum. Further, the titanium nitride film 8 has good wettability with the amalgam 5, and the amalgam 5 has a contact hole 4 in order to reduce the interfacial tension between them.
It will flow smoothly into the interior.

Next, a third embodiment of the present invention will be described.
This will be described with reference to FIGS. First, FIG.
As shown in (a), as a previous step, a BP having a film thickness of about 500 to 1000 nm is formed as an interlayer insulating film on the lower wiring 2 made of a polycrystalline silicon film formed on the silicon substrate 1.
The SG film 3 is formed and the hole diameter reaching the lower layer wiring 2 is 0.2 to
A contact hole 4 of about 0.4 μm is opened in the BPSG film 3. After that, the inner surface of the contact hole 4 and the BPSG
An aluminum film 9 having a film thickness of about 500 to 1000 nm is formed on the film 3 by a sputtering method. The aluminum film 9 may be formed by the CVD method or the vapor deposition method.

Next, as shown in FIG.
Is applied to the entire surface of the substrate by spin coating. Here, the volume ratio of the mercury 10 to the aluminum film 9 is 2
It is desirable to make it 0 times or more. Therefore, the rotation speed in spin coating is reduced to, for example, 300 rpm or less, and mercury is applied in a thickness of, for example, 20 μm or more.
When the metal used for the wiring is copper, the volume ratio of mercury to copper is preferably 100 times or more, and in the case of platinum, the volume ratio of mercury to platinum is preferably 10 times or more. In the case of thallium, it is desirable that the volume ratio of mercury to thallium be twice or more.

By the application of this mercury 10, as shown in FIG. 3C, the inside of the contact hole 4 and the BPSG film 3 are formed.
An aluminum amalgam layer 6 formed by the reaction of the mercury 10 and the aluminum film 9 is formed thereon.

Next, heat treatment at about 400 ° C. is performed to evaporate and remove the mercury in the amalgam layer 6.
As a result, as shown in FIG. 3D, an aluminum thin film 7 which completely fills the contact hole 4 with a purity of 99.999% or more is formed inside the contact hole 4 and on the BPSG film 3. After that, the aluminum thin film 7 is processed into a desired wiring pattern.

In this embodiment, since the liquid-state amalgam layer 6 having a high fluidity at room temperature is formed by the reaction between the mercury 10 and the aluminum film 9, even the contact hole 4 having a high aspect ratio is formed. The aluminum thin film 7 having high coverage and high purity can be formed regardless of the surface state of the BPSG film 3. Moreover, since heat of about 400 ° C. is only applied to evaporate mercury from the amalgam, hillocks are not formed on the surface of the aluminum thin film 7.

Further, in this embodiment, it is possible to easily control the film thickness of the finally formed aluminum thin film 7 by the sputtering amount of the aluminum film 9 formed first.

Next, regarding the fourth embodiment of the present invention,
This will be described with reference to FIGS. First, FIG.
As shown in (a), as a previous step, a BP having a film thickness of about 500 to 1000 nm is formed as an interlayer insulating film on the lower wiring 2 made of a polycrystalline silicon film formed on the silicon substrate 1.
The SG film 3 is formed and the hole diameter reaching the lower layer wiring 2 is 0.2 to
A contact hole 4 of about 0.4 μm is opened in the BPSG film 3. After that, the inner surface of the contact hole 4 and the BPSG
Titanium nitride (Ti) having a film thickness of about 20 to 50 nm is formed on the film 3.
N) The film 8 is formed by the sputtering method.

Next, as shown in FIG. 4B, a film thickness of 500 to 1 is formed on the inner surface of the contact hole 4 and the titanium nitride film 8.
An aluminum film 9 of about 000 nm is formed by the sputtering method.

Next, as shown in FIG.
Is applied to the entire surface by spin coating. This mercury 10
4D, an amalgam layer 6 of aluminum formed by the reaction of the mercury 10 and the aluminum film 9 is formed inside the contact hole 4 and on the titanium nitride film 8 as shown in FIG. 4D. .

Next, heat treatment at about 400 ° C. is performed to evaporate and remove mercury in the amalgam layer 6.
As a result, as shown in FIG. 4E, the aluminum thin film 7 which completely fills the contact hole 4 with a purity of 99.999% or more inside the contact hole 4 and on the titanium nitride film 8.
Is formed. After that, the aluminum thin film 7 is processed into a desired wiring pattern.

In this embodiment, as in the third embodiment, the reaction between the mercury 10 and the aluminum film 9 forms the liquid amalgam layer 6 having a high fluidity at room temperature. It is possible to form the aluminum thin film 7 having a high coverage and a high purity regardless of the surface state of the BPSG film 3 even for the contact hole 4 having a high contact angle. Moreover, since heat of about 400 ° C. is only applied to evaporate mercury from the amalgam, hillocks are not formed on the surface of the aluminum thin film 7. Furthermore, it is possible to easily control the film thickness of the finally formed aluminum thin film 7 by adjusting the amount of sputtering of the aluminum film 9 formed first.

Further, as in the second embodiment, since the titanium nitride film 8 is interposed between the aluminum thin film 7 and the lower layer wiring 2 and functions as a barrier film, the electromigration resistance life of the aluminum thin film 7 is improved. In addition, when the impurity diffusion layer formed on the surface of the silicon substrate 1 and the aluminum thin film 7 are connected, alloy spike due to aluminum can be prevented. Further, the titanium nitride film 8 reduces the interfacial tension between the amalgam 5 and the amalgam 5, so that the amalgam 5 smoothly flows into the contact hole 4.

[0060]

As described above, according to the present invention,
By removing the mercury contained in the amalgam layer by heat-treating the amalgam layer of the metal for which the wiring is to be formed, the wiring made of the metal is formed, so heat of about 400 ° C. is required to evaporate the mercury from the amalgam. Only added, no heat treatment at high temperature is required. Therefore, a hillock is not formed on the surface of the metal wiring, and a leak current does not flow between the wirings due to the hillock. Therefore, it is possible to obtain highly pure and highly reliable metal wiring.

Further, when wiring is formed in the contact hole portion, liquid amalgam, which has a high fluidity at room temperature, forms the contact hole regardless of the surface condition of the interlayer insulating film even for the contact hole having a high aspect ratio. Embed completely. Therefore, the metal wiring can be formed with high coverage, and it is possible to prevent the occurrence of disconnection defects and the like.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a method of forming a metal wiring according to a first embodiment of the present invention in the order of steps.

FIG. 2 is a cross-sectional view showing a method of forming a metal wiring according to a second embodiment of the present invention in the order of steps.

FIG. 3 is a cross-sectional view showing a method of forming a metal wiring according to a third embodiment of the present invention in the order of steps.

FIG. 4 is a cross-sectional view showing a method of forming a metal wiring according to a fourth embodiment of the present invention in the order of steps.

[Explanation of symbols]

 1 Silicon Substrate 2 Lower Layer Wiring 3 BPSG Film (Interlayer Insulating Film) 4 Contact Hole 5 Amalgam 6 Amalgam Layer 7 Aluminum Thin Film 8 Titanium Nitride Film 9 Aluminum Film 10 Mercury

Claims (16)

[Claims] 1. A method of manufacturing a semiconductor device, comprising: a step of forming a metal amalgam layer; and a step of subjecting the metal amalgam layer to a heat treatment to remove mercury contained in the amalgam layer. A method for manufacturing a semiconductor device, comprising: 2. A method of manufacturing a semiconductor device, comprising: forming an insulating film on a base conductive layer; forming a contact hole reaching the base conductive layer in the insulating film; A step of forming a metal amalgam layer inside and on the insulating film, and a step of subjecting the amalgam layer to a heat treatment to remove mercury contained in the amalgam layer. Production method. 3. A method of manufacturing a semiconductor device, comprising: forming an opening portion penetrating the insulating film in an insulating film above a semiconductor substrate; and forming a metal inside the opening portion and on the insulating film. And a step of performing a heat treatment on the amalgam layer to remove mercury contained in the amalgam layer. 4. The method of manufacturing a semiconductor device according to claim 1, wherein the metal is aluminum (Al), copper (Cu), platinum (Pt), thallium (Tl). A method for manufacturing a semiconductor device, comprising at least one selected from the following. 5. The method of manufacturing a semiconductor device according to claim 1, wherein the heat treatment is performed on the amalgam layer in a reduced pressure atmosphere of 100 Torr or less. A method for manufacturing a semiconductor device, comprising: 6. The method of manufacturing a semiconductor device according to claim 1, wherein the step of applying the heat treatment is performed on the amalgam layer 40.
A method of manufacturing a semiconductor device, which comprises performing heat treatment at a temperature of 0 ° C to 450 ° C. 7. The method of manufacturing a semiconductor device according to claim 1, wherein the volume ratio of mercury to aluminum in the amalgam layer is 20 times or more. Manufacturing method. 8. The method of manufacturing a semiconductor device according to claim 1, further comprising a step of forming the amalgam layer in a wiring pattern after the step of removing the mercury. A method for manufacturing a characteristic semiconductor device. 9. The method of manufacturing a semiconductor device according to claim 2, wherein the step of forming the amalgam layer applies the amalgam layer of the metal inside the contact hole and on the insulating film. A method of manufacturing a semiconductor device, comprising: 10. The method of manufacturing a semiconductor device according to claim 2, wherein the step of forming the amalgam layer includes the step of forming the metal film inside the contact hole and on the insulating film. And a step of applying mercury to the metal film, the method for manufacturing a semiconductor device. 11. The method of manufacturing a semiconductor device according to claim 2, further comprising a step of forming a conductive film inside the contact hole and on the insulating film after the step of forming the contact hole. A method of manufacturing a semiconductor device, comprising: 12. The method of manufacturing a semiconductor device according to claim 11, wherein the conductive film is titanium (Ti), nickel (Ni), cobalt (Co), tungsten (W), titanium nitride (T).
iN) and at least one selected from titanium tungsten (TiW). 13. The method of manufacturing a semiconductor device according to claim 3, wherein in the step of forming the amalgam layer, an amalgam layer of the metal is applied inside the opening and on the insulating film. A method of manufacturing a semiconductor device, comprising the steps of: 14. The method of manufacturing a semiconductor device according to claim 3, wherein the step of forming the amalgam layer includes a step of forming a metal film inside the opening and on the insulating film. And a step of applying mercury to the metal film, the method for manufacturing a semiconductor device. 15. The method for manufacturing a semiconductor device according to claim 3, wherein after the step of forming the opening, a conductive film is formed inside the opening and on the insulating film. A method of manufacturing a semiconductor device, further comprising: 16. The method of manufacturing a semiconductor device according to claim 15, wherein the conductive film is titanium (Ti), nickel (Ni), cobalt (Co), tungsten (W), titanium nitride (T).
iN) and at least one selected from titanium tungsten (TiW).